Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [history]

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

1
vote
0answers
29 views

Non-differential total exact element notation question [duplicate]

I have questions regarding the notation in thermodynamics books of "d bar" (instead of delta) for the non-differential total exact elements like for work $\delta W$. When did it appear? Where are ...
-2
votes
0answers
37 views

How did people in pre-Ampere period deduce this? [closed]

How did people before Ampere (eg-Coulomb) who used magnetic-pole model, know that only two surfaces (north and south poles) of a bar magnet exerts and experiences force while the rest of the surfaces ...
0
votes
2answers
89 views

How did Newton know that there is force between two mass? [duplicate]

Newton's Law of Gravitation states: $$F=\frac{GM_1M_2}{r^2}$$ How did he recognize that there is a force between two masses?
0
votes
1answer
89 views

How did scientists before Coulomb ensured this fundamental property of magnets? [closed]

Firstly, please note that I am talking about the period BEFORE electricity and magnetism were unified. So I am NOT seeking for answers based on Ampere atomic current model of magnets. I have read the ...
3
votes
0answers
69 views

How did we first discover oxygen exists as $\rm O_2$ and not just $\rm O$?

How did we first discover oxygen exists as $\rm O_2$ and not just $\rm O$ ? (similarly hydrogen as $\rm H_2$ and not $\rm H$) I vaguely remember knowing a story about how the chemical formula of ...
0
votes
0answers
26 views

What is the origin of the product notation for vectors in Joos & Freeman? German or American?

In Theoretical Physics, 3rd Ed., By: Georg Joos, Ira M. Freeman the operation commonly called the cross product is denoted using square brackets. That is: given vectors $\mathbf{A}$ and $\mathbf{B}$, ...
8
votes
4answers
2k views

Why did Michelson believe the aether was moving?

If a wave moves east towards California the wave-motion would be slower north-south. Is this the kind of way they were thinking about the aether as medium for light, of what was later, by Lorentz, ...
-1
votes
1answer
57 views

Is it a coincidence that 1 liter water has a mass of 1 kg while 1 cubic meter has 1000 liters of water?

1 Cubic Meter has 1000 liters of liquid. Meter is a unit independent of Kilogram. Then why does 1 liter of water at max density (4°C) have a mass of 1 Kg?Is it a mere coincidence?
3
votes
1answer
38 views

Enrico Fermi and neutron interactions

Enrico Fermi and his team were studying neutron absorption and the subsequent gamma ray emissions, in the 1930’s era. They calculated, based on the size of the nucleus and the speed of the neutron, ...
16
votes
2answers
1k views

What's the significance of the nickel crystal in the Davisson and Germer experiment?

Davisson and Germer, in 1927, conducted an successful experiment to prove the existence of matter waves. What's the meaning of using the nickel crystal? I mean, why didn't they use any other materials?...
4
votes
2answers
86 views

Where did the concept of field come from?

What made scientists start to think about what was previously 'forces-exerted-by' (Newtonian view) to fields (e.g. electric fields and magnetic fields)?
6
votes
0answers
50 views

Why is equipartition law called a theorem too, in some books? [closed]

In some books, the equipartition law is called a theorem. But a law is an observation, and cannot be proved. On the other hand, a theorem is something established using earlier assertions. So what ...
1
vote
1answer
59 views

A sound argument for existence of Americas, along al-Biruni's lines?

In 11-th century, Al-Biruni computed circumference of Earth with high accuracy, and mapped all then-known terrain. He then argued that the unknown part of the globe cannot be all ocean, predicting ...
0
votes
0answers
21 views

What experiment confirmed the presence of the electric force between two charged particles?

What experiment confirmed the presence of the electric force between two charged particles physically placed at some distance from each other? In that experiment, were the two particles were ...
0
votes
2answers
60 views

When were each of our “ultimate fate of the universe” theories widely accepted?

I'm trying to piece together a sort of timeline for the prevailing "ultimate fate of the universe" theories, specifically from the dawn of the twentieth century through today. I know the Big Bang ...
0
votes
1answer
41 views

Quantization and wave-particle dualism of light

I'm studying atomic spectras and got puzzled about light-quantization. I'll expose my effort to understand it so far. Blackbody radiation Around the year $1900$ Planck explained blackbody radiation ...
1
vote
1answer
27 views

Historic method to produce cophasal illumination before lasers?

