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Science, Mathematics, & Technology Timeline

While we can never touch reality, science moves us ever closer.

Modern Present - 1950

Summary of change:

Environmental: Humans and their livestock (mostly pigs and cows) now have 22 times the mass than wild mammals. Domesticated birds have two times the mass of wild birds. Plant mass has halved since civilization began.


CO2 (carbon dioxide) in atmosphere passes 417 parts per million. Highest since beginning of the industrial revolution.


NASA announces the Artemis program to put the first woman and next man on the Moon by 2024. Source

Within the program is the Artemis Accord.

First all women team to win Noble prize

Geneticist Jennifer Doudna and Emmanuelle Charpentier receive the Nobel Prize in Chemistry for their groundbreaking invention of CRISPR-Cas9 for editing genes.

Greta Thunberg speaks at the United Nations on climate and global warming. Speech see 1980's related U.S. political history and Rachel Carson's early warnings


Earth’ s human population 7.6 billion

China’s Chang’e 4 lands on the dark side of the moon. Its biosphere germinates the first seeds (cotton) on the moon. January 3, 2018. Source

Black Hole Image

First image of a Black Hole is recorded with the help of Katie Bouman, who developed the algorithm necessary to create the image. The black sphere captures all light with its massive gravity. The photons (light) that surround the event horizon create the glow as matter spirals into the hole. The black hole is at the center of the Messier 87 (M87) galaxy, 53 million light years from Earth. It has a mass of 6.5 billion suns with an event horizon a bit larger than our Solar System, itty-bitty by cosmic standards.

First AI (artificial intelligence) to predict people's emotional state

Kevin LaBar creates a model that uses fMRI scans to associate brain blood flow patterns to seven feelings: countentedness, amusement, surprise, fear, anger, sadness, & neutrality.

His work builds on Jack Gallant's mapping 1000's of concept words to brain locations. Numbers, body parts, principles such as truth. He found every word is maps to multiple regions. He believes each region represents an idea associated with its meaning or related experience. Number tracks to tactile, visual, and number.

Source Discover. The Shape of Thought, December, 2019


Number and intensity of wild fires increase. Wild Fires graph

California Camp fire sets a record for the deadliest and most destructive fire in California history. Burns 153 336 acres, destroys 18 804 structures, displaces 52 000 people and kills 85 people.

Japan's Hayabusa 2 spacecraft drops multiple probes onto the surface of the Ryuga Asteroid. The probes hop across the asteroid: take pictures, measure temperatures, magnetism, look for water and organic molecules. The main spacecraft will land three times and collect samples and return to Earth in 2020. Source See Hayabusa1.

NASA announced its Mars rover found evidence for ancient life and methane in the Martian atmosphere, suggests microbes have existed and still might exist today.

The B-52 bomber is still flying. By Gordon F. Sander January 20, 2018

Somalian plate is separating from the African Continent See Africa's Big Break. by Shannon Hall in Discover magazine May 2018.

CO2 (carbon dioxide) in atmosphere passes 400 parts per million. Highest since beginning of the industrial revolution.

Wheat genome sequenced. Source


Hurricane Maria devastates Puerto Rico and kills 2 975 people, in September.

First artificial species created

Mycoplasma mycoides JCVI-syn3.0 has 473 genes and was created by J. C. Venter. He started with the living organism Mycoplasma genitalium, the smallest organism (has 525 genes) and the first organism to be sequenced, by removing and adding genes until it sustained life and reproduced.

First time police use a robot to kill a suspect

After a sniper killed 12 police officers in Dallas, police armed a small robot with a bomb and detonated it next to the shooter.

2016 March

The Great Math Mystery

According to Mario Livio, all numbers (one, two, ...) are invented concepts, and humans have discovered that numbers have all kinds of intricate relationships. Humans invented the concept and then discovered the relations among the different concepts. Therefore, math is both invented and discovered. It may feel like it's already there, but it comes from the creativity of human beings. Source

Cruise ship Crystal Serenity along with 100 tourists steamed from Alaska to New York through the Northwest Passage for the first time in recorded history.

OSIRIS-REx launched and arrives at Bennu asteroid (101955) in 2018. If finds the surface weathered by space exposure, has abundant organic material, and evidence of past erosion by liquid water. It collects 60 g of material to arrive on Earth 2023.


Paris agreement on climate change.


Higgs boson discovered at CERN on July 4, 2012.

Peter Ware Higgs, a theoretical physicist proposes the electro weak theory and broken symmetry could explain the origin of elementary particle mass in general and W and Z bosons in particular through a Higgs mechanism. This same mechanism was proposed by other physicists about the same time and it predicted the existence of a new particle, the Higgs boson. Both discoveries add support for the Standard Model of particle physics.

On March 14, 2013, the Higgs boson was tentatively confirmed to be + parity and zero spin. Making it the first known fundamental scalar particle to be verified in nature.

Curiosity arrives on Mars and begins to sift soil and rock samples for organic molecules. in 2015 from two different sites it finds evidence of a goopy fossilized building block (kerogen) for oil and gas on Earth were found, sulfur bearing carbon rings, and traces of methane in the atmosphere rise and fall with the season.

Voyger I entered intersteller space on August 25, 2012. In another 40,000 years it will leave the solar system and the Sun's gravitational influence. Source Ed Stone

Google brain project created an algorithm that was capable of learning to identify a cat.


First spacecraft to land on an asteroid and return to Earth is Japan's Asteroid Explorer Hayabusa (MUSES-C). It traveled to Itokawa asteroid and brought back samples. It also was the first to use ion engines to navigate. Source


Scalbard Global Seed Vault on the island of Spitsbergen near Longyearbyen Norway opens. It was created to preserve a wide variety of plant seeds as spare copies held as a worldwide gene bank in case of a regional or global crises. Source


The number of people living in urban areas (cities) is greater than the number of people living in rural areas.

Massachusetts v. Environmental Protection Agency, 549 U.S. 497, in a 5-4 decision found:

  1. The petitioners were found to have standing.A state has a right to act in the interest of its citizens as to whether "its mountains shall be stripped of their forests and its inhabitants shall breathe pure air."
  2. The Court held the CAA gives the EPA the authority to regulate tailpipe emissions of greenhouse gases. The CAA defines "air pollutant" as "any air pollution agent or combination of such agents, including any physical, chemical, biological, radioactive ... substance or matter which is emitted into or otherwise enters the ambient air".
  3. The Court found the EPA's current rationale for not regulating to be inadequate and required the agency to articulate a reasonable basis in order to avoid regulation.

Chief Justice Roberts dissent argued the alleged injury: Massachusetts' loss of land because of rising sea levels is too speculative and without adequate scientific support and the effect of obliging the EPA to enforce automobile emissions as a solution is hypothetical at best.

Scalia's dissent found the Court has no jurisdiction to decide the case because the petitioners lack standing.



The New Horizon space probe is launched.

It travels to Pluto and then Arrokoth in the Kuiper belt at the edge of the solar system. The original positional locating system is unable to center Arrokoth to photograph. Marc Huie recommends using a new star mapping system created from the Gaia satellite from mapping quasars as a reference frame. It works perfectly. Source


Hurricane Katrina devastates the north Gulf Coast killing 1,833 people.


First mammal, Dolly the sheep, is cloned. Followed by dogs, rabbits, pigs, and primates in 2018, with Zhongshan Zhongshan and Hua Hua.

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is opened for signatures. Nations have signed it, but not all have ratified it. However, most nations agreed to the verification procedures and are gathering and transmitting data to the CTBTO headquarters. Thus, no nuclear explosion goes undetected.


Self flying plane (autonomous vehicle)

A Boeing 737 with a Global positioning system (GPS) landed itself 110 times in a row. Source


Congress killed the Superconducting Super Collider


Confirmed microwave background radiation of the big bang

The COBE ( NASA's Cosmic Background Explorer satellite) team announced they detected the three-degree Kelvin electromagnetic background radiation in all directions of the sky that was emitted 380,000 years after the Big Bang.


Al Gore introduced legislation to create ARAPANET, a public network that became the internet, which will eventually connect anyone anywhere instantly. See 1990, 1989.


Hubble telescope launched April 24, 1990.

The Hubble telescope will collect millions of observations of space objects expanding the size and the universe and the number of known objects in it. See NASA for great photos and more about Hubble.

Tim Berners-Lees and Robert Cailliau utilize ideas of a server, TCP, DNS, HTTP, HTML, URL, and a browser to make the WWW and the first web page at: http://info.cern.ch/hypertext/WWW/TheProject.html

See 1989, 1991.



Tim Berners-Lee designs the Distributed Information System (internet) for particle physicists to communcate more effectively and efficiently. See 1990 and 1991.


The first world leader, Margaret Thatcher, calls for action on climate change.


Treaty to ban chlorofluorocarbons, to protect the ozone layer, is ratified by 197 countries.


Nuclear power plant in Pripyat, Ukraine (Chernobyl) explodes to become the worst nuclear accident in the history of nuclear power.


Organ Transplant

Organ transplants are largely unsuccessful because the body rejectes the new organ. Thomas Starzl works for many years to improve on transplant success. First, with the drug cyclosporine, approved by the FDA in 1983. Later with tacrolimus, approved by the FDA in 1994. Over his career he investigates: preservation, immunosuppression, infectious diseases, oncology, growth factor physiology, and immunology. The Puzzle People: Memoirs of a Transplant Surgeon. University of Pittsburgh Press.


Stanley Prusiner claims prions replicate without nucleic acids.

He publishes: scrapie, a degenerative disease of the central nervous system of sheep, is cause by prions. Prions are misfolded proteins that have the ability to transmit their misfolded shape onto normal proteins without RNA, DNA, or a virus. Also cause other degenerative diseases: mad cow disease and chronic wasting disease. Shifts & drifts in prion science. Science October 2, 2020


Micro Computers


Diamond v. Chakbrabarty - Can life be patented

Asked to rule if a patent for a human-made, genetically engineered bacterium capable of breaking down crude oil, a property which is possessed by no naturally occurring bacteria could be patented.

  1. At questions is: are living things patentable?
  2. Does a micro-organism constitutes a manufactured or composition of matter?

Ruled, it was a nonnaturally occurring organism that was manufactured or a composition of matter of human ingenuity with a distinctive name and character of use.

Referenced: 1930 Plant Patent Act, allowed protection of certain asexually reproduced plants and the 1970 Plant Variety Protection Act, protected certain sexually reproduced plants.



Global positioning system (GPS)

Brad Parkinson and his team had proof of the concept for a global positioning system (GPS) . Source


Gossamer Condor, became the first nonstop human-powered flight in 1977. The Condor designed and built by Paul MacCready stayed aloft for seven minutes and flew a figure eight course. The flight won a prize of $100,000, which was offered by British industrialist Henry Kremer 18 years earlier. The Condor now hangs in the National Air and Space Museum in Washington, D.C. More about Paul and ...

Have Blue, the first stealth aircraft designed and built at Lockheed's Skunk Works took flight over Nevada. More

Voyger 1 is launched and continues its voyage.

  • Voyger 1 was launched Septeber 5, 1977.
  • In 1990 the blue dot photo 2,was taken.
  • On February 17, 1998 it became the most distant human made object
  • In 1998 it crosses the termination shock
  • On February 13, 2010 it passes the reach of the solar wind
  • On August 25, 2012 in reaches interstellar space

Pale Blue Dot image

Photo of Earth taken by Voyager 1 between Uranus and Neptune. Original: NASA JP

Three domains: bacteria, archaea, eukaryotesTangled Tree cover Carl R. Woese discovered cells whose 16S rRNA genetic materials were evolutionary older than known bacteria. This discovery resulted in a three-domain (archaea, bacteria, & eukaryote) biological classification system and understanding of how evolutionary differences can be used for classification. His work lead to the separation of prokaryotes into two groups: Bacteria and Archaea. Woese reasoned the differences in genes of these two groups and the eukaryotes (multicellular fungi, plants, & animals) to be classified as three separate domains.

Source The Tangled Tree by David Quammen


Earth’ s human population 4 billion


First use of precision guided bombs

On July 23rd, laser-guided bombs were used to target and destroy the Than Hoa Bridge and Longbien Bridge. The Than Hoa Bridge was destroyed by a 3,000-pound laser-guided bomb dropped by an F-4 Phantom jet, and Longbien Bridge was destroyed by a 2,000-pound TV-guided bomb. Source


Treaty on the Non-Proliferation of Nuclear Weapons (NPT) to prevent the spread of nuclear weapons and promote peaceful uses of nuclear energy. See 1963 and 1996

Environmental Acts ALL pass in the Senate without a single dissenting vote and signed into law by President Nixon.

  • The Clean Air Act (1970),
  • Clean Water Act (1972), and the
  • Endangered Species Act (1973)



Buzz Aldrin Apollo 14

Apollo program with first Moon landing of Apollo 11

  • Apollo 1 accident fire kills Virgil Gus Grissom, Edward White, & Roger Chaffee. 1, 27, 1967
  • Apoll0 4 no crew Earth orbiting mission to test Saturn V as a launch vehicle. 11, 9, 1967
  • Apollo 5 no crew Earth orbit with test flight of lunar module. 1, 22, 1968
  • Apollo 7 first crew flight Walter Schirre, Donn Eisele * Walteer Cunningham 10, 11, 1968
  • Apollo 8 takes three astronauts (Frank Borman, Jim Lovell, & William Anders) to the dark side of the moon and back. 12, 21 1968
  • Apollo 9 tests the lunar module for the first time while in Earth orbit. 3, 3, 1969
  • Apollo 10 tests all aspects of a complete crewed lunar landing, except the landing. First crewed spacecraft to operate in lunar orbit. Thomas Stafford, John Young, & Eugene Cernan. 5, 18, 1969
  • Lunar lander on Moon
  • Apollo 11 Neil Armstrong is the first man to step on the moon and first broadcast from the surface with "One small step for man, a giant leap for mankind." Accompanied by Buzz Aldrin & Michael Collins. Michael orbits the moon. Includes a two and one-half hour moon walk.
  • Apollo 12 Second lunar landing with an eight hour moon walk. Found bacteria could survive from Earth through space to the moon onan unmanned lander. 11, 14, 1969 Charles Conrad, Richard Gordon, & Alan Bean
  • Apollo 13 Third planned lunar landing, however, the lunar landing is aborted when an oxygen tank explodes two days after launch. Mission control and astronauts ( Jim Lovell, Jack Schwigert, Fraed Haise) engineer a solution and return safely to Earth. 4, 11, 1970
  • Apollo 14, Third lunar landing, Alan Shepart, Stuart Roosa, & Edgar Mitchell 1, 31, 1971
  • Lander docking with command module
  • Apollo 15, Fourth lunar landing, David Scott, Alfred Worden, & James Irwin 7, 26, 1971 first use of lunar rover.
  • Apollo 16, Fifth lunar landing John Young, THomas Mattingly, Charles Duke. 4, 16, 1972
  • later went to the moon and
  • Apollo 17 Sixth lunar landing. Harrison Schmitt, Eugene Cernan, & Ronald Evans. Longest rover exploration and returns more soil and rock samples than previous. 12, 7, 1972
    It is the last mission. However, several movie legends and conspiracy theories will claim additional secret NASA missions.
  • After Apollo 17 the Apollo program goes on to launch Skylab and ends with the docking of the Apollo - Soyuz vehicles.


Tragedy of the Commons

Garrett Hardin writes his Tragedy of the Commons to describe problems for common resources. He explains how herders, who seek to maximize production, can increase herd size and over graze a common range. Production that exceeds the range's capacity will cause livestock to suffer, production to fall, and the ultimate tragedy: no rancher being able to graze the field, due to overconsumption. However, persuasive forces, such as: from a collective cooperative agreement or monarch who apply coercion or social pressure for conservation of land could achieve a sustainable environmental with appropriate management. The idea of tragedy of the commons can be expanded to other land uses. Provide food, shelter, aesthetic value, watershed for quality water to sustain agriculture and human health; conservation of wild life; healthy oceans; clean atmosphere with balanced amounts of oxygen nitrogen, carbon dioxide, life sustaining climate; transportation; and intellectual knowledge rights.

