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12 votes
Accepted

What exactly was the Rutherford model of the atom?

"The Rutherford planetary model" was not exactly... anything, it was a vague umbrella term. The inspection of Rutherford's 1911 paper shows that Rutherford did not propose even one of the ...
Conifold's user avatar
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10 votes

Hidden agenda of the Galileo trial?

The Assayer & Redondi's "G3" Michele Camerota's 2008 Complete Dictionary of Scientific Biography entry on Galileo describes this theory in a section entitled "Atomism and the ...
Geremia's user avatar
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9 votes
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How did J.J. Thomson learn that what he discovered was different than an atom or a molecule?

Thomson drew his conclusion based on his calculation of the charge to mass ratio of the "corpuscular carriers of negative charge in cathode rays". Quoting Thomson's Nobel Lecture of 1906: ...
nwr's user avatar
  • 6,954
8 votes

To what extent were the scientists involved in the Manhattan project aware of the goals?

The sources are abundant and easy to find, for example Leslie Groves, Now it can be told. A history of Manhattan project (written by a project leader from the military side), Robert Jungk, Brighter ...
Alexandre Eremenko's user avatar
7 votes

Who popularized the atom icon (atomic whirl or planetary model)

Prompted by some strange answers from chatGPT, I googled "atomic energy artists 1940s", which led me via a Pinterest collection of images to Herbert Bayer. Hebert Bayer provided an image for ...
Karsten Theis's user avatar
5 votes

Did the plum pudding model of the atom make any successful predictions?

Yes, qualitative ones. Thomson's model consists of a series of orbits, in each orbit a different number of electrons (less electrons for inner orbits, more for outer ones) all disposed in equally ...
cesaruliana's user avatar
5 votes
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Did Ludwig Boltzmann read Albert Einstein's publication published on Brownian motion one year before Boltzmann passed away?

I’m afraid he no longer cared. According to Boltzmann biographer E. Broda (1981): (p. 9): One might have thought Boltzmann would, after 1900, in lectures and writings refer to Planck’s work on ...
Francois Ziegler's user avatar
5 votes
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What was the relation between Euclid's points and Democritus' atoms?

They were the opposite of close. Geometers and atomists were bitter ideological enemies since before Euclid. The reason for such high passions was that Greek view of geometry was different from the ...
Conifold's user avatar
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5 votes
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Before the discovery of the neutron, how did scientists explain standard atomic weights?

Historically, the discovery of naturally-occurring isotopes of chemical elements by means of the mass-spectrograph provided a correct explanation for the fractional character of the experimentally-...
terry-s's user avatar
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4 votes

To what extent were the scientists involved in the Manhattan project aware of the goals?

The website http://manhattanprojectvoices.org is full of interviews with participants in the Manhattan project. Some interviews address exactly the question asked here. For example, here are two ...
Dan Fox's user avatar
  • 383
4 votes

To what extent were the scientists involved in the Manhattan project aware of the goals?

New scientific and engineering personal arriving at Los Alamos were given a series of lectures about the project, the relevant physics and the proposed designs of the weapons. These were later ...
simplicio's user avatar
  • 604
4 votes

Did Sommerfeld derive or measure the fine structure constant the first time he introduced it?

Computed (as $\alpha=e^2/\hbar c$) in equation (12a), p. 51 of: Zur Quantentheorie der Spektrallinien, Ann. Physik (4) 51 (1916) 1–94. (Earlier he had used $\alpha = (e^2/2\hbar c)^2$ in equation (16)...
Francois Ziegler's user avatar
4 votes
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In what sense did J.J. Thompson split the atom?

The cathode ray experiments separated an electron from an atom. This is usually not considered splitting the atom. The discovery of alpha radiation showed that the atom could be broken up, and that ...
Jon Custer's user avatar
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4 votes
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How did Antonius Van den Broek come up with his hypothesis that the atomic number matches the charge of the nucleus?

