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

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0
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1answer
35 views

Wind resistance [closed]

You have a metal plate/sign (max weight $5\, \text{kg}$) $1200\, \text{mm}$ long and $400\, \text{mm}$ high pivot/hinge at its base. A windspeed of $90 - 100\, \text{km/h}$ is applied to one face of ...
6
votes
1answer
69 views

Is there a tool to measure the chemical potential of a system?

Let's suppose I put you inside a room filled with a gas. You can measure its pressure directly with a barometer. You can measure its temperature directly with a thermometer. Can you measure its ...
4
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0answers
75 views

How can one confirm creation of magnetic graphene?

Recently my high school physics teacher contacted me looking for an expert to ask about this situation. I am paraphrasing his correspondence below: I just had a a student accidentally create ...
0
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0answers
47 views

Obtaining an angular distribution from the Klein-Nishina formula

I'm having trouble on how one might obtain an angular distribution from the Klein-Nishina formula for compton scattering of polarised photons, more specifically on how this report is obtaining it. ...
0
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0answers
19 views

Circularly Magnetized Neodymium Torus With Minimum Flux Leakage

I'd like to conduct some experiments related to Aharonov-Bohm. In particular, I'd like to investigate the irrotational vector potential gradient. A simple geometry for this is the major axis of a ...
0
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0answers
13 views

magnetic field due to current carrying coils

In the Helmholtz configuration, why is the magnetic field between the two coils uniform (I know the mathematical expression)? Can anyone please explain this physically? When the distance between the ...
1
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0answers
89 views

How would you build a small cyclotron (particle accelerator)? [closed]

I heard Michio Kaku built a small cyclotron when he was young. I bought a book called "Principles of charged particle acceleration" where it explains the basic functioning of particle accelerators. ...
0
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2answers
26 views

i have a thin film deposited on a glass substrate, when i measure trasmittance for it ,should i use a reference glass or air? and why

i have a thin film deposited on a glass substrate, when i measure trasmittance (T) for it ,should i use a reference glass or air? and why regarding these points: for bare glass T=88 % for thin film ...
3
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1answer
114 views

Is it experimentally proven that photons travel at speed $c$ in vacuum?

Are there experiments which show that single photons (not classical em waves) travel exactly at $c$ in vacuum? What is the error bar in that case? The question is posed due to the fact that loop ...
1
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1answer
58 views

Experiment: releasing the copper bar above a permanent magnet

A classic experiment shows that when we drop a magnet through a copper coil long tube, there is eddy current induced in the coil. Then, due to lenz law, the motion of the magnet will be opposed and it ...
1
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0answers
39 views

Coupling into FC/APC fiber

I am currently attempting to couple a 405nm laser diode into FC/APC fibre. The fibre is mounted on a flexure stage approximately 15.3mm from an f=15.29mm lens. I have managed to couple into the core ...
5
votes
1answer
53 views

Will the speed of the wind produced by a fan increase continously to infinity with the propeller spin speed?

Imagine a scenario: On a stand, an $RC$ plane motor is mounted on a stand. The motor has a $8x4$ prop attached to it. In the theoretical model, if the spin of the motor can be increased infinitely ...
1
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1answer
44 views

Can the helium from a gas bottle lift the bottle?

Does a gas bottle full of helium contain so much helium that, if the helium can expand into a baloon, can lift the empty gas bottle? And input on this question highly appreciated...
1
vote
1answer
37 views

Cryogenic (LN2) gas vs liquid for cooling

For cooling, would you recommend using gas over liquid or vice-versa? What is the temperature differential between gas and liquid? In other words, at standard volumes and pressures from a gas ...
3
votes
1answer
36 views

Sound attenuation when holes size less than wavelength

The actual problem is as follows. There is a gap between a transducer and its circular mounting collar that is about half the wavelength of the incoming sound. What I do not want is for the incoming ...
3
votes
2answers
106 views

How mass is determined in dynamics?

Mass is one of the most core and complicated concepts in dynamics. I have tried many books but I still don't have a good idea of how the mass of any object is determined relative to another. In The ...
4
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2answers
98 views

How do we know what happens to stars during their life cycle?