Science December 13, 1968

Decoded how DNA is transribed into RNA to build proteins.

Har Gobind Khorana, found that DNA's four letter codes: A, T, C and G are transcribed into RNA and then translated, three at a time, to build proteins with amino acids. He studied nucleic acids, molecules that make genes, and confirmed the 64 unique three-letter words that determine the order of amino acids needed to make specific proteins.

In 1972, Khorana made a second breakthrough, constructing the world's first synthetic gene. In 1976 he injected the gene into a living bacterium. Source The Gene


Discover microwave background radiation of the big bang

Detected electromagnetic background radiation that seemed to be coming from all directions of the sky. Thought to be emitted 380,000 years after the Big Bang. See 1992

16 October 3 pm China detonates its first atomic bomb and announces its policy of no first use in a conflict.

Qian Xuesen was born in China. Received a scholarship to MIT gained a security clearance and worked on classified weapons research in the U.S. During the Red scare. The FBI revoked his clearance and put him under house arrest. He returned to China and worked on their nuclear weapon program, ballistic missle program, aerodynamics, and systems engineering to control social science and engineering problems (Three Gorges Dam on the Yangtze River). His work sets the stage for state surveillance to control reality in later years, 2016. Source

James F. Holland researches and develops combination chemotherapy as a treatment of acute leukemia in children based on two key concepts: first, cancer cells are naturally resistant to chemotherapy, and second, resistance can be overcome more effectively when multiple drugs are given at the same time instead of one after another. His research changes acute lymphoblastic leukemia from an incurable illness to one with a high survival rate.

First stop motion photograph taken

Dr. Edgerton, invents the stroboscope and uses it to capture photographs of rapid motion. Pictures that seem to stop time. His photos include a bullet shot through an apple, a milk drop above a splash wave, and many more.



Treaty to ban atmospheric nuclear testing to eliminate radioactive fallout as a source of pollution is signed.

First live instant replay on TV is run in the third quarter of the Army v. Navy football game, December 7, 1963.

Valentina Tereshkova is the first woman to orbit Earth.

Fian Fossey begins her life long study of gorillas. See her story


Silent Spring cover Rachel Carson

Rachel Carson publishes Silent Spring

In it she claims everything is connected, we all share the same molecules, and humans have the capacity to destroy nature.
PBS Rachel Carson video 2017 (1:53:11) and Life & Legacy of Rachel Carson

  • Creates the environmental movement
  • At 10 she wins a prize for her story published in St. Nicholas Magazine 1918.
  • Graduates Parnassus, PA High School 1925
  • Graduatea Pennsylvania College for Women (Chatham University) 1929
  • Employed at Woods Hole Marine Biological Laboratory
  • Earn an MA in zoology at Johns Hopkins University in 1932.
  • Writes 52 short radio programs on marine life: Romance Under the Waters in 1935.
  • Undersea Atlantic Monthly article in 1937
  • Works at the U.S. Fish and Wildlife Service as a fish & aquatic marine biologist 1939-1951
  • Notes the subartic growing season is longer, growth rings are fatter, and cod are migrating farther north. She concludes: "The long trend is toward a warmer earth." 1951
  • Reader's Digest turns down her article on DDT effects on the environment because it is thought to be too controversial. Chemical companies claim it is only harmful to bugs.
  • The Sea Around Us prize winning book, published in 1952, a study of the oceans. Followed by The Edge of the Sea in 1955.
  • Japanese seamen on board the Lucky Dragon die of radiation exposure 1954. She asks: How much radiation does it take to harm life? How much to kill? Strontium 90. leukemia, birth defects ...
  • Help Your Child to Wonder. 1956
  • Our Ever-Changing Shore. 1957
  • Silent Spring published 1962 Relates pesticide effects to radioactive build up. What is a wise use of pesticides?
  • CBS Reports with Eric Sevareid airs The Silent Spring of Rachel Carson on national television 1963 in spite of the fact all sponsers with draw commercial support.
  • Who does the land, air, forest, water belong to? What is the commons?
  • She set out to save a species ... Us.

Big box store architecture can be tracked to 1962 when Walmart, Target, and Kmart stores open a few months apart. Inside stores with huge areas of undivided retail space for customers to purchase large supplies of retail goods and outside big parking lots with easy access to highways to attract shoppers.

Two Telstar communication satellites are launched. The first in July 1962 and the second in May 1963. They enable the first TV signals, telephone calls, fax images and live transatlantic feed to be relayed from space.


December 1961. President Kennedy authorizes the use of defoliants in Vietnam.


1960 Earth’ s human population 3 billion

The Green Revolution, and Norman Borlaug develope new strains of wheat and rice to use in developing countries for higher yields. He first developes a short strain of wheat and other varieties for Mexico, which increases wheat production three times.

Later, India and Pakistan ask him to help their countries with their agricultural revolution.

He developes techniques to create mutations for finding new hybrids, which he uses to develop different strains of wheat, rice, sorgum, millet, cassova, triticale, maize, and tubers. It is estimated these varieties were able to save billions of people from starvation. The down side is the large amounts of chemical fertilizers and pesticides required to maintain high yields. Source

Jane Goodall begins her life long study of chimpanzees.See her story

Over 90% of homes in USA have a television.

Laser (light amplification by stimulated emission of radiation) is invented.

Laser is a device that amplifies coherent light by energizing electromagnetic radiation.

The first laser is built by Theodore H. Maiman at Hughes Research Laboratories, based on ideas by Charles Hard Townes and Arthur Leonard Schawlow.

Later applications include: laser pointers, laser surgery, tatoo removal, cutting materials, welding, fiber-optics, optical disk drives, laser printers, barcode scanners, DNA sequencing instruments, instruments to mark targets, instruments to measuring range and speed, laser lighting displays ...

First SETI (search for extraterrestrial intelligence) experiment

Frank Drake turns the telescope at the National Radio Astronomy Observatory toward Tau Ceti and Epsilon Eridani (close stars) to search for interstellar communications (project Ozma). A high altitude plane signals a false alarm. However, it demonstrates such a search is reasonable and feasible.


America enters space age

ARPA launches America's first communication satellite (SCORE) into orbit with an American Atlas rocket. A previously recorded meassage is onboard and on December 19, 1958, with a second attempt with a radio signal from Earth, it is turned on and President Eisenhower's pre recorded speech is broadcasted on a short-wave radio frequency from outer space. Message below: Source

This is the President of the United States speaking. Through the marvels of scientific advance, my voice is coming to you from a satellite circlin g in outer space. My message is a simple one. Though this unique means, I convey to you and all mankind, America's wish for peace on earth and good will to men everywhere.

NASA launces its first satellite, Explorer 1, into space on January 31, 1958 aboard a Jupiter C rocket developed by the team headed by Dr. Wernher von Braun. The primary scientific purpose is to measure cosmic ray radiation in Earth orbit.The experiment, conducted by Dr. James Van Allen, measures a lower cosmic ray count than expected. This lead to the discovery of the Van Allen Belts of charged particles concentrated in space by Earth's magnetic field. Source

Alan Shepard is the first American to reach space on a suborbital flight on May 5, 1961. Three weeks after the Soviet cosmonaut Yuri Gagarin.

In 1962 astronaut John Glenn orbited the Earth three times in the Mercury spacecraft Friendship 7, re-entered the Earth's atmosphere, and splashed down in the North Atlantic Ocean.

Female mathematicians, or human computers, support the engineers. Amoung them is Katherine Johnson. She developes precise trajectory calculations for human spaceflights and lunar orbits. Margot Lee Shettelry writes about her in the book Hidden Figures, which the movie of the same name is based.

See Apollo program 1969

Nuclear research

ARPA funded research to investigate the possibility of creating an electron shield, to destroy enemy intercontinental ballistic missiles (ICBM), by exploding atomic bombs in the atmosphere. The funding included an actual icbm launch with an atomic bomb that was exploded in the atmosphere to test feasibility (ARGUS test). Source

Investigate the creation of a space vehicle powered by hundreds of nuclear bombs (Orion).

Lego bricks were invented by the family company found by Ole Kirk Kristiansen in 1932. The word Lego was shortened from Danish leg godtz - meaning play well. In 2018 the company moves to make environmentally responsible bricks with a small environmental footprint. Source

Anthropocene Epoch (present - .01 mya)

Anthropocene Epoch (present - .01 mya) can be identified by the measurement of radioactive traces in organic materials that was alive during the atomic bomb tests of the 1950's and 60's. Might be considered as a sign post, along with the introduction of plastic into the environment, for the extinction of many species. Will humans be among them?


The start of the Space Age
The Soviet Union launches
Sputnik 1, the earth's first artificial satellite, on October 4, 1957

Shortly after, two more Soviet satellites are launched, one with a dog, into space. The satellites orbit Earth approximately once every 90 minutes. See America enters space race 1958

Strategic Air Command (SAC) south of Omaha, NE under the command of General LeMay employs nearly a quarter of a million men and its hangars contained over 2,000 strategic aircraft, including over 700 B-52s.


Federal Aid Highway Act passes Congress

Construction of the U.S. Interstate Highway System with controlled access highways propossed by Dwight D. Eisenhower starts.

Shipping container is invented and patented in 1956 by Malcolm Mc Lean. A trucker who owned and operated a large fleet of trucks, designs it for more efficient and faster intercontinental trade.


AI (artificial intelligence) is used by John McCarthy and Marvin Minsky extending the questions: Can machines think? Later explored in films such as: 2001: A Space Odyssey and The Terminator. They coined the term to focus discussion on the programing of machines as opposed to the philosophical ideas associated with the term used in the 1948 book Cybernetics by Norbert Wiener.


Solar cell

On April 25, 1954, Bell Labs announces the invention of the first practical silicon solar cell. Originated from Aleksandr Stoletov the first solar cell based on the photoelectric effect in 1894. Source Timeline solar cells

See article on how variation of Sun angle, duration effects the amount of Solar radiation energy (insolation).


MUexperimentStanley Miller created amino acids. His experiment put an electrical charge in a flask with methane, ammonia, hydrogen and water. The results may explain how organic materials were created on Earth billions of years ago.

By The original uploader was Carny at Hebrew Wikipedia (Transferred from he.wikipedia to Commons.)


James Watson and Francis Crick demonstrated a model for deoxyribonucleic acid (DNA) as a double helix twisted ladder. Essential for understanding how genes control the chemical processes within living organisms.

The 4 Level Freeway Stack opens in Los Angles. It is 32 lanes of traffic to change directions 8 ways.

See source article
Freeway stack image


Maria Tharp discoveres the Mid-Atlantic Ridge from mapping data.

When Maria transfers data from a 5000 foot scroll onto sheets of white linen to map the bottom of the Atlantic Ocean a long rift valley appears. Such a ridge is suggested by Wegner's theory of continental drift. However, most people believe continents are to massive to drift so she is told by her superior to redo her work. After she does the results are compared to another map by Bruce Heezen and both describe rift valleys in the mid-ocean ridge. The results are published and read in 1957, by the ocean explorer Jacques Cousteau. He doubts Tharp's conclusions and tacks her map to the dining room wall of his ship, determined to prove her wrong. However, after viewing film he took of the Atlantic Ocean floor, he saw a deep valley ridge where Tharp had mapped it. Source "Connect the Dots: Mapping the Seafloor and Discovering the Mid-ocean Ridge" by Marie Tharp, Chapter 2 in Lamont-Doherty Earth Observatory of Columbia

Great London Fog or Big Smog

A five day air-pollution event in the United Kingdom caused by cold weather and a lack of wind to move massive amounts of smoke created by the buring of coal and other fossil fuels for home use, transportation, and industry is believed to have killed 12,000 and sickened 25,000. It leads to the Clean Air Act in 1956. Source

First amino acid sequence of a protein

Frederick Sanger found a protein is a genetically created sequence of amino acids. He uses this ideas to determine the complete amino acid sequence of two polypeptide [protein] chains - bovine insulin A (1951) and bovine insulin B (1952). Next he determines how amide groups are distributed, and the location of the disulphide linkages which complete his deduction of the structure of insulin, in 1954. Source


Henrietta Lacks dies of cervical cancer on October 4, 1951, at age 31. C

Her cells are taken from her body and used to create the HeLa cell line. These cells are found to grow quickly, are very hardy and survive longer than usual human cells. They became widely used in thousands of medical research experiments (cancer, polio vaccine, HIV, effects of toxins and radiation on cells, gene mapping, testing sensativity of cosmetics and other substance on cells, invitro fertilization, ... ). Since the cells were taken without her or her families permission their use and ownership eventually began discussion on ethical and legal use of peoples cells and genetic material. Source

1950 is designated as B.P. (before present)

Willard Libby, invents carbon-14 dating around 1950. Therefore, scientists agree to use January 1, 1950 as the reference date for before present (BP) when dating.


First bikini

French textile engineer fashion designer Louis Reardé designs a two piece swim suit, the bikini (Bikini Atoll is where atomic bombs were tested), and has Micheline Bernardini model it on July 5, 1946.

Previously, bikini like clothing is carved on a statue in Turkey about 5,600 BCE and paintings and other artifacts from Greece and Rome also show bikini style clothing.


Manhattan Project's Trinity test successfully detonates the first atomic bomb in Alamogordo, New Mexico on July 16, 1945, at 5:29:45 a.m.

Views of photos and videos of atomic test explosions. Compiled by Gregg Spriggs, at Lawrence Livermore National Laboratory in California for the public to see the destructive power.

How to Solve It coverGeorge Polya studies and identifies a heuristic to systematically solve problems. His classical book: How to Solve It, has been been found by students and educators as an authority for solving problems. In it he suggests four steps for solving mathematical problems:

  1. Understand the problem
  2. Make a plan
  3. Carry out the plan
  4. Look back on your work and ask, How could it be better?


Frozen food developer Clarence Birdseye learns from the Inuit that trout caught through holes in the ice can be frozen instantly in the air (which was 30 degrees below zero) tastes like it fresh trout when it was cooked later. Unlike when food is frozen in the more usual slower way.

This leads him to develope a flash freezing method to create better tsting frozen meals and vegetables, which and changes the way the world eats and provides people with quality food that isn't in season. Source and more.

Erwin Schrodinger publishes What Is Life? In it he seeks answers to

" ... how can the events in space and time, which take place within the spatial boundary of a living organism be accounted for by physics and chemistry?"

This book is credited by many of the pioneers in the study of genetics and DNA as inspiring their work.


First digital speech encryption system, SIGSALY or The Green Hornet, is developed by Bell Telephone Laboratories and built by Western Electric. It is used to communicate from Washington to London during WWII. Communications such as confidential talks between British Prime Minister Winston Churchill and US President Roosevelt. The system uses the highly-secure One-Time Pad (OTP) encryption. Source


Space age

The V-2 missile fires successfully from Peenemund island off Germany's Baltic coast. Directed by German rocket scientist Wernher von Braun.


Penicillin Howard Florey and Ernst Boris Chain isolated, purified, and created an injectable form of penicillin to use as an antibiotic.


A study showed bacteria could develop a resistance to penicillin. Even before penicillin was used to treat infections. However, the idea of killing bad bacteria and an increase in the discovery of antibiotics would accelerate the use of antibiotics in ways to contribute to resistant microbes rather than considering a more targeted and efficient use of antibiotics to reduce the evolution of drug resistant organisms.


DDT was found to kill insects and began to be used extensively as an insecticide. Sprays attached to mowers to spray yards before picnics, shelf paper with DDT embedded, paint, varnish, there were no limits on its use. Thought it would raise the standard of living, rid the world of malaria, fire ants and other pests that caused disease and harmed crops.

DDT poster


1936 - 1938

City planning for green space and community ...

