History
Modern physics |
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Schrödinger equation |
History of modern physics |
Founders Max Planck · Albert Einstein |
Branches
Quantum mechanics Quantum chromodynamics Quantum electrodynamics Quantum statistical mechanics Condensed matter physics Nuclear physics Particle physics · Atomic physics General relativity · Special relativity |
Scientists Röntgen · Becquerel · Lorentz · Planck · Curie · Wien · Skłodowska-Curie · Sommerfeld · Rutherford · Soddy · Onnes · Einstein · Wilczek · Born · Weyl · Bohr · Schrödinger · de Broglie · Laue · Bose · Compton · Pauli · Walton · Fermi · Waals · Heisenberg · Dyson · Zeeman · Moseley · Hilbert · Gödel · Jordan · Dirac · Wigner · Hawking · P.W Anderson · Thomson · Poincaré · Wheeler · Laue · Penrose · Millikan · Nambu · von Neumann · Higgs · Hahn · Feynman · Lee · Lenard · Salam · 't Hooft · Bell · Gell-Mann · J. J. Thomson · Raman · Bragg · Bardeen · Shockley · Chadwick · Lawrence |
The history of nuclear physics as a discipline distinct from atomic physics starts with the discovery of radioactivity by Henri Becquerel in 1896, while investigating phosphorescence in uranium salts. The discovery of the electron by J. J. Thomson a year later was an indication that the atom had internal structure. At the turn of the 20th century the accepted model of the atom was J. J. Thomson's plum pudding model in which the atom was a large positively charged ball with small negatively charged electrons embedded inside of it. By the turn of the century physicists had also discovered three types of radiation emanating from atoms, which they named alpha, beta, and gamma radiation. Experiments in 1911 by Otto Hahn, and by James Chadwick in 1914 discovered that the beta decay spectrum was continuous rather than discrete. That is, electrons were ejected from the atom with a range of energies, rather than the discrete amounts of energies that were observed in gamma and alpha decays. This was a problem for nuclear physics at the time, because it indicated that energy was not conserved in these decays.
In 1905, Albert Einstein formulated the idea of mass–energy equivalence. While the work on radioactivity by Becquerel and Marie Curie predates this, an explanation of the source of the energy of radioactivity would have to wait for the discovery that the nucleus itself was composed of smaller constituents, the nucleons.
Read more about this topic: Nuclear Physics
Famous quotes containing the word history:
“Perhaps universal history is the history of the diverse intonation of some metaphors.”
—Jorge Luis Borges (18991986)
“I am not a literary man.... I am a man of science, and I am interested in that branch of Anthropology which deals with the history of human speech.”
—J.A.H. (James Augustus Henry)
“... that there is no other way,
That the history of creation proceeds according to
Stringent laws, and that things
Do get done in this way, but never the things
We set out to accomplish and wanted so desperately
To see come into being.”
—John Ashbery (b. 1927)