Transcript A VERY BRIEF HISTORY OF TIME

A VERY BRIEF HISTORY OF TIME
By: Brian Williams
What are “things” made of?
Aristotle- four elements
 Earth, Water, Air, and Fire
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Atomic Theory- All things are made up of small,
indivisible pieces of matter called atoms.
Proposed by John Dalton in the early 1800’s.
What makes “matter” move?
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Pre-Newton- Science was descriptive,
based on observation
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Isaac Newton- Provided qualitative
descriptions of motion, developed three
laws of motion; the father of “Classical
Mechanics”
What is matter REALLY made of?
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Electron- Discovered in 1897 by J.J. Thomson, using
cathode rays. Thomson was able to measure e/m, and
thus deduce the mass of the electron.
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Nucleus- Discovered in 1910 by Ernest Rutherford while
doing experiments with alpha particles.
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Bohr Model- negatively charged electrons orbit a small,
positively charged nucleus, the atom consists of mostly
empty space.
What’s the problem?
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The Bohr Model wasn’t consistent with
classical mechanics.
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In fact, there was no way for classical
mechanics to explain the atom, so a new
theory was required!