4
votes
1answer
53 views

How did Fizeau make his famous speed-of-light experiment?

I heard once in a TED talk how Fizeau measured the speed of light in the 19th century. Here is the link https://www.youtube.com/watch?v=F8UFGu2M2gM You can read about it here in Wikipedia: ...
17
votes
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 ...
1
vote
0answers
40 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 ...
3
votes
1answer
150 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 ...
0
votes
1answer
126 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 ...
2
votes
2answers
110 views

Is Galilei's reasoning on free fall valid?

Galileo Galilei discovered by experiments that all bodies tend to fall with the same rapidity (I use it in an intuitive sense, you can replace it by 'acceleration' used in today's physics language), ...
2
votes
0answers
24 views

What were the immediate consequences Yang-Lee work on Weak Interaction?

I am studying the history of Modern Physics and Yang-Lee earned their Nobel the next year after the Cobalt experiments. I am familiar with the chronology, but am not clear what those findings meant to ...
-4
votes
1answer
68 views

Free 'fall' on an Inclined Plane

I guess we can say that two identical balls on the same inclined plane with different heigths reach the ground at the same time. So, who was the first one to observe it? ...
0
votes
1answer
165 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?
3
votes
2answers
128 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 ...
14
votes
3answers
628 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 ...
3
votes
2answers
334 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 ...
4
votes
2answers
868 views

First experiment which was used to prove existence of Electromagnetic waves

When I was in high school I heard from my physics teacher in the last year of high school when he was starting the chapter of electromagnetic waves that the first person who proved existence of ...
0
votes
2answers
604 views

What were the intention/conclusions for Michelson-Morley experiment?

Which of the following were the intentions of M&M? to disprove the existence of aether. to show that the aether has no effect on matter and energy and therefore is as good as non-existent. ...
4
votes
5answers
724 views

Regarding string theory: how to refute the argument “if it cannot be tested experimentally then it is not science”? [duplicate]

Possible Duplicate: What differs string theory from philosophy or religion? I find a lot of people disbelieve in string theory, saying that since it cannot be tested experimentally then it ...
1
vote
3answers
263 views

Quantum experiments in the pre-industrial era

Could an 18th century or earlier scientist have come across phenomena which require quantum theories to explain them, given the apparatus available at the time? I'll choose 1805 as the cut-off date, ...
15
votes
6answers
8k 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 ...
29
votes
11answers
11k views

How did Newton discover his second law?

I've always assumed/been told that Newton's 2nd law is an empirical law — it must be discovered by experiment. If this is the case, what experiments did Newton do to discover this? Is it related to ...