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460 BCE
Democritus - Atomism
Democritus was an Ancient Greek philosopher who lived circa 460 - 370 BCE. He is most known for his Atomic Theory, the belief that the world is made of an infinite number of indestructible and indivisible objects called atoms^1. He believed that physical reality was made of these atoms which were all the same and that differences in material were based on the shape of the atom e.g. atoms in were smooth and atoms in stone were rough. cont. in doc -
94 BCE
Lucretius - On The Nature Of things
Titus Lucretius Carus was a Roman philosopher and Poet born in approx. 94 BCE. He is best know for his work De Rerum Natura meaning, On the Nature of Things. In the poem, Lucretius discusses and elaborates on atomism proposing among other things that atoms can not be created nor destroyed and that their constant motion cannot be stopped. He described the motion of atoms like a flock of sheep on a distant hill, appearing as a still mass from afar but filled with motion and noise up close. -
Microscopes
Zacharias Janssen is credited with the initial invention of the microscope. It was a series of three cylinders fitted inside one another each holding a magnifying lens, this design could magnify objects up to 10 times when fully extended^4. Microscopes had a massive impact on early science because they allowed scientists to really see what was happening in organisms and on objects and example of this is in 1661 Marcello Malpighi used one to prove the theory of blood circulation^5. -
John Dalton - Atomic Theory
John Dalton was born in September 1776 and is the man who proposed and proved the atomic theory. While very similar to Democritus's Atomism Dalton thought that atoms were not all alike and instead vary in size and weight/mass. He also proposed the Law of Multiple Proportions, which says that when multiple atoms form a compound it is always in ratios of whole numbers because atoms cannot be divided e.g. water is H2O and not H2.5O because half an atom is impossible. cont. in doc. -
Nuclear Power
In 1934 Enrico Fermi conducted experiments on the splitting of atoms and the results. In 1939 he and Neils Bohr discussed the theory of a self-sustaining fission reaction. In November 1942 construction of the first nuclear reactor called the Chicago Pile-1 began, and on December 2, 1942, at 3:25 pm the Chicago Pile-1 began a self-sustaining nuclear fission reaction and became the first non-theoretical example of nuclear power^7. cont. in doc.