for questions about design, process, data, or analysis of experiments and observations.

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1answer
183 views

Examples to illustrate temperature dependant radiation by examples of temperature to color relation

I'm looking for a set of examples to illustrate the relation of temperature and color of "glowing" bodies. It should allow to build an intuitive understanding of this relation, so it's not about ...
1
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1answer
87 views

Alpha scattering, observations and conclusions

For Rutherford's alpha scattering experiment where he fired alpha particles at a thin sheet of metal to determine the size of the nucleus, please can someone give me the direct link between his ...
1
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1answer
488 views

Numerical aperture of a lens

Using a laser setup, I was asked to determine the aperture of a given lens and then use some geometrical arguments and compare the theoretical value from the manufacturer and the experimental value. ...
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3answers
528 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?
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1answer
57 views

Is there experimental evidence of time order inversion for spacelike events?

The title sums up the question. Given two events separated by a spacelike interval, say one takes place after the other in an inertial frame, then by a suitable boost we may invert the time order of ...
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2answers
124 views

Need an intermediate resistivity part/material

I need a part or material for a planned experiment (the experiment is similar to those described in my articles http://arxiv.org/abs/1208.0066 and http://arxiv.org/abs/1109.1626 ). The problem is that ...
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3answers
428 views

Reproducing the OPERA result

Are there any other facilities that would be capable of independantly verifying the opera result? In other words, a completely different source/detector for $\nu_{\mu}$ beams? Alternatively, there ...
9
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5answers
829 views

Is double-slit experiment dependent on rate at which electrons are fired at slit?

I am a mathematician and I am studying string theory. For this purpose I studied quantum theory. After reading Feynman's book in which he described the double-slit experiment (Young's experiment) I ...
7
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2answers
468 views

Fairly Broad Spectrum Light Source Options

I tried this sight before to find filtering options and got fantastic results, so let's try again! I am setting up an experiment that requires light of two different frequencies (445nm and 350nm). ...
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0answers
112 views

Large Hadron Collider 2015 upgrade, what may we discover?

I realise that the initial answer to my question that may come to mind is, "we don't know yet, obviously" But my question is hopefully not opinion based. For example, does this upgrade have a ...
6
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3answers
279 views

Hollow gold bar

A scammer got a hollow gold bar and fills it with a combination of lead and air, with the same average density as gold. What's the simplest way of discovering the fraud? I know that x-rays will see ...
5
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3answers
279 views

Has anyone tried Michelson-Morley in an accelerated frame?

After doing much more digging than I thought I had to do, I found out that the speed of light is NOT invariant in an accelerated reference frame. Has anyone done any experiments to confirm this? In ...
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4answers
4k views

Efficiencies of Coupling Light into a Fiber

I am in AMO Physics and work a lot with optics. I just wanted to get an idea of what coupling efficiencies one "should" get in a "reasonable time"* by coupling light into a fiber using different ...
5
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3answers
328 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 ...
5
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2answers
690 views

Experiments that measure the time a gas takes to reach equilibrium

If you take two ideal gases at different temperatures, and allow them to share energy through heat, they'll eventually reach a thermodynamic equilibrium state that has higher entropy than the ...
4
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1answer
236 views

Is this a photograph of an electron-positron annihilation? [closed]

With degrees in Mechanical and Electrical engineering but no advanced education in physics, I submit a query based on ellipsometric macro photography of TEMS supplied by FDA/NIH. In one TEM a ...
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5answers
597 views

Neutrino versus Anti-neutrino Detection

Is there a that detection method in use that can distinguish between a neutrino from its anti-neutrino?
3
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1answer
96 views

Is it possible that viscous flow has a higher lift to drag ratio than inviscid flow?

I have a code for airflow around an airfoil. When I compare viscous and non-viscous flow at the same Mach number for a cruise, viscous flow has a higher lift to drag ratio than non-viscous flow. Is it ...
3
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0answers
240 views

Where does an LED use energy other than emitting light?

I have a quantum formula describing what kind of photon should be emitted by an LED depending on its voltage. Of course the colour is depending on the material, but every type of LED also needs its ...
3
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1answer
82 views

Why do electrons in a superconductor lack energy to produce “massive” photons

My two questions are based around looking for a good, simple (if possible) explanation of the Cooper pair effect in superconductors. I follow the idea that, in intuitive terms, "a Cooper Pair" ...
3
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0answers
58 views

How could we find preons?

If I understand correctly, scientists were able to find strong evidence for the existence of quarks by using deep inelastic scattering. If quarks (hypothetically) are composed of preons, could we use ...
3
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1answer
4k views

What is Transverse Energy?

What is transverse energy? Why we use transverse total energy instead of energy and transverse momentum in place of Total momentum in the particle detectors?
3
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1answer
70 views

The synthesis of $^{254}\text{No}$

How is $^{254}\text{No}$ synthesised? Could you explain the reaction where it is preceded by $^{208}\text{Pb}(^{48}\text{Ca}, 2\text{n})$? References to articles are well enough—I was somehow unable ...
3
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2answers
859 views

Missing transverse energy, exact definition

This might seem basic, but it is a bit confusing. You hear about missing transverse energy a lot in SUSY searches due to the LSP which cannot be detected. Let's say I have the 4-vector for the LSP. ...
3
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1answer
944 views

Lab observation correct? As distance decreases, velocity increases, stderr decreases

The experiment goes like this: Allow a moving cart to move from the top of an incline plane ($x_0$) downwards. The time taken will be recorded by the picket fence (those things you see wired up). ...
3
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1answer
2k views

What is a Pseudoscalar particle?