Greenbelt, Maryland, is constructed from 1936 to 1938 by thousands of laborers, through the New Deal programs. Clarence S. Stein is a consultant and creates design guidelines. Later Stein works to preserve the town as an example of a socially and environmentally responsible community design that can be used as a prototype for future desgins. Designs that combine superblocks of houses and apartments with pedestrian walkways through communal green space which join to a central area with commercial and recreational structures separate from roads for automobile travel. In addition, the federal government promotes cooperative enterprises and associations in Greenbelt as a way to foster affordable houseing and an enduring sense of community. While the cooperative nature of the towns are deemed a failure, the physical layout of the town is replicated by private developers. Source
More information related to the political aspects of this social experiment.


Sulfa drug and antibiotics

Sulfa, also called sulfonamide, a synthetic antibiotic with a sulfanilamide molecular structure is the first chemical substance systematically created to treat and prevent bacterial infections in humans. Their effects were first observed in 1932, by Gerhard Domagk who notices that red dye Prontosil kills Streptococcus infections in mice. Later researchers find the active agent is sulfanilamide, or para-aminobenzenesulfonamide, a metabolic product of Prontosil.


Edwin P. Hubble supports the expansion of the universe with his measurements of shifting spectral lines of light emitted from distant galaxies.


Penicillin. Alexander Fleming accidentally contaminates colonies of bacteria with penicillium and notices the bacteria in those areas do not grow. He isolates the mold, grows it, and finds it contains a substance capable of killing many bacteria that infect humans.

Dirac and the electron wave equation and the positron

Dirac presentsto the Royal Society of London a relativistic wave equation for the electron. His equation requires four wave functions and introduces spins. It included an extra set of solutions with negative values of energy. In 1931 Dirac suggests this implies the existence of the antielectron, or positron. Later discovered in cosmic rays by Carl Anderson.

The Dirac equation as a path to the concept of quanta, and its role in quantum electrodynamics. by Mario Bacelar Valente


Holland Tunnel opens

It is the first vehicle tunnel, under the Hudson River, between Lower Manhattan in New York City and Jersey City, New Jersey.

Plans to bridge the Hudson River are first suggested in 1906. However, in 1919 it is decided to build a tunnel under the river. Construction starts in 1920 to build, what is at the time, the longest continuous underwater vehicular tunnel in the world. Clifford Milburn Holland is the chief engineer until his death in 1924. The problem of supplying breathable air to motorists in a closed system with running gasoline engines is solved by Ole Singstad, who designs the first mechanical ventilation system and supervises the tunnel's completion.


Hans Berger invens the EEG (electroencephalograph). It records brain waves. He also discovers the alpha wave.


Earth’ s human population reaches 2 billion


First evidence to support Einstein's Theory of General Relativity

May 29, 1919, during a solar eclipse, the path of star light is measured as it travels past our Sun. The measurement finds the star's light bends by the amount predicted by Einstein's Theory of General Relativity, of how light interacts with mass which warps time and space.

Atomic 1920 - 1860


Walter Reed Hospital

Influenza pandemic of 1918-1919

An influenza (Spanish flu H1N1) pandemic from 1918-1919 becomes the deadliest in modern history. It infects around 500 million people worldwide (one-third of the Earth's present population) kills 18-20 million in India, 40 million in Japan and between 50-100 million worldwide. In Nebraska 20,000 people were infected and 1500 died The Chautauqua Reader 2018.

The first case is identified at the U.S. Army infirmary in Fort Riley, Kansas on March 4 and by the end of the month there are 1,100 cases. The point of origin is a farm in Haskell County, Kansas. Troops embark to Estaples, France and take the virus with them. The virus spread quickly through Europe and to the rest of the world.

Army ward Kansas 1918

The story of how this epidemic changed the world is in Pale Rider. More people died from this epedemic than died in World War I. It is the most devastating epidemic in recorded history. See vaccination fact sheet
See also Pandemic related Pod casts with first person accounts and more: Going Viral: The Mother of all Pandemics


Chemistry: fertilizer, chlorine gas, and zyklon B gas.

Fritz Haber and his team weaponized chlorine gas, which was the first large scale use in, Ypres France, in 1915.

Haber and Jeroen Bosch create the Haber process, which makes ammonia fertilizer (NH3) from atmospheric nitrogen and hydrogen gas (1909). The first agricultural fertilizer not from animal sources. This process increases the food supply and saves millions of people from starvation and earns Haber the Nobel Prize in Chemistry in 1918.

Haber left Germany for Switzerland and died in exile in 1933. Nazi scientists found his notes that described a gas called Zyklon B, which Haber's team had developed as a pesticide. The Nazis use this gas to kill millions in the Holocaust. Source

A commercial video on the social and ethical consequences of scientific work related to Haber's decisions. (35:00 minutes)

Later, in early 1920's when the Geneva Convention considered a ban of chemical weapons, General Amos Fries looked for other uses for these chemicals and the use of tear gas on civilian crowds is popularized to maintain the production of these gases. Source


Quantum theory

Niels Bohr theorizes electrons circle a nucleus in unique orbits depending on their unique energy levels, which are proportional in size to the frequency of the radiation it represents. Electrons jump from one level to another when they absorb or emit this packet of energy called a quantum. These particles only exist at a level never in between with quantum leaps from level to level being instantaneous and random.

Los Angeles Aquaduct is completed. Chief Engineer William Mulholland constructs it to bring water from the Owens River to Los Angeles 233-miles south. Thought to be second engineering feat to the Panama Canal. Source

X-ray crystallography is use by William Bragg and his son William Lawrence Bragg. The proces uses X-rays to reveal the crystal structure of salt and diamonds. Later, in late 1950's, the process is extended to discover the structures of proteins and later protein complexes.


Suture technique



Alexis Carrel and Charles Guthrie solve the problem of how to sew (suture) two blood vessels together. Blood vessels being tubular were difficult to sew for several reasons, which were solved by their triangular suture method. Source







Hudson & Manhattan Tunnel opens

The construction of the tunnels is an engineering marvel. Tunneling under the river, providing breathable air, and of course tunneling. The tunnel system lets railroads travel under the Hudson river to Pennsylvania Station in New York City.

Previously, all rail service terminates on the west shore of the Hudson River, in Weehawken, New Jersey. To go to Manhattan everything is transfered to ferries, weather permitting. Source

Also 1927 Holland Tunnel

Vitamins as essential for health were recognized by Casimir Funk, who collected information about human diseases, beriberi, scurvy, and pellagra, and concluded they were caused by a chemical deficiency of amine compounds. Thus, he called them vital amines. Which was later shortened to vitamin when it was found not all vitamins contain amines. See the discovery stories five vitamins:

  1. The Case of the Night-blind Fishermen - vitamin A
  2. The Case of the Wobbling Hens - vitamin B1, thiamin
  3. The Case of the Volunteer Victims - vitamin B3, niacin
  4. The Case of the Pine Needle Soup - vitamin C, ascorbic acid
  5. The Case of the Invisible Rays - vitamin D

Forest management and forest fires and the Big Burn

The summer found the mountains hot, dry and highly combustible, which feed more than 1,000 fires in northeast Washington, northern Idaho, and western Montana, most created by lightening. August 20, 1910, winds greater than 72 mph spread small fires into big ones. 36 hours burnt an area the size of Connecticut (3 million acres). Kills at least 85, changes forest management, and leads to the creation of Smokey the Bear (voice by Sam Elliot). Other American devastating fires.


Ford assembly line

Henry Ford used standardized parts and an efficient assembly line to create an affordable car for the common man. A car every 22 seconds rolled off the line.

Critical discovery to measure the size of the universe with variable stars

Henrietta Swan Leavitt observed Cepheid variable stars in the Small Magellanic Cloud and discovered their brightness was greater the longer it took them to complete one cycle. This period-luminosity function of Cepheid variable stars provided a way to move beyond the use of parallax to measure distances to stars.


The pure food and drug act was the first consumer protection law to protect the American food supply. It was the passed by Congress. American women, doctors, and editors helped Congress to pass the bill.

The Jungle by Upton Sinclair kept public attention on the importance of food inspection laws to insure a safe meat supplly from meat packing plants.

Later congress created the Food and Drug Administration (FDA) to ban foreign and interstate traffic in contaminated and mislabeled food and drug products. To achieve this:

  • It directed the U.S. Bureau of Chemistry to inspect products and refer offenders to prosecutors.
  • It required labels to identify active ingredients
  • Required products to be within purity levels established by the United States Pharmacopeia or the National Formulary.
  • Today the FDA is responsible for protecting and promoting public health through the control and supervision of food safety, tobacco products, dietary supplements, prescription and over-the-counter pharmaceutical drugs/medications, vaccines, biopharmaceuticals, blood transfusions, medical devices, electromagnetic radiation emitting devices, cosmetics, animal foods & feed, and veterinary products. Source

The Poison Squad is a book that tells the story of how its first chief chemist: Harvey Washington Wiley, citizens, and government can work together in meaningful ways for consumer protection.


Nettie Stevens Discovers male chromosome determines sex

Stevens observed a difference between female and male mealworm sex cells. She noticed the sperm had two versions of their 20th chromosome: a smaller version and a largeer one. She then concluded the spermatozoa, which contains the smaller chromosome determines a male mealworn, while spermatozoa that contains 10 equal sized chromosomes determines a female mealworm. She did not call them X and Y chromosomes. That terminology was coined later. Source


Wright BrothersFirst flight

Orville Wright pilots the first heavier than air craft to fly over 120 feet in 12 seconds. Orville and Wilbur Wright design, build, and fly a propeller driven biplane powered by gasoline at Kitty Hawk, NC. The Wright Brothers: How they invented the airplane by Russell Freedman. Excellent source of their lives, building their planes, creation of the aerospace industry, and government involvement.

1902 +

Chemical fertilizer (Nitrogen)

Haber developed a process that used nitrogen (N2) and methane (CH4) gas to make ammonia (NH3) economically. Bosch conducted more than 20 000 experiemnts to find a catalyst and industrialize the process. It has been used to produce so much fertilizer that about 50% of all nitrogen atoms in humans today come from the Haber-Bosch process.

Wilhelm Ostwald used the ammonia (NH3) from Haber's process and developed an additional process to produce nitric acid (HNO3).

Nitric acid ammonia can be mixed to make a more neutral compound ammonium nitrate. It is a good fertilizer because it has a high concentration of nitrogen and can be stored and blended with other fertilizer components. Source

Mt. Pelee on the Caribbean island of Martinique erupts and kills around 30,000 islanders within minutes, leaving two survivors. A citizen group meet a few days before the eruption and decide the smoke and ash does not require an evacuation.


The era of big oil began ( January 10, 1901, ) when a well at Spindletop (Beaumont, Texas) struck oil at a depth of 1 139 ft. The Lucas Gusher went 150 feet in the air and blew 100,000 barrels (4 200 000 gallons) per day for nine days before it was capped. Beaumont became a boomtown as its population grew from 10 000 to 50 000 in three months.


One in 38 railroad employees was injured on the job - and 1:399 died. Source Doctors Derailed: How Railway Surgeons Advanced Medicine. Discover Magazine. July/ August 2016.

Chicago River is reversed

As Chicago, IL grows its sewage and industrial waste flows into the Chicago River which flows into Lake Michigan. As Chicago grows, this becomes a problem since as Lake Michigan is the source of the cities drinking water. The pollution carries diseases like typhoid and cholera, which enters the water supply. Ellis Chesbrough, engineer, suggests to reverse the flow of the river so it flows south into the Mississippi River toward St. Louis with the largest earth moving project by any city government. Source


The Chlorine Revolution started in Jersey City, NJ when the water supply from the Passaic River was contaminated. To provide a clean water supply the city contracted Patrick H. Flynn to develop a new source. Twenty-three miles west of the city on the Rockaway River a dam was built to create a reservoir. However, after the contstruction there were several times a year rain would cause the sewage system to overflow and contaminate the water. The city claimed the engineer should have planned better and refused to pay for the construction. Flynn consulted with Dr. John L. Leal who believed bacteria contaminated the water and suggested it could be treaated with chloride of lime (chlorine). The water was treated succesfully, the judge accepted the soution, and ordered the city to pay for the construction. Source The Chlorine Revolution: Water Disinfection and the Fight to Save Lives, by Michael McGuire, 2013. Purified water has saved millions of lives and raised life expectancies by some estimates forty years. See Chlorination and public health


The Food ExplorerDavid Fairchild was a botanist, financed by Barbour Lathrop who convinced James Wilson, the Secretary of Agriculture, to accept seeds and plant cuttings David ships to DC to distribute to farmers to diversify American food production. He shipped magoes and dwarf oranges from Jamaica, avocadoes from Santiago, Chile, fava beans and broccoli from Venice, Italy along wiht seedless grapes: purple sultanina, and light-green varieties to become raisins. Kale from Croatia and hops from Polepy, Czech Republic. He also brought Cherry trees from Japan as ornamentals for his garden that became the inspiration for the DC tidal basin cherry blossoms that was a gift from the city of Tokyo.

Source The Food Explorer: The true adventures of the globe-trotting botanist who transformed what America eats. by Daniel Stone

First T-shirt

The U.S. Navy began issues slip-on white cotton undergarments with no buttons a crew-neck and short-sleeves to wear under uniforms. Sailors wore them without their uniforms in submarines and tropical climates. Later T-shirts became popular for workers in industries, agriculture, and young boys because they are easily cleaned, inexpensive, and fit well. T-shirt appears in the Merriam-Webster Dictionary in 1920 and becomes more popular in 1947 when Marlon Brando wears one in A Streetcar Named Desire. After which it becomes a fashionable garment.


Radio waves

Guglielmo Marconi, an electrical engineer explored long-distance radio transmission, and developed Marconi's law and a radio telegraph system. Often credited as the inventor of radio, An entrepreneur, businessman, and founder in Britain in 1897 of The Wireless Telegraph & Signal Company. Later the Marconi Company, built on the work of previous experimenters and physicists, and became a commercial success in radio.


First fiber glass. Charles V. Boys used a cross bow, a hot glass rod as an arrow that he heated to the point of melting, and then fired it. The result was a few microns diameter thread 30 m long. He found it to be very strong and used it to build devices to measure radiation and gravity. Unknown to him it was the first fiber glass. Source


First book on soap bubbles: Soap -Bubbles and the Force which mould them


First use of the term scientist. The British philosopher, William Whewell, at the British Association for the Advancement of Science. suggested that since the practitioners of art are called artists, then the practitioners of science ought to be called scientists. Suggesting they should no longer be called philosophers.

First modern vending machines

  • FIrst vending machine see 50BCE
  • 1883 In England Percival Everitt invented a machine that dispensed postcards, envelopes, and paper in railway stations and post offices.
  • 1884 In the U. S. William Henry Fruen patented an Automatic Liquid-Drawing Device that dispensed drinks.
  • 1888 the Thomas Adams Gum Company built machines to sell gum at New York City train platforms.
  • 1897 Pulver Manufacturing Company added animation of small figures to encourage people to buy gum from their machines.


Pullman Company town

Pullman's philosophy was, happy workers make more productive workers and the quality of his company owned and maintained houses were good for worker housing. As a result the majority of Pullman employees lived in his houses, which contained two to seven rooms with each having direct access to a private yard, woodshed and paved alley. A variety of housing types were available within each block and from block to block designed to meet different income, status, and family makeup. Source

1880 + -

Light bulb and electrical systems. Joseph Swan installed light bulbs in homes and landmarks in England in the early 1880's. His house was the first in the world to be lit by a lightbulb and the first house in the world to use hydroelectric power. Others who worked on the light bulb: Henry Woodward, Matthew Evans, William Sawyer and Albon Man.

The home of Lord Armstrong at Cragside was also among the first houses to be lit by electricity. He started his company and lit the Savoy Theatre in the City of Westminster, London making it the first public building in the world to be lit entirely by electricity.

