| 450-300 BC |
Leucippus, Democritos, Epicurus |
|
. . . Greek Atomists |
| 335 BC |
Aristotle |
|
continuous elements
(earth, air, fire, water) |
| 300 BC |
Zeno of Cition (founder of Stoics) |
|
popularizes Aristotelian view. |
| 60 BC |
Titus Lucretius Carus of Rome |
|
epitomizes ``Atomist''
philosophy. |
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| 1879 |
Josef Stefan |
[expt] |
power emitted as blackbody radiation
varies as T4 |
| 1884 |
Ludwig Boltzmann |
[theor] |
explains Stefan's empirical law |
| 1885 |
Johann Jakob Balmer |
[expt] |
empirical description of
line spectra
emitted by H atoms |
| 1890 |
Johannes Robert Rydberg |
[expt] |
line spectra cont'd |
| 1893 |
Wilhelm Wien |
[expt] |
blackbody spectrum displacement law:
peak wavelength varies as 1/T |
| 1895 |
Wilhelm Conrad Roentgen |
[expt] |
discovers X-rays |
| 1897 |
Joseph John Thomson |
[expt] |
measures boldmath q/m
of the electron |
| 1900 |
Max Planck |
[theor] |
derives correct blackbody radiation spectrum |
| 1902 |
Philipp E.A. von Lenard |
[expt] |
measures
photoelectric effect |
| 1905 |
Albert Einstein |
[theor] |
explains
photoelectric effect |
| 1905 |
Albert Einstein |
[theor] |
publishes
Special Theory of Relativity
(STR) |
| 1905 |
Albert Einstein |
[theor] |
explains Brownian motion
(gives mass of atoms!) |
| 1905 |
Ernest Rutherford |
[expt] |
performs first
alpha-scattering
experiments at McGill Univ. (Canada) |
| 1907 |
Robert A. Milliken |
[expt] |
measures electron charge
(now know both qe
and me). |
| 1912 |
William (H. & L.) Bragg |
[expt] |
shows that X-rays
scatter off crystal lattices |
| 1913 |
Hans Geiger & Ernest Marsden |
[expt] |
confirm
Rutherford scattering
results at Univ. of Manchester (U.K.) |
| 1913 |
Niels Henrik David Bohr |
[theor] |
pictures H atom
with quantized angular momentum |
| 1916 |
Albert Einstein |
[theor] |
publishes
General Theory of Relativity (GTR) |
| 1916 |
Robert Andrews Milliken |
[expt] |
confirms
photoelectric effect
in detail |
| 1922 |
Arthur Holly Compton |
[expt] |
scatters X-rays
off electrons |
| 1924 |
Louis Victor de Broglie |
[theor] |
hypothesizes
``matter waves''
with
 |
| 1925 |
Wolfgang Pauli |
[theor] |
formulates his
exclusion principle |
| 1925 |
Max Born
& Werner Heisenberg |
[theor] |
introduce
quantum mechanics |
| 1926 |
Erwin Schroedinger |
[theor] |
develops a nonrelativistic
wave equation
for quantum mechanics |
| 1927 |
Werner Heisenberg |
[theor] |
formulates his
uncertainty principle |
| 1928 |
Paul A.M. Dirac |
[theor] |
develops a
relativistic wave equation
for electrons and predicts
antimatter |
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