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

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How did Lord Rayleigh derive/determine the phase function for his scattering model?

I've been researching the question for quite some time, as I understand it the phase function is actually an approximation due to the particle-wave duality inherent in participating media such as the ...
2
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4answers
531 views

Video documentaries about physics? [closed]

Does anyone know about good video documentaries about physics, possibly on YouTube? I've seen a couple of them about string theory, but I could not find many others.
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5answers
14k views

How was Avogadro's number first determined?

I read on Wikipedia how the numerical value of Avogadro's number can be found by doing an experiment, provided you have the numerical value of Faraday's constant; but it seems to me that Faraday's ...
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1answer
297 views

How did Newton find the relationship between force, mass and acceleration? [duplicate]

I have been told always that $F$ is directly proportional to acceleration. My question is that for finding such a relationship there should be source that produces desired force and in which the ...
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1answer
15k views

What did Marie Curie do for atomic theory?

There appears to be a distinct lack of agreement in the physics community on what exactly Marie Curie did for atomic theory. Many journals state that Curie was responsible for shifting scientific ...
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2answers
8k views

Is there a good Modern English translation of Newton's “Philosophiæ Naturalis Principia Mathematica” available for free viewing or download?

I have found several nice versions available for purchase, but all of the free ones are either Latin, old English, or pixellated. I searched google and was only able to locate the free ones linked to ...
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0answers
63 views

What is the origin of the kinetic theory of temperature?

Count Rumford's experiments with canon barrels are often cited here, but the kinetic theory certainly precedes them. Another candidate is Daniel Bernoulli, who, in his 1738 book Hydrodynamica showed ...
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1answer
189 views

Example for bias in experiments due to “social pressure”

I remember the example for the bias in experiments: A famous physicist got a wrong result for a constant. Due to his fame, the published results of other experimenters only slowly reached the correct ...
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3answers
134 views

When was the earliest understanding that the stars were similar to the Sun?

When did astronomers realise that the stars were similar to the Sun? I'm not asking for when this was established, but when also the hypothesis was first proposed.
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1answer
626 views

How did Eratosthenes know the suns rays are parallel?

Eratosthenes famously observed that the suns rays were perpendicular to the ground in one location, yet non-perpendicular to the ground at a location some miles to the north. On the assumption that ...
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1answer
317 views

Why are lab Magnets painted red?

Wy are lab magnets painted red in color? I tried searching everywhere but couldn't get a satisfactory answer.
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0answers
132 views

Victorian cosmology after the second law of thermodynamics but before relativity?

In the 19th century, most astronomers adopted an island universe model, in which our galaxy was the only object in an infinite space. They didn't know that the "spiral nebulae" were other galaxies. ...
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2answers
257 views

Historical reason behind using $ν$ instead of $f$ to stand for frequency in the equation $E=hν$?

Normally, we use the letter $f$ to stand for frequency in equations. $$T = 1/f$$ $$v = \lambda f$$ $$Φ +E_k = h f$$ So I'm curious as why the letter $ν$ (nu) is used to represent frequency in the ...
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1answer
60 views

Availability of the Larkin's paper: Application of superconductivity theory methods to the problem of the masses of elementary particles (1961)

Discussing with colleagues (mostly condensed matter ones), we were astonished there is no mention about the work by Larkin in the announcement of the Nobel Prize committee this year. The title of the ...
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1answer
178 views

Tycho's stellar parallax measurements

How, exactly, did Tycho Brahe do his measurements of (no) stellar parallax? All the descriptions of parallax that I have been able to find seem to talk about the change in position of a nearby star ...
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1answer
1k views

Why is the partition function called ''partition function''?

The partition function plays a central role in statistical mechanics. But why is it called ''partition function''?
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2answers
590 views

Electromagnetic Momentum

My book says : The fact that electromagnetic radiation of energy carried momentum was known from classical theory and from the experiments of Nichols and Hull in 1903. This relation is also consistent ...
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1answer
122 views

How Was the Speed of Light Discovered? [closed]

The title pretty much says everything; I just want to know how the speed of light was discovered.
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2answers
1k views

How do formulas get figured out?

Many of the formulas I learn in school are derived from more basic formulas — as long you your math is right and assuming the more basic formulas you used are correct, you are bound to get to a ...
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3answers
291 views

How do people work out the trajectories of planets and stars just by looking at them?

I've been thinking about how astronomers can look at bright dots in the sky and deduce a whole bunch of things from their movements. I'm particularly interested in how people like Kepler and Galileo, ...
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2answers
168 views

When did we learn that stars die?

As we all know, the stars we see in the night sky might already be dead. I was wondering though, when was this fact or conclusion commonly established? Today, most people (let's assume with an above ...
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0answers
73 views

How would Einstein's later years have been different with modern computers? [closed]

This is a historical question partly, and maybe too broad for this site, but would require some familiarity with modern physics research practice so hopefully appropriate here. Einstein's later ...
5
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2answers
184 views

How do people historically have come to use the Yang-Mills theory in physics?

There are many books, in which Yang-Mills theory is introduced "just like that". But I didn't find some book with set of historical arguments, which had led people to using it in quantum field theory. ...
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3answers
812 views

Accidental, unplanned breakthroughs in physics [closed]

There is possibly some idioms or saying like this, ``If you try too hard for something, you will never get it. If you do not aim for something, it may fall on you accidentally, not as you originally ...
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2answers
327 views

Complex Versus Real Wave Velocities in Quantum Mechanics

There's a fantastic quote in Schrodinger's second 1926 paper1 that apparently provides some motivation for the discrete energy levels (I think) that I'm having trouble interpreting: I would not ...
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1answer
267 views

Why is it easier to measure the specific charge of an electron over the charge?

