for questions about design, process, data, or analysis of experiments and observations.
2
votes
2answers
138 views
How the nucleon structure has been identified experimentally?
It is known that nucleons (proton, neutron) are composed of partons (quarks, etc.). How was this identified experimentally? In particular, how it has been identified that nucleons comprise of more ...
1
vote
1answer
265 views
Enlightening experimental physics books/resources
Most book recommendations I've seen are usually geared toward theoretical understanding. It would be nice to know at least one or two classic experimental physics books.
e.g. from Carl Brannen's ...
10
votes
5answers
937 views
The square in the Newton's law of universal gravitation is really a square?
When I was in the university (in the late 90s, circa 1995) I was told there had been research investigating the $2$ (the square of distance) in the Newton's law of universal gravitation.
...
4
votes
1answer
183 views
Pendulum: Deduce proportionality from experiment
I know, very easy for all of you, but I'm a beginner in physics ... ;)
I have to work with the mathematical pendulum. After some experiments (changing mass, chaning pendulum's length etc.), I could ...
1
vote
5answers
169 views
Normal distribution of x, xdot
I have some real measurements from a process and I happened to look at the mutual distribution of (x(t), xdot(t)). I found that they seem to follow 2d normal distribution around (mu, 0). See image, ...
1
vote
3answers
272 views
What is the reason behind specific values for charge of electrons, protons?
Why do things like protons and neutrons have specific values. Also speed of light is a speed in which even if you go towards it, the speed does not vary. But why does light have to travel at speed?
5
votes
7answers
876 views
What is the proof that the universal constants ($G$, $\hbar$, $\ldots$) are really constant in time and space?
Cavendish measured the gravitation constant $G$, but actually he measured that constant on the Earth. What’s the proof that the value of the gravitation constant if measured on Neptune would remain ...
1
vote
1answer
527 views
Oil drop experiment--How was the result so accurate?
I remember while learning about Millikan's oil drop experiment and being pretty skeptical about the setup. I know that there is a lot of controversy regarding manipulation of data, but the fact is; he ...
2
votes
2answers
210 views
Correlation Functions, Symmetries and Measurements
Is there a book that goes deep into correlation functions? What I'm interested in a book/article that explains in the detail the relation of the correlation functions with symmetries and how one can ...
4
votes
3answers
181 views
Could we prove that neutrinos have mass by measuring their gravitational signature?
It is now said that neutrinos have mass. If an object has mass then it also emits a gravitational field. I appreciate the neutrinos mass is predicted to be small, but as there are so many produced ...
2
votes
1answer
198 views
Experimental proof of gravitational redshift of light
Has the gravitational red shift been proven for electromagnetic waves only or also for a single photon?
2
votes
1answer
121 views
How was Be-8's Half-Life of 7E-17 Second Determined?
Radionuclides occur with half-lives in a vast range of over 37 magnitudes as listed in this site. In question 7584, Lubos Motl explained how Gyr half-lives were determined. This method doesn't appear ...
1
vote
3answers
208 views
Intensity distribution of a LED light source
The light source: 190 high power LEDs in NIR.
I have the datasheet of the LED.
I want to make a graph showing the spatial distribution, and to measure the intensity of the beam on the whole field of ...
5
votes
2answers
106 views
What is it called when a fluid will “jump” to grab onto an object that comes very close?
I'm doing an experiment where I bring a probe very close to a well full of fluid and then very slowly lower it to obtain some force deformation values. The material behaves very much like a fluid and ...
4
votes
2answers
250 views
Accuracy of various optical instruments
I understand that this may not be the type of question allowed here, but I'm not sure. Feel free to close this if you feel that it shouldn't be here
I'm planning on carrying out a certain set of ...
26
votes
0answers
504 views
What is the upper-limit on intrinsic heating due to dark matter?
Cold dark matter is thought to fill our galactic neighborhood with a density $\rho$ of about 0.3 GeV/cm${}^3$ and with a velocity $v$ of roughly 200 to 300 km/s. (The velocity dispersion is much ...
