Timeline of Significant Science, Mathematical, & Technological Events
Modern Present - 1950
Summary of change
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
Higgs boson experiments
Peter Ware Higgs, is a theoretical physicist who proposed 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.
The Higgs was experimentally discovered at CERN on July 4, 2012.
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.
Both discoveries add support for the Standard Model of particle physics.
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
The number of people living in urban areas was greater than the number of people living in rural areas.
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.
1989, 1990, & 1991
1989 - Tim Berners-Lee designed the Distributed Information System for particle physicists to communcate more effectively and efficiently.
1990 Tim Berners-Lees and Robert Cailliau utilized 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
1991 Al Gore introduced legislation to create ARAPANET, a public network that became the internet.
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.
- At questions is: are living things patentable?
- 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.
1977 - present ...
Is launched 9-5, 1977; takes blue dot phot 2, 1990; becomes most distant human made object 2-17, 1998; crosses the termination shock; Passes reach of the solar wind 2-13, 2010; reaches interstellar space 8-25, 2012.
Photo of Earth taken by VOyager 1 between Uranus and Neptune. Original: NASA JP
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
Sputnik launched by Russia
was invented and patented in 1956 by Malcolm Mc Lean. He was a trucker who owned and operated a large fleet of trucks.
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).
1936 Hoover dam
Edwin P. Hubble supported the expansion of the universe with his measurements of shifting spectral lines of light emitted from distant galaxies.
1936 - 1938
City planning for green space and community ...
Greenbelt, Maryland, was constructed from 1936 to 1938 by thousands of laborers, through the New Deal programs. Clarence S. Stein was a consultant and created design guidelines. Later Stein worked to preserve the town as an example of socially and environmentally responsible community design that could be a prototype for future desgins. Designs that combined superblocks of houses and apartments that had pedestrian walkways through communal green space which joined to a central area with commercial and recreational structures separate from roads for automobile travel. In addition, the federal government promoted cooperative enterprises and associations in Greenbelt as a way to foster affordability and an enduring sense of community. While the cooperative nature of the towns were deemed a failure, the physical layout of the town was replicated by private developers. Source 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 was the first chemical substances systematically used to treat and prevent bacterial infections in humans. Their effects were first observed in 1932, by Gerhard Domagk who noticed that red dye Prontosil killed Streptococcus infections in mice. Later researchers found the active agent was sulfanilamide, or para-aminobenzenesulfonamide, a metabolic product of Prontosil.
Summary of change
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.
Chemical fertilizer (Nitrogen)
Haber developed a process that used nitrogen (N2) and methane (CH4) gas to make ammonia (NH3) economically. Ostwald used the ammonia (NH3) from Haber's process and develandoped 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 then be stored and blended with the other fertilizer components. Source
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
FROM THE JULY/AUGUST 2016 ISSUE
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 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.
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.
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.
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.
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.
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
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® Devil logo is thought to be the oldest food trademark. Source
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.
Industrial 1860 - 1500
Summary of change
The 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
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
A Drop of London Water, from Punch, 1850
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.
Preservation of food was perfected by Nicolas Appert who preserved fruits, vegetables, meat, soup, and milk by boiling and storing them in airtight glass containers. It was developed so Napoleon could feed his troops in the field. Source
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
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).
James Watt improved a version of the steam engine making it available for work and the industrial age.
Washington Crop rotation
George Washington experimented with crop rotation on a three year cycle and five year cycle. He drew elaborate charts that divided his fields so the amount of each crop was equalized as flax, hay, clover, buckwheat, turnips, and potatoes were rotated through the different fields. Later he expanded to a seven year cycle as shown in the pictured chart. See 1700 Townshend crop rotation.
Jean-Jacques Rousseau - (1712 -1778)
French author who wrote:
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.
Townshend Crop rotation
Charles Townshend, investigated a crop rotation based on what he heard the Dutch and Flemish farmers used. He found crops grew better with fewer weeds, fewer pests, and returned nutrients to the soil. He rotated 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 1760 Washington crop rotation.
- Published Principia Mathematica
- First claimed ... Forceg = G * ((M1 * M2) / d2)
Adapted from Isaac Newton [Public domain], via Wikimedia Commons
First printing press in the American Colonies is assembled at Harvard College.
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 (Kitāb al-manāẓir).
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 turned his telescope upward and observed the planets orbiting the Sun and four moons orbiting Jupiter. Dropped different sized canon balls of the Tower of Pisa and demonstrated that heavy and light objects fall at the same rate.
He also explored inertia and friction. See Galileo Explains It All
The Gregorian calendar / Western calendar / Christian calendar, is named for Pope Gregory XIII, who introduced it in October 1582.
Nicolas Copernicus used his calculations to support the idea the Sun was the center of the solar system with planets orbiting around it.
Printing with movable type
Johannes Gutenberg, invented printing with movable type. Small metal prisms (lead) that were cast precisely and in large quantities so they could be set into a grid, used, reset, and used again. He also used 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 or Korean printing, or current European printing by stamping letters on a surfaces or woodblock printing. Source
Ibn al-Haytham’s most important work: Optics (Kitāb al-manāẓir).
