Questions tagged [physics]

For questions about the scientific discipline that concerns itself with analysing the laws of nature in full generality

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Help in Understanding Emission theory of Empedocles

Empedocles state that the Eyes have fire in them surrounded by water, by this fire ray of the beam goes from eyes to object, then we see that thing, But Question arises to me, Than why not people able ...
Abhishek Yadav's user avatar
3 votes
0 answers
126 views

Did Maxwell discuss charge quantization?

I once read in Wikipedia that James Clerk Maxwell included the possibility that charge could be both quantified and continuous. Since the electron hadn't been discovered in 1873, does Maxwell discuss ...
David Jonsson's user avatar
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139 views

In which work was Boltzmann's entropy originally introduced?

I get an impression from this enyclopedia entry that the primary source of the Boltzmann entropy equation $S = k \log W$ might be 1866, Über die Mechanische Bedeutung des Zweiten Hauptsatzes der ...
Galen's user avatar
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To what extent did d'Alembert want to avoid the newtonian concept of force?

The context of this question: In everyday life we use push and pull all the time to get things moving, to move ourselves. To ride a bicycle: our feet push the pedals to get moving. To accelerate we ...
Cleonis's user avatar
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265 views

The abstraction of mathematics from physics

When and how did mathematics come to be abstracted away from the physical world? At first, mathematics would originate in its simplest form of counting and addition as to keep track of certain ...
Joseph_Kopp's user avatar
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76 views

What concept did pre-modern people have about thermodynamic phenomena?

How did people before the advent of modern science in the 17th century conceive thermodynamic phenomena? I want to know how people in Ancient Mesopotamia, Egypt, Greece, Rome, China and in the Middle ...
Don Al's user avatar
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The housing of the Cavendish Experiment

[I posted this to History, but it was suggested that History of Science and Mathematics would be a better choice. So I'm posting it here too.] I’m working to build the Cavendish experiment of 1798 ...
zeynel's user avatar
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How has the modelling of classical electrodynamics changed since Maxwell?

Maxwell published his Treatise on Electricity and Magnetism in 1873, 150 years ago; before the discovery of quantized charges, special relativity, quantum field theory etc. How has the mathematical ...
Larry Harson's user avatar
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185 views

Upon which incorrect equation of Euler did Sophie Germain rely in her work that won a prix extraordinaire from the Paris Academy of Sciences?

Wikipedia's Sophie Germain; Work in elasticity; Subsequent attempts for the Prize says: Germain had derived the correct differential equation (a special case of the Kirchhoff–Love equation),31 but ...
uhoh's user avatar
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Context behind Planck's "A new scientific truth does not triumph by convincing its opponents...but rather because its opponents eventually die..."?

The open access paper Lehtola & Karttunen (2022) Free and open source software for computational chemistry education (found in this answer) contains the following paragraph: 2 FREE AND OPEN ...
uhoh's user avatar
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5 votes
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Are there anonymous contributions to physics with large impact?

Based on this question Are there any anonymous contributions to mathematics that had a great impact? , I would like to ask the same question for physics. Physics is different from mathematics in the ...
Mauricio's user avatar
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Bardeen's missing talk

Back in 1968, James M. Bardeen gave a talk at the GR5 (5th international conference on gravitation and the theory of relativity), in which he presented a slight modification of the Schwarzschild ...
Ivica Smolić's user avatar
1 vote
2 answers
211 views

What data did Copernicus use to construct his heliocentric model?

I think Copernicus and his contemporaries were modeling based on some data. What data was Copernicus using and who created it?
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3 votes
1 answer
877 views

Why is electric potential denoted by $\phi$?

I haven't found any explanation for it, and I'm curious.
EB97's user avatar
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What were some 19th century objections to the existence of absolute zero?

William Thomson (Lord Kelvin) proposed the existence of an absolute zero in 1848(1) by linearly extrapolating the experimentally determined volume-temperature law for gases. I recently learned that ...
Euclid Looked On Beauty Bare's user avatar
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Units in J.J. Thompson's m/e experiment

The original paper by J.J. Thompson, where he exposes his experiment to measure $m/e$ can be found here. (Note that Thompson actually measured $m/e$ whereas the modern discussion is in terms of $e/m$.)...
ZeroTheHero's user avatar
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0 answers
83 views

How did Cross and Dot signs come in vector multiplication?

We use cross sign in vector multiplication that gives vector result and dot sign that gives scalar result. But how did the dot sign come in scalar product and the cross sign in vector product? It ...
Ashfaqul Hasan's user avatar
3 votes
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167 views

Are there any good books on the history of condensed matter?