8
votes
1answer
332 views
Could LEP II have discovered a 125GeV Higgs?
LEP II eliminated the Higgs up to 114.5GeV. If it had been run for longer could it have detected a Higgs at 125GeV?
I Googled for this without any luck, though I did find a comment that LEP II topped ...
3
votes
3answers
157 views
If a measured value is oscillating so fast between two numbers, what does the detector read?
There is a picture usually depicted in introductory quantum mechanics about how the probability pattern appears in the classical limit, that the oscillation is too fast and that it cannot be resolved ...
0
votes
1answer
328 views
Examples of immiscible or wall-climbing liquids
I am very interested in the physics of immiscible fluids. I would like to ask you if you know any source or list of experiments done by others, with two or three liquids. I am interested in the final ...
2
votes
1answer
123 views
Consistently oscillating micron sized particles in a liquid
I have an idea that would involve the measurement of an oscillating substance whilst the substance is immersed in a liquid. However, the method that I would use to measure the frequency of these ...
2
votes
2answers
302 views
Testing conservation laws experimentally
How conservation laws are tested experimentally independently from each other? what do I mean by that question?
It seems that to test one conservation law experimentally, such as conservation of ...
0
votes
0answers
38 views
Why has the ether been disregarded as a valid medium through which light can propagate? [duplicate]
Possible Duplicate:
Ether theory acceptance
Although the Einstein's theory of relativity seemed to make the concept of an ether obsolete, did it necessarily invalidate it? Are there any ...
2
votes
1answer
222 views
How does physics scattering experiments relate to real life? And what does the scientist gain from such experiments?
How does physics scattering experiments relate to real life? And what does the scientist gain from such experiments? I am having a hard time figuring the answer out. Please help.
1
vote
2answers
181 views
Where to find cross section data for e- + p -> p + e-?
Where to find cross section data for e- + p -> p + e-?
PDG's cross section data listing does not include it.
1
vote
0answers
99 views
What narrow-linewidth laser system runs at 2100nm with 1W of power?
For an experiment at our university we need a laser that runs at about 2.1 μm (about 20nm higher or lower would be fine too.
We have found a multitude of lasers that achieve this (typically Thulium- ...
3
votes
1answer
583 views
How can Kaluza-Klein particles be told apart from winding modes at the LHC?
I`ve already asked this in the comments below this article ...
3
votes
2answers
2k views
What is p_T? (transverse momentum?)
I've been looking at a few papers in experimental physics (from the ATLAS collaboration, for example) and I've often run across phrases such as "high-p_T electron." What exactly is p_T? Is it simply ...
3
votes
2answers
246 views
Have experiments ever suggested two different values to the same divergent series?
I believe to have understood that some physical experiments suggest finite values to divergent series (please correct me if I'm wrong, my understanding of these matters is limited).
I heard, for ...
5
votes
3answers
338 views
Why echos cannot be heard inside the room?
If I go camping and shout anywhere, in the forest , or on a cliff, I usually hear the echo of my voice.
Why when I shout in my room I do not hear any echos?
3
votes
1answer
259 views
What are the advantages of the ILC over the LHC?
USA Today has an article on Japan's interest as the site for the $10 billion future International Linear Collider. This accelerator will utilize electron/positron collisions (like CERN's former LEP ...
0
votes
2answers
191 views
Effect of coarse vacuum on consumer electronics?
What is the long-term effects of storing materials in consumer electronics in a vacuum? Ie, plastics, electronic circuits and optical glasses?
4
votes
0answers
103 views
Is there precision experimental evidence for Furry's theorem — that only even degree VEVs are non-zero?
Is there precision experimental evidence for or contradicting Furry's theorem -- that only even degree VEVs are non-zero, specifically for the EM field?
2
votes
1answer
78 views
Gravity waves detectors; are they all similar?
Are the gravity waves detectors all working on the same
principle/effect ?
3
votes
2answers
189 views
Why is the observed signal the convolution of the true signal with the instrumental function?