- 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 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.
Summary of change
2 000 years ago
Romans made cement and used it to make concret for water pipes, docks in harbors ...
Calculated size of the Earth
Eratosthenes, heard of a well in Syene that on summer solstice (June 21) the Sun light up the well right down to the water and cast no shadow on the side (meaning the sun was directly overhead [zenith]). On the same day the Sun, in Alexandria, was 7 degrees off the zenith (point directly overhead). Using geometry he calculate the Earth's diameter as 12,800 km or about 8ooo miles around the poles and equator. Source explanation of measurement
300 - 400
Nomadic tribes of Northern Asia invaded China, eastern Asia, and Europe. With superior horse skills and the stirrup destroyed villages, the current political structures, and changed peoples lives.
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.
Aristotle - 380 - 322 BCE
Explanation with rhetoric and logic. Deductive reasoning (as opposed to inductive reasoning) or syllogism. Reasoning in which a conclusion is drawn (validly or not) from propositions (premises). Each shares an idea not present in the conclusion. All dogs are mammals, all mammals are animals, therefore, all dogs are animals.
Believed there was 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 was their natural place to be. Believed forces were requird to keep things moving. He had no concept of inertia. See Galileo and Newton.
Petra a city carved in rock by the Nabataeans in the desert of southern Jordan, They also created an irrigation system to supply their water and discovered a 4 degree slope made for efficient water flow. Excavations also show how the Nabataeans created a water supply system for the desert city, an artificial oasis, with flood control multiple dams, storage in cisterns, and water transported in conduits from sources miles away. Source
The idea of atoms
Democritus - 470 - 370 BCE
Democritus considered all matter was made of atoms, which were small, invisible, surrounded by space, could not be subdivided, and lasted forever. There were an infinite number of them that make up the physical world. They were different in shape, arrangement, position, and magnitude. He also believed space was a void or vacuum that was infinite. Source
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 was 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.
With the development of iron it would provide a much better material and along with the idea of fastening to the foot with nails. Sine iron was valuable and could be melted and reused, it makes discovery of it in archaeological digs more 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
What are the pros and cons between horses, mules, and oxens as what is best for ... Consider strength, speed, health, and food requirements ...
Plato and Socrates
Explanation through 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.
The first teachers of rhetoric, the art (arte) and process of effective public speaking, in the Greek world were known as the Sophists, or wise men. They taught by example skills of civic life and explored a wide range of human experience within Greek culture. Not being of Athens they often clashed culturally and philosophically with the Athenians.
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.
They taught art had the highest value in life and 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 was its power to motivate, influence, and please people. Therefore, oration was taught as an art form, which was used to please, motivate, and influence other people through quality speaking. Maybe the historical basis for Declamations which are students interpretations of famous speeches they regive to demonstrate their ability to understand and apply the purpose and power of the speech and skill in public speaking. Samples
1 754 BCE
King Hammurabi, wrote a code to regulate water usage:
- The distribution of water based on the acres farmed.
- Required each farmer to maintain the canals on his property.
- Required the collective administration of the canal by all users.
1 000 - 4 000 BCE
- 1045 Bejing
- 1100 Kirkuk
- 1500 Balkh
- 4000 Faiyum
- 4200 Sosa
4 000 BCE
Egypt and Mesopotamia (present day Iraq and Iran) used flood water from the Nile or Tigris/Euphrates river to water crops.
The Egyptians used 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
Eribil became a city.
8 000 years ago
Domesticate potato in Peru.
9 000 years ago
Kennewick man skeleton found in Washington shares DNA that suggests it is an ancestory of the Native American tribes of the Coville Reservation.
Olmec Domesticate maize, corn.
Jericho became a city.
10 000 years ago
Summary of change
10 000 years ago ...
One might think that many hunter–gatherer societies stumbled upon domestication and took up farming. However, this seemed to happen in only nine places around the world: Fertile Crescent, China, Mesoamerica, Andes/Amazonia, eastern United States, Sahel, tropical West Africa, Ethiopia and New Guinea.
History from now until today includes many tales of hunter–gatherer societies being driven out, infected, conquered, and exterminated by farming societies where farming is possible. Except the Huns and Atilla see 300-400 & 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 BC. 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.
Source Nature, Jared Diamond
13 000 years ago and maybe earlier ...
Humans began to farm rather than maintain a hunting and gathering existance. The belief that farming was a step up is probable inaccurate as farming required more work, lower adult status and resulted in worse nutritional conditions, poorer sanitation, and more disease. What ever the circumstances the result was changes in plants, animals, and human behaviour that interacted with each other and lead to humans building of cities . Source Evolution, consequences and future of plant and animal domestication, by Jared Diamond.
It may also be possible that the food supply of wild animals was shrinking to a point of unsustainability as 100's of large mammals had been hunted to extinction by humans. Source Sapien
Cooking, grinding, leeching, soaking
Wheat, barley, seeds with non shattering seed pod or head
Goats, sheep, cattle, chicken, pigs, For the species which were not domesticated. Is the reason that it was difficulty to domesticate each of those species?, or Were the indigenous people that lived where the species was native not inclined to domesticate them?
