Questions tagged [physics]
For questions about the scientific discipline that concerns itself with analyzing the laws of nature in full generality. It is one of the largest branches of natural science. Before applying this tag to a question, please consider using the "theoretical-physics" or "experimental-physics" tags instead, as they are more descriptive.
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Did Heisenberg ever accept Schrödinger's formulation of quantum mechanics or at least, did he relax his negative views about it?
Both Heisenberg and Schrödinger found each other's way of formulating Quantum Mechanics quite repellent.
My question is: Did any of the two changed their views towards each other (specially ...
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1answer
82 views
Portrait of Stephen Butterworth
Does anybody know of a portrait of Stephen Butterworth (1885 - 1958), a British physicist?
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60 views
Historical accounts of a oft-cited quip by astronomer Walter Baade
I am looking for any documented, historical reference to an oft-cited humorous reply by German astronomer Walter Baade (1893 – 1960).
After having asked if other astronomers were familliar with the ...
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24 views
Who originally worked out the magnetic field produced by a solenoid and toroid?
Although, it seems very easy to find the magnetic field produced by a solenoid or a toroid, all we got to do is to make a suitable an Amperian Loop and take the $\mathbf B$ out of the integral and so ...
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1answer
42 views
Lawrence and Segre: Further information about relationship
There is a oft-repeated story (https://en.wikipedia.org/wiki/Emilio_Segr%C3%A8) about Lawrence, upon discovering that Segre was legally trapped in the USA, unable to return to Italy due to fascist ...
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102 views
What made Newton realize that the law of gravitation was 'universal'? [duplicate]
Newton's law of gravitation operative near the earth is the same law causes the earth and the other planets to go around the sun and other heavenly phenomena. Was it a giant leap of faith by Newton or ...
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30 views
Did pre-Galilean astronomy inspire Mach's principle?
Was Mach, in his formulation of "Mach's principle," influenced by pre-Galilean astronomy, such as that of Aristotle in On the Heavens, where heavenly bodies influence terrestrial ones?
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21 views
What experiment proved that electric current is charge transport? [duplicate]
To my knowledge, neither Volta nor Ampere nor Oersted, the founding fathers of electric current, knew that current is the transport of charge. Who, then, and by which experiment, proved the nature of ...
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1answer
681 views
Who first solved the classical harmonic oscillator?
There is a question Who solved the quantum harmonic oscillator?, but not one for the classical oscillator. Wikipedia's article Harmonic Oscillator does not have historical information either. So who ...
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1answer
180 views
How did 19th century physicists do their undergraduate/graduate studies?
I have read that
In 1847, he became aware of physicist James Prescott Joule’s argument for the mutual convertibility of heat and mechanical work and for their mechanical equivalence.
We study ...
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45 views
Can you suggest good resources for reading about history of science especially physics? [duplicate]
I'm looking for good resources of history of sciences (especially physics) which cover history from the time of Newton and Galileo (or before them) till the modern physics world (21st century).
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Advance of the perihelion of Mercury
When I did my MSc in astrophysics back in '95-'96, I was told that there had been an attempt around the early 20th century to account for the advance of the perihelion of Mercury by altering the ...
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1answer
251 views
Who introduced the “dagger”symbol as conjugate transpose in quantum mechanics?
The $\dagger$ symbol is often used in quantum mechanics,and also often in general mathematics to represent the conjugate transpose operation.For Hermitian matrices we can write $$A^\dagger=A$$Who ...
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What exactly was Lagrange's “grave mistake” with respect to rotating bodies under hydrostatic equilibrium?
A comment below What would be different about satellite orbits if Earth were prolate? Would we have Sun-synchronous and Molniya orbits? got me reading Wikipedia's Jacobi ellipsoid which begins:
...
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53 views
Dirac and proton-electron annihilation
Wikipedia says:
Robert Oppenheimer argued strongly against the proton being the negative-energy electron solution to Dirac's equation. He asserted that if it were, the hydrogen atom would rapidly ...
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1answer
89 views
What is the explanation of rope's strength in Galileo's Two New Sciences?
