The historical development of physics concepts: who did what and when.

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What exactly were the “asymmetries which do not appear to be inherent in the phenomena” in Einstein's 1905 SR paper?

The first ¶ of Einstein's "On the Electrodynamics of Moving Bodies" says (my emphases): It is known that Maxwell's electrodynamics—as usually understood at the present time—when applied to moving ...
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2k views

Did Einstein know about Michelson-Morley experiment?

The second postulate of special relativity deals with constancy of light in inertial reference frames. But, how did Einstein came to this conclusion? Did he knew about the Michelson-Morley experiment?
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What did Einstein contribute to Special Relativity that hadn't already been done by Lorentz in 1904 and Poincaré in 1905? [duplicate]

What did Einstein contribute to what is now called Special Relativity theory that hadn't already been done by Lorentz in his 1904 "Electromagnetic Phenomena in a System Moving with any Velocity ...
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29 views

Why are Bose-Einstein Condensates (BECs) named after Bose and Einstein?

Why are Bose-Einstein Condensates (BECs) named after Bose and Einstein? What did Einstein contribute to BECs? What were the relevant papers?
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33 views

How did Fizeau control the cog's rotations per second?

In Fizeau's cog experiment to determine the speed of light, how would he have had a way to accurately determine the number of rotations per second of the cog, given the experiment was conducted in ...
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917 views

History of the names “Feynman-gauge” & “Landau-gauge”. How arised & how settled?

Edit: Use this PO.org question instead. Warning: Students, stay away from antiquities. The aim to learn is to survive. Hi. Today the nomenclatures Feynman gauge and Landau gauge seem established, ...
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127 views

How did steady-state universe deal with entropy?

Until the 1960's the general consensus was that the universe is infinite years old (steady-state). The second law of thermodynamics says that entropy always increases, so we'd expect that within a ...
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Galileo's pendulum and any references

In some texts about the simple pendulum we use to see references about some "experiments" Galileo Galilei did realize and whereby he found some important results, including that the period of the ...
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34 views

History of Turbulence suggestions

I am looking for extensive historical accounts of turbulence that ideally is strong in math and physics (at least giving references). Any suggestions? The only book I found is "A Voyage Through ...
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2k views

Why was the first discovered neutrino an anti-neutrino?

In the search for neutrinos, Cowan and Reines discovered the electron anti-neutrino and named it as such. Why is the particle they discovered the anti-variety? The reason we call electrons 'electrons'...
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374 views

What was Feynman's famous formula?

In Welton(1983), Memories of Feynman, Welton mentions two formulas which he denotes as Feynman's Famous Formula (FFF) and FFF #2. Which famous formulas is he talking about? Is he maybe talking about ...
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2k views

The possibility of free electrical energy?

Please excuse my lack of knowledge/understanding. Question: Why Nikola Tesla's Free Energy concept was never worked upon? Even today. Context: Now that we know Nikola Tesla was a genius and did ...
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111 views

Who determined the half-life of Uranium 235 and how?

By Wiki, the half-life of Uranium 235 is as long as 703,800,000 years. This is huge. Therefore, on an human time scale, the decay is very small. This should pose difficulty for determining the half-...
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9k views

Why is a second equal to the duration of exactly 9,192,631,770 periods of radiations?

Why is a second equal to the duration of 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom? Why is the number ...
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3k views

Were the Michelson-Morley results a surprise?

How unexpected were the Michelson-Morley experiment results? Did physicists have theoretical reasons to predict that the speed of light would result to be invariant?
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Schrödinger's interpretation of his wave function before Born

The below shows some excerpt from Feynman's lecture notes. 21–4 The meaning of the wave function When Schrödinger first discovered his equation he discovered the conservation law of Eq. (21....
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37 views

Which experiments of harmonic generation at low frequencies preceded Franken's SHG?

In The Principles of Nonlinear Optics by Shen, he says that the generation of harmonics at low frequencies were long-known before Franken did SHG in the optical range. Franken's idea was simple. ...
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138 views

What is the inconsistency between Maxwell's electrodynamics and newtonian mechanics?

As far as I understand, when a modification of a theory is made it is because some observation required this modifcation. Quantum Mechanics is a nice example of that: observations of microscopic ...
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251 views

Doppler effect of matter waves

We all know that the relativistic mass of a moving object in Special relativity increases for an observer who is measuring it for a moving object. We also know the the concept of particle-wave ...
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2k views

Planck's distribution and Bose-Einstein distribution?

If the application of the Bose-Einstein distribution is in blackbody radiation, then what is Planck's distribution? Are they same? How did Planck know that he should use a Bose-Einstein distribution ...
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196 views

Why did Albert Einstein receive a nobel prize? [closed]

We all know that he received the prize due to his explanation of photoelectric effect. But the photoelectric effect, it’s a mere 3-4 page topic and uses a simple equation that typically anyone can ...
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132 views

Did Newton conduct any experiments to find something called momentum, or was he such a great genius that he was able to spot it intuitively?

I wanted to go to the depth of the discovery of classical mechanics, instead of just reading, accepting and learning things. Now my question is not a single question, but it can answer many of my ...
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86 views

Is electromotive force really a force? [duplicate]

As far the definition goes emf of electromotive force is basically potential difference. It even has dimensions of potential. Then why is it called a force?
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Classification of experimentally-determined physics laws? [duplicate]

Has anyone classified (or attempted to classify) all the experimentally-determined laws of physics, such as with a simple diagram or even in a full-length book?
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2k views

Historic derivation of Wien's law

Every book I've read, including a lot of websites, Wikipedia, etc, say that Wien derived this: $$\rho_\nu(T)=\rho(\nu,T)=\nu^3f\left(\frac{\nu}{T}\right)$$ Being $\rho_v(T)$ the spectral enegy ...
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542 views

Why is an electron negatively charged, and what is the difference between negative and positive charges?

