-
138,000 BCE
Big Bang (13.8 billion years ago)
The rapid expansion (from a size smaller than an atom) and cooling down of the universe. Caused the continuous expansion of the universe that still occurs today. -
137,000 BCE
Stars Light Up (13.7 billion years ago)
Gravity began to create concentrations of heat that continued to grow until they became so hot that hydrogen atoms fused, releasing immense amounts of energy and creating stars. -
60,000 BCE
Hominids Appear (~6,000,000 yrs. ago)
An early evolutionary form of humans. The most recent ones have been dated around 160,000 yrs. -
276 BCE
Eratosthenes
Made the first (accurate) measurements of the circumference of our Earth using the angle of the sun's rays. -
100
Ptolemy
Presented the theory that all matter was made up of one of 4 elements: fire, water, earth, and air, and that our universe was geocentric. -
Feb 19, 1473
Copernicus
Disproved Ptolemy's geocentric theory and proposed the heliocentric theory, which is still used in modern society. -
Dec 14, 1546
Tycho Brahe
Another man who disproved Ptolemy's theories (specifically that the planets and their orbits are perfect circles/spheres). -
Jan 22, 1561
Francis Bacon
He is considered the father of empiricism who (once again) disproved another one of Ptolemy's theories. -
Feb 15, 1564
Galileo
Was one of the first people to believe in Copernicus's theory of a heliocentric universe, and provided more evidence for it. -
René Descartes
He invented analytical geometry, and believed that nothing was true unless it could be (beyond a doubt) proven). -
John Locke
Created the periodic table to help organize the chemical elements for all the world, and tried to estimate the properties of future elements. -
Leavitt
She discovered red and blue shift, paving the way for future astronomer Edwin Hubble and disproving Newton's theory. -
Alfred Wegener
Made the theory of tectonic plates, though no one believed him until after he died (trying to prove it). -
Hubble
Using Leavitt's red/blue shift theory, he discovered that the universe isn't infinite and has actually been growing exponentially. -
Harry Hess
Proved Wegener's theory of continental drift by showing the world how new crust was pushed up from the mantle through seafloor spreading. -
Marie Curie
Along with her husband, she discovered radiation and it's side effects, in addition to a couple of new elements. -
Present Day
Today we still use information and theories from most of these scientists and astronomers, and continue to advance these fields every day.