Around the same time Edison found how to make longer burning light bulbs using: 1. a more effective incandescent material, 2. creating a higher vacuum in the bulb, and 3. using a high resistance. Higher resistance also allowed power to be distributed from a central source, making an economical sytem. This lead to a completly integrated system of electric lighting with a centrally located massive generator and a parallel-distribution system. All built by the Edison Illuminating Company of New York that could supply electricity to 59 customers in a square-mile area of lower Manhattan. Thus Edison's genius was not only the light bulb, but the system to make it work in a community.



Treaty of the meter in Paris, May 20, 1875, is attended by 17 countries who create the international bureau of weights and measures, which adopts the metric system internationally. See also metric system history and U.S.

Andrew Carnegie returned from England in 1872 having learned about the Bessemer process for making steel. He increased the scale of the furnace and built his first steel mill, Edgar Thomson Steel Works, in 1875 in Braddock, Pennsylvania, (near Pittsburgh).

For the first time steel could be mass produced inexpensively. This first mill was so successful Carnegie was able to use the profits to buy other Pittsburgh steel mills and create the Carnegie Steel Company in 1892.


Barbed wire. Joseph Glidden was granted a patent for barbed wire on November 24, 1874. He went into partnership with a merchant, Isaac Ellwood, and they formed The Barb Fence Company. Source of invention.

DDT was synthesized in 1874. However, it was not until 1939 that it was discovered it could be used as an insecticde.

First bridge across the Mississippi River south of the Missouri River opens

The Eads Bridge, named for James Buchanan Eads, the bridge's designer and builder, is a highway and railway bridge that connects St. Louis, Missouri and East St. Louis, Illinois, near the present day Gateway Arch.

A Caison is build in the river to construct a 100 foot deep pier anchored to bed rock. Air is pumped to workers who must take precautions to avoid the bends. The structure is the longest steel arch bridge. When it was finished some people are afraid it collapse so 14 locomotives were lined up across it to show its strength.


National Weather Service established


Transcontinental railroad was opened for through traffic on May 10, 1869 with a ceremonial driving of the last spike. The spike, referred to as the golden spike, was driven with a silver hammer, at Promontory Summit, Utah.

Riverside, Illinois was the first planned suburb, and the Chicago suburbs of the mid-19th century weren't exactly suburbs yet but towns near the downtown.

Periodic Table of Elements was created by Demitri Mendeleev. Source

Mendeleev's , Demitri Mendeleev, presented to the Russian Chemical Society in March, 1869 his Periodic Law. He stated, ... elements arranged according to the value of their atomic weights [today atomic mass or number is more accurate] present a clear periodicity of properties.

His version had 70 elements with gaps where he believed unknown elements belonged. Using the properties of periodicity he successfully predicted properties for three or the gap elements. Source

Periodic table today


First Planned suburb

Riverside, Illinois was the first planned commuter suburb. It was a suburb of Chicago Illinois accesible by train. Although at the time it wasn't known as a suburb, but as a town near the downtown. While towns were designed in a familiar checker board fashion, Riverside was the first where roads were curvalinear and didn't meet wiht 90 degree angles. Designed by Frederick Law Olmsted. Source

First Canned meat

Deviled ham meat spread was first canned in 1868 by the Underwood Deviled Ham company. The company was found in 1822 by William Underwood who then packed food in glass containers. In 1836 he changed to steel cans coated with tin.

Underwood's Devil logo is thought to be the oldest food trademark. Source

Underwood Deviled Ham Spread Ad


John A. Roebling Suspension Bridge opens

Across the Ohio River connecting Cincinnati, Ohio and Covington, Kentucky. It is the longest suspension bridge in the world at 1,057 feet (322 m) main span made from the first iron rope cable. Later in 1883 Roebling's most famous, Brooklyn Bridge is longer at 1,595.5 feet.


Speed of light, is measured as 298 000 km/s by Leon Foucault he designs a more accurate method to measure the speed of light.

1861 +

Maxwell's electric and magnetic equations:
James Clark Maxwell's
published equations to describe how electric and magnetic fields are generated, interact, and are changed by each other and their charges and currents.

Explanation of Maxwell equations

Industrial 1860 - 1500


Oil well
he first successful oil wells was drilled in northwestern Pennsylvania. Known as the Drake Well, after "Colonel" Edwin Drake. It began an international search for oil and energy use for the next hundred... years... Source

Charles Darwin publishes On the Origin of Species.

He and Alfred Wallace share their ideas on how life changes and adapts, evolution. His only statement in this book on humans being shaped by evolution is: Light will be thrown on the origin of man and his history. Ten years later, he does in two books: The Descent of Man and Selection in Relations to Sex, and The Expression of the Emotions in Man and Animals.


First Trans Atlantic Cable completed ...

It connects N. America to Ireland. The first message is sent by Queen Victoria to US president James Buchanan congratulating him on the successful completion of this great international work. The message travels through 2 500 miles of cable and takes 16 hours. Its Accomplished by Cyrus Field with grit, etermination, and persistence for over ten years.

Can opener invented
Ezra J. Warner invented and received a patent for the first can openerin 1858. It used by the US military in the civil war.

In 1866 William Lyman improved it with a wheel that rotated along the top rim of the can and received a patent for it in 1870. Source

1855 + -

Elevator, lifting devices with ropes and pulleys were described and used by Archimedes, in the Roman Colosseums, Louis XV, and others. However, they were slow and unreliable with the use of ropes, which could wear out and fail. In 1852, Elisha Graves Otis invented a safety break in 1852 that changed that. If there was a cable break, a spring would push pawls on the car into position racks on the sides of the shaft and hold the car in place. Such a devise was installed at a five-story department store in New York City in 1857.

Commercial passenger elevators allowed the building of the world's first skyscrapers opening cities to an explosion of population and real estate value as building rose literally hundreds of floors. The Otis Elevator Company, is a subsidiary of United Technologies Corporation, the world's largest manufacturer of vertical transport systems. Source



Dr. John Snow investigated the death of over 500 people, in the Golden Square neighborhood of London. He collected data on where the dead people had lived, mapped it, and his analysis lead him to discover a geographic relationship to indicate the source of the cholera epidemic as a local well. He recommended the removal of the pump handle, which the St. James Parish ordered done.


Dr John Gorrie, found that when yellow fever patients were cooled with ice, they had a better chance of recovering. Being in the south ice was only available when it was imported from New England. To make ice available all year he explored how make ice with refrigeration and cool rooms with air conditioning. His invention was granted a patent for a machine that made ice by compressing and cooling air. Source


A Drop of London Water, from Punch, 1850

Drop of water



Guano as fertilizer
Europe and other countries with depleated soils sought ways to keep their soils fertile. One was to add manure to the soil. A recent discovery of on Peru's Chincha Islands was mountains of bird excrement several hundred feet deep in places. The guano deposits were high quality and with a high demand, the idea that a fortune could be made sent investors to the region to mine and sell guano as fertilizer. Soon countries were exploring the world for other areas rich in Guano and claiming mining rights. Wars and territorial disputes developed.


Friedrich Wilhelm Bessel used parallax to calculate the distance to the star, 61 Cygni, and concluded it was 10.3 light years.


First iron plow is made by John Deere.


Browning motion

Robert Brown, looks at plant pollen (Clarkia pulchella) placed in water and sees particles jiggling randomly in the water.


England deliberately exterminated beavers in the Oregon Bridge Creek to keep trappers (particularly U.S.) from going into Oregon and claiming the Territory for the United States.


Erie Canal

Construction begins to create a water route from the Atlantic Ocean to the Great Lakes. It is created as the New York State Canal System. It begins in Albany, New York and extends 363 miles to Buffalo, upstream of Niagra Falls, on Lake Erie. Before rail travel, 60% of all goods traveling east and west traveled on the Erie Canal. Source So noteworthy Thomas S. Allen wrote a song for it: Erie Canal - five verses worth 3:53). More history on the song.


Renѐ Laennec was a muscian and physician who invented the stethoscope. He recorded his first observations of the heart as musical notation and pioneered listing to chest sounds to diagnose various medical conditions.


Views of the Cordilleras published by Alexander von Humboldt

Alexander links science with the human experience to include science, art, culture, geography, history, and linguistics. His ideas include:

  • All diverse people of the world are one species.
  • No one group of people is superior to or dominant over others.
  • Opposes colonialism, imperialism, & slavery.
  • Claims science is not perfect, but necessary, but not sufficient to develop a healthy relationship with the living world and its environment.
  • Introduces the concept of isotherm: a region defined by its average mean temperature of 6 degrees C for its growing season, which matches the global tree line. An area that supports more diverse life than any other terrestrial system.


Preservation of food is perfected by Nicolas Appert who preserves fruits, vegetables, meat, soup, and milk by boiling and storing them in airtight glass containers. It is developed so Napoleon can feed his troops in the field. Source


Robert Malthus publishes An Essay on the Principle of Population.

He argues population will increase at a rate greater than food production. He bases his conclusion on a finite limit of land for crops, a geometric rate of population growth, and a arithmetic rate of increasing food production. His theory influences Darwin and his theory of natural selection; and years later Keynes and his Keynesian economics.


France creates the to standardize measurement across France on April, 7, 1795. It is a measurement system based on the decimal system, uses the meter for length, liter for volume, and the kilogram for mass. It was later dropped by Napoleon in 1812 and readopted in 1840. See 1875 for international conference. Source See also metric system history and U.S.


British citizens board The Hankey and two other ships and sail to West Africa.

They propose to start a colony to undermine the Atlantic slave trade by hiring rather than enslaving Africans. Poor planning and tropical diseases, especially yellow fever decimate the colonists. They give up their efforts, depart and return to England by way of the Caribbean Islands. Taking yellow fever with them, they create an epidemiological tragedy, transforming North America, Europe, Africa, and the Caribbean islands. See more.

Eli Whitney invents the cotton gin and its effect on slavery

Whitney had a genius ability to reconize an develop innovations. In South Carolina he observed how hard it was to remove seeds from cotton so he invented the cotton gin, a machine that could clean ten times as much cotton as a slave by hand. Source


James Madison recognizes that a census could be a scientific method to decide how to distribute political power. If a census were conducted every ten years, the data could be used to determine how many representatives each state would have. Therefore, a way to guarantee the House of Representatives would equably represent future population changes.

  • His idea was mandated by Article I, Section 2 of the United States Constitution.
  • The first census of the United States that recorded the population of the United States as of Census Day, August 2, 1790.
  • A scientific accurate census can provide information to make wise social, economic, health, medical research, technological, and other important decisions.
  • If conducted well it becomes a valuable source to create representative samples for quality research.


Immanuel Kant (1724-1804) Philosopher

Kant claimed that everything we know is a construction by our perceptions, which are shaped by our minds abilities and lack of abilities, of what we percieve as our observations of the world. It is our empirical intuition and subjective reasoning about these perceptions we synthesize and recognize as our consciousness and existence and understanding in the world with our observation and reasoning. That pure reasoning (rationalism) without observable data would lead to illusion about the world. Understanding is a function of imagination that bridges thought and perception of observable data to allow us to believe our consciousness exists and there are objects and events in our world which we can discover and understand with our reasoning.

Critique of Pure Reason (1781).



First English language Encyclopaedia Britannica published in Edinburgh, Scotland. Source


Joseph Priestly discovers many gases

  • Hydrogen, 1766, and shows water is a compound of oxygen and hydrogen.
  • Hydrochloric acid, 1772.
  • Laughing gas, 1772
  • Oxygen, 1774
  • How to make carbon monoxide and ammonia.
  • Worked on combustion and photosynthesis.
  • Nitrogen is credited to first be discovered by Daniel Rutherford in 1772, who called it noxious air. However, Scheele, Cavendish, Priestley, and others worked with it also.


Steam engine

James Watt improved on Thomas Newcomen's version of the steam engine (1712 to pump water from coal mines) making it available for work and the industrial age. He added a separate condenser so the cylinder could be kept heated with each stroke, a shaft that rotated instead of moving up and down, and other improvements to make it practical for multiple uses.

It will changes our understanding of energy economics, and our social institutions by speeding production and lead to an increased standard of living, consumption, and waste for some at the expense of others and all life systems on which we depend for survival.


Emile cover Jean-Jacques Rousseau - (1712 -1778)

Wrote and published Emile or a Treatise on Education.

The book is considered the first educational philosophy book as well as the first child psychology book.

Rousseau claims children have a natural goodness and can become critical life long learners and educated citizens if they can survive a corrupted society.

Rousseau is sometimes referred to as the father of modern child psychology.

Also: Education timeline - Rousseau


Washington Crop rotation

George Washington experimented with crop rotation on a three year cycle and five year cycle. He drew elaborate charts that showed how he divided his fields and the amounts of crops was equalized with flax, hay, clover, buckwheat, turnips, and potatoes being rotated through different fields. Later he expanded to a seven year cycle as shown in the table. See also Townshend crop rotation.

Washington's crop rotation table


Classification system

Carl Linnaeus created a systematic framework for the classification of animals and plants based on visual observation of related properties among organisms. Any classification system opens debate to how general or specific the differences between the relationships used for classification should be. Deciding if properties should be widened or narrowed to include more or less species of organisms in a group.


Ben Franklin flies a kite

An American polymath, Founding Father, writer, printer, philosopher, politician, postmaster, scientist, inventor, statesman, and diplomat.

  • Experiments with electricity and demonstrates it has positive and negative charges in experiments with Leyden Jars and a kite. The kite is not struck by lightning but it drew electricity to the key and Leyden jar.
  • It appears that he knew enough about grounding to protect himself from being electro shocked. Source
  • Uses his knowledge that clouds have electric charges and combine to create lightening leads him to create lightening rods to protect buildings.
  • Claims the Aurora borealis are created with electrical charges.
  • Collects weather data.
  • Maps the Gulf Stream.
  • Ben Franklin is an anti-vaxer until his child died of small pox, then became an advocate for vacination and made sure his family and friends got vacinated.
  • Claims colds are passed from person to person usually within close contact
  • Links lead to health problems.
  • Flexible urinary catheter.
  • Invents bifocals.
  • Creates the Franklin stove to increase heat distribution inside and decrease smoke
  • Experiments with swim fins. Finds they work on his hands, but ones for his feet aren’t as successful, Finds wood doesn’t make good swim fins.
  • Invents the armonica a musical instrument made with glass and works with vibrations by rubbing glass.



Earth’ s human population 600 million

Townshend Crop rotation

Charles Townshend, investigated a crop rotation based on Dutch and Flemish farming practices. His experiments found crops grew better with fewer weeds, fewer pests, and returned nutrients to the soil when he rotated crops through four years: wheat in the first year, clover (or ryegrass) in the second, oats or barley in the third, and turnips or rutabagas in the fourth. See also Washington crop rotation.


Principia Mathemaatica coverIsaac Newton

  1. Published Principia Mathematica
  2. First claimed ... Forceg = G * ((M1 * M2) / d2)
  3. 1660's demonstrated white light is all colors.





Adapted from Isaac Newton [Public domain], via Wikimedia Commons


Maria Merian portraitMaria Sibylla Merian publishes first proof a butterfly, caterpillar, & larvae; are one organism

Maria Sibylla Merian, a German naturalist and illustrator observes insects from a young age. She raises silk worms as a teenager, learns illustration from her stepfather, and publishes her first book in 1675. In 1679 she publishes the first of two volumes on caterpillars and the second in 1683, where she documents metamorphosis and life cycles of 186 European insect species. Source


Leeuwenhoek microscopeAntonie van Leeuwenhoek used a simple magnifying glass to observe the quality of fabric. He later ground lenses and refined his method for better magnification. He left 247 microscopes and 172 lenses, nine microscopes are known to have survived with a magnification of up to 200 times. The best microscopes of the time. He was the first to observe and noted: protozoa, bacteria, red blood cells, spermatozoa, and closer observations of other organisms. The microscope provided the technology necessary for microbiology and cell biology. Thanks ... Antonie van Leeuwenhoek


Boyle's Gas law and a vacuum

Robert Boyle and Charles Hooke used a vacuum pump, invented by Otto von Guericke (1649), to investigate the properties of air and properties of a vacuum: sound does not travel through a vacuum, but magnetism does, liquids vaporized quicker in a vacuum, animals died in a vacuum (see famous public bird demonstrations), and animals could be frozen. The importance of the relationship of temperature and pressure wasn't realized until much later with refrigeration and heat pumps.