I'm reading Galileo's Two New Sciences. But as other Scientific Book it is hard. I am having trouble in First day, where SIMPLICO asks this question(Page 7):
"But how can one make a rope one ...
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73 views
What did Hans Bethe think of von Neumann's quantum logic?
Nobel laureate Hans Bethe was a friend of mathematician-physicist John von Neumann, and he once said:
"I have sometimes wondered whether a brain like von Neumann's does not indicate a species ...
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2answers
112 views
What is the history behind defining temperature as measure of hotness?
I know that when two bodies of different temperature are kept in contact "heat" flows from hotter body to colder. But how did anyone know that it is the "hotness" that flows, one could have said that ...
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1answer
54 views
When was spin of subatomic particles other than the electron discovered?
The idea of a spin angular momentum was first proposed in a 1925 publication by George Uhlenbeck and Samuel Goudsmit to explain hyperfine splitting in atomic spectra.
At what time was it measured ...
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1answer
115 views
Einstein praising Sophus Lie
p. 153 of
Raúl M. Falcón Ganfornina and Juan Núñez Valdés, “Mathematical Foundations of Santilli Isotopies,” trans. Alan Aversa, Algebras, Groups, and Geometries 32 (2015): 135–308.
quotes (but does ...
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65 views
How does the concept of centre of mass came to existence?
I am wondering as how does the concept of centre of mass came into being. Considering the usefulness of the concept how were the physicist able to define such a quantity. I mean was it just trial and ...
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55 views
How did the terms stress and strain come to describe two different things?
In physics, stress essentially captures forces in a body, where as strain captures displacements. Two dimensionally very different concepts. If you look it up in a thesaurus, stress and strain are ...
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1answer
175 views
What is the origin of the concept of reduced mass?
I am looking for the origin of the concept of reduced mass as used in vibrational spectroscopy e.g. vibration of a diatomic molecule. Most of the texts simply define reduced mass as the sum of the ...
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177 views
Did anyone mention the possibility of antimatter before 1928?
In 1932 positron and annihilation were discovered, but in 1928 Dirac had provided a formula allowing for the positron
Did anyone between that date and the discovery of electron ever imagine or ...
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1answer
55 views
What is Leroy Grumman Medal won by theoretical physicist Kenneth G. Wilson?
I happened to find that one of the most important inventors of the renormalization group, Kenneth G. Wilson, won the Leroy Randle Grumman Award Medal in 1986, 4 years after his Nobel prize. Details in ...
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1answer
135 views
How did $SU(2)$ came into physics?
It is natural for physicists to consider the group $SO(3)$. Presumably, $SU(2)$ came into physics because of quantum mechanics. How did people realize that when studying rotation of a physical system, ...
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1answer
116 views
What is the ancient cosmic canon of proportion and its role in the history of science?
Who had direct inside knowledge of the canon through the alleged secret oral tradition? Some possible examples that have been alluded to include Pythagoras, Plato, Euclid, Copernicus, Galileo, Kepler, ...
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1answer
78 views
How was (non-instantaneous) electric current first discovered?
How was (non-instantaneous) electric current first discovered and what were some of the main first thoughts on it?
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137 views
What happened to the undergrad students who attended the Feynman Lecture Series in 1961-63?
Note: This question was originally asked here, but I was wondering if I could get further clarification as this has truly intrigued me.
In the academic years of 1962-2 and 1962-3, Richard Feynman ...
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1answer
1k views
Why do many names of technical and scientific subjects end with “ics”?
The names of many technical and scientific subjects, like mathematics, physics, statistics, etc., etc., end with letters "ics". What is meant by this, if anything? Was there any logic behind it or is ...
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1answer
91 views
When did the use of Sine and Cosine as functions become mainstream?
In the work of early physicists like Newton, everything is explained in terms of cumbersome (in today's standards) geometry. They don't talk about "cosines" of certain angle, but about proportions ...
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1answer
86 views
Are these Newton's quotes apocryphal?
I have stumbled upon the following alleged Newton's quotes, but I could not find them in any of their works.
No great discovery was ever made without a bold guess.
No sciences are better ...
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Who discovered the covering homomorphism between SU(2) and SO(3)?