Van den Broek's train of thought is described in detail by Scerri in The Gulf between chemistry and philosophy of chemistry. His starting points in the 1907 article were Rutherford's remarks on the ...
Conifold's user avatar
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4 votes

Who popularized the atom icon (atomic whirl or planetary model)

I'm adding this as an extended comment, taking advantage of the answer modality. It changes the subject a little, since the "atomic" fib is the 500lb gorilla in the room: The electron ...
Cosmas Zachos's user avatar
3 votes

How did Einstein know the Avogadro Number?

Although the concept of the existence of the atoms originates from the ancient Greek, for them it was yet more a philosophical concept, they were very far from any experimental proof.1 Later, mainly ...
peterh's user avatar
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3 votes

Was there any atomic model(s) that came between Bohr's and the actual beginning of Quantum Mechanics in early 20s?

To my knowledge the first documented atomic model considering Planck’s action quantum was formulated by the Austrian Arthur Erich Haas (1884-1941). He hypothesized in 1910 a relation between the ...
Realist753's user avatar
3 votes
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History of molecular constituency and structure

Avogadro's Law says that the number of molecules in a fixed volume of gas under fixed temperature and pressure does not depend on the gas. So the number of water molecules in one cubic meter of vapor ...
Alexandre Eremenko's user avatar
2 votes

How was proton determined to be a common component of all atoms?

A great source on the history of particle physics is Pais's Inward Bound, see also references in In which experiments the charge to mass ratio of proton was determined? thread on Physics SE. Charge ...
Conifold's user avatar
  • 77.8k
2 votes

What was the relation between Euclid's points and Democritus' atoms?

The difference between a point (as in Euclid) and atom in Democritus is that an interval (or a plane or solid figure) in Euclid is infinitely divisible, every interval, no matter how small can be ...
Alexandre Eremenko's user avatar
2 votes

The Discovery of Atoms

Consult the Wikipedia page for atom. In its historical introduction, it presents a ladder of theories and discoveries establishing our current knowledge: First evidence-based theory Brownian motion ...
Bence Mélykúti's user avatar
2 votes

Is string theory today facing the same backlash that atomic theory faced during its inception?

Lots of mathematical physicists don't actually care about the physics and focus on the mathematics. This is not new with string theory. What is new with string theory is that a great deal of ...
Mozibur Ullah's user avatar
2 votes
Accepted

Who associated the sharp, principal, diffuse, fundamental spectral terms with electron's momentum?

Yes, those terms come from spectroscopy; they refer to the appearance of the spectral lines. It wasn't until quantum mechanics that atomic spectra were understood as an effect of electron energy ...
Geremia's user avatar
  • 5,381
2 votes

Did the plum pudding model of the atom make any successful predictions?

Rutherford said: In J. J. Thomson’s model of the atom the positive electricity was supposed (for mathematical reasons) to be distributed throughout a large sphere with the negative corpuscles moving ...
akhmeteli's user avatar
  • 1,001
2 votes

In Geiger-Marsden experiments how was charge of alpha particle and charge of gold atom found?

As for the properties of $\alpha$-particles, there is some information in Rutherford's Nobel lecture: "Strutt (Lord Rayleigh) in 1901 and Sir William Crookes in 1902 suggested that they might ...
akhmeteli's user avatar
  • 1,001
1 vote
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The case of Felix Exner and Brownian motion

Exner's paper on Brownian Motion was published in Annelan der Physik und Chemie (1900): Volume 2 Issue 4 available on archive.org (in German), starting on page 842. So yes, it is the Felix Maria von ...
nwr's user avatar
  • 6,954
1 vote

How did Thomson claim that charge on hydrogen ion was equal to charge on electron without knowing charge on electron?

The materials (chemical compounds e.g. water) used in the experiments were not electrically charged. So a positive charge on any (electrolytic) ionic part of them must be neutralised by the negative ...
terry-s's user avatar
  • 4,610
1 vote

What exactly was the Rutherford model of the atom?

The Nagaokan model was suggested by Nagoaka and who called it the Saturnian model. He proposed it in 1904, contra Thomsons 'plum pudding' model. It might have been more accurately called the planetary ...
Mozibur Ullah's user avatar

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