It is common knowledge than Sun-sized stars will eventually become red giants, and later they will get gradually smaller again until they cool down into a brown dwarf, and that bigger stars can ...
1
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1answer
80 views

Holographic universe experiment?

I heard a passing news story which a satellite employed to prove or disprove the Holographic Universe theory came back disproving the Holographic Universe Theory. I searched for recent news reports ...
0
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1answer
30 views

Where can I find the Auger emission spectra of the most common chemical elements?

I am looking for an online resource where I can find the Auger emission spectra of (most common) chemical elements, i need them for AES (Auger Emission Spectroscopy). Thank you.
0
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1answer
81 views

The confusion of fractional error calculation

I need to find the focal length of a lens by using equation 1/u + 1/v=1/f I have: u= 50+-3 mm v= 200+-5 mm I calculate the value of f as 40mm. Now i need to find the uncertainty in this value. ...
1
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0answers
27 views

Is it possible to make a capacitor of required specifications using aluminium foil? [closed]

I wanted to make a FM radio transmitter but I was not able to get a capacitor with the exact rating of certain micro farad and pF. But I live in a poor country and I can not find them in the local ...
3
votes
1answer
132 views

Wavelength of electromagnetic waves [closed]

How can you determine experimentally the wave length of an electromagnetic wave having wave length in the visible range and that in the ultra violet range?
0
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1answer
141 views

Fusion, Magnets and Quantum Generators [closed]

I cannot even play like I'm even at this level, but this is the fusion reactor in Germany called the Wendelstein 7-X stellarator. These doughnut-shaped magnets (often seen on Physic Exchange) are ...
1
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1answer
90 views

What is an Unbalanced Interferometer

I have read in some papers about a so-called unbalanced interferometer. This appears particularly in the context of Experimentally verifying the Englert-Greenberger-Yasin Duality Relation. However, I ...
0
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0answers
14 views

Book Recommendation for relativistic scattering theory [duplicate]

I am looking for books on relativistic scattering theory with particular emphasis on application to experimental high energy physics. Does anyone have excellent recommendation?
0
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2answers
49 views

Question about Cavendish experiment

I got a question. In Cavendish experiment was used lead in both of spheres. Can we repeat that experiment with balls made from stone or anything else. Because lead could be a byproduct of radioactive ...
0
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0answers
36 views

Sum rule in X-ray Photoelectron Spectroscopy (XPS)

What is the sum rule in X-ray Photoelectron Spectroscopy (XPS)? how can I derive it? Can anybody explain the principle of sum rule in XPS or in spectroscopy in general? How can I apply it to a ...
0
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1answer
37 views

Perfect vacuum in experiment [closed]

When conducting experiments to determine the speed of light in a perfect vacuum does that vacuum(?) replicate outer space?
1
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0answers
24 views

How can one induce rapid temperature changes in a controlled environment?

What kind of processes are there using which it is possible to change the temperature of a material as fast as possible. You are allowed to use any material you want. Constraints - It should ...
1
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0answers
32 views

Single Photon Counting Module [closed]

I have a single photon counting module from Picoquant (tau-SPAD) . When it is powered on, the TTL output has a constant value of around 4 volts (as opposed to occasional TTL spikes indicating photon ...
1
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2answers
43 views

Electropermanent Magnet not working?

I have made an electropermanent magnet based on summary provided on this blog. Here are my details - I have used AlNiCo and Neodymium Magnet together in the core with 10mm diameter and 20mm length. ...
2
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0answers
59 views

What are the reasons for accepting Coulomb's law? [duplicate]

I read the Coulomb's first memoir on Electricity and Magnetism (Louis L. Bucciarelli english translated version), and found it to contain only three trials (as complained by many) to reach the ...
0
votes
1answer
406 views

comparison between current and voltage sensitivity

Current sensitivity of galvanometer is defined as deflection per unit current. $$\frac{\phi}{I}=\frac{NAB}{k}$$ Here, $\phi$ is the angular deflection,k is the torsional constant of the spring,NAB is ...
1
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0answers
37 views

Experimental Bases for Schrodinger Equation and Matrix Mechanics

I am curious about the motivation for developing the Schrodinger equation (SE), and its subsequent acceptance. Are the primary experimental findings that led to the development of the SE: 1) the ...
3
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2answers
125 views

How is dark matter detected?