Imagine we are observing a star. The light coming from a star enters an optical instrument that will give us some observed data, such as the spectrum of light say.
What we observe is not the true ...
1
vote
1answer
156 views
Light filter for an experiment
I'm looking for a filter that lets through as many wavelengths as possible (from 200 to 5000 nm).
Is that even possible?
16
votes
1answer
1k views
How did they measure the speed of light observing Jupiter's moons, centuries ago?
I am interested in the pratical method and I like to discover
if it is cheap enough to be done as an experiment in a high school.
Thank you.
4
votes
2answers
193 views
What do “local” and “global” mean when talking about standard deviations in experimental particle physics?
I found the following sentence:
The excess is most compatible with a SM Higgs hypothesis in the vicinity
of 124 GeV and below, but the statistical significance (2.6σ local and 1.9σ
global after ...
1
vote
1answer
192 views
Light vs neutrino speed comparison in a real tunnel
Given current accuracy of the techniques, is it possible to identify a real, existing tunnel (stright I think) to make the direct comparison of the speed of light and of neutrinos?
The hypotetical ...
5
votes
2answers
140 views
How should one combine the uncertainties from the ATLAS and CMS measurements?
First off, a naive theorist question - How are measurements divided between the different detectors at the LHC? I would imagine that for a short run time, say, the CMS detector is active and all the ...
3
votes
1answer
462 views
What's the Standard Model width of a 125 GeV Higgs?
There's a fairly broad mass spread in the new results out of Atlas and CMS. I'm curious how this fits with the expected SM width.
0
votes
0answers
75 views
What are the difficulties and their potential solutions regarding the creation of a functional lightsaber? [closed]
We all know there's serious pitfalls on the road to creating a functional lightsaber such as the ones in Star Wars.
Let's assume it is possible, what would be the technical difficulties and their ...
2
votes
0answers
193 views
Levitation rotation speed involving laser acceleration, pyrolytic graphite and a vacuum
The experment would involve a small NIB magnet levitating between or on the diamagnetic material pyrolytic graphite, unlike other forms of levitation this doesn't require power to run such as ...
2
votes
2answers
677 views
Testing the temperature of an open flame
How, and what device do you need, to obtain the exact temperature of an open flame? For the purpose of this question, you wanted to maintain 375 degrees. You can control the flame, but have no idea ...
6
votes
2answers
452 views
Quantum Computing, Qubit Creation/Entanglement
I am currently a high school student researching quantum computing. I was referred to this site by Google and a friend. Currently I am researching the qubit part of quantum computing. My question is ...
5
votes
1answer
196 views
What is the smallest distance between a decaying vertex and an interaction point a detector can measure?
A short lived particle is created at the interaction point and then decaying a distance $d$ away, in some detector. My question is what is the smallest distance $d$ that can be measured ...
1
vote
0answers
135 views
What are the most seminal Soviet papers in experimental physics? [closed]
Soviet physicists have made well-known contributions to many areas of theoretical physics, but I've heard much less about their experimental work. What are the most seminal experimental papers that ...
1
vote
1answer
153 views
Spin Echo Experiment [closed]
I'm doing an spin echo experiment for different dilutions of Glycerol as an undergraduate physics lab experiment. At the end of my experiment I will need to extend it and do some initiatives! I have a ...
3
votes
1answer
532 views
Escape velocity of a rocket standing on Ganymede (Moon of Jupiter)
I want to calculate the escape velocity of a rocket, standing on the surface of Ganymede (moon of Jupiter) and trying to leave Ganymede.
My thinking was, the kinetic energy $E_{\text{KIN}}$ must be ...
0
votes
1answer
233 views
Where to find experimental/theoretical value of (charge) radius of particles?
Where to find experimental/theoretical value of (charge) radius of particles like proton, neutron, $pi^+$, etc. ?
1
vote
0answers
74 views
How to set the electric potential on a certain boundary to a certain value experimentally?
In electrostatic boundary value problems, usually the potential is set to some function or a constant on a certain boundary. It is never taught or told in textbooks how such assignment might be ...