Their first discovery of air properties is Boyle's Law. They used a glass tube and filed it with different amounts of mercury to vary the pressure on a fixed weight of air. They discovered that pressure times volume equals a constant (p*v=c) if temperature was constant. In other words, when you increase the pressure on a gas, the gas's volume shrinks proportionally. It would be a few years before Charles discovered the next gas law in 1787.

Boyle's air pressure experiment


Robert Boyle publishes The Skeptical Chymist in which he claims everything (matter) is composed of bound atoms (corpuscular, particles, atomism)  of a single kind of matter distinguishable only by their motion and shape. 


The pendulum clock is invented by Christiaan Huygens. It is the most precise time piece until mid 1900’s.


All living things come from an egg. William Harvey


First vacuum & first barometer

Evangelista Torricelli used a suggestion by Galileo and filled a 4 foot glass tube with mercury and inverted it into a dish of mercury. He observed some mercury flowed out of the tube and left a space in the tube above the mercury. Being sealed he concluded the empty space was a vacuum. From his day to day observations and observations from moving it up a moutain side, he concluded the variation of the height of the mercury was caused by changes in the amount of air above dish of mercury pushing down on it, atmospheric pressure. His experiments on air and vacuums explained why water pumps at that time were unable to raise water more than about 33 feet. His ideas would related to Boyles Gas law and engines.


First printing press in the American Colonies is assembled at Harvard College.


Bacon image

Sir Francis Bacon (1561-1626) published his Novum Organum, where he describes a system of logic he believes is superior to Aristotle's syllogism (360 BCE ) or deductive reasoning. It becomes known as the Baconian method, inductive reasoning and the scientific method. Bacon may have been inspired by Ibn al-Haytham's Optics (Kitab al-manazir).

He believed it was the best way to draw conclusions about the natural world. An inductive approach of skeptical observation and experimentation with facts and explanation leading to conclusion. Because of this he has been called the father of empiricism and the father of the scientific method.

"British - Francis Bacon - Google Art Project" by British (School, Details of artist on Google Art Project) - UwEFEzZpMHs4JA at Google Cultural Institute, zoom level maximum. Licensed under Public Domain via Commons.


Galileo Galilei (1564-1642) Published Starry Messenger (1610).

  • Turned his telescope upward and observed the mountains of the moon, additional stars, planets orbiting the Sun, and four moons orbiting Jupiter; then wrote about it in Starry Messenger.
  • His stance that facts should govern life not belief and support of the Copernican theory (Earth orbits the Sun) got him put under house arrest, forbade him to write any more, and wasn't allowed visits by mathematicians. 1633. Source
  • Dropped different sized canon balls of the Tower of Pisa and demonstrated that heavy and light objects fall at the same rate.
  • Explored inertia and friction. Source

Pre industrial revolution

CO2 (carbon dioxide) in atmosphere is 270 parts per million.


The Gregorian calendar / Western calendar / Christian calendar, is named for Pope Gregory XIII, who introduced it in October 1582.


Nicolas Copernicus uses his calculations to support the idea the Sun is the center of the solar system with planets orbiting around it.


In the late 1400's on the Murano island, (Venice) glassmakers develop cristallo, a transparent colorless plate glass, that is polished, and backed with lead and antimony to make a rough surface with a dim reflection (mirror).

In 1507 Andrea & Domenico d'Angelo del Gallo brother glassmakers on Murano improve the method by applying a mercury-tin amalgamon to the backside of the high quality transparent glass. This revolutionary technique is so valuable the Republic of Venice forbids any glassmaker from leaving the island. Eventually the technique makes its way to France and beyond.

The production of high quality mirrors leads to study and experiement with light in new ways as well as to artist who could study their own images and create, for the first time, self-portraits.


Horses arrive in America


Spanish arrive in Santo Domingo (Hispanola Island. Today - Republic of Haiti and the Dominican Republic). Inhabited by Taino Indians.


Printing with movable type

Johannes Gutenberg, invents the printing press with movable type. It uses small metal prisms (lead) that are precisely cast in large quantities so they can be set into a grid, used, reset, and used again. He also uses a new press, similar to those used in wine making, new papermaking and bookbinding techniques, and an oil-based printing ink. All improvements to Chinese, Korean printing, and current European printing of stamping letters on a surfaces or woodblock. Source


First European artifacts arrive to North America

Blue beads from Italy travel west along the Silk Road and across the Bering Strait before being dropped in North Alaska. Twine found with them dates to 1397 - 1488. Source


Black Death wipes out half of the Europe population. The Black Death or bubonic plague, is caused by the bacterium Yersinia pestis that is transferred from wild rodents to humans.


Glassmaking becomes industrialized when the Venetian Republic, thought the 1 000 degree furnaces might be a fire hazard for the cities mostly wooden buildings, To prevent the city buring down, the glassmakers were ordered to move their foundries to the small nearby island Murano. The move brings many glassmakers together and Murano becomes a hot spot for glassmakers to develop and maintain their craft and art of quality glass making through today. See 1507 for later developments. Source


Microscopic contaminants

Hildegard of Birgen is a nun and humanitarian in Germany who teaches and believes microscopic organism contaminate water and food. Long before the invention of the microscope and discover of microbes. She works to find ways to purify water and food.


Magnetic compass

Chinese scholars discover a needle could be heated till red, held in a north south orientation, and cooled. Then floated in liquid or suspended on a silk thread and it would point north and south. Therefore, it is valuable for navigation and used by the Song Dynasty, China, for military navigation areound 1040 and for maritime navigation around 1111.

Earlier, around 206 BC, magnetic devices were used to divine wisdom in the Han Dynasty around. Source Smith College Museum of Ancient Inventions


Book cover Optics

Optics was written between 1028 & 1038

Ibn al-Haytham's most important work: Optics (Kitab al-manazir).

  • Described scientific discovery as observation reasoned with induction in a cautious manner to make conclusions without being swayed by opinion. Influenced Roger Bacon
  • Combined experiments with mathematical reasoning.
  • Includes an accurate model of the eye and vision, laws of reflection, refraction with the relationship between angles of incidence and refraction, and describes motion in mediums with different densities.


See: 1001 Inventions and the World of Ibn Al-Haytham and A Journey of Science from Darkness into Light.

1000 CE

Mississippi culture begins in North America

Cities are built with mounds in the center and surrounded by defensive barriers.

Cities like Holly Bluff (Lake George), Mississippi and Toltec in Arkansas, and Cahokia (east side of Saint Louis with a population of 10 000 plus with another 20 000 plus in its suburbs), Mississippi, Spiro, Okalahoma, Aztalan, Wisconsin. Also includes Muskogee, Caddo, Crow, Pawnee, Ho-Chunk.

Large corn fields to feed the large populations along with pigweed, and sunflowers. They forage for other plants, fruit, and nuts and fish and hunt. Their networks of trade provide copper, shells, pearls, stone, mica, and wood. They make jewelry, pipes, textile, pottery, stone and shell art. Large amounts of art with statues of humans and animals. Two famous pieces are the Piasa a mythical animal painting and the Rattlesnake Disk carved stone. Lasted till European contact by DeSoto.1539


Soap workshop, in Israel, makes soap by mixing olive oil with ashes from saltwort plants, heated for seven days, poured into shallow pans, let harden for ten days, slicing it into bars, and left to dry for two months. https://www.smithsonianmag.com/smart-news/1200-year-old-olive-oil-soap-factory-discovered-israel-180975599/

800 CE

Algorithm Muhammad ibn Musa al-Khwarizmi invents algebra

His most noted work is: Hisab al-jabr w'al-muqabala. In it he introduces natural numbers, focuses mostly on how to solve equations: linear or quadratic, with units, roots and squares. He explains the solutions with words and uses no symbols of algebraic notation.

In Latin his name is Algorismus, Therefore, he is given credit for inventing the algorithm. Before the algorithm merchants and scholars use the abacus. The new system, along with a dust board, democratize computation. In the Renaissance, in Europe, those who know how to multiply and divide with algorithms are guaranteed a professional career. In 1621 the first slide rule is made. The first mechanical calculator in 1642 by Pascal and the first handheld calculator 1967.


City state and Agriculture: 1 000 C. E. - 10 000 BCE


Mysterious fog plunges Europe, the Middle East, & west Asia into darkness for 18 months.

"For the sun gave forth its light without brightbness, like the moon, during the whole year" Procopius

  • Temperatures fall and lower temperatures cause snow in the summer, crop failure, people starve, Irish record wheat failure from 536-539. Later in 541 a plague in Pelusiam, Egypt (known as the Plague of Justinian) kills 33-50% of the eastern Roman empire population, contributing to its collapse.
  • Tree ring research in 1990 supported that summers around 540 were unusually cold. Later in 2018 ice from Swiss glaciers suggest a cataclysmic volcano erupted in Iceland in 536 and two more massive eruptions in 540 and 547. It is believed these eruptions caused economic problems that reduced trade and manufacturing until around 640 where ice samples indicate an increase of airborne lead from silver smelting. Source


Mouth harp is lost in the Altai Mountains in Russia. It measures about 4.3 inches long and 3.3 inches wide and will still make music in 2018. Source

300 - 400

Hun's range


Nomadic tribes of Northern Asia invaded China, eastern Asia, and Europe. With their superior horse skills and the stirrup; they destroy villages, the current political structures, and change peoples lives.


Earth’ s human population 200 million.


Mount Vesuvius, near the Bay of Naples in Italy, erupts in 79 and buries Pompeii in ash preserving artifacts to be found later to see how Romans lived during this time. Source

The ancient Roman town of Baia, a fashionable resort for Romans, on the shore of the Gulf of Naples, sank into the sea also as a result of Vesuvius volcanic action.

C. E. (current era) -------------------- B. C. E. (before current era)

37 BCE

Cement - Romans made cement and used it to make concret for water pipes, docks in harbors ... Source

50 BCE

First vending machine in recorded history is in Alexandria, Egypt. It is invented by a Greek mathematician and engineer Hero of Alexandriato dispensed holy water at Egyptian temples. See 1880's

Hero wrote on a variety of topics that include mathematics, engineering, physics, and pneumatics. The writings include the first record of a wind powered machine (a windwheel), steam powered machines, machines that used sound and light, syringe for liquid and air, a fountain, and how to calculate square root.

200 BCE

Xiongnu combine their horse technology with military skill and become fierce mounted archers. They roam the Mongolian steppes for hundreds of years and engage civilizations from Iran, Central Asia, and China. Collecting artifacts from these areas as well as Roman glass, Persian textiles, and Greek silver. They are so successful China builds the Great Wall to try to stop their raiding. Archeological evidence supports this as well as DNA evidence that shows multiethnic DNA in their remains from all the empires they raided.

240 BCE

Eratosthenes Measures the Earth with shadows
& becomes known as the father of geography

Eratosthenes, heard of a well in Syene, Egypt that on summer solstice (June 21) the Sun lit the water at the bottom of the well and cast no shadow on the sides (meaning the sun was directly overhead [zenith]). On the same day, in Alexandria, the Sun was 7 degrees off the zenith (point directly overhead). Using geometry he calculate the Earth's diameter as 12,800 km or about 28,ooo miles around the poles and equator. Source
See math / science activity to measure and calculate Earth's circumference

300 BCE

Hopewell culture ranges from Kansas to New York and Florida to Canada after Adena. They trade, art, jewelry, ceramic, and stone figures. Construction uses horizon based astronomy and circle square combinations. Between 400 CE - 500 CE stopped mound building and their trade network collapses.

Around 450 CE the bow and arrow arrives from Canada and corn from the southwest, but probably not a common crop until 700 or 800 CE. They build small farmsteads and villages with a central plaza. Evidence of violent deaths increases and palisades are build around villages. Build effigy mounds in the shapes of animals (birds, panthers, lizards, turtles) for burials till 1 000 CE when Mississippi culture begins

Euclid writes his Geometry book, Elements

Euclid lives in Athens, Greece and Alexandria, Egypt. He is known as the Greek mathematician who found geometry. It is said the King Ptolemy I of Egypt told him he wanted to learn geometry. Euclid replied, he would have to study long hours and memorize a large book of information. The King demanded a shortcut, to which Euclid replied, "There is no royal road to geometry."

310 BCE

Sun centered solar system

Aristarchus of Samos, built on Herakleides Sun centered theory and described accurate orbits of Earth and the Sun's other planets encircling it and the orbit of the Moon around the Earth. This symbolically marks the end of Greek scientific philosophy as those who came after stuck to myths that put the Earth at the center.

331 BCE

Alexander the Great founds Alexandria, Egypt as a pharaonic town. It is the capital of Egypt until Muslims conquer Egypt in 641 AD, and move the capital to Fustat, later Cairo.

350 BCE

Babylonians use a trapazoid to predict Jupiter's motion across the sky.

Numbers are inscribed in a clay tablet to calculate the distance Jupiter travels by charting the plantet's motion (velocity) over 60 days. The results form a right-angled trapezoid with a downward slanting top with the area equal to the distance Jupiter travels. See Babylonians Tracked Jupiter with Fancy Math. By Megan Gannon, February 1, 2016: Scientific American.

360 BCE

Aristotle - 380 - 322 BCE

Explanation with rhetoric and logic. While Socrates and Plato use reasoning Aristotle develops a system of rules and strategies, syllogism, it is the begining of logical deductive reasoning (as opposed to inductive reasoning). Reasoning in which a conclusion is drawn (validly or not) from propositions (premises) that share an idea not present in the conclusion, for example. Categorical syllogism, uses two premises and a conclusion:

  • All humans are vertebrates; no insect is a vertebrate, therefore, no humans are insects.
  • All dogs are mammals, all mammals are animals, therefore, all dogs are animals.

Aristotle believes.

  • There is a natural order to the world that could be determined with logic without observation.
  • Objects would naturally come to rest (without a force acting on them).
  • Solid objects would fall to Earth, because that is their natural place to be.
  • Believes forces were requird to keep things moving. Had no concept of inertia. See Galileo and Newton.

Aristotle claims.

  • Heredity needs a message and material to explain how traits are passed from parent to children to grandchildren and beyond.
  • He recognizes Pythagoras ideas need to be extended to include information being passed from the mother and ancesters from both sides of the parents to the baby.
  • He claims there is mutual contributions of information to a baby that passes from the male in the semen and from the female in the blood.

Atlantis symbolAtlantis

Greek philosopher Plato writes about Atlantis in 360 BCE in his dialogues where he describes it as an island city by the straits of the Pillars of Hercules, today Straits of Gibraltar. Over the years people have searched for this lost city. Recent research suggests it might have been located near Spain.

Image is symbol for Atlantis.


380 BCE

Petra is an acient city carved in rocks by the Nabataeans in the desert of southern Jordan. See - Nova video (53:05)
Nabataeans create an irrigation system for their city's water needs. To do so they solve several problems for water to be moved over a long distance.

  • Discover an optimal shape and size of pipes so sediment wouldn't clog the flow.
  • Discover how smoothly pipes pipes need to be set so the flow rate deliveres appropriate amounts of water. For example, rapid flow creates ripples and reduces water volume compared to a smooth flow.
  • They cnclude: shape, size, smoothness, and slope of pipes affect flow (2.5 degree slope works for an efficient water flow).
  • Excavations show how the Nabataeans create their water supply system for their desert city. It includes: an artificial oasis, flood controls, multiple dams, storage in cisterns, and water transported in conduits from sources miles away. Source for detailed descriptions of Petra's Water supply and distribution.
Image source Bernard Gagnon (Own work)

More information and images for Petra.

