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

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E&M and geometry - a historical perspective

Recently, I was contemplating the beautiful formulation of electromagnetism (specifically Maxwell's equations) in terms of differential forms: $$F=\mathrm{d} A\implies \mathrm{d}F=0 ...
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4answers
3k views

Historically, how do we know that Earth moves around Sun? And it does so in an elliptical orbit?

I know the basics of solar system like how Earth moves around Sun, and that we have so many planets, elliptical orbit of earth, and how far is sun from earth etc etc. I want to take a step back and ...
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0answers
31 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? ...
4
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1answer
181 views

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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3answers
421 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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2answers
436 views

How were noble gases discovered?

Noble gases are chemically neutral. They don't react with anything. So, how were they discovered?
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43 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 ...
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3answers
251 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?
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63 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 ...
4
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1answer
997 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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1answer
61 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 ...
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2answers
85 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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6answers
2k 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 ...
3
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1answer
275 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
53 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?
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92 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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0answers
87 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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44 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 ...
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1answer
372 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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3answers
767 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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2answers
2k views

Did Einstein know about Michelson-Morley experiment?

The second postulate of special relativity deals with constancy of light in inertial reference frames. But, how did Einstein came to this conclusion? Did he knew about the Michelson-Morley experiment? ...
5
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2answers
759 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 ?
6
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1answer
109 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 ...
4
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1answer
335 views

Origin of Laue equations?

The Bragg condition (by Bragg in 1913) can be derived by the Laue equations that is making use of the Miller indices and all the latice/crystal stuff (so basically it's bringing Bragg's law to more ...
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2answers
701 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 ...
4
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1answer
206 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?
4
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1answer
80 views

How bright was the AGN eruption at the center of the Milky Way ~2 Ma ago?

The black hole at the center of the Milky Way is believed to have erupted as an active galactic nucleus (AGN) approximately 2 million years ago, at which time it would have been visible to early ...
5
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4answers
604 views

Why isn't V. A. Fabricant given the credit for the discovery of the laser?

In another question here I asked for help in finding old Russian papers in physics and as an example I gave the founding papers on the laser by Basov and Prokhorov (from 1945 and 1954). In an answer ...
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1answer
75 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
144 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?
5
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2answers
392 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?
7
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1answer
203 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
458 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 ...
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0answers
62 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
111 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".
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4answers
412 views

How accurate are Mayan astronomical “ephemerides”?

Because of the hype surrounding the "end" of the Mayan calendar (along with the usual cultural relativism and Western guilt) it is nearly impossible to find an objective quantitative assessment of the ...
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0answers
265 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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2answers
141 views

Was the fractional model of quarks electric charge found before discovery of the $\Delta^{++}$?

From Wikipedia: Existence of the $\Delta^{++}$ , with its unusual +2 electric charge, was a crucial clue in the development of the quark model. the fractional model of Quarks electric charge was ...
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Why did Einstein get credit for formulating the theory of special relativity?

See The Principle of Relativity here: The Principles of Mathematical Physics. This was written by Poincaré in 1904, a year before Einstein published his theory of relativity. It appears from this and ...
6
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1answer
305 views

Earliest example of naturalness/fine-tuning arguments

The notion of naturalness is important in particle physics, especially supersymmetry. I was a little surprised, then, that the idea, or at least the name, is apparently only ~30 years old ('t Hooft, ...
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2answers
375 views

The notion called aether

I am trying to learn relativity theory and going through an introductory text on special relativity. I stumbled on the Michelson-Morley experiment. The book claims (accounts) that the result of this ...
6
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1answer
160 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 ...
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4answers
154 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 & ...
7
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287 views

Physics history book with some math

I am looking for a book explaining physics from, say, Galileo and Newton till now; the book should be written using some math, similarly to my physics books when I was at the university (Halliday ...
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2answers
103 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 ...
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345 views

On the theoretical aspects of the development of the first nuclear bombs

I've just read that 68 years ago Little Boy was dropped on Hiroshima, which made me wonder about some rather historical facts about the development of the first nuclear bombs; they seem to be several ...
0
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1answer
384 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
236 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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981 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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1answer
166 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 ...