The electron was discovered in 1897 and the $e/m$ ratio was measured at that time ,but the charge $e$ itself was measured in 1911. Why was it not possible to measure it earlier?
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2answers
258 views

Examples of “pseudo quantum effects” in history of physics

Are there any examples in the history of physics where a phenomenon was considered by the physics community to be not explainable by classical physics and needed a quantum explanation whereas some ...
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2answers
149 views

Questions about gravitational and inertial mass [duplicate]

What differences between gravitational mass and inertial mass? I cannot tell the differences between them. In history, which concept was put forward firstly? Are there some experiments to prove ...
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1answer
186 views

Developement of modern condensed matter physics [closed]

Do you know any resources describing historical aspects of developments of modern condensed matter physics (many body physics etc)? Thanks.
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1answer
332 views

Why was the conversion factor of the metric unit bar chosen the way it was?

The unit bar for pressure is clearly a metric unit, but its order of magnitude is a bit strange. In the centimeter–gram–second system of units we have: ...
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3answers
823 views

Historical background of wave function collapse

I wonder what were the main experiments that led people to develop the concept of wave function collapse? (I think I am correct in including the Born Rule within the general umbrella of the collapse ...
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1answer
152 views

Why nuclear tests move under ground since 1964?

According to this database: http://www.ga.gov.au/oracle/nuclear-explosion.jsp Since 1962, 99% of USA Nuclear tests was underground. Since 1964, 99% of Soviet Nuclear tests was underground. Is it ...
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1answer
125 views

If transported back to the 18th century could you solve the Longitude Problem without an accurate clock?

Seeing an interesting BBC article today at http://www.bbc.co.uk/news/science-environment-23514521 about the Longitude Problem, I wondered if it could have been solved, in a way practical at the time ...
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1answer
171 views

What cause scientists to study Black Body Radiation?

After spending hours understanding what exactly Black Body radiation and Ultraviolet catastrophe is, I cannot help myself asking what was the reason that make scientists such as Wilhelm Wien and Max ...
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1answer
2k views

What happened to David John Candlin?

This is an ultra-soft question about relatively recent history. While reading some of Mandelstam's papers, I noticed that he cites David John Candlin consistenly whenever he does anything with ...
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2answers
359 views

Who formulated the idea of mass?

This may sound like a dumb question, but googling didn't seem to help. Mostly because I'm having a hard time formulating the question, and anything with "mass" seems to direct me to "Mass Effect". I ...
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2answers
538 views

Why were the fathers of quantum mechanics so sure radioactive decay was indeterministic?

The classic example of an indeterministic system is a radioactive isotope, e.g. the one that kills Schrödinger's cat. I get there are arguments against hidden variables in quantum mechanics, but how ...
37
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2answers
15k views

Lev Landau's “Theoretical Minimum”

The great russian physicist Lev Landau developed a famous entry exam to test his students. This "Theoretical Minimum" contained everything he considered elementary for a young theoretical physicist. ...
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2answers
304 views

Biggest experimental validations of postulates of Quantum Mechanics

What are some experimental results that validate postulates of Quantum mechanics completely beyond any doubt ? Since there are alternate theories being used by various physicists to describe the same ...
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2answers
539 views

How many stars did people think there were in the 11th century (or thereabouts)?

I hope this isn't too off-topic. Someone showed me a reference to a French, 11th century biblical commentator who implied that there were over 600,000 stars. This got me thinking, how many stars did ...
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3answers
3k views
2
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1answer
128 views

Since when the term 'mass' is being used in physics?

I was wondering who used the term 'mass' in physics and in what context? The Online Etymology Dictionary says it is in use since 1704. According to the Wiki article the year is contemporary to the ...
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1answer
2k views

Who (and Why) started the “electrons are negative, protons are positive” convention? [duplicate]

For some reason everyone labels electrons using a minus sign and protons using a positive sign, even though the opposite seems more intuitive: Who started the convention that electrons should be ...
3
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1answer
186 views

Where did the concept of energy come from?

Energy seems to me to be a very abstract thing, and while it clearly works out very nicely, I don't understand how anyone would have thought to come up with it. Where does the concept of energy find ...
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1answer
211 views

History of Newtons law of gravitation

I have some questions about the history of Newtons law of universal gravitation. Did Newton discover his three laws of motion before he discovered the universal law of gravitation? I know two ...
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2answers
59 views

Did physical models of galaxies come before they were actually observed?

Black holes were first predicted by astrophysics, then observed. Was the existence of galaxies first predicted by astrophysics, or first observed by astronomers?
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2answers
422 views

Discovery of $E=hf$?

How was the equation $E=hf$ discovered? Was the proportional expression between energy and frequency of light $E\propto f$ discovered only by experiment? Or is there some logical(theoretical) senses ...
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3answers
2k views

Origin of Ladder Operator methods

Ladder operators are found in various contexts (such as calculating the spectra of the harmonic oscillator and angular momentum) in almost all introductory Quantum Mechanics textbooks. And every book ...
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0answers
116 views

Historical aspect of wave theory of light

Huygens thought light as a wave. Wave is a propagation of physical disturbance. We now know that light is electromagnetic field. Electric and magnetic field fluctuates here. What Huygens really ...
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6answers
7k views

Who discovered momentum?

I read some text about momentum in Wikipedia, but I didn't find any information who discovered momentum. Is the momentum a philosophic principle?