400 BCE

The idea of atoms

Democritus - 470 - 370 BCE

Democritus considers all matter is made of atoms, which were small, invisible particles surrounded by space, could not be subdivided, and last forever. There is an infinite number of them that make up the physical world. They are different in shape, arrangement, position, and magnitude. He also believes space is a void or vacuum that is infinite. Source

Horse technology

A horseshoe is essential to protect the foot of horses if they are to be used productively for agriculture and transportation. They protect the foot from repeated wear and cracking in dirt, mud, and on rock.

Early protection is created with leather or other materials wrapped around the foot and fastened with thongs. Sometimes metal or other materials were inserted inside the boot shaped material. Literature includes early reports of shoes of bronze, silver, and gold being on horses of important leaders.

The development of iron provides a much better material and along with the idea of fastening it to the foot with nails. Since iron is valuable and could be melted and reused, it makes discovery of it in archaeological digs unlikely.

Sculptures of horses with shoes are rare, but a few are known.

Four bronze horseshoes with nail holes were found in an Italian tomb dated around 400 B.C.E. Source see also domestication of horse.

What are the pros and cons between horses, mules, and oxens as what is best for ... Consider strength, speed, health, and food requirements ...

Thonis-Heracleion, an ancient island city on the mouth of the Nile River.

After Carnac it is the legitimate capital of Egypt where Pharaohs receive the divine rights to rule. It is a major trading port until Alexander the Great conqueres Egypt and builds Alexandria in 331 BCE and made it the capital.

Later the Nile changes course, the land liquifies, and the city sinks into the Mediterranean Sea. It is lost to history until archeologist find its ruins in 2000. The find includes many everyday artifacts, temples, statues of gods and pharaohs, a Stele with a record of tax rates for imports and exports, and over 64 ship wrecks. Source

415 BCE

Hippocratic oath

Hippocrates is a Greek physician regarded as the father of medicine. Around 60 medical writings have survived with his name, many probably not written by him.

  • First written information about the flu 412 BCE
  • Best known for the Hippocratic Oath, which bears his name, but he may not have written, and the high ethical standards it sets.

407 BCE

Plato and Socrates 427 - 347 BCE

Develops a philosophy of education - learning happens when the teacher asks key questions. Socratic Method. Source The Republic. Key beliefs and ideas.

Education is based on interests, abilities, and stations in life.

Utopian ideal is to produce philosopher kings or guardians rule to the State.

Built on Greek rhetoric: the art and process of effective public speaking. First taught by the sophists (480 BCE).

Dialectic reasoning or dialectics (Socratic method, Hindu, Buddhist, Medieval, Hegelian dialectics, Marxist, Talmudic, and Neo-orthodoxy), and modern debate. All involve conversations between two or more people arguing different points of view for the purpose of establishing truth with reasoned argument.

Socrates valued truth as the highest value. Truth discovered through conversation with reason and logic (dialectic reasoning). Logic, not emotion, to discover truth for persuasion and make choices to guide one's life. To Socrates, truth, not art, was the greater good to guide one's life. Therefore, Socrates opposed the sophists and their teaching of rhetoric as art and as emotional oratory requiring neither logic nor proof.

Dialectic method, rhetoric, and debate can have fundamental differences. In theory debate may be considered as unemotional and committed to rational argument. However, in practice debaters can present emotionally charged ideas to suppress rational thought, hoping to persuade others to their point of view. See rhetoric (480 BCE) sophists

Plato wrote about how all civilizations will fail and includes the destruction of a city he called Atlantis in his Dialogue. So is his tale based on history or is it fiction?

480 BCE

Sophists - 480 - 390 BCE

The first teachers of rhetoric (the art (arte) and process of effective public speaking) in the Greek world they are known as Sophists (wise men). They teach by example, skills of civic life and explore a wide range of human experience about Greek culture. Not being Athenians, they often clash culturally and philosophically with Athenians.

Sophists taught art and thought have the highest value in life. Therefore, it should be used to make choices and to seek it out in all things. To them the artistic quality of a speech or oration is its power to motivate, influence, and please people. Therefore, oration is taught as an art form, used to please, motivate, and influence other people through quality speaking. Maybe the historical basis for Declamations, which are student’s interpretations of famous speeches regiven to demonstrate the student's ability to understand and apply the purpose and power of the speech and skill in public speaking. Samples

Rhetoric is a method or art of speaking or discourse/ conversation to persuade, inform, or motivate an audience. Concepts of rational appeal (logos), emotional appeal, (pathos), and ethical appeal (ethos) are all intentionally used to persuade and convince people of a particular idea or argument. Read more: rhetoric

500 BCE

Buttress Source

Parmenides, (515-430BCE) Greek philosopher, is known to use logic with an extended arguments for his views rather than just a view of reality. However, he never systematically studied or formed logical principals, proofs, for valid arguments.

530 BCE

Pythagoras lived in Croton, Greece. His work included.

  • Made famous a theorem for the area of right triangles.
  • Explained the similarities between parents and children were caused when semen travels throughout a male body, where it absorbs mystical vapor from all parts of the body to create a blueprint to build a baby so when the semen is transported to the mother to provide a message with instructions for the female to provide the matter to build and nourish the fetus. Which he wrongly thought was the only purpose of a female in reproduction. This became known as spermism. See Aristotle

570 BCE

Thales of Miletus (620 BCE - 46 BCE) creates theorems (by exhaustion) as logical proof for general geometric ideas. He visits Egypt and observes Egyptians using geometry while building. He is credited for five:

  1. A circle is bisected by its diameter,
  2. Angles in a triangle, which are opposite two sides of equal length, are equal
  3. Opposite angles, formed by intersecting straight lines, are equal.
  4. An angle inscribed inside a semicircle, is a right angle.
  5. A triangle can be determined if its base and the two angles adjacent to the base are given.

597 BCE

Early science experiment with control group

Jerusalem is captured by King Nebuchadnezzar II and some citizens of Judea are rounded up and sent to Babylon as hostages. The young are raised and educated in the King's court. Daniel, among them, a devout Jew, did not want to eat non kosher meat and drink wine. Thus, he asks his overseer, Melzar, for a vegetarian diet and water. Melzar, afraid for his life if David doesn't thrive and learn, did not want to grant this request.

David suggests an experiment: for ten days he and nine others are given a vegetarian diet with water (experimental group) and another group of ten are given the King’s meat and wine (control group). At the end of ten days, if they weren’t healthy he would eat the King’s meat. At the end of ten days David’s group was fairer and fatter in flesh (Daniel 1:15), than the meat group. Thereafter, Melzar allows their diet.

750 BCE

The Great Dam of Marin on the Wadi Adhanah watershed, near the ancient city of Ma'rib the capital of Saba (a prosperous trading nation, with control of the frankincense and spice routes in Arabia and Abyssinia) is built in the eighth century BCE may be the oldest dam. Source

1 000 BCE

Adena culture east of the Ohio River build a year round villages in North America

It inhabitants make pottery and develop agriculture. Build burial shell mounds, then earth mounds, then no mounds. Hunt, collect nuts, farm, and grow: sunflowers, pumpkins, squash, goosefoot, maygrass, pigweed, and tobacco. Make pipes, loincloth, jewelry, trad for copper (Great Lakes), shells (Gulf of Mexico), mica (North Carolina), and trade. Their pipes travel from Canada to the Gulf Coast. Survive till Hopewell culture 300 BCE.

1 450 BCE

First artificial hand? Bronze and gold artifacts that resemble a hand are made. Maybe used for rituals. Source

1 500 BCE

North America’s first city in Poverty Point, Louisiana,

Late Archaic people build, what most archaeologists consider, the continent’s first city with 4,000 – 5,000 inhabitants. It has a central plaza, earthen pyramids, concentric platform mounds, and hundreds of houses. Eat clams, oysters, fish, reptiles, pecans, acorns, and walnuts. Had earth ovens, pottery, cooking balls, and fishing nets. Occupied till about 700 BCE.

Water and sewer system

Minoan plumbing, sewer, and storm drainage is well developed and the Minoan civilization flourishes on the Isle of Crete, in the Mediterranean Sea, from 2600 to 1600 BCE. Source

1 620 BCE

Mediterranean Sea MapVolcanoes, earthquakes, and tsunamies destroy towns in and around the Mediterranean Sea.

  • Pavlopetri - sinks into the Mediterranean Sea from multiple earthquake events. 1700-1500 BCE
  • Mycenaean destroyed by earthquake
  • About 1620 BCE a Volcano on Thera, an island in the Mediterranean produced and exported saffron trading with Europe, Africa, Asia. The Thera volcano destroyed all civilization on the island with Pyroclastic flows. It caused earthquakes and tsunamies that severely impacted Minoan settlements in the Mediterranean and
  • created tsunamis that destroyed the Konos on the Island of Crete. The Konos are the origins of the Minoans who influenced the Mycenaean civilization from the 15th to the 13th century BCE throughout the Peloponnese in Greece and the Aegean.

1 754 BCE

Water regulations

King Hammurabi, writes a code to regulate water usage:

  1. The distribution of water is based on the acres farmed.
  2. Requires each farmer to maintain the canals on his property.
  3. Requires the collective administration of the canal by all users.

1 920 BCE

China's Great Flood

China's first Emperor, Yu, is said to have tamed a great flood. Researchers have found evidence of a landslide and flood on the Yellow River around 1920 BCE. Source Finding China's Great Flood New study finds truth in an ancient myth. By Bridget Alex|Wednesday, December 21, 2016

2 000 BCE

Iron objects are produced at a variety of sites in Niger around 2000 BCE +- 500 years. Source

2 100 BCE

Corn arrives in western New Mexico and eastern Arizona rock shelters and cooking pits.

2 650 BCE

First dentist Hesy-Re's tomb had panels that described him as chief of dentist and physicians. Source

2 480 - 3 000 BCE

Stonehenge near Amesbury, UK is built. Source

2 5000 BCE

First bow and arrow in North America is used above the Great Lakes to hunt a variety of game.

2 51o BCE

Three pyramids known as the Giza pyramids seen often in pictures and videos. Menkaure pyramid in 2 510 BCE, Khafre pyramid in 2570BCE, and Khafu pyramid in 2580BCE, being the largest and best built.

2 686 BCE

Egyptians bury dead under six step pyramids built by Djoser south of Giza. Followed by the Bent Pyramid in 2613 built by King Sneferu.

3 0oo BCE

Egyptians bury dead under piles of dirt.

4 000 BCE

Copper first used in North America near the Great Lakes thousands of artifacts: jewelry, spearheads, axes, and fishhooks.

4 6oo BCE

Egyptians bury royalty in underground chambers below structures of mud bricks and stones called mastabas.

3 200 BCE

Newgrange stone chamber is built by Irish farmers in Boyne Valley, Ireland

Astronomical site built before Stonehenge and Giza Pyramids. A mound 85 meters in diameter and 13.5 meters high over a 1 acre area. A 19 meter stone tunnel, aligns with the rising sun on the Winter Solstice and leads into a chamber with 3 alcoves. It is surrounded by 97 large stones (kerbstones) some engraved with megalithic art.

3 300 BCE

Cuneiform - writing first appeaars in Uruk later Mesopotamia, in Sumer
The oldest known mathematical problems is written on a cuneiform tablet. It calculates the surface area of a rectangular shaped field.

Bronze (smelted from tine and copper) is made in Sumer
History notes the Bronze age as a historic mile stone. However, different societies learned how to make Bronze at different times. Greeks about 3000 B.C. British and Chinese around 1900 BCE - 1700 BCE, Egypt 1475

3 500 BCE

Domestication of the Cacao tree

Chocolate is made by the Mayo-Chinchipe in Ecuador by grinding cacao beans into a paste and then combine it with combinations of water, corn, fruit, chili peppers, and honey to make a porridge or beverage. About 1850 Europeans added sugar and cocoa butter and later in 1870 the Swiss added milk powder to make milk chocolate.

3 700 BCE

Horse domestication begins on the Kazakh steppe with the Botai hunter gatherers who put mare's milk in pots and used riding bits with horses. Riding horses vastly changed human civilization and as humans changed the horse genome changed. Source

4 000 BCE

First plow

What can be considered a plow, more than a hoe, is made in Egypt and Sumeria. Their use requires hard work to push or pull them through the ground; and they are not able to plow very deep.

  • Paintings show several men pulling them and later about 2000 BCE show them connected to oxen horns. Over the years, Egyptians learn to better harnesses to oxen, without choking them, to plow better and improve their agricultural yields.
  • While the plow makes farming more efficient it requires more strength to plow than hoe. As a result farming becames a more male dominated activity.
  • For example, early society in Pakistan, who use a plow, has only 16% of the ag workers being women. In Burundi, where they use hoes, 90% of the ag workers are women.
  • John Deere is credited in 1837 to have made the first iron plow.

Irrigation Nileometer image

Egypt and Mesopotamia (present day Iraq and Iran) use flood water from the Nile or Tigris/Euphrates river to water crops.

The Egyptians use a verticle column (Nilometer) and a series of stairs to measure the depth of water. Several still exist and can be seen today. Source Image source: Baldiri (Own work) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons

3 000 BCE The first reservoir may have been made by King Menes along with dams and canals to diverted water from the Nile into Lake Moeris. Source

4 200 BCE

Cities continually inhabited

While gathering places or temporary cities for trade, social gatherings, and religious ceremonies are known some cities begin to be continuously inhabited. Archeologist continue to discover more and earlier settlements.

It is interesting that when a person enters a city, they recognize it as a city, even if it is an ancient city or a city of today. Yet it is more difficult to define what one is in specific terms. Some characteristics of cities: allow for diversification of ideas, specialization of labor, social interactions, development of a common culture, language, and experience, more interdependence, creativity, novelty, technology, and a general scaling up until a limit of resources is reached.

While people settle into larger communities they are not closed. Human historically are mobile seeking trade, ideas, mates, cultural exchanges, and unique experiences.

  • Sosa 4200 BCE
  • Faiyum 4000 BCE
  • Erbil 4000 BCE
  • Kirkuk 1100 BCE
  • Balkh 1150 BCE
  • Bejing 1045 BCE

4 400 BCE

Cats (Feline) are domestic, as indicated by DNA, began in southwestern Asia through southeast Europe 6 400 years ago.

5 000 years BCE

Breeding of dogs in Siberia. Skulls were measure and their ratios of snout height to skill length and cranium height to skull length distinguished them as dogs. Dogs werebred to be large enough to pull a sled, but not too large to overheat. Source

4 6oo BCE

Egyptians bury dead under piles of dirt.

6 000 BCE

Rock art with dogsRock art shows domesticated dogs used to hunt. Dogs on leash were maybe being trained. Source Science

Potatoes are domestic in Peru. It was taken to Europe by the Spanish (1500's) and did not become an important food until 1800's during famines.

Catalhoyuk, Turkey citizens lived in houses that were built and supplied in a manner that suggest equality with no apparent leadership. Artifacts also suggest domestication and use of clay appears to have affected the environment in harmful ways: as evidence of deforestation, extensive burning, erosion and of large-scale grazing were also found. Source

Copper is used in Asia

7 000 BCE

Kennewick man lives in present day Washington state. His DNA relates to today's Native American tribes of the Coville Reservation as suggested by his skeleton found in Washington. A study of his DNA in 2015 finds it is Haplogroup Q-M3, and his mitochondrial DNA Haplogroup is X2a.

Olmec Domesticate maize (corn) in Mexico. Research suggests different varieties of maize are partially domesticated before being traded or spread from Mexico. These partially domesticated seeds, each with sufficient alleles to independently become modern, did so in different locations in the Americas after their dispersal. Source Did Maize Dispersal Precede Domestication. Science. December 14, 2018

Jericho becomes a city.