Nobody has yet defined the actual meaning of a charge, or why a negative charge is different from a positive charge. Everybody knows that positive charge is due to protons and negative charge is due ...
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What are the original papers on the hydrogen spectral lines?

I am trying to find original sources for experiments that had observed spectral lines from hydrogen or other gases. I am looking into experiments that motivated Niels Bohr to write his ideas on the ...
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Why was the Stark effect discovered much later than the Zeeman effect?

This is strange. The Zeeman effect involves the magnetic field. The Stark effect involves the electric field. In the course of classical electrodynamics, we get the impression that for many physical ...
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1answer
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What is really sought when we purpose Einstein's postulates in Special Relativity?

Special Relativity can be motivated by looking at Maxwell's Electrodynamics and noticing that there is some kind of inconsistency between it and Newtonian Mechanics. Indeed, as Einstein pointed out on ...
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Good book on the history of Quantum Mechanics?

Can anyone recommend a good book on the history of Quantum Mechanics, preferably one that is technical and not afraid to explain the maths (I did a degree in Physics many years ago) and also that ...
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419 views

Velocity distribution in ion source (electron bombardment) for Bainbridge mass spectrometer

Consider the following schematics of a Bainbridge mass spectrometer (Source: http://www.schoolphysics.co.uk/age16-19/Atomic%20physics/Atomic%20structure%20and%20ions/text/Mass_spectrometer/images/...
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32 views

Thermal de Broglie wavelength - definition

The thermal de Broglie wavelenght is often defined by the formula $\lambda=\frac{h}{\sqrt{2\pi mkT}}$ but equally frequently is it defined as de Broglie wavelength for a free ideal gas of massive ...
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64 views

How does Compton scattering demonstrate particle over wave behavior?

Why is Compton scattering thought to demonstrate light's behavior as a particle over that as a wave. I'm interested in the thoughts at the time of Compton, but also how it contradicts current theory ...
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945 views

Meaning of the word “Moment”?

This question is more of a question about the origin of a physical term moment used in many contexts. My question is about the linguistic or historical meaning of the word "moment". Please don't ...
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How did Max Born come up with his rule? [duplicate]

In his rule, he stated that the probability is norm-squared of wave function, $|\psi|^2$. And as far as I knew, no one else at that time had "right" interpretation of the wave function. Even ...
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Where can i get an online version of original works of Aristotlean physics (for free)? [closed]

I am trying to search for original works of Aristotle in physics. Pls refer an online version and kindle version is very much appreciated.
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500 views

How did we realize that light travels at a finite speed?

We all know that light travels at a finite speed of nearly $3\times10^8\mathrm{m\,s^{-1}}$. But how did we come to think that light has a finite speed? Why did the scientists try to calculate the ...
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57 views

Secrets of Alexander Markovich Polyakov [closed]

I just became aware that this guy is a real genius. I tried looking on Wikipedia for some details about his life and to find out about the process and history behind some of his works especially "...
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12k views

Electric field of a negative charge

How was it discovered that the electric field of a negative charge points towards the charge itself? Is it true? (Courtesy of wikipedia)
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How did scientists calculate the number of atoms in one mole of a substance? [duplicate]

Please explain me about the basic methods about how can we calculate that 1 mole of a substance contains 6.022140857 × 10 23 molecules? Tell how the modern scientists calculated it and how Avogadro ...
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358 views

What was Newton's own explanation of Newton's rings?

What was Newton's own explanation of Newton's rings? Newton advocated a corpuscular theory of light, but his rings would most conveniently be explained by a wave theory. How did he explain his own ...
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370 views

Who developed the phase space path integral?

The original path integral introducted by Feynman is $$ \lim_{N\to +\infty} \int \left\{\prod_{n=1}^{N-1} \frac{\mathrm{d}q_n}{\sqrt{2 \pi i \hslash \varepsilon}} \right\} \exp\left[{\frac{i}{\hslash}...
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1answer
52 views

How was the concept of work-energy developed? [duplicate]

I doubt that the concept of work-energy was actually discovered this way. However in the algebra based physics book I am reading, work done by a constant net force is defined as $W = fcos \theta s$ ...
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1answer
166 views

What is the angular distance between Ptolemaic perigees of Mercury?

In his excellent treatment of the history of the science of astronomical distances and sizes, Albert van Helden says (p.29) that The complicated [Ptolemaic] model of Mercury has the curious ...
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Do the LIGO observations constitute proof of a black hole merger, and what happened to the black holes?

Information says that the gravitational waves, recently detected by LIGO, correspond (according to Einstein theory equations) to the effect of two black holes merging (with the masses of both black ...
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1answer
64 views

Which was the first Coulomb's constant value? [closed]

Which was the first Coulomb's constant value? I didn't found any info in the Internet. I need the first value of K to compare it with my experiment. Could you please help me?
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1answer
59 views

(Constant) Value Of Gravitational Pull $g$ Of Earth [closed]

I want to know How the value of $g$ was found and what experiments did Newton conduct to land upon the value that we use, which is 9.8 m/s^2. I tried to search for it but I couldn't find much ...
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Bohr on wholeness?

I vaguely remember that it was Bohr who insisted that in a quantum experiment the whole experimental situation (but excluding the classical preparation and detection devices) must be considered as a ...