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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Who used spinors to describe spinning tops?
Spinors are well known in Quantum Mechanics and for many, are indicative of QM. However, I have read that they were also used to describe spinning tops. Who was this by and were they an important ...
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Why is Richard Feynman so often thought to be anti-Philosophy when he said this? [closed]
In the introduction to his The Meaning of it all, Richard Feynman said:
The ideas I wish to describe are old ideas. There is practically nothing that I am going to say tonight that could not have ...
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Did the knowledge of Wootz steel actually become 'lost'?
Wootz steel was manufactured in Southern India around two millennia ago. With some people saying as far back as 500 BCE, however, the actual physical evidence of such a steel is by 200 AD. The ...
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49 views
Do we know how Feynmans religious views changed throughout his life?
According to Feynman, there was a quota for Jews at American Universities and when he was accepted on a graduate programme - I think at Princeton - they were told "he's Jewish but he doesn't act ...
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Did Feynman ever consider Ancient Greek Science as being lost?
Richard Feynman wrote in the first book of his Lectures:
If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, ...
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Did Feynman ever consider, given what he said in his Lectures, that science began not just in the modern period?
Feynman famously described there to be Greek and Babylonian way of doing science; which suggests that he considered that science began before the Greeks. Did he ever flesh this out in an essay?
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47 views
How were wavelengths in the electromagnetic spectrum first found?
We now all “know” that visible light has a wavelength between about 380 nanometres and 700 nanometres, and that shorter wavelength are the domain of UV, X-rays, and gamma rays; and longer wavelengths ...
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2answers
103 views
How did the current physics curriculum came to be?
By far, looking at several curriculums of High School/First-Year Undergraduate physics. The curriculum always starts with Mechanics, moves into Electricity/Electromagnetism and ends with Modern ...
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1answer
55 views
When were white holes theorised?
It seems to me that once black holes were theorised then the obvious singularity at its centre - though only ratified after Hawking and Penrose's singularity theorems - one would have to ask where the ...
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42 views
Why do physicists call their Hilbert space of states simply the Hilbert space?
In mathematics it's well known that a Hilbert space is a simply a descriptive terminology. It doesn't say, what is ontologically under consideration. One can have Hilbert spaces of a great many things,...
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What prompted Bose's move to Dhaka University in 1921?
Satyendra Nath Bose who discovered boson statistics and is credited by Einstein for also discovering the Bose-Einstein condensate was born in Calcutta, was educated there at Presidency College and ...
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111 views
Names of the electromagnetic units in SI
The unit of charge is the Coulomb, named after Charles Augustin de Coulomb. This makes sense because Coulomb's law talks about the force between two charges.
But I have seen that the SI unit of ...
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388 views
Did C.S Peirce make any noteworthy contributions to physics or chemistry?
According to this article
Peirce was the first to experimentally tie a unit, the meter, to an
absolute standard, the wavelength of a spectral line
Did C.S Peirce make any other noteworthy ...
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1answer
89 views
What is the name of the “largest complete history” of physics?
Somewhere in the world is housed what is thought to be the largest complete history of physics. I recall it being of some ridiculous length, something like hundreds or thousands of volumes. I cannot, ...
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50 views
When were the SUVAT equations derived for the first time?
It's one of the first things learned in Physics.
However, what's the history behind deriving the SUVAT equations?
And, there were other equivalent equations used before SUVAT came into the curriculum?
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Were tricycles a direct (or indirect) inspiration for the invention of bicycles?
I was surprised to learn that the earliest verifiable bicycle was the draisine, invented in 1817 by Baron Karl Drasine in Germany and who patented it the following year. This is much later than I ...
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51 views
Is it true that Newton used the gedankenexperiment of a cannonball revolving around the earth to find the inverse square law of gravity?
I have often heared that Newton compared the centripetal acceleration of an (imaginary) cannonball revolving around the earth just above the surface with the centripetal acceleration of the moon and ...