Who discovered this? It is quite nontrivial and very important in quantum mechanics.
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Identification of scientists in de Gennes book
Petit Point: A Candid Portrait on the Aberrations of Science is a charming book written by the French physicist Pierre-Gilles de Gennes containing short essays on some of the prominent scientists that ...
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Theory criteria from Misner-Thorne-Wheeler
In chapter 39.1 of Gravitation, by Misner, Thorne and Wheeler, it is asserted, quite reasonably, that a theory of gravitation (and, I assume, quite generally) must satisfy the three following criteria ...
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770 views
What is the origin of the $\hbar$ symbol?
Equations involving Planck's constant, $h ,$ are often simplified by instead writing them in terms of the reduced Planck's constant, $\hbar \equiv \frac{h}{2 \pi}.$ But where did the symbol for the ...
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125 views
Does Einstein's original derivation of $E=mc^2$ exist and what is it?
I read an article published by Scientific American stating that Einstein did not prove the equation within the context of Special Relativity but I am skeptical. I was hoping someone could point me in ...
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449 views
Why are 'speed' and 'velocity' not given the same name?
Position is a vector. Distance/length is a name of its magnitude.
Velocity is a vector. Speed is a name of its magnitude.
Acceleration is a name of a vector and its magnitude.
Force is a name of a ...
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Did Paul Dirac believe in multiple universes?
Prominent physicist Paul Dirac proposed a hypothesis that said that constants and laws of physics would evolve with time into different constants and laws of nature.
This hypothesis was used by ...
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98 views
Feynman's statement about the importance of basic science
I remember reading in the line that Feynman saying if the best technicians were tasked to build a radio they would make longer and thicker cables and transfer message but it took a physicist to ...
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Did Werner Heisenberg ever agree or propose the existence of some kind of multiverse?
I was watching a video (https://www.youtube.com/watch?v=muJYTeQlvC4) where the director of a videogame company speaks about one of its most successful games. This game is set in a floating city which ...
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426 views
Where did the false “equal transit-time” explanation of lift originate from?
It's supposedly a "widely circulated" false claim that wings generate lift because of their asymmetric shape, forcing air above to travel faster so that they meet up on the trailing edge at the same ...
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1answer
82 views
Reference for history of physics with description of mathematical models
I am interested in some reference text, for example, textbook that would describe going from old times (say, Greece) till modern times:
1) definitions of units and measurements
2) describing ...
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91 views
What did people mean by the term Force in earlier times?
Initially I used to believe that before Newton gave his Laws of Motion, people thought that Force was something that caused motion. It was Newton who first said that Force is something that causes ...
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57 views
Did Wheeler ever propose the existence of a multiverse containing parallel simultaneous universes?
It is known that the physicist John Archibald Wheeler proposed the existence of a multiverse in the form of a set of cycles of Big Bangs and Big Crunches (Cyclic/Oscillatory Multiverse Model).
But I ...
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1answer
123 views
Did physicist David Bohm ever propose the existence of a multiverse?
Did physicist David Bohm ever propose the existence of any kind of multiverse?
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102 views
Does Heliocentrism predate Copernicus?
I have seen this mentioned on the interwebs a few times. people have mentioned that some Greek thinkers and Islamic astronomers came up with heliocentrism before Copernicus and that Copernicus copied ...
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How did Gibbs discover Gibbs entropy?
I have read and I think that I agree with the idea that if we have to choose probability distribution for an unknown system then it is a good idea to choose a distribution that has the least bias.
I ...
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1answer
108 views
What was this experiment tainted by the observer effect?
I once heard a cautionary tale about the dangers of the observer-expectancy effect. It was at least presented as a true example from the history of science, but I'm having trouble identifying the ...
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Who discovered Maxwell-Faraday equation, $\nabla\times E=-\frac{\partial B}{\partial t}$? Was it Maxwell or Neumann?
I have been trying to find out who discovered Maxwell-Faraday equation, $\nabla\times E=-\frac{\partial B}{\partial t}$. Was it Maxwell himself, or was it Franz Ernst Neumann who derived it?
The ...
