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

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George Green's definition of Green's function

This is a curious question about the way George Green could have defined his Green's function. All the definitions I see have only Dirac-delta $\delta(x−x′)$ function as their source on the RHS. But ...
6
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1answer
297 views

History of the names “Feynman-gauge” & “Landau-gauge”. How arised & how settled?

Warning: Students, stay away from antiquities. The aim to learn is to survive. Hi. Today the nomenclatures Feynman gauge and Landau gauge seem established, but could you explain the history? It's ...
4
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3answers
121 views

Special relativity and imaginary coefficient of the time coordinate

I read somewhere that part of Minkowski's inspiration for his formulation of Minkowski space was Poincare's observation that time could be understood as a fourth spatial dimension with an imaginary ...
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0answers
41 views

Newton and the change of mass with time [duplicate]

I always thought that $force$ is $mass * acceleration$. Well, that's what I learnt at school a while back. Now, I have been enlightened that force is in fact the rate of change of momentum. What ...
6
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1answer
78 views

Is there is a specific original source where the “quantum operator ordering issue” is stated?

During my research, when the quantum operator ordering ambiguity is mentioned is deemed usually in the likes of "the well-known problem of ordering in quantum mechanics". However, could anybody point ...
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0answers
34 views

Difference between action-at-a-distance and a field according to Maxwell?

My question is more on a historical note that involves Maxwell’s equations. Besides the information that I have obtained from textbooks, I am mainly getting it from History of Maxwell's Equations and ...
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3answers
168 views

Didn't anybody see an apple falling before Isaac Newton? [closed]

We all know that Isaac Newton developed the gravitational theory (as is often told) when an apple fell on his head. But my question is, didn't anyone before him notice it?
4
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1answer
140 views

Newton's original proof of gravitation for non-point-mass objects

Suppose we have two bodies, one very large (Earth), and one very small (a cannon ball). If the cannon ball is some distance away from the Earth, to find out the force produced on the cannot ball, we ...
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3answers
705 views

The path integral and Feynman diagrams

This question is somewhat of a historical one, but it also contains some physics. I am curious to find how exactly the concept of Feynman diagrams arose (I assume from Feynman's path integral)? The ...
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1answer
40 views

Predicting Faraday's law, Changing Fields

Are there other equations that we can predict Faraday's law from? I know that each of Maxwell's equations are 'fundamental', but I feel like Gauss's law and Ampere's Law are very "nice", and for some ...
3
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1answer
124 views

Velocity distribution in ion source (electron bombardment) for Bainbridge mass spectrometer

Consider the following schematics of a Bainbridge mass spectrometer (Source: ...
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0answers
48 views

How was physics taught in the past? [closed]

Were there physics teaching aids used in the past? Or did professors just basically follow the textbook the students read? In other words: How was physics was taught in the past?
6
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5answers
379 views

Infinities in Newtons law of gravity (for point particles)

Newtons law of gravity for two particles of mass $m_1$ and $m_2$ is: $G\frac{m_1.m_2}{r^2}$. Supposing that the particles are point particles then gravitional attraction will bring them closer ...
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2answers
57 views

Origin of the word Permittivity

Who coined the word "permittivity"? It appears that first usage was in 1887. Please cite your source.
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0answers
49 views

History of Physics books [closed]

I would like some book reference regarding the history of physics. I'm a civil engineering student, and I want to have some basics on the type of developments regarding my field of specialization ...
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6answers
1k views

Which experiment gave scientists reason to believe nuclear fission/fusion produced energy?

Every piece of knowledge in science has a beginning lying in someone's experiment. I would like to know which experiment gave scientists the reason to believe nuclear fission/fusion existed and was ...
2
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0answers
59 views

Dingle vs. Bondi: Twin Paradox Debate on BBC radio?

Herbert Dingle and H. Bondi debated the twin paradox on BBC radio before 1971. Does anyone have a link to the audio of this debate? thanks
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0answers
41 views

Any photon colliders in the past?