Motza (Israel) is an 80 acre settlement with workshops, public halls, and private homes linked by roads and alleys with evidence of art and trade. Source Discover. Lots o' Motza Jan/Feb 2020 by Bridget Alex

8 000 BCE or 10 000 BP

Sheep are domestic in the Mesopotamian area for: food, clothing and shelter. The use of wool developes over time as the quality of wool needs to be bred for a more dense fleece, achieved with finer fibers and less kemp. Source Sheep industry fact sheets

The Archaic period in North America

Mammoths, mastodons and Bison antiquus are extinct. Native cultures are still hunters, but hunt smaller prey, deer, rabbits, turkeys, geese, and fish. If available, elk and bison. To supplement they ate more seeds, nuts, fruits, and fibrous plants. Therefore, inventing grinding stones and the mortar and pestle, leeching acorns. They travel in small groups 20-30 and hunt with atlatls and spears. The climate warms, water increaes, grasslands and forrests grow more dense and about 3 000 BP groups tend to stay in one place and diversify. Where possible they live in rock shelters. Other places, they build simple houses in shallow pits and cover them with log frames, domes, or tents.

Hunter gatherers: prior 8 000 BCE

8 000 BCE or ≈ 10 000 years ago BP see 1950

.01 million (10 000) BP (Cenozoic Era, Quaternary Period, Holocene Epoch .01-1.8 mya )

Europe England land bridge

Ice age ends. Measurements of Greenland ice packs show an increase of temperature as measured in the change of hydrogen chemistry.

Melting ice submerges the land between present day United Kingdom and Europe as ocean levels rise about 120 feet.

10 000 BP ...

Women participate in big game hunting

Randall Haas and his team find numerous projectile points and stone tools buried alongside the skeletal remains of a woman, who was probably a great hunter between 17 and 19 years old. Astonished by the fact that she had the kit of a hunter they review the published records of 429 burials across the Americas in the late Pleistocene and early Holocene epochs. The team identifies 27 individuals buried with big-game hunting tools. Eleven are female and fifteen male. Therefore, it suggests that female participation in big-game hunting was very likely and non gender labor practices are likely routine. Source

Food production center of the world


Evidence suggests hunter gatherer societies stumbled upon plant and animal domestication only nine places around the world:

  1. Fertile Crescent,
  2. China,
  3. Mesoamerica,
  4. Andes/Amazonia,
  5. Eastern United States,
  6. Sahel,
  7. Tropical West Africa,
  8. Ethiopia and
  9. New Guinea.

History, includes many tales of hunter gatherer societies being driven out, infected, conquered, and exterminated by farming societies where farming is possible. Except the Huns 300-400 and Ghengis Khan 1225.

Hunter gatherers of the Fertile Crescent domesticated wheats, barley, peas, sheep, goats, cows and pigs to become the first farmers and herders, beginning around 8500 BCE. This led to major changes: shorter birth intervals (from four years to one year) political changes (social classes, kings, soldiers, empires, professional armies), and technology (metal tools, writing, ...). These were tools of conquest and allowed them to spread into Europe, North Africa, western India, and central Asia. However, having no other advantages power shifted to Greece then Italy and then to northwest Europe. While human societies in the Fertile Crescent inadvertently committed slow ecological suicide as low rainfall caused deforestation, soil erosion and salinization.

Some advantages and disadvantages of agriculture:

  • One calorie seed can grow 50 calories.
  • One acre of farmed land can grow 1 000 times what hunting and gathering can provide per acre.
  • A 60 lb bushel of wheat can make 70 loaves of bread.
  • Early agricultural communities are more malnourished, have more famines, people are shorter, life expectancies decreases by five years, and there are more conflicts and war than hunting gathering tribes.

Source Nature, Jared Diamond

See earlier steps toward agriculture.

West Africa, Niger River Basin is the location of the continent's traditional agricultural crops:

  • Yams domesticated in the Niger River Basin betwen eastern Ghana and western Nigeria.
  • Pearl millet domesticated north of the Niger River in western Sahara Desert, north Mali and Mauritania.
  • African rice domesticated in western Africa in north Mali.
  • Sorghum domesticated in East Africa in Egypt.

Source Plant Genomics Unearths Africa's Fertile Crescent. Elizabeth Pennisi. Science, May 3, 2019.

11 000 BP

First Stone Temple?

A temple at Gobekli Tepe, Turkey is where hunter gatherers congregate to share in spiritual celebrations. The artifacts at the site suggest religion predates agriculture and possible permanent settlements built while while humans were still hunters and gatherers. Artifacts carved on the surfaces represent images of foxes, lions, scorpions, vultures, and T shaped pilars that some believe represent humans. Findings suggest early people had beliefs and those beliefs evolved and centered on human's place in nature.

  • Humans as spirits in a spiritual world among animals, weather, and other Earthly spirits.
  • Humans with nature.
  • Humans as master of nature.
  • Humans as servants of nature.
  • Three skulls were found with red ochre, grooves, circular holes that seem to be cut at time of death or near death as there was no indication of healing. Could have been suspended by cords for ritual situations. Source


11 500 BP ...

Skull of Luzia Woman dates to around 11, 500 years ago is found in a cave at Lapa Vermelha, Pedro Leopoldo, Great Belo Horizonte, Brazil in 1975.

An infant is at the Upward Sun River in the Tana River Basin in Alaska. The infant's genetics suggest her ancestors settled Beringia and her descendants headed south into North America. The site was found in 2008. The infant's bones, date to around 11 500 year ago. Science January 5, 2018.

12 000+ BP ...

Extinction of Wooly mammoth seems to be the last of the large animals to become extinct. Others include: Columbian mammoth, American mastodon, Beautiful armadillo, Stag moose, Giant beaver, Jefferson's ground sloth, Harlan's ground sloth, Flat-headed peccary, & short-faced bear. Source

Folsom culture follows Clovis in North america. They mainly hunting bison using their new invention, bison jumps. Their culture disappears 10 000 BP.

13 000 BP and maybe earlier ...

Humans in Americas

  • Naia, a teenage girl, explores an underwater cave in the Yucatan Peninsula, Mexico. Her skeleton is found and dates to 13,000 years ago. Her DNA indicates she descends from early Native Americans, who likely crossed the Bering Strait. Her ancestry is Asian, from Beringia, haplogroup D. Source
    Learn more about Naia on Nova First Face of America February 7, 2018.
  • A boy explores in Montana where his skeleton is found in Montana at the Anzick site in 1968. In 2014 his haplogroup is found to be D1, commonly found in South America.
  • Arlington Springs Man lives on Channel Islands off the west coast near Santa Barbara, California. Two of his leg bones are found in 1959 and later date to 13,000 BP.

Clovis stone tools are created. Dates for their production are from 13 500 to 12 700 BP, just 800 years. Most are found in th e eastern and central United States, with oldest sites in Texas and northern Mexico. Did the Clovis people hunt mammoth or mostly forage for plants, hunt small mammals, and catch fish. Along with Clovis points, scrapers, blades, drills and needles are in their tool kits. Source


Steps toward agriculture

Some humans begin to plant and cultivate plants (farming) rather than a sole reliance on hunting and gathering. The idea farming is superior to hunting and gathering at this time is probable inaccurate, since farming requires more work, lower adult status, and results in worse nutritional conditions, poorer sanitation, and more disease. What ever the circumstances, farming causes changes in plants, animals, and human behaviour as they interacted with each other, build cities, and live in them. Source Evolution, consequences and future of plant and animal domestication, by Jared Diamond.

Steps toward agriculture may be caused as the food supply of wild animals is shrinking to an unsustainable point, as 100's of large mammals are hunted to extinction. Source Sapien

Known technology:

  • Cooking, grinding, leeching, soaking
  • Domestication of wheat, barley, and other seeds with non shattering seed pod or head
  • Domestication of goats, sheep, cattle, chicken, and pigs

Whay is the reason some species are not domesticated? Is it too difficulty to domesticate them? or Are indigenous people who live where the species are native, not inclined to domesticate them?

13 200 BP

Ancient American West coast dwellers leave a footprint on Calvert Island, British Columbia and fish hooks on Cedros Island, Mexico. Believed to be America's oldest human footprint. Source. On the Trail of Ancient Mariners by Lizzie Wade

Human's are making stone tools in the Chiquihuite cave in the Astillero Mountains, 9000 feet above sea level. Some 1,900 stone points or tools used for cutting, chopping, scraping, or as weapons with advanced flaking skills. More than 90 percent of the artifacts are greenish or blackish stone. Most material dates between 13,000 and 16,600 years BP. The cave may have been used for 10, 000 years. Source

13 800 BP and maybe earlier ...

A village is established off the Central Coast of British Columbia, Canada on the ancestral grounds of the Heiltsuk Nation. The archaeological evidence supports Heiltsuk oral tradition that claims the tribe lives along the coast in a land that didn't freeze during the ice age. Source

14 000 BP

Humans arrive to the Americas by boat possibly by island hopping down the west coast. Source. On the Trail of Ancient Mariners by Lizzie Wade

14 300 BP

Human cook in Paisley Caves, Oregon. Hearths and extinct animal bones are found inside the caves in 1938. Fossilized excrement, (coprolites) are dated to 14 300 BP.

14 400 BP

First Bread is made by hunter gathers in Jordan, on stone hearths, from wild grains and tubers. Source

14 550 BP

Page-Ladson, Florida bifacial knives are being used on animals that are extinct today. Source

15 000 BP

Dogs are domestic. Possibly they could have been earlier, maybe 30 000 years ago. Do dogs befriend humans or humans dogs? Source

Some suggest all domesticated dogs descended from dogs domesticated in Siberia about 23, 000 years BP and divided into four groups with the genetic marker A2b. These groups traveled with the humans who domesticated them eventually dividing into four groups. One group to North America about 15 000 years BP. Science January 29, 2020

Dog breeding and rock art 8 000 years

16 000 BP

Humans at Cooper's Ferry Idaho, North America, use late upper paleolithic flake stone blades similar to those used at this time in northeastern Asia. Suggesting arrival by boat and before Clovis tools (13,000BP). The blades are not similar to the Clovis tools, which are fluted bifacial stemmed lanceolate points. Source Science August 30, 2019

17 000 BP

Bison scuptures from 15 000 BCECave Art at Tuc d'Audoubert, France.

Two bison sculptures are created. Each about 24 x 18 x 4 inches with smooth surfaces that have finger marks from being smoothed when wet, hair carved with a tool, and jaw lines cut with fingernails. Both bison are ready to mate. (15 000 BCE)

The cave also includes numerous paintings, engravings, abstract symbols, one anthropomorphic mask and one image of a female vulva. Source

More on prehistoric art timeline

Seashell and cave art

The first musical score & concert

A person may have created a song, scored it on the wall of the cave, to play it in Marsoulas Cave in Magdalenian, France.

Red pigment is placed on a conch shell, which has been crafted to play three notes: C, C-sharp, & D. The pigment on the shell matches red dots and lines on the cave walls that form a bison silhouette. Could it have been a musical score? Was it for entertainment, spiritual requests for a successful hunt, or ...


23 000 BP

At the Ohalo II agricultural site, on the shore of Galilee, people clear land, sow wheat and barley and harvest them. Ehud Weiss and his team collect 150 000 specimens of plant remains from the site and date them to 25 000 BCE. The find suggests human migration to North America is along the coast instead of overland.

28 000 BP

Solutrean stone tools are made in North East America from 19,000 BCE and 26,000 BCE

These stone tools are similar to Solutrean tools made in Spain, Portugal and southern France. How Solutreans arrive and carry their tools across North America is questionable, however, the tools are there and seem to lead to Clovis tool creation later. See 13,000 years ago.

38 000 BP

Beringia, a the land bridge connects Siberia to Alaska during the last Glacial Maximum. Sea levels are around 400 feet lower than today.

Humans cross it before it sinks into the ocean. See animated map.

  • First group about 38 000 BP
  • A second group enters 16,500 BP, mix with the local populations and quickly migrate south, all the way to South America.
  • A third group possibly enter Beringia 15,000 BP.

40 800 BP

Cave art is created in the European El Castillo cave. The art indicates Homo Sapien & Neanderthals are both capable of artistic self expression. Source Discover Magazine January / February 2013

Cave art

Other old drawings were found on the island of Sulawesi, in Indonesia. at least 35,400 years old. Source

42 000 BP

Mungo man lives in the dunes of a long gone lake, Lake Mungo in Australia, as indicated by a skeleton found and dated to 42,000 years ago.

43 000 BP

Flute, maybe the oldest known musical instrument created from bird bone and mammoth ivory is found in a cave in southern Germany and dates to 43 ooo years ago.

44 000 BP

44 000 BP

Indonesian cave painting of hunters corraling a dwarf buffalo with ropes & spears.

Cave hunting painting

45 000 BP

Cave art of a pig is created in Indonesia

Cave art of pig

50 000 BP

World's oldest needle

A needle 7 centimeters (2 3/4 inch) long with a hole to insert a thread for sewing is in use where it is found in 2016 at the Denisovans Cave where Denisovans live. Source

The needle is an important techn0logical advancement to enable humans to make clothing by joining animal hides with sinew and make strong, weather tight, and water proof seams. Humans would not be able to migrate through and live in cold regions on Earth without it.

Neanderthal's use birch sap and a complex process to manufacture a tar to cover tool grips or handles.

64 800 BP

Neanderthals create art in three caves in Iberia, Spain. It dates to 64 800 years ago. The date implies the art has a Neanderthal origin, since humans did not arrive until thousands of years later. Source Science. U-Th dating of carbobate crusts reveals Neanderthal origin of Iberian cave art 2-22-2018

65 000 BP

Humans arrived in Australia and create stone tools, ground ochre, slabs of ochre, and ochre in crayon form. These artifacts are found at Madjebdebe, Australia and date to 65,000 years ago. Source A find in Australia hints at very early human exit from Africa

50 000 - 700 000 BP

Homo floresiensis (hobbit) is alive as indicated by fossils:

  • fossils dating 50,000 years ago found in Liang Bua cave in Indonesia.
  • fossils dating to 70, 000 years old found at Mata Menge.

See Discover magazine stories

100 000 BP

Homo sapiens Qafzeh live in caves of Qafzeh, east of Nazareth, Israel. Bones are classified as Homo sapien and dated to 92,000 years old.

Additional remains are found at Skhul, on Mount Carmel, Israel and labeled as Homo sapiens Skhul and date to 115,000 years old. These remains indicate lanky slender bodies adapted to hot moist climates and unsuitable for a cooler ice age that arrived around 75 000 years ago, which may have resulted in their extinction. Evidence also suggests Neanderthal, built more stocky, were better able to retain heat and survive through ice ages. While none of these may have meet during this time in this area of the world, it does suggest their existence overlapped. Source When Neanderthals Replaced Us by Theodora Sutcliffe.

Ochre carving

Blombos Cave South Africa is a red ochre factory. Artifacts incude: grindstones, pebbles dipped in ochre used as a stamp, abalone shells used as containers to mix ochre with bone, charcoal, quartz, and other materials to make paint, and these artifact may be the earliest piece of art. Ochre can be used as a cosmetic, sunscreen, mosquito repellent, medicine, antiseptic, and tanning and preserving hides.

Campfires are lit in a South Africa cave. Source Do campfires enable society? As groups can gather around the campfire.

120 000 BP

Auroch bone carving

An auroch bone fragment engraved with six lines is left at a site in Israel. Art, communication, doodling? Source


129,000 - 116,000 BP

Sea levels rise 20-30 feet as global tempertures are 2 degrees C above preindustrial levels. Causes changes in Earth's orbit and spin and melts Antarctic ice.

180 000 BP

Earliest homo sapien outside Africa?

Misliya-1, Homo sapien at Misliya Cave, at Mount Carmel, Israel. An upper jawbone with teeth is found and dated to 180,000 BP. Source

"While all of the anatomical details in Misliya-1 are fully consistent with modern humans, some features are also found in Neanderthals and other human groups ... ‚" Dr. Rolf Quam,

193 000 BP

Neanderthals occupy Denisovan Cave on and off from 193,000 years ago until 97,000 years ago. Science May 2017

Also found there: Ornaments from bone, teeth, mammoth ivory, and ostrich shell deposits from 43,000 - 49,000 years ago. Science February 2019

200 000 BP

Homo sapiens evolve in Africa about 200,000 BP. Genetic similarities between Eurasians, Oceanians, and Americans indicate all non-African humans descend from a small population that left Africa about 60,000 BP.

