Big History Knowledge Timeline by Genevieve Pepper

Claudius Ptolemy - 140 AD

genevievepepper — 2024-01-25 18:11:05 UTC

Created the geocentric universe theory. Which was the basis of our understanding of how celestial objects move for over a thousand years.

Nicholas Copernicus - 1543

genevievepepper — 2024-01-25 18:13:14 UTC

Building off Ptolemey’s theory, he created the Heliocentric solar-system theory. Launching modern astronomy and setting off a scientific revolution.

Galileo Galilei - 1610

genevievepepper — 2024-01-25 18:21:05 UTC

Created the first telescope, helping prove Copernicus’s Heliocentric theory. He used the telescope to discover the moons of Jupiter.

Issac Newton - 1687

genevievepepper — 2024-01-25 18:27:22 UTC

Developed the three basic laws of motion and the theory of universal gravity. Laid the foundation of our understanding of current physics.

Edwin Hubble - 1929

genevievepepper — 2024-01-25 18:28:32 UTC

Discovered that the universe was larger than originally believed and that the Universe is expanding. Using the observation of redshift from distant galaxies being stretched.

Henrietta Leavitt - 1912

genevievepepper — 2024-01-25 18:46:54 UTC

Discovered 2400 Cepheid variable stars. Cepheid variables have luminosity periods. Using that, she estimated the distance of stars and proved that there are other galaxies.

Dimitri Mendeleev - 1868

genevievepepper — 2024-01-25 18:56:52 UTC

Created the periodic table, which helps sort elements by their increasing atomic mass. The table even had space for elements yet to be discovered.

Marie Curie - 1904

genevievepepper — 2024-01-25 19:04:06 UTC

Helped us better understand the atom - that energy was within some atoms resulting in radioactivity. Also discovered 2 new elements.

Alfred Wegener - 1912

genevievepepper — 2024-01-29 16:59:56 UTC

Discovered that continents move. Saw that continents lined up together on a map, and have geological similarities. Did not have enough evidence to prove it.

Harry Hess - 1960

genevievepepper — 2024-01-29 17:10:21 UTC

Explored the ocean floor, discovering mid-ocean-ridges. He fathered the sea-floor spreading theory. Added on to the Pangea and Wegener’s theory.

Charles Darwin - 1859

genevievepepper — 2024-01-29 17:16:42 UTC

Studied finches in the Galapagos islands, ultimately resulting in the creation of the natural selection theory. Pathing the way for future evolutionary research.

Walter Alvarez - 1980

genevievepepper — 2024-01-29 17:23:59 UTC

Discovered that an asteroid killed the dinosaurs, by observing rock’s sedimentary layers. He proved scientists wrong as they believed that change could only happen slowly.

Francis Crick & James Watson - 1953

genevievepepper — 2024-01-29 17:25:28 UTC

X-ray crystallography was used to better understand DNA. Franklin took a clear photo, and Watson built a model. He and Crick discovered the double helix.

Rosalind Franklin - 1952

genevievepepper — 2024-01-29 17:31:59 UTC

Was very skilled in X-ray diffraction. Created photo 51, demonstrating the double helix. Crick and Watson could not have done what they did without her.

Louis and Mary Leakey - 1959

genevievepepper — 2024-02-07 22:47:46 UTC

Palaeoanthropologists who proved that humans are related to apes. Had found skulls and bones in Africa that were similar to apes.

Jane Goodall - 1960

genevievepepper — 2024-02-07 22:55:56 UTC

She found that chimpanzees are much more intelligent than what was originally thought. They use tools. Also protected them - Funded the Jane Goodall Institute.