People have been thinking about a photon-photon collider (see this and this) as an add-on or to supplement the ILC, the next generation linear collider. My question is, have there been any ...
5
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3answers
422 views

Why didn't we replace our SI units with a better system? [closed]

Intro It seems to me that the SI units we use today are nothing but the result of a historical 'coincidence'. I recently began researching about natural (absolute) systems of units, which are ...
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1answer
154 views

Definition of metre

We know that 1 meter is the distance travelled by light in vacuum within a time interval of 1/299,792,458 second. My question is why we didn't take a simpler number like 1/300,000.000 or why not just ...
4
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1answer
172 views

Did Maxwell invent the math to describe the ideas of electromagnetism?

Did he invent surface and line integrals, or did they already exist when he formulated his equations. If they did, already exist, how did they come about in pure math?
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0answers
83 views

Were Maxwell's equations first formulated by McCullough?

Some years ago, I heard a talk about a an Irish or Scottish physicist named McCullough who had formulated Maxwell's equations several years before Maxwell. This fellow was recognized for his work, ...
5
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2answers
280 views

Alpha particle deflection by 180 degree in Rutherford's gold foil experiment

Did some of the aplha particles back trace their path after hitting the gold foil ? (Turn by 180 degrees.) If so, how were they detected ?
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0answers
30 views

Helmholtz's “Ueber die Bewegungsgleichungen der Elektricität für ruhende leitende Körper” in English?

Is Helmholtz's 1870 paper "Ueber die Bewegungsgleichungen der Elektricität für ruhende leitende Körper," Journal für die reine und angewandte Mathematik 72:57-129 translated into English anywhere? ...
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1answer
64 views

Why so much geometry in principia and others

I was recently reading 'On the the shoulders of giants' by stephen hawking and looked at many physics(mechanics) problems solved by Copernicus,Newton etc. why is there so much of geometry used by ...
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2answers
65 views

Could Charles-Augustin de Coulomb measure the charge in Coulombs?

Did Charles-Augustin de Coulomb know: Coulomb's constant Coulomb (as a unit) if not then what was the first time it was measured?
4
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2answers
323 views

Where does this term “shell” with prefix “on-/off-” come from?

Is there some historical reasons or is there a specific reason behind it? This question is connected to: Why on-shell vs. off-shell matters?
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1answer
154 views

Lorentz's Amsterdam Proceedings 12:986 (1904) paper?

I am looking for this paper by H. A. Lorentz: Amsterdam Proceedings 12 (1904) 986. (See also Arch. Neér. Sciences Exactes et Naturelles 25 (1882) 363.) I have also seen it cited using the ...
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1answer
121 views

Why does milli- mean 1/1000 [closed]

I suppose this is also an English question, but I'll ask it here first. Why does the milli- prefix mean 1/1000 when it sounds so much like million? According to the internet, this dates back to the ...
6
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1answer
73 views

How did Lyman discover his series?

How did Lyman discover his series in hydrogen atom? How did he know that the final energy level is the first level and not the second or the third or etc.? Or how did the other scientists know which ...
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0answers
60 views

What is the event in history where iterated functions became appropriate for modeling physics?

Wolfram as well as Aldrovandi and Freitas 1 maintain that iterated functions $f^t(x)$ are a valid alternative to PDEs for modelling physics. Instead of just citing 1, I want to be able to cite the ...
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1answer
73 views

How big was the first transistor?

The first working point-contact transistor made in 1947 by Bell Labs. I'm looking for specific dimensions, all I've been able to find is "Fits in the palm of your hand".
3
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1answer
240 views

Why have $n$, $\ell$, $m_\ell$, $m_s$ been picked as quantum number symbols $\mathbf{\text{in this order}}$?