23 000 years ago
Ohalo II located on the shore of Galilee was clearing land, sowing wheat and barley and harvesting them 23 000 years ago. Ehud Weiss and his team have collected
150 000 specimens of plant remains from the site.
1.8 million years ago (Cenozoic Era, Quarternary Period 1.8 mya-today)
First humans, mammoths, mastodons, saber-toothed cats.
2.2 million years ago
South Africa Sterkfontein Cave a hominin Australopithecus afarensis or A. prometheus? Little Foot. Source & image
2.6 million years ago (Cenozoic Era, Neogene Period 24 - 1.8 mya)
Stone tools found at Gona in Ethiopia, were dated to 2.6 million years ago. They match tools known as the Oldowan, named after Olduvai Gorge in Tanzania, where Louis Leakey found similar tools in the 1930s. These tools were so well knapped that they were believed to have evolved from a less technological tool-making culture.
2.8 million years ago
Fossilized jaw found at Ledi-Geraru, Ethiopia was dated as 2.8 million years old and classified as Homo genus.
3.3 million years ago
Stone tools at the Lomekwi site near Kenya's Lake Turkana were found by Sonia Harmand and her team, which were dated to 3.3 million years old . Source
3.3 - 3.5 million years ago
A hominin jawbones was dated and classified as Australopithecus deyiremeda. They were found in the Afar region in Ethiopia. Source & image
24 million years ago (Cenozoic Era, Neogene Period 24-1.8 mya)
Australopithecus appears. First sheep, cattle, modern whales, bears, mice, rats, apes, monkeys, dogs, modern birds appear.
50 million years ago
Australia broke away from Antarctica and trapped Mungo Man in Australia.
65 million years ago (Cenozoic Era, Paleogene Period 65-24 mya )
An asteroid about 6 miles or 10 km diameter crashed in Chicxulub, Mexico creating a massive crater about 110 miles or 180 km diameter. The explosion would have released as much energy as 100 trillion tons of TNT, more than a billion times energy than the bombs that destroyed Hiroshima and Nagasaki.
This event was at the end of the Cretaceous Era and the extinction of the dinosaurs who were among the 80% of life on Earth that were unable to survive during a time know as one of the six mass extinctions. See PBS and what killed the dinosaur?
First deer, cats, pigs, tapirs, and rhinos, elephants, horses, owls, shrews, hedgehogs, and rabbits evolve.)
Summary of change
The Earth itself evolved over a very long time, when compared to a human life span, and eventually conditions provided material sources and a habitat suitable for life to evolve complex organisms and 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
145 million (Mesozoic Era, Cretaceous Period 146 to 65 mya )
First flowering plants, snakes, crocodilians.
Mass extinction at the end of this period kills dinosaurs, and others.
Know as the K-T extinction (Cretaceous–Tertiary) and K–Pg extinction (Cretaceous–Paleogene)
200 million (Mesozoic Era, Jurassic Period 208 to 146 mya)
Oceans were full of fish, squid, ammonites, the great ichthyosaurs and long-necked plesiosaurs. Huge plant-eating dinosaurs roamed the Earth that ate huge ferns, palm-like cycads, and a type of seed plant, bennettitaleans. Smaller carnivores hunted the herbivores. Vertebrates took to the air, like the pterosaurs and the first birds.
245 million years ago (Mesozoic Era, Triassic Period 245 to 208 mya )
First mammals, dinosaurs, frogs, turtles, crocodyloformes.
280 million years ago (Paleozoic Era, Permian Period 280 to 245 mya )
Sail-back reptiles. Amphibians abundant. Pangaea forms. Ends with mass extinction.
360 million years ago (Paleozoic Era, Carboniferous Period 360 to 280 mya)
Widespread coal swamps. First reptiles, winged insects.
408 million years ago (Paleozoic Era, Devonian Period 408 to 360 mya)
First amphibians, sharks, bony fish, ammonoids, and spiders. Many fish.
438 million years ago (Paleozoic Era, Silurian Period 438 to 408 mya )
First insects, vascular plants on land.
505 million years ago (Paleozoic Era, Ordovician Period 505 to 438 mya )
First land plants, corals, Nautiloids. Ends in mass extinction.
540 million years ago (Paleozoic Era, Cambrian Period 540 to 500 mya )
Evolution of many life forms. First shellfish, primitive fish, trilobites, corals, mollusks.
4.5 billion years ago (Precambrian time, 4.5 bya to 540 mya)
The Precambrium as a geologic time starts with the Earth's formation, 4.5 billion years ago and goes to the beginning of the Cambrian Paleozoic Era, Cambrian Period, 540 mya. Since the Precambrian is not considered a geologic eon, era, period, or epoch, it is referred to as Precambrian or Precambrian Time. It spans most of the Earth's history (90%).
The Earth's primitive atmosphere and oceans evolved complex molecules that evolved into the first living cells.
13.8 billion years ago
Big bang ... The creation of the Universe logically has three options: 1. needs a creation that is most likely cataclysmic event, 2. a non creation event with the Universe always being in existence, or the Universe is an illusion and it doesn't exist as a physical entity.