In a bunch of old papers, written before lasers, the authors often refer to illumination with the same characteristics as a laser: single spatial mode and temporally lockstep. For example in: On the ...
-2
votes
1answer
83 views

How to prove Kepler's 3rd law? [duplicate]

How to prove Kepler's 3rd law? How did Kepler proved it? Is it possible to prove the third law without applying Newton's universal law of gravitation?
2
votes
1answer
60 views

Where does the proportionality symbol originate from? [closed]

Does anyone know where the proportionality symbol $ \propto $ originates from (historically)? As someone who is eager to learn about the history of physics & mathematics, this question popped ...
3
votes
0answers
54 views

Feynman lectures: historical updates?

I'm reading the Feynman Lectures and wonder if there is an overview over the historical Statements such as 12–6 Nuclear forces [...] no one has ever calculated the force between two nuclei Is ...
1
vote
1answer
46 views

Apparition of scale invariance

When did "scale invariance" started to be seen as an important concept in the theory of phase transition? Phase transition and critical points started to be investigated in earnest in the middle of ...
1
vote
1answer
199 views

How did Planck arrive at the idea that energy is quantized? [duplicate]

Max Planck, arguably the leading theoretical Physicist of his day, apparently used of experimental data to formulate his equation for black body radiation, which was a major step in the birth of ...
2
votes
1answer
43 views

Original Derivations of Euler Equations or Navier-Stokes Equations

I've seen the derivations for both viscous and inviscid momentum balance in fluid flow in courses, but I'm curious as to where the original derivation for the equations now referred to Euler equations ...
5
votes
1answer
67 views

Why did physicists in the 1950s and 1960s suspect the weak and EM interactions were at some level the same interaction?

Around the 1950s and 1960s there was a lot of work in particle physics motivated by two issues - finding a workable quantum field model for the weak interaction, and finding a model that unified the ...
6
votes
4answers
235 views

How was the Ancient Greek theory of vision disproved?

Ancient Greeks and ancient Indians believed that the way in which vision works is that a beam goes out of the eye and hits an object. Whereas now we know that light reflects off the objects and then ...
1
vote
0answers
41 views

Who first noticed that the radiation pressure formula $p=U/c$ agreed with $E=pc$ from special relativity?

Does anyone know behind stories? As it seems that $p=\frac Uc$ was known before the advent of special theory of relativity, (Halliday, Resnick, Walker says that Maxwell derived this.) when $E=pc$ was ...
0
votes
1answer
45 views

Proposal of the Virasoro modes and algebra

Hi I am wondering what the first published paper on Virasoro modes was? And what about Virasoro algebra?
16
votes
3answers
5k views

How did we 'discover' dark matter? [closed]

I'm an astrophysics student and I've been researching this topic and there is one point that keeps eluding me. How did the scientific community realize that there had to be dark matter in the ...
0
votes
1answer
61 views

Has experimental search for free fractional electric charge elementary particles been put to an end?

Since Quantum Chromo-Dynamics theory has been supposed to explain quarks confinement, has experimental search for free fractional electric charge elementary particles been put to an end? If not, what ...
0
votes
1answer
57 views

Why do we use $Q$ for heat?

Of course letters are of few interest if something at all. But when reading some notes the question just appeared: Why do we use $Q$ for heat? Googling it shows many links but none of them seems ...
0
votes
0answers
76 views

Has any of Cantor's ideas survived in modern physics?

Cantor's reason for devising set theory, i.e., for his "painstaking and hardly rewarding business of investigating point sets", was its application to reality. "I refer you to what I have found in ...
1
vote
0answers
36 views

Have there been any patented physical models or computational algorithms? [closed]

There was a recent question (linked below) on the Law SE about the potential to patent algorithms. It appears there is a lot of gray area in the subject. Of course natural laws cannot be subject to ...
2
votes
1answer
79 views

What was Planck's motivation for the frequency dependence in $E=nh\nu$?

Many accounts of the history of quantum physics explain how Planck resorted to quantizing energy in an "act of desperation" while attempting to solve blackbody radiation, only to discover by surprise ...
1
vote
1answer
108 views

How could Eratosthenes know the angle of the sun's rays in Alexandria?

The measurement of the Earth's radius by Eratosthenes is famously the first of its kind. As I understand, it relies on the fact that the sun's rays are parallel. At noon, the light falls directly ...
1
vote
0answers
38 views

Textbook on the history of General Relativity?