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1answer
73 views
Were Feynman diagrams important for the creation of the electroweak theory?
Feynman diagrams representing the interactions of subatomic particles were introduced by Richard Feynman in 1948. The first published Feynman diagram appeared in Physical Review in 1949.
Did Feynman ...
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71 views
How did Galileo derive the law for a falling body without calculus?
I am asking how did Galileo Galilei derive the equation for height as a function of time, which we now write as $y=\frac{1}{2}gt^2$. We now know that the equation is the solution of Newton's second ...
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1answer
54 views
Have units in physics any link with the origins of type theory in logic?
It is well known that the theory of types, first introduced by Bertrand Russell in 1903 and developed with Whitehead in their Principia Mathematica (1910), was a way to deal with paradoxes in set ...
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78 views
The reason behind defining the direction of angular velocity towards the axis of rotation?
This is one of those questions which has confused a lot of students like me and I know similar questions have been asked on Physics Stack exchange but I literally want to know what was the reason ...
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1answer
99 views
Did physicists correct an error of mathematicians in counting twisted cubics in the quintic?
One problem in enumerative geometry consists in counting the number of rational curves of degree $d$ in the plane going through $n$ general points. If $n = 3d-1$, this number, denoted $N_d$, is finite ...
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Why did Galileo express himself in terms of ratios when describing laws of accelerated motion?
I opened the same question on Physics Stack Exchange, but it seems more suited for this site.
I've been reading about Galileo's experiment with inclined planes, and he ends up saying something along ...
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77 views
Who first defined pressure?
Before learning any topic, I always find the reason of "Why definitions are created for that particular topic?"
In fluid statistics, I encountered a term called "pressure".
But I ...
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1answer
72 views
In which article did the physicist Sheldon Glashow introduce his electroweak theory?
In which article did Glashow introduce (1961?) a unified description of the electromagnetic and weak interactions, i.e., the electroweak interaction that earned him the Nobel prize in physics?
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Quotation reference: “functions which can be evaluated under 1 sec are as good as analytically available”
I have a vague memory of a (possibly-apocryphal) quote by a physicist (I remember it as being Giorgio Parisi, which could be wrong), saying something to the effect of
"any function which can be ...
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223 views
What exactly was the Rutherford model of the atom?
I was recently doing research on the "Rutherford model" of the atom. I found that there seem to be three different accounts of Ernest Rutherford's theory circulating online:
Electrons move ...
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2answers
116 views
History behind the heat equation
Who was the first mathematician/physicist to derive the heat equation $u_t=\Delta u$ and when? Was it already known to explain most diffusion phenomena? How much time passed between the first ...
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3answers
191 views
What are some historical examples in physics of heuristic proofs of mathematical results?
In the proceedings of the XIth International Congress of Mathematical Physics Edward Witten wrote (p. 704)
[$\dots$] when a mathematical result is really relevant to a physics problem it often ...
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98 views
Einstein's handwritten manuscript on General Relativity
The book "The Road to Relativity" by Gutfreund and Renn annotates Einstein's original handwritten manuscript from 1916 - "The Foundation of the General Theory of Relativity." I can ...
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1answer
328 views
Why does Riazuddin not have a last name?
Riazuddin was a Pakistani theoretical physicist, his name looks a little bit different to me from others because he doesn't have a last name. There are some others Pakistani theoretical physicists ...
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1answer
557 views
How did J.J. Thomson learn that what he discovered was different than an atom or a molecule?
Wikipedia says he discovered that the electron was different than an atom or molecule. His line of reasoning is not shown. I additionally searched stack exchange and unless I missed it.....
I am lost ...
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Where exactly did George Brown publish the first paper about Turnstile antennas?
In its most basic form the Turnstile antenna is two half-wave dipole antennas that are perpendicular and driven 90 degrees out of phase. For a recent review see Crossed Dipole Antennas: A review (also ...