Can someone explain to me what is a pseudoscalar particle? And how do experiments figure out that what they're dealing with is a scalar or pseudoscalar?
3
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1answer
254 views

Has the Higgs really been discovered at CERN?

Many news media round the world such as this http://www.scientificamerican.com/article.cfm?id=higgs-lhc have reported the possible discovery of the Higgs at CERN, to be announced at a conference on ...
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2answers
329 views

Pressures Necessary for Carbon Detonation

Carbon detonation is a characteristic event of Type 1a Supernova (EDIT: where an accreting white dwarf near the Chandrashankar limit of 1.4 solar masses explodes), an extremely important standard ...
3
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2answers
1k views

Physical vapor deposition of SiO2

Could you suggest any if it's possible to deposit a layer of SiO2 via PVD? Why doesn't it widely used? Is that correct that I need ~1600C in vacuum? Could you suggest any books/papers about that? ...
2
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2answers
266 views

Has the speed of gravity been measured experimentally? How? [duplicate]

In Newtonian physics, changes in gravity propagate instantly. In general and special relativity, gravity propagates at the speed of light, $c$. From reading answers to questions about gravity on this ...
2
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1answer
222 views

Signs of supersymmetry and thus dark matter at CERN

The Large Hadron Collider at CERN has just re-started after a two year pause and is now running at unprecedented levels of 6.5 TeV, with collisions that will release up to 13.5 TeV. With this increase ...
2
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1answer
134 views

Effect of small changes in atmospheric pressure on open cylinder piston

OK, I'm not a physics student, but I played one for 2 semesters 35 years ago... now I'm a competitive shooter working a theory about why small changes in atmospheric conditions cause our hyper-tuned ...
2
votes
1answer
274 views

Problem on Einstein - de Haas experiment

I am a Physics student (4th year) and I'm trying to study the Einstein - de Haas effect in laboratory. That is what I got: a suspended Iron cylinder with about 5 cm height and a radius of 0.8 cm is ...
2
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1answer
88 views

Can a nuclear bomb be used as the power source for a laser beam

My previous post "Using nuclear bombs to detect near earth orbit objects" asked about using nuclear devices to detect Earth directed asteroids and low albedo comets. Now I want to explore a method of ...
2
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1answer
107 views

Using nuclear bombs to detect near earth orbit objects

This question is based on an article written some years ago by A. C. Clarke, in which he attempted to solve two problems with one solution. His idea was to remove the Earth's stockpile of nuclear ...
2
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2answers
139 views

Is a Thomson's lamp physically realistic? [closed]

The Thomson's lamp is a philosophical puzzle that can be describe as follows: Consider a lamp with a toggle switch. Flicking the switch once turns the lamp on. Another flick will turn the lamp off. ...
2
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1answer
165 views

Cold welding of a metallic surface

I have heard of cold welding, it's said that it's only possible if the surface is very clean. Can cold welding be accomplished by shearing a metal object and then immediately touching the newly ...
2
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1answer
119 views

References on experimental realization of quantum one-dimensional infinite-well model

Can someone point me to the examples, or references, of experimental realization of the quantum one-dimensional infinite-well model? [EDIT] The motivation of this question is the curiosity - though ...
2
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0answers
29 views

Experiments proving/disproving extra dimensions [duplicate]

I have been recently reading quite a little about Kaluza Klein theories. I am still far from mastering this but I am curious if any experiment that may disprove or give hints of the existence of extra ...
2
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2answers
411 views

Oil drop experiment and quantization of charge

How to systematically show that the resulting charges in oil drop experiment are integers multiplied by $e$ in other word how to extract $e$ from the data?
2
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1answer
715 views

What is the speed of a neutral pion and how is it measured?

Alvager et al 1964 purportedly disproved Ritz's emitter theory in an experiment that generated neutral pions with a vellocity of $v =B.c$ where B is slightly smaller than one. How is the velocity of ...
2
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2answers
849 views

What does one need to learn to become a experimental particles physicist? [closed]

I know one needs E&M, classical, quantum, statmech at the graduate level. But what more does one need? Are quantum field theory, relativistic QM, advanced math needed? or just an advanced course ...
2
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1answer
149 views

Basic question about probability and measurements

Say I have a Galton box, i.e. a ball dropping on a row of solid bodies. Now I want to calculate the probability distribution of the movement of the ball based on the properties of the body (case A). ...
2
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1answer
102 views

Gravity waves detectors; are they all similar?

Are the gravity waves detectors all working on the same principle/effect ?
2
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2answers
233 views

Reference for solid state particle detector

I'm looking for a good introductory text on solid state devices for particle detection.
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0answers
70 views

Smallest measurable time increment

What is the smallest increment of time which can be measured using modern methods, and is not theoretical?
1
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1answer
470 views

Work function definition

As in this post How would I calculate the work function of a metal, the definition is given by "the minimum thermodynamic work (i.e. energy) needed to remove an electron from a solid to a point in the ...
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0answers
64 views

How to express Allan variance without neglecting clock drift

Allan variance, $\sigma^2[ \tau ]$, or its square root (Allan deviation, $\sigma[ \tau ]$) is a quantity (as function of parameter $\tau$) which is said to be a measure of (or related to) "stability ...
1
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1answer
119 views

Is this a photograph of Surface Plasmon Resonance?

Does this photograph depict surface plasmon resonance? PHOTO 1 - Ellipsometric style photograph produces blue-green and purple resonance waves from nanogold-like tubule. PHOTO 1 was cropped from ...
1
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1answer
82 views

Getting nonphysical results when solving for the index of refraction of a slab?

I'm trying to computationally find the refractive indices (real and imaginary) for a thin slab suspended in air (so the only indices to deal with are air and my material's). I've experimentally taken ...