Dispersal nao from Africa Source Science December 8, 2017

287 000 BP

Denisovans move into the Denisova Cave, Russia and occupy it off and on from 287,000 to 50,000 BP. Denisovan artifacts, charcoal, DNA and one bone are left. DNA from the bone is found to be a young women whose mother is Neanderthal and father Denisovan. Science February 2019

A lower jaw bone is found on the Tibetan Plateau, dated to 160 000 BP and proteins identify it as Denisovan. Science May 3, 2019. DNA for later populations 100 000, 60 000, & 45 000 is also found. Science October 30, 2020

300 000 BP

Homo sapiens use middle stone age tools (MSA) at Jebel Irhoud, Morocco. Science June 9, 2017

307 000 BP

Pieces of ochre with marks of human alteration and obsidian from about 60 miles away are left at Olorgesailie, Kenya. Indicates humans range further than previously thought and possibly trade with others. Pigment of Our Imagination: The story of human evolution is written in ochre. by Gemma Tarlach Discover April 2018. See also Blombos Cave.

540 000 BP

shell image

A Shell with zig-zag etchings is left at a site on the Solo River in Java. It is found by Eugene Dubois along with bones classified as Homo-erectus, Trinil 2 sart. Is the shell art, doodles, or a means for communicating?  Jonathon Keats: in Discover July 2015 also Smithsonian article

780 000 BP

Magnetic poles flip orientation. Source The Spinning Magnet by Alanna Mitchell

900 000 BP

Homo erectus makes big Acheulean hand axes, scrapers, and butchers meat at Olorgesailie, Kenya. A prehistoric site where artifacts are found dating from 1.2 million BP - 499,000 BP and a skull cap to about 900,000 BP.

1.6 million BP

Homo ergaster is thought to be the first hominid with long striding legs. Campable of long sustained walking and running.

Human chimp musclulature evolution



1.8 million BP (Cenozoic Era, Quaternary Period, Pleistocene Epoch .01-1.8 mya )

Stone tools

Homo erectus intentionally forms stone tools into teardrop shapes. Acheulean hand axes. Creation of these tools requires sensory motor control, memory, visualizing an object within an object, hence, planning. Source

Hippo bone hand axe (right) is discovered in Ethiopia and dates to 1.4-million BP, which is likely made by Homo erectus. Source

First humans, mammoths, mastodons, saber-toothed cats.

1.9 million BP

Australopithecus (southern ape) sediba lives in South Africa. An adult female and young are in a cavern near Johannesburg. Their specimens are found by a 9 year old in 2008. Australopithecus sediba's hands and feet suggest it has grasping ablities to climb trees and the ability to make tools. The remains suggest a direct link to Homo habilis. Source

2 million BP

Homo erectus uses fire to cook meat. Many years before Homo Sapien appears.

2.6 million BP (Cenozoic Era, Miocene Epoch 24 - 1.8 mya)

It appears humans begin to eat meat and use weapons, around this time period as stone tools are found at Gona, Ethiopia and date to 2.6 million BP.
These tools match tools known as the Oldowan, named after Olduvai Gorge, Tanzania, where Louis Leakey found similar tools in the 1930s. Those tools were so well knapped that they were believed to have evolved from a less technological tool-making culture.

A strong similarity between marks these tools made and the marks on fossil zebra bones, indicate stone tools were used to butcher animals by at least 2.6 million BP. Humans and food source

Stone tools

2.8 million BP

Fossilized jaw found at Ledi-Geraru, Ethiopia dates as 2.8 million years old and classified in the Homo genus.

3.18 million BP

Lucy roams across Ethiopia, Africa

Discovered in 1974 she is classified as Australopithecus afarenis. Upright a terrestrial hunter and gatherer that probable spent some time in trees. It has been speculated that fractures she suffered might have been from falling.

Afarensis is small and completely non-technological. No one has ever argued that they were predatory. They are bipedal, ground-eating apes. Michael Bisson

3.3 million BP

Stone tools are at a Lomekwi site near Kenya's Lake Turkana. They are found by Sonia Harmand and her team, and dated as 3.3 million years old . Source

3.3 - 3.5 million BP

Australopithecus deyiremeda is living in the Afar region in Ethiopia. Their hominin jawbones are found, dated, and classified Source & image along with animal bones dated to the same time, 3.4 million BP, suggesting Australopithecus butchered meat. Source

3.6 million BP

First evidence of bipedalism

Footprints are left by three Australopithecus afarensis hominids who walk on volcanic ash at Laetoli near Olduvai. They are preserved and Mary Leakey discovers them in 1978.

3.67 million BP

A hominid skeleton named Little Foot a female Australopithecus afarensis or A. prometheus inhabits the South Africa Sterkfontein Cave. It is discovered in 1997 and exposed over the next twenty years. It becomes the most complete skeleton of its kind found at the time and dates to about 4 million BP.

Australopithecus afarensis is believed to have lived around 2.9 million to 4.1 million BP. Source & images

3.9 million BP

Australopithecus affarensis (Lucy) appears 3.8 million BP.

Australopithecus anamensis appears 4 million BP. Source Stunning skull shakes human family tree. Science August 30, 2019


First sheep, cattle, modern whales, bears, mice, rats, apes, monkeys, dogs, and modern birds appear.

5.3 million BP (Cenozoic Era, Tertiary Period, Pliocene Epoch 1.8-5.3 mya )

23.8 million BP (Cenozoic Era, Tertiary Period, Miocene Epoch 5.3-23.8 mya )

33.7 million BP (Cenozoic Era, Tertiary Period, Oligocene Epoch 23.8-33.7 mya )

54.8 million BP (Cenozoic Era, Tertiary Period, Eocene Epoch 33.7-54.8 mya )

65 million BP (Cenozoic Era, Tertiary Period, Paleocene Epoch 54.8-65 mya )

First deer, cats, pigs, tapirs, and rhinos, elephants, horses, owls, shrews, hedgehogs, and rabbits evolve.

Cenozoic Era begins - Rise of the Mammals video (53:16)

EarthViewer - An interactive application to explore what the Earth looks like at different times. Explore what Earth looks like 250 million BP? Or 1 billion BP? Or 4.5 billion BP?

EarthViewer lets you see continents grow and shift as you scroll through billions of years and explore changes in atmospheric composition, temperature, biodiversity, day length, and solar luminosity over deep time.

Mesozoic era, Paleozoic era, & Precambrian


Mesozoic era includes three periods

  1. Cretaceous period - between 65.5 and 145.5 million years BP.
  2. Jurassic period 144-208 mya, &
  3. Triassic period 208-245 mya

Paleozoic era about 251 - 540 million BP

  1. Permian Period 245 - 280 mya
  2. Carboniferous Period 280 - 360 mya
  3. Devonian Period 360 - 408 mya
  4. Silurian Period 408 - 438 mya
  5. Ordovician Period 438 - 505 mya
  6. Cambrian Period 500 - 540 mya

Precambrian 540 mya - 4.6 billion BP includes about 90% of the time the Earth has existed.

Summary of change

The Earth itself evolves over a very long time period, compared to human life spans. The millions of years eventually provides conditions and materials for habitats suitable for life to evolve complex organisms: most recently Homo sapien.

  • A geological period is a basic unit of geological time in which a single type of rock system is formed.
  • A geological era is a time period of two or more periods.

More information on eras, periods, and evolution of life see Earth science Australia

Mesozoic era 65.5 - 250 million BP

66 million BP (Mesozoic Era, Cretaceous Period 65.5 - 145.5 mya )

First snakes, crocodilians, and many flowering plants (angiosperms).

Mass extinction, known as the K-T extinction (Cretaceous - Tertiary extinction) and K-Pg (Cretaceous - Paleogene extinction) ends the Mesozoic Era Cretaceous Period with these mass extinctions. The dinosaurs, ammonites, mollusks are among the 80% of life on Earth that is unable to survive during this time, known as one of the six mass extinctions. Mammals and birds thrive afterward. See PBS and what killed the dinosaur?

It can be labeled as a critical boundary at 66 million BP.

The boundary of the Mesozoic era results in mass extinctions believed as a result of an asteroid strike, which can be measured by the strong trace of the element iridium it left in rocks and tektites that have been found at sites around the world, both a result of the impact. One recent and site, Tanis, ND part of the Hell Creek Formation, is one site, with some astonishing artifacts.

The asteroid, about 6 miles (10 km) in diameter, crashes in Chicxulub, Mexico creating a crater about 110 miles (180 km) in diameter and 18 miles (29 km) deep. The explosion releases as much energy as 100 trillion tons of TNT, more than a billion times more energy than the bombs that destroyed Hiroshima and Nagasaki.

About the same time period Deccan Traps in India erupts releasing significant amounts of volcanic ash over a time scale that extends before and after the Chicxulub impact. These eruptions likely also contributed to the K-T extinction. Source

85 million BP

Australia breaks away from Antarctica

174 million BP

First flowering plants Nanjinganthus dendrostyla (angiosperm)

200 million (Mesozoic Era, Jurassic Period 144-208 mya)

Oceans full of fish, squid, ammonites, the great ichthyosaurs, and long-necked plesiosaurs. Huge plant-eating dinosaurs roam the Earth and eat huge ferns, palm-like cycads, and a type of seed plant, bennettitaleans. Smaller carnivores hunt the herbivores. Vertebrates take to the air, like the pterosaurs and the first birds.

End triassic with volcanic activity in Atlantic Ocean. 80% of species conodont (robbon fish) and reptiles. Ddionosaurs, archosaur, and crocodile relatives thrive.

245 million BP (Mesozoic Era, Triassic Period 208-245 mya )

First mammals, dinosaurs, frogs, turtles, crocodyloformes.

Paleozoic era about 251 - 540 million BP

280 million BP (Paleozoic Era, Permian Period 245-280 mya )

Sail-back reptiles. Amphibians abundant. Synapsids (predicessors of mammals), Podocarps (group of ancient ferns), red pine of New Zealand, Yellowwood of South Africa, corystosperms (seed ferns). Pangaea forms.

Volcanic activity in Siberia creates toxic gases, ash, wildfires, and decreases the ozone layer and the mass extinction of 96 % of all species. Notably, amphibians and synapsids. T

Fungus thrives and dinosaurs and mammals evolve.

300 million BP

Both oxygen and ozone levels reach current levels with many different kinds of complex land plants and animals.

360 million BP (Paleozoic Era, Carboniferous Period 280-360 mya)

Widespread coal swamps. First reptiles, winged insects.

End of Devonian with series of climate changes. Possible volcanic activity in Siberia. Extinction of armored fish, coral, trilobites. Vertebrates under one meter and tetrapods thrive.

408 million BP (Paleozoic Era, Devonian Period 360-408 mya)

First amphibians, sharks, bony fish, ammonoids, and spiders. Many fish.

438 million BP (Paleozoic Era, Silurian Period 408-438 mya )

First insects and vascular plants on land.

450 million BP

The ozone level is close to its present value as land plants evolve.

End of Ordovician with climate shift from cold ice sheets to sudden melting. About 443 BP. Extinction of trilobites, corals, brachiopods. Sea sponges and brachiopods thrive.

505 million BP (Paleozoic Era, Ordovician Period 438-505 mya )

First land plants, corals, Nautiloids. Ends in mass extinction.

540 million BP (Paleozoic Era, Cambrian Period 500 to 540 mya )

Evolution of first shellfish, primitive fish, trilobites, corals, mollusks.

Precambrian 540 million BP

The Precambrium (a geologic time) starts with the Earth's formation, 4.6 billion BP and lasts to the beginning of the Paleozoic Era Cambrian Period, 540 mya.

The Precambrian is not considered a geologic eon, era, period, or epoch, it is simply referred to as Precambrian or Precambrian Time. It spans most of the Earth's history (90%).

Oxygen concentration increases to about ten percent of the current level.

Precambrian 900 million - 1 billion BP

A Canadian fungi (Ourasphaira giraldae) evolves. It is .1 millimeters long with branching filaments and bulbous structure with cell walls made of chitin. Chitin is necesary for insect and crustacean exoskeletons and fish scales.

3.5 billion BP

Cyanobacteria, an oxygen-producing organism evolves.

Cyanobacteria uses carbon dioxide and water for photosynthesis and release oxygen as a waste product. Over time, the oxygen they produce accumulates in the atmosphere, where some is converted to ozone, which is important for the development of life on land, because it protects Earth's surface from too much ultraviolet radiation which is fatal to life.

3.9 billion BP

First life on Earth

Microfossils of tiny creatures are locked in different samples of rock in northern Canada. Sample date from 3.8 - 4.3 billion years & 3.95 billion years BP.


Earth cools enough to form liquid water and solid land.

4.6 billion BP

Earth's primitive atmosphere and oceans evolve complex molecules (maybe RNA) that the will evolve into the first living cells.

4.51 billion BP

Moon forms

4.53 billion BP

Earth forms

4.6 billion BP

Birth of our Solar System

13.1 billion BP

First black hole forms

13.8 billion BP plus 3 minutes


The Big Bang creates HeH+ (hydrogen, helium, and traces of deuterium and lithium ions) in three minutes.

13.8 billion BP

Big bang ... Creates the Universe? Logically creation has three options:

  1. A cataclysmic creation - most likely
  2. A non creation - meaning the Universe is always in existence
  3. A Universe that is an illusion - meaning it doesn't exist as a physical entity.


What are the top inventions of all time?

101 Inventions that Changed the World source Vimeo (1:28:17) by MeghanATBReese

  1. wheel and axle
  2. printing press
  3. light bulb with carbon filament
  4. steam engine
  5. transistor
  6. lever
  7. computer
  8. fire
  9. bronze
  10. internal combustion engine
  11. paper
  12. internet
  13. automobile
  14. penicillin Fleming
  15. compass
  16. vaccine
  17. telegraph
  18. concrete
  19. sail
  20. radio
  21. anesthesia
  22. ether
  23. telescope
  24. water wheel
  25. electric generator
  26. mould board plow
  27. refrigeration
  28. microprocessor
  29. telephone
  30. mechanical clock
  31. satellite
  32. arch
  33. cotton gin
  34. boat
  35. dynamite
  36. birth control
  37. airplane
  38. eye glasses
  39. electric motor
  40. cellphone
  41. keel
  42. candle
  43. Archimedes screw
  44. windmill
  45. flush toilet
  46. nail
  47. jet engine
  48. still camera
  49. rocket
  50. plastic
  51. x-ray
  52. differential gear
  53. laser
  54. nuclear power
  55. mechanical reaper
  56. software
  57. aqueduct
  58. oil lamp
  59. bellows
  60. digital camera
  61. stirrup
  62. MRI
  63. hammer
  64. I beam
  65. magnetic
  66. recording tape
  67. steam turbine
  68. saw
  69. phonograph
  70. arc welder
  71. bridge suspension
  72. radar
  73. gyroscope
  74. copy machine
  75. valve
  76. canal lock
  77. microwave oven
  78. paddle
  79. bike
  80. light house
  81. pacemaker
  82. skyscraper
  83. robots
  84. pneumatic tire
  85. solar panel
  86. barbed wire
  87. builders level
  88. nylon
  89. elevator break
  90. chisel
  91. credit card
  92. movie camera
  93. screw propeller
  94. lock and key
  95. kevlar
  96. Ben Franklin wood stove
  97. CD
  98. prosthetic limbs
  99. condom
  100. wooden peg
  101. SCUBA

Where is pottery, television, toothbrush, writing, mathematics, smart phone, ... other?


Dr. Robert Sweetland's notes
thehob.net or homeofbob.com or schoolofbob.com