Skip to main content
12 votes
Accepted

Was it suspected that the speed of electricity was equal to the speed of light?

For a long time it was not only believed but even ascertained that electric signals moved not just as fast but faster than light, even "instantaneously". The original experiments involving ...
Conifold's user avatar
  • 77k
10 votes
Accepted

What was Pierre-Simon Laplace's reaction to Young's double slit experiment?

Short answer: Pierre-Simon Laplace was skeptic of Thomas Young, but he had to go silent after the works of Augustin-Jean Fresnel and François Arago. Long answer Laplace was the reference for the ...
Mauricio's user avatar
  • 3,927
10 votes
Accepted

How did people explain color before the splitting of white light was discovered?

On a common sense view color requires no "explanation": the world is full of objects, they have qualities (properties) — size, shape, weight, texture, etc. — color is one of them. This was ...
Conifold's user avatar
  • 77k
8 votes

How Einstein got the first idea for special relativity?

Einstein was reading Maxwell. Axiom a) follows from Maxwell's electromagnetic theory of light. Axiom b) is stated imprecisely in your message. The actual axiom is that you cannot detect the absolute ...
Alexandre Eremenko's user avatar
6 votes
Accepted

Does Fermat's Principle of Least Time imply that he believed light moved at a finite speed?

Yes, Fermat believed that the speed of light was finite, initially in reaction to the muddle created by Descartes, who wanted to have it both ways, the speed being infinite, yet different in different ...
Conifold's user avatar
  • 77k
6 votes
Accepted

Ideas about the speed of light between Galileo and Romer?

I do not think it is a virtue to make unsupported assertions just because we happen to believe them now. Following available evidence does not makes one not smart or disappointing, that is how science ...
Conifold's user avatar
  • 77k
6 votes
Accepted

When was single-slit diffraction first observed?

Fraunhofer is credited not with discovering the single slit diffraction, but with explaining the far-field diffraction pattern from a single slit. Fresnel explained the near-field pattern before him, ...
Conifold's user avatar
  • 77k
6 votes

How did people explain color before the splitting of white light was discovered?

Aristotle' s explanation of color was as follows: "Firstly, white and black may be juxtaposed in such a way that by the minuteness of of the division of its parts each is invisible while their product ...
Margaret Friedland's user avatar
6 votes
Accepted

Why is the Michelson–Morley experiment so much more famous than its rivals?

Because it was the most accurate. The use of interferometers to measure length deviations eliminated the concern that the ether wind didn't register because the instruments were too blunt, or because ...
Conifold's user avatar
  • 77k
5 votes

How Einstein got the first idea for special relativity?

Einstein himself wrote, in a letter of 14 December 1915 to Moritz Schlick, that he was primarily inspired by David Hume and Ernst Mach. According to the paper How Hume and Mach Helped Einstein Find ...
nwr's user avatar
  • 6,869
5 votes
Accepted

Would they have known you can't go faster than light in 1790

Would they have known you can't go faster than light in 1790? No, they did not know. In 1783, John Michell considered what would happen to light if an object were too massive. He considered that ...
Mauricio's user avatar
  • 3,927
5 votes
Accepted

What was Isaac Newton's contribution to optics?

Contribution of Newton to optics is enormous. He is considered a founding father of physical optics. I can only give some examples. His main discovery was that the sunlight can be dissolved into ...
Alexandre Eremenko's user avatar
4 votes
Accepted

What was the original reason physicists first believed that light must follow a geodesic?

It is the so-called Fermat Principle in geometric optics: light chooses the path which takes it least time to travel. Since the speed of light (in the given homogeneous medium) is constant, this must ...
Alexandre Eremenko's user avatar
3 votes
Accepted

Who wrote the equation $c=\lambda\nu$ for the first time?

Relations between the frequency and length of a string are known since Antiquity, but a more precise mathematical treatment would have to wait until the invention of calculus. The wave equation was ...
Mauricio's user avatar
  • 3,927
3 votes

Light propagated instantaneously rather than gradually

What Roemer was says is that the astronomer's predictions were based on an infinite speed of light, but this is not correct: The speed of light is finite and the extra time it takes light to cross ...
Mark Olson's user avatar
3 votes
Accepted

What was the reason Einstein included reflection from a moving mirror in his relativity paper?

Miller (1981) specifically addressed your question in Chapter 11 of this book: Albert Einstein's special theory of relativity. Emergence (1905) and early interpretation (1905–1911), Reading: Addison–...
Batiatus's user avatar
  • 496
2 votes
Accepted

How exactly did Hertz's experiments confirm Maxwell's theory?

This article on the Institute for Electrical and Electronics Engineers site gives a detailed account of the history involved. For those not wishing to read the entire article, I provide the relevant ...
nwr's user avatar
  • 6,869
2 votes
Accepted

How was light polarization interpreted when first discovered?

Short version: they either considered a wave in the aether (the aether being some mysterious medium that filled space allowing for only transverse waves) or corpuscules with additional degrees of ...
Mauricio's user avatar
  • 3,927
2 votes

Why did Maxwell predict radiation pressure?

According to Brian Clegg's biography of Maxwell the idea that light could exert pressure only came to Maxwell's attention shortly after the publication of his Treatise while "pulling at the ...
nwr's user avatar
  • 6,869
2 votes
Accepted

Reference request concerning an alleged Jewish contribution to the early theory of light refraction, and to the first geometry textbook in Europe

Possible sources : For Dioscorides, we have Moses Hamon that owned a famous Ms of De Materia Medica (later known as : Vienna Dioscurides) and sold it, through Ogier Ghiselin de Busbecq (a Flemish ...
Mauro ALLEGRANZA's user avatar
1 vote

"Tension" between Electromagnetism and Newton's laws

This is an extended comment on the answer of @Pentcho Valev. In his first paper on relativity Einstein does not mention the Micheson-Morley experiment. When asked later he said that this was not of ...
Alexandre Eremenko's user avatar
1 vote

Why was the question of the nature of light limited to the wave theory or the particle one ?

A possible simple answer is that experiments on light manifested only the wave aspect of light behaviour or the particle one. These two aspects were not compatible, in the sense that light behaved as ...
Federico Coda Zabetta's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible