Timeline - 11-AGPALO

Greek Era (400 B.C.)

Leucippus and Democritus’ atomic theory posited that all matter is made up small indestructible units he called atoms. However, Leucippus' works are unknown and too vague whilst Democritus was only the one who was recognized.

ISAAC NEWTON (1704)

Isaac Newton theorized a mechanical universe with small, solid masses in motion.

JOHN DALTON (1803)

John Dalton proposed that elements consisted of atoms that were identical and had the same mass and that compounds were atoms from different elements combined together.

MICHAEL FARADAY (1832)

Michael Faraday developed the two laws of electrochemistry. Studied the effect of electricity on solutions, coined term "electrolysis" as a splitting of molecules with electricity, developed laws of electrolysis. Faraday himself was not a proponent of atomism.

DMITRI MENDELEEV (1869)

Dmitri Mendeleev created the periodic table.

JAMES CLERK MAXWELL (1873)

James Clerk Maxwell proposed the theory of electromagnetism and made the connection between light and electromagnetic waves.

JJ THOMSON(1897)

J.J. Thomson discovered electrons. Used a CRT to experimentally determine the charge to mass ratio (e/m) of an electron =1.759 x 10 8 coulombs/gram. Hear Thompson talk about the size of an atom. Examine Thompson's 3 experiments to verify atoms had parts.

MAX PLANCK (1858 - 1947 C.E.)

He proposed the idea of quantization to explain how a hot, glowing object emitted light.

HANTARO NAGAOKA (1865 - 1950 C.E.)

Proposed an atomic model called the Saturnian Model to describe the structure of an atom.

Robert Andrews Millikan (1868 - 1953 C.E.)

Millikan is credited for finding the charge and mass of an electron. He did so by conducting the oil drop experiment in 1909. he put a charge on a tiny drop of oil, and measured how strong an electric field had to be, to stop the oil drop from falling.

ERNEST RUTHERFORD (1871 – 1937 C.E.)

Rutherford discovered protons and the nucleus. He showed that atoms have (+) particles in the center, and are mostly empty space. He called these (+) particles protons. He called the center of atoms the nucleus.

Albert Einstein (1879 - 1955 C.E.)

He was the first person to show a way to prove the existence of atoms—using an ordinary microscope!

NIELS BOHR (1885 - 1962 C.E.)

Niels Bohr improved on Rutherford’s model.

Erwin Schrödinger (1887 - 1961 C.E.)

Erwin Shrodinger described how electrons move in wave form, and developed the Schrodinger equation which describes how the quantum state of a system changes with time.

James Chadwick (1891 - 1974 C.E.)

James Chadwick discovers the neutron component of the atomic nucleus, explaining the nuclear fission of uranium 235. This also made it possible to produce elements heavier than uranium in the lab.

Peter Higgs (1929 C.E. - Present) 2012

The Higgs Boson particle (or god particle) was speculated by Peter Higgs in 1964. Thought, recently, the particle has been discovered by CERN in 2012. It proved the existence of the Higgs field, and stated that the god particle gave the other particles mass.

Alan Guth (1947 C.E. - Present) 2014

Alan Guth had a theory in the 1970s, called inflation. Inflation builds upon the Big Bang theory; the big bang theory states that the universe is constantly expanding, the inflation theory states that the universe expands at different speeds at different times. The inflation period is less than a second where the universe almost doubles in size. There is evidence in 2014, that inflation exists. The cause of it is gravitational waves.