Condensed matter is probably as impactful as quantum mechanics, but has less coverage in popular media than other branches like particle physics. Condensed matter experiments have led to many Nobel ...
Mauricio's user avatar
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What motivated formulation of the Hamilton-Jacobi equation?

I'm late to the Hamilton-Jacobi equation party and would like to know more about the historical context of its origin. What motivated its construction/discovery? What were its affordances over other ...
bblohowiak's user avatar
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1 answer
303 views

Separation between Physics and Mathematics

When and under which circumstances did Physics and Mathematics take separate routes? Even though connections between Mathematics and Physics have been strong and prosperous at all times the methods, ...
Leandro Caniglia's user avatar
1 vote
1 answer
147 views

Physical theories and Mathematics [closed]

I study pure mathematics. In pure mathematics, we begin from some axioms and obtain theorems. I am also interested in studying physics. I have some questions about the relationship between physical ...
S Ali Mousavi's user avatar
4 votes
0 answers
115 views

Einstein's overdetermination theory

In 1923 [1], Einstein proposed an idea for a classical theory that would explain some features of quantum mechanics, via the overdetermination of the EoM, so that only certain configurations would be ...
Slereah's user avatar
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On implications of Schrodingers Cat regarding macroscopic quantum states and decoherence

How exactly did Schrodingers Cat lead to development regarding macroscopic quantum states and decoherence? One often hears that the thought experiment was the initiator to the question, whether ...
manuel459's user avatar
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1 answer
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Scientific Collaborations during World War

Nowadays, scientific progress is often based on very big collaborations, like the discovery of gravitational waves by the Ligo and Virgo collaborations. But also in many other branches of science, ...
G. Blaickner's user avatar
19 votes
1 answer
4k views

What did Schroedinger try to say with the cat thought experiment?

In many books one finds different explanations. Specifically popular seems to be that he "argued against the Copenhagen interpretation". But what did he really intend to communicate? I for ...
manuel459's user avatar
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4 answers
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Is there any theorem/physical law with different names in more than two different languages/regions?

Mathematical statements and physics equations often are named after a person (like Pythagoras theorem or Newton's second law). Reading from different authors with different origins one may sometimes ...
Mauricio's user avatar
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10 votes
2 answers
3k views

Did a Chinese astronomical text conduct the "Galileo's Ship" thought experiment around the 2nd century BCE?

A math and physics magazine I was browsing through contains the quotation The Earth is moving constantly, but people do not know it; like the crew in an enclosed ship, they do not notice it. The ...
Mark Eichenlaub's user avatar
1 vote
2 answers
285 views

Source documents for Bronstein's Cube of Physics

The "cube of physics" is a quite useful summary of physics, for historical$^1$ and teaching$^2$ purposes, that is best explained (as far as I know) in "Physics On A Cube" by Jeremy ...
ccampisano's user avatar
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1 answer
134 views

Notation of Poynting vector

I know that the Poynting vector is defined as the cross-product $\vec{E}\times\vec{H}$ and that is "usually" denoted by $\vec{S}$ or $\vec{N}$. I wonder if there is a particular reason for ...
aghin00's user avatar
3 votes
0 answers
156 views

How did Rutherford detect the deflected alpha particles?

All I know is that detecting the deflecting alpha particles was a very tedious process, so much so that that was probably one reason why he asked Hans Geiger and Ernest Marsden to do the experiment. ...
Adil Mohammed's user avatar
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0 answers
86 views

What is the "legendary Chicago machine" Rosenfeld refers to in his 1963 paper *On quantization of fields*?

There's a famous paper by L. Rosenfeld (On quantization of fields. Nuclear Physics 40, 353–356 (1963). doi:10.1016/0029-5582(63)90279-7) in which he criticizes the theoretical arguments leading to the ...
Níckolas Alves's user avatar
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1 answer
208 views

Had Albert Einstein tried to use the Galilean transformation on Maxwell's equations before AE's Special Theory?

I am looking for what motivated Albert Einstein in the direction of his Special Theory. I have read that it is unclear if he was set on that path by the Michelson-Morley experiments. Was AE aware ...
goedelite's user avatar
5 votes
1 answer
221 views

Are there any direct comments by Isaac Newton on Leibniz's living force / vis-viva?

The living force or the vis-viva is a quantity usually attributed to Leibniz (although there were a few other people who identified it as a conserved quantity in certain collisions earlier). Many ...
Maximal Ideal's user avatar
5 votes
1 answer
183 views

Have there been instances in physics where different scientists have interpreted the same data differently? [closed]

Have there been instances in physics where different scientists have interpreted the same data differently? If yes, can you please give me specific examples and explain why one interpretation was ...
Vedant Rana's user avatar
2 votes
0 answers
70 views

Who first measured the increase of mass with speed?