What methods do we use to detect Dark Matter? If I understand correctly, due to lack of electromagnetic interaction it should be able to phase through normal matter nearly like through void - since ...
1
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0answers
14 views

Removing conductive silver paste from a stainless steel plate

I've been doing some STM experiments on TMD material held down with silver paste. is there any recommend solvent for removing the paste? I was going to use IPA or ethanol in a sonic bath...any ...
8
votes
1answer
110 views

Detailed form of light waves in vacuum and how to test it experimentally?

Consider a light wave in vacuum. Do the $\vec{B}$ and $\vec{E}$ fields have to be orthogonal to each other? Since you can add constants to a solution to Maxwell's equation it doesn't seem neccesary ...
1
vote
1answer
180 views

why shadows become dark when light intensity increases? [closed]

I observed following phenomena today: in my room with some lightings, there is a stuff toy placed in front of a wall. The ambient lighting doesn't cause any shadow on the wall currently. Scene 1: ...
-1
votes
1answer
77 views

Decide Refractive index of a unknown piece of glass [closed]

Problem: The task is to find $n_2$ by Fresnel's equation from given data. My attempt at solution: I begin from this equation: $$R= \left|\frac{(n_2\cos\theta_i - n_1\cos\theta_t)}{(n_2\cos\theta_i ...
3
votes
2answers
51 views

What is crater's influence on laser ablation?

In many laser ablation experiments (especially Pulsed Laser Deposition), target is moving to avoid crater formation. But I can't find any source that says why it is needed to avoid it. So why is ...
3
votes
1answer
51 views

100x magnifying optics system for short laser pulse

I am now designing an experiment that consists of a 400 nm short pulse (~300 fs). In the experiment, we need to magnify the transverse profile of the pulse by 100x. That's the problem. I was ...
0
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0answers
31 views

Extreme charge density in thin capacitor plates

Suppose we made a 1 square meter parallel plate capacitor from two sheets of graphene separated by a very strong dielectric of arbitrary thickness. Then we charge the capacitor just short of the ...
0
votes
2answers
51 views

Experimental proof of gravity propagation? [duplicate]

The last research aim to find gravitons which are boson, so if I correctly understand they are virtual particles. Out of theorical assumptions, Is there exist an experimental proof that the ...
0
votes
1answer
53 views

Does gravity affects on electrons in a noticeable way? [closed]

Is there a way to force a free electron move in a low speed in order to observe it actually hitting 'on the floor'?
0
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0answers
55 views

How to compare optical fibers of different material, NA and diameter

For an experiment I would like to figure out how different optical fibers behave in terms of losses at both ends and their attenuation for a given wavelength. Let's say, I have three different ...
1
vote
1answer
39 views

Do liquids creep from cold to hot like gases?

Consider the U-tube water experiment below with the left red block at 10C and the right red block at 90C. I think the right level will become about 3% higher than the left level simply because hotter ...
1
vote
2answers
73 views

How to measure 8 μm surface bumps?

I want to measure surface bumps which are larger in size than $8\ \mathrm{\mu m}$ on a uncoated plastic mirror. So it can be any number of smaller bumps and that would not effect the application. I ...
0
votes
2answers
28 views

smallest possible length of copper wire, where I can measure capacitance via multimeter [closed]

I am a new highschool physics instructor and I want to show to my students the basic concept inside the capacitors. i plan on showing them via simple 2 copper wires side by side each other, supplied ...
1
vote
1answer
69 views

Rate in Fermi's golden rule

There is a very clear derivation of Fermi's golden rule (actually Dirac's) here. Everything runs smoothly until, somehow, the equivalence $$ \Gamma_{a \rightarrow b} = \frac{P_{a \rightarrow b}}{t} ...
0
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1answer
61 views

Is there any evidence of black holes existing? [duplicate]

Yes, I am aware of observations of "massive objects", for example near the center of the galaxy. But is there any evidence that the object in question is a black hole, with all its commonly attributed ...