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.

621 questions
Filter by
Sorted by
Tagged with
29 views

Why did nuclear physics predate semiconductor physics?

Why was nuclear physics able to be developed before semiconductor physics? It seems nuclear physics is based upon even more fundamental interactions than semiconductor physics but the atomic bomb was ...
5k views

Which physicists died very young or in a tragic way?

Inspired by Which mathematicians died very young or in a tragic way? , I wonder which physicists had similar fates. A quick search lead me to Heinrich Hertz who died from a malignant bone condition at ...
1k views

How did Stern or Gerlach, of Stern-Gerlach experiment, create individual silver atoms? How were they accelerated?

How, a century ago, could Stern and/or Gerlach KNOW that they had created single silver atoms? How were they moved, or accelerated?
38 views

How did Kirchhoff express his voltage law (KVL)

It is sometimes claimed that Kirchhoff's Voltage Law (KVL) is equivalent to the statement that a given electric field is conservative. When a given electric field is not conservative, it is claimed ...
53 views

Since when is it commonplace to use conservation of energy for dynamics problems?

If I throw an object, I can derive its trajectory using the forces acted on it. I can also do the same using conservation of energy. Since when is it commonplace to use conservation of energy for ...
154 views

What was the decisive argument against Le Sage's theory of gravity?

Le Sage's theory described gravity by means of corpuscules, small particles pervading space that hit masses all around. Between two masses a shadow comes about. None of them are present there. Masses ...
102 views

In Newton's cannon image, where do the shapes drawn into the sphere come from?

I find quite interesting the choice for the shapes drawn into the sphere that resembles continents. Was this choice arbitrary or do we know if there is some justification behind it?
7k views

Has there been an equivalent in physics to Ramanujan in maths?

Ramanujan's story is a well known story of the Indian young man who turned out to be a mathematical genius without a scholarly education. He was "discovered" by the mathematician Hardy at ...
180 views

How come that the "heroes" in physics are gone?

I'm not sure if this question can be answered objectively but I still ask. Once upon a time there were people like Galileo, Newton, Einstein, Feynman, Curie, Tesla, Dirac, Schrödinger, maybe Chopra, ...
69 views

On the origin of "sandwiches" in quantum mechanics

The term "sandwich" and the verb "to sandwich" appear pretty common but informally in quantum mechanics. Generally when describing some kind of inner product of the form: \langle ...
246 views

Why is periodic motion always represented as a sine function

Why was periodic motion started to be represented as a sine function at the beginning? Is it because it is perhaps the simplest periodic function? Is there certainly any reason behind this ...
100 views

Was Einstein's "Maschinchen" a predecessor of the photomultiplier tube?

Einstein once got involved in true experimental physics. That is, he designed his little machine (Maschinchen, in German, a word that makes me laugh; Einstein's Maschinchen...) to detect small ...
41 views

How was the first calculation of the g-factor done?

Dirac said the magnetic g-factor (a measure of the electron's wiggling in a magnetic field) is exactly 2. Quantum field theory introduced a g-factor that diverged a bit from 2. It needs an increasing ...
114 views

Earliest numeric value for helium D3 line

In late 1868, Norman Lockyer discovered the existence of the D3 emission line of helium in the solar spectrum. What was the earliest published example of a numeric value for the wavelength of this ...
77 views

What was the attitude towards atoms around the turn of the nineteenth century?

Einstein invented, on his own, a statistical mechanics, presupposing the existence of atoms. I can't imagine he was unaware of the shortly-before-invented statistical approach by Boltzmann and others, ...
351 views

Whatever happened to quaternions?

Quaternions were made up by Hamilton. They are an extension of complex numbers. It is said that he first introduced "3d tertions". He was thinking what the relation between i and j had to be ...
47 views

Where there scientists before Einstein who viewed space(time) as being elastic?

Einstein was the first who saw spacetime as a mallable substance to be malled with mass. As far as I know there were no people who suggested such a view of spacetime before him. But I could be wrong. ...
70 views

I read: Suddenly – boink! -an apple hits him on the head. “Aha!” he shouts, or perhaps, “Eureka!” In a flash he understands that the very same force that brought the apple crashing toward the ground ...
182 views

Why didn't the phase space formulation of Quantum Mechanics get the upper hand?

At university I learned quantum mechanics in or position or momentum variables. Later (in fact on this site), I learned about the phase space formulation in which both are used at the same time. The ...
73 views

Was Becquerel's discovery of radioactivity inspired by his father?

Becquerel was awarded the Nobel prize for his discovery of radioactivity. He was researching phosphoresence and decided one day to place the stuff he used in a drawer to keep it out of the sun. He put ...
4k views

What are examples of serendipity in the history of the sciences and math?

Cosmic microwave background radiation was discovered after Penzias & Wilson couldn't get rid of the noise generated by their horn. In fact, the noise was their discovery. The strings in string ...
58 views

Is there any literature or articles which expand more on Einstein's thoughts about Dostoyevsky's novels?

It is a well known fact that he admired Dostoyevsky even more than scientists. I'm looking for things like, Einstein's opinions about his religious discourse? What did he think of his bold statements ...
38 views

Did proponents of classical and statistical thermodynamics get along well with each other?

Proponents of classical thermodynamics believed the subject matter to be continuous, while the statistical thermodynamics proponents' subject matter was made up of atoms and variations of collectives ...
112 views

What does the Fourier transform have to do with heat?