I have studied General Relativity from various textbooks already, and the subject fascinated me immensely. I was wandering if there is any textbook that deals with the chronological "steps" that ...
2
votes
1answer
106 views

Why was the fraction 1/31,556,925.9747, in the 1956-1968 definition of the second in terms of ephemeris time, chosen?

The recent question Why are leap seconds needed so often? pulled up some interesting details about the definition of the second, and I'd like to have some of them confirmed explicitly. I'm ...
2
votes
1answer
40 views

Corrections to plasmons theory. (History of Plasmons)

Is it true that around 70's there was a huge change in theory that describes plasmons (SPP, to be precise)? Recently I stumbled upon an interesting (but old) paper about plasmons. Authors of that ...
1
vote
0answers
57 views

What was the implication of Quaternions in modern (21th) physics and usage in electrodynamics in 19th century? [closed]

I'm doing a study about number theory in physics where I put some focus into the usage of Quaternions. See: https://en.wikipedia.org/wiki/Quaternion#Use_in_physics Right now I conclude that the ...
0
votes
1answer
70 views

Enrico Fermi's photo and the wrong fine structure constant

This photo about the Italian supreme physicist Enrico Fermi is rather famous. Yet nobody ever questioned, as far as I know, the wrongness of the fine structure constant written on it. So I ...
0
votes
1answer
78 views

What is the physical basis of Born's interpretations?

Did anyone has any idea how Born came up with the probabilistic interpretation of quantum mechanics. It is by all means very bizarre. And then it leads to the idea of copenhagen interpretation. Also ...
0
votes
1answer
31 views

Clarification in deduction of Ampere's original experiments

I am reading Ampere's original work. Therein he describes an experiment called "equilibrium of opposite current experiment". In this experiment, two immobile straight wires with current flowing in ...
1
vote
0answers
38 views

Scattering amplitude of strong interactions, Euler's Beta function and strings

On reading the answer by Ron Maimon to the "Gabriele Veneziano, strong nuclear force and beta-function" I became puzzled: Why the fact of the Beta function implication leads to the idea of a string ...
1
vote
1answer
74 views

Pauli's first paper about the spin

Wikipedia states, that the spin degree of freedom was first formulated by Pauli in 1924: In 1924 Wolfgang Pauli introduced what he called a "two-valued quantum degree of freedom" associated with ...
0
votes
3answers
103 views

Why did Newton introduced inertial and gravitational mass in the first place?

This might be a silly question but I really don't understand what was the reason for which Newton ended up differentiating mass into inertial and gravitational. Why did he think it necessary to do so? ...
1
vote
1answer
92 views

Has the definition of “statistical mechanics” changed from its original meaning?

I guess this never registered with me when I read the Feynman Lectures on Physics in the past. But I have wondered, from time to time, what distinguishes statistical mechanics from, say, kinetic ...
0
votes
0answers
10 views

How would you replicate the measurements and calculations originally used by Delambre, Mechain et al to establish the length of the meter?

Meter was then defined as one ten-millionth of the distance between the equator and the North Pole. In practice, the researchers measured the distance between dunkerque and Barcelona, "then reported ...
1
vote
1answer
71 views

Origin of physics laws [closed]

I am a math student and I have been self studying physics lately. I am going to take a course on electromagnetism this year, so I searched for books that are mathematically rigorous on that topic. And ...
5
votes
1answer
203 views

How did Heisenberg come up with the Canonical Commutation relation ($\hat X \hat P-\hat P\hat X=i\hbar$)?

All answers to questions like this dodge the question by saying it's a postulate of Matrix Mechanics, so let me rephrase it. Instead of how to derive the CCR, how does it follow from Heisenberg's ...
0
votes
4answers
123 views

Why do physicists multiply the time component of a space-time vector by $c$ to define the conventional four-vector?

When I think of a space-time vector, I think of it as a geometrical object in Minkowski space with the physical properties of magnitude and orientation wrt other space-time vectors. I can use four ...
1
vote
0answers
89 views

Where did Paul Gerber go wrong in arriving at the same equation as Einstein in explaining the Mercury anomaly?

We know that Einstein admitted that Paul Gerber's 1898 formula explaining the anomaly of Mercury's perihelion was the same as his own. Reportedly Gerber had made a mistake somewhere, so - even though ...