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114 views
Was de Broglie, the physicist who suggested matter behaves like waves, a prince? [closed]
Hi guys, I've been reading about the wave-particle duality of matter, and I came across this statement that said de Broglie was a prince. Is that true?
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Different versions of mass during early years of special relativity
My question is basically about four different versions of mass from the early years of special relativity when the concept of relativistic mass was acceptable. I'd appreciate it if you try to keep ...
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Was the wide use of mercury in experiments in the 19th century related to alchemy?
We know that Newton's hair samples showed high level of mercury and of course he used mercury like crazy in his alchemy experiments (as did many/all alchemists not just in the west but also China) and ...
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2answers
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Why did energy-momentum relationship have to wait until 1928 to be established?
This web page shows how to derive energy-momentum relationship, $E_{total}^2=p^{2}c^{2}+\left( mc^{2}\right) ^{2}$, given the following equations. Please note that some sources make a distinction ...
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What was Claudio Bunster's role in the Human Rights Commission in Chile?
Claudio Bunster, a Chilean physicist, was educated in the University of Chile and Princeton. He returned to Chile when the Pinochet dictatorship was at its height and, against all expectations, and ...
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Why isn't the history of mechanics dated from Archimedes time?
It's often said - and more often written - and perhaps, even more spoken of - that modern physics began with Galileo due to his application of mathematics to motion. This is the position taken by ...
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What was known about the properties of the nucleus before the Liquid drop model was proposed?
What was known about the properties of the nucleus (its shape, its density etc) and the nuclear forces before the Liquid drop model was proposed? I believe that some empirical knowledge must be out ...
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184 views
kinetic energy formula written as mv^2
I stumbled across the following quote and couldn't understand how one wouldn't use the factor of 1/2 without completely disrupting the work-energy principle. Though, informal, energy is defined as the ...
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100 views
Where did the contour integral sign appear for the first time?
A simple question: Where did the contour integral sign appear for the first time?
Wikipedia says that it was introduced by physicist Arnold Sommefield in 1917 ( Table of mathematical symbols by ...
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1answer
136 views
Is string theory today facing the same backlash that atomic theory faced during its inception?
I read in this Quanta article that although many critics say that it is far removed from nature, it has developed many powerful tools. Furthermore some don’t care if it’s a theory of everything and ...
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68 views
Some questions about radioactivity around 1900
All the questions are closely related to each other therefore, in my opinion, it wouldn't make much sense to ask them separately. I'm trying to find the answers in historical context. I appreciate ...
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70 views
Are “galvanic” and “voltaic” synonymous?
The OED defines galvanism (coined ~1792) as
Electricity developed by chemical action
and voltaic (coined ~1813) as
Used in producing electricity by chemical action after the method discovered by ...
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1answer
78 views
Why do we use $U$ for potential energy in classical mechanics?
I am unaware if someone has asked this before, but I am studying classical mechanics and I don’t know why do we use $U$ for potential energy. I have read that Rankine used it first, but I can’t find ...
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What are the stories of physicists's prediction of problems that future generation will be busy with/topics that revolutionize future of physics?
There are stories that famous physicists made predictions of a list of problems; problems that the future generation of physicists will be busy with or revolutionize the future of physics in the ...
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How did Millikan consider utilizing oil to help determine the charge of the electron?
Robert Millikan's oil drop experiment help to find the charge of electrons using oil. An x-ray was aimed at the oil drops to give them a charge, and the droplets were attracted to the negative plate. ...
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429 views
Who made the first derivation of the angle to maximise projectile range, which turned out to be wrong?
I remember hearing once that the first "proof" that the angle to maximise projectile range gave the correct answer, 45 degrees, but was later found that the proof was wrong. I can't remember ...
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Why are there so many German terms in the field of radiative transfer?
A lot of phenomena in radiative transfer are named after a person who studied them (Rayleigh scattering, Mie scattering, Bragg diffraction, Kikuchi lines, Tyndall effect,...). Others are designated by ...