For example the current version of the Fourier analysis article on Wikipedia says the study is: […] named after Joseph Fourier, who showed that representing a function as a sum of trigonometric ...
33 views

How did Mach's view on spacetime differ from Einstein's?

We can read in Wikipedia: Mach's principle, in cosmology, hypothesis that the inertial forces experienced by a body in nonuniform motion are determined by the quantity and distribution of matter in ...
63 views

What inspired the use of the term "gauge" in gauge theories?

Gauge theories in physics are theories that introduce extra fields, the mediating fields, after the non-mediated fields are gauged. Now to gauge something means that you set some reference point from ...
20 views

What can be said about Galileo's tower experiment? Did it take place? [duplicate]

In Wikipedia we can read that Galileo didn't actually performed his tower experiment: According to the story, Galileo discovered through this experiment that the objects fell with the same ...
53 views

Did aesthetics play a role in the construction of the Standard Model?

The Standard Model is a sophisticated mathematical framework to capture the behavior of elementary particles. It is a dream castle which is built on loose sand and every change in its construction or ...
82 views

Before the advent of the quark model, was there evidence that the hadrons were composite structures?

When the quark model wasn' t there yet, was there evidence that hadrons are composite structures? In hindsight of course yes. But at the time back then, were there signs? Maybe not noticed, but which ...
78 views

When was the concept of “Power” defined?

I know the Watt, as a unit of measuring power was defined somewhere in early 1900's. But who was the first physicist to consider "work over time"? Perhaps Newton? Problem with searching ...
109 views

Soviet atomic bomb development — advantage of knowing it could be done, was this ever said by any Soviet scientist?

I have heard it said that even if Fuchs had not provided details which must have been invaluable — just knowing, for example, that implosion and explosive lenses were employed without any further ...
201 views

Why did the Copenhagen interpretation of quantum mechanics got the upperhand?

The Copenhagen interpretation of quantum mechanics is nowadays the interpretation that prevails over other interpretations (or theories). Basically, it states that all processes in Nature are ...
38 views

Why can't it be said that Lorentz invented Special Relativity? [duplicate]

It is well known that Lorenz found the transformations of space and time to account for the observations made by Michelson and Morley. Before their experiments, an absolute aether was supposed to ...
51 views

First occurrence of the Langevin function in scientific literature

The Langevin function $\mathcal{L}(x) = \mathrm{coth}(x) - \frac{1}{x}$ is named after the French physicist Paul Langevin (1872-1946). The Wikipedia article on the Brillouin and Langevin functions ...
1k views

Who first proposed the theory of tidal locking?

I'm interested in the history of the concept of tidal locking but haven't been able to find any articles presenting a timeline of its development. I'm hoping to have a look at the first published ...
172 views

Best history of Maxwell and his equations

I've done my B.S. in Electrical Engineering as well as mathematics but I'd like to get a proper, or complete history of Maxwell and the history of his derivation of the equations and the newness of ...
79 views

Who first defined velocity and acceleration?

I'm asking who was the first to use and define velocity and acceleration in the modern, now standard way, with velocity being the first derivative of position and acceleration being the second ...
92 views

Did anyone ever propose a hypercomplex numbers system with more than one anisotropic axis?

The real number axis is asymmetric against zero: for instance, multiplication of two negative or two positive numbers will produce a positive number, a square root of a negative number is not real, ...
52 views

Was Kants theory of space and time inspired by that of colour?

Kants theory of space, time and causality is that they are the very forms of experience and ground all the other phenomena that we can experience. He called them the forms of sensibility. Kant studied ...
85 views

Is there any evidence that Einstein knew of Cliffords speculation on the nature of gravity and electromagnetism?

Around 1870, William Clifford published a short note in The Proceedings of the Cambridge Philosophical Society describing all forces as an aspect of the curvature of space. This is the basis of ...
184 views

A technical and historical introduction to quantum mechanics

I am curious to understand the history of QM. In particular, how did the physicists conclude that observables can be treated as operators, or the use of complex state spaces, or that Eigenvalues of ...
91 views

How is it possible that Pierre and Marie Curie's daughter Ève was so healthy?

I know that problems caused by radiation are pretty much random and unexpected at low levels of exposition but this randomness begins to be more probable when the exposition grows and this makes me ...
172 views

Who named Black Hole?

A black hole is a compact region of spacetime where gravity is so strong that nothing, even light, can escape from its event horizon, and, interestingly, Einstein didn't accept this viewpoint. Now, I'...
115 views

History of rotational / rigid body mechanics

In teaching introductory mechanics classes, I like to give my students a much-abridged sketch of some history of mechanics, starting with Aristotle and ending with Galileo and Newton. Most of the ...
26 views

History of experimental verification of the identity of voltaic and static electricity and references

What where the crucial experiments which showed the identity of voltaic and static electricity? How did the experiments work in detail and what are the original references for it? In "A History ...
51 views

How did the concept of work being the dot product of force and displacement come into existence?

Well this is really a silly question. However I am curious to know about this topic. Concept of each of the quantities discussed in physics have come into existence based on some basic human thoughts. ...
31 views

In which year the notion of star death started?

In which year, does the fact: every star will ultimately die came in to existence?
61 views

When was "Faraday's Law of Induction" first expressed in a quantified form?

An often used definition of "Faraday's Law of Induction" goes something like this (found in Wikipedia) The electromotive force around a closed path is equal to the negative of the time rate ...