I’m learning about electron configurations and don’t quite understand why $n$, $\ell$, $m_\ell$, $m_s$ have been picked as symbols for the quantum numbers. As far as I understand it, the principal ...
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0answers
154 views

How did the scientific community receive Einstein's theories when he published them? [closed]

By now, we have had multiple indications through observations and experiments that Einstein's theories on general and special relativity are correct. We recently had our second observation of ...
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0answers
96 views

Lennard-Jones induced pseudo-molecules

It can be shown that the Lennard-Jones potential - which describes the interaction between particles in non-ideal gases - gives rise to pseudo-molecules: after a triple "collision" of three ...
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2answers
448 views

Why isn't general relativity the obvious thing to try after special relativity?

To preface my question, I ask this as a mathematics student, so I don't have a very good sense of how physicists think. Here is the historical context I'm imagining (in particular taking into account ...
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0answers
60 views

Actions at a distance vs. contact interaction

The ancestors could not imagine an action at a distance (in German: "Fernwirkung"). Today physicists don't take serious its opposite anymore (in German: "Kontaktwechselwirkung"). So my first question ...
3
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1answer
175 views

Electrons skip randomly around their orbits

I read where the electron (as well as a few other particles) skips around in its orbit randomly rather than move around the orbit smoothly. This effect has been repeatedly observed in the laboratory ...
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5answers
707 views

What was Feynman's “much better way of presenting the electrodynamics” — which did **not** appear in the Feynman lectures?

Does anyone know what Feynman was referring to in this interview which appears at the beginning of The Feynman Tips on Physics? Note that he is referring to something that did not appear in the ...
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4answers
106 views

Newtonian physics vs Special relativity - what is the most “relative”?

This might be a question purely of words and the meaning of them but isn't Newtonian physics more "relative" than Einstein's Special relativity? Newtonian physics predicts that laws of momentum & ...
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0answers
21 views

Why does Leyden jars have a high breakdown voltage

I have often heared, that Leyden jars are used because they have a high breakdown voltage. For that reason the are used for example in Whimshurst machines. But what is the physical reason that they ...
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2answers
70 views

How do you know which atoms are in a specific piece of matter?

If you have a piece of matter in front of you, how can you know of which atoms it consists? And starting from nothing, how can I discover all the elements (or just a lot of them) of the periodic ...
5
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1answer
102 views

How did Kepler arrive at his laws?

How did Kepler arrive at his laws? If one already knows the distances to the planets (and the eccentricity of the orbits etc.) it is understandable how one might proceed to establish the second and ...
0
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1answer
171 views

Electrostatics-Coulomb's Law

Coulomb's Law is an experimental result $$F=k_e\frac{q_1 q_2}{d}.$$ How did or What did Coulomb do to verify this law as it is applicable for point charges at rest and in reality charges won't be at ...
5
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1answer
146 views

How Hamilton's Principle was found?

Hamilton's principle states that the actual path a particle follows from points $p_1$ and $p_2$ in the configuration space between times $t_1$ and $t_2$ is such that the integral $$S = ...
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1answer
157 views

Who popularized $E=mc^2$?

When asking a layman for a mathematical or physical equation you will almost certainly get the answer "$E$ equals $m$ $c$ squared". In fact, $E=mc^2$ is something like a symbol of physics in popular ...
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4answers
685 views

Hilbert, Gödel, and “God equations” - a 19th century lesson for 21st century physicists?

It seems there are a lot of respected physicists appearing on pop-sci programs (discovery channel, science channel, etc.) these days spreading the gospel of "we can know, we must know." Three ...
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25 views

Origin of the names for the decay chains

Is there any reason for the names of the decay chains? As shown in this chart (larger version here): only the Thorium chain starts on an isotope of the element it takes its name from, and it can ...
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0answers
33 views

James Joule's Conservation of Energy

Is there a manifest or documentation of the original Conservation of Energy as stated by James Joule word for word? Edit 1.1: I found Joule's Memoir on google, skimming through to find any conclusive ...
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1answer
146 views

Are there correct physical predictions made only from thought experiments other than in General Relativity? [closed]

When Einstein started to think about gravitation, he completely created a new theory that no experiment supported. He based his reasoning, as he explained it later, on small thought experiments ...