Wiki (https://en.wikipedia.org/wiki/Electromagnetic_mass) says that: Thomson (1893) noticed that electromagnetic momentum and energy of charged bodies, and therefore their masses, depend on the speed ...
user157860's user avatar
0 votes
0 answers
91 views

How did the US get enough U235 for "Little Boy"

The answer to a different question (Where did Fermi get the U235 for the first nuclear pile) about U235, was that Fermi used natural uranium for his reactor. This explains, in particular, the origin ...
Alfred's user avatar
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3 votes
1 answer
184 views

Is there a source for a footnote in *A Canticle for Leibowitz* about the definition of the electron, "Negative Twist of Nothingness"

In a French edition of Fiat Homo (first part of A Canticle for Leibowitz) I found the following footnote about the definition of the electron given by Brother Francis to another monk, namely “Torsion ...
Alfred's user avatar
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1 vote
0 answers
64 views

Who was the first scientist to give a formula for the probability density function of the position of a photon in the double slit experiment?

The double-slit experiment shows the fundamentally probabilistic nature of quantum mechanical phenomena. On Wikipedia one can read: This type of experiment was first performed, using light, by Thomas ...
AdVen's user avatar
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3 votes
0 answers
69 views

Why is the magnetic force on a current-carrying wire sometimes called the Laplace force?

Educated in the UK, I've been used to calling the force on a current-carrying wire in a magnetic field 'the motor effect force'. But I'm increasingly aware of another (less clumsy?) name for it: 'the ...
Philip Wood's user avatar
2 votes
1 answer
163 views

Who introduced velocity potential?

Wikipedia cites John Anderson’s A History of Aerodynamics and says that velocity potential was introduced by Lagrange in 1788. However, I could trace it at least to Euler 1752, where he published his ...
timur's user avatar
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4 votes
1 answer
368 views

Who introduced gravitational potential?

Some sources say that gravitational potential was introduced by Lagrange in 1773, and others say that it was introduced by Bernoulli in 1738. I sifted through Daniel Bernoulli's Hydrodynamica (...
timur's user avatar
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0 votes
0 answers
63 views

How was it determined that charge and current were made of the same stuff?

Even in my earliest physics course we took for granted that charges are made of electrons (or their absence) and currents are due to the motion of electrons. But the electron is a very modern concept ...
Diffycue's user avatar
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7 votes
1 answer
1k views

Why is it said that Marie Curie died due to her work but the same isn't said for Fermi?

I learnt in school that Marie Curie died from her work at 66 years. On the other hand, Enrico Fermi, who also handled a lot of radioactive substances died of stomach cancer at the age of just 53. It ...
Rohit Pandey's user avatar
0 votes
3 answers
237 views

What was the first time that a Physical quantity was squared to describe a physical phenomenon?

When was the first time we see a square in an equation describing some physical effect? Well, there is the area of circle (or square of course ...), but a circle area is not - in this question ...
d_e's user avatar
  • 261
2 votes
1 answer
169 views

How did Heisenberg build the P Q matrix terms?

I learnt in some Wikipedia articles that the terms of the P and Q matrices designed by Heisenberg were composed of Fourier coefficients. Could you provide some explanation on how these coefficients ...
JCRCan's user avatar
  • 21
3 votes
1 answer
191 views

de Broglie's conception of the electron

I've been working on de Broglie's thesis (English PDF, Original French PDF) for a course, and I've found something that's been bothering me. My training is in Physics, and so I'm not particularly ...
Philip's user avatar
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5 votes
0 answers
220 views

What's the origin of the claim that a single uranium atom fissioning would release enough energy to visibly move a grain of sand?

There's a fairly widespread claim that the energy released by the fission of a single atom of uranium would release enough energy to make a grain of sand visibly jump. Richard Rhodes's The Making of ...
DylanSp's user avatar
  • 221
4 votes
0 answers
268 views

Earliest measurement of proton's mass

I was looking for the earliest experiment or the paper which shows the determination of the mass of proton. In NIST CODATA, the mass of proton is listed as "1.672 621 923 69 x 10$^{-27 }$kg"....
AChem's user avatar
  • 4,049
7 votes
1 answer
656 views

Did Ibn Al-Haytham believe that the Moon reflects sunlight or that it is self-luminous?

There are at least two articles about Ibn Al-Haytham in Encyclopedia First and Second Both these articles have one major difference that is according to the First article: The Light of the Stars (III ...
Abhishek Yadav's user avatar
3 votes
1 answer
147 views

Ideas about the speed of light between Galileo and Romer?

I know that the great Galileo made no real progress measuring the speed of light -- he disappointingly suggested that it might be infinite. I read that he concluded (based on his attempts to measure ...
releseabe's user avatar
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