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

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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
70 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 ...
1
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1answer
63 views

What are some experiments verifying Maxwell's 4th equation?

Please give me the link to some paper, website or book that you know about which discusses in detail some experiments which quantitatively verify Maxwell's 4th equation, which is $$\quad ...
4
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0answers
63 views

Measuring the Dirac field

If the Dirac field $\psi(x)$ is to the electron as the Electromagnetic field is to the photon, why is it that we can measure the Electromagnetic field, whereas the Dirac field we cannot?
3
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1answer
35 views

Machine readable database of gamma lines

Friends of mine did a lab experiment where they recorded $\gamma$-spectra in the range from 0 to 1500 keV with a soil sample. The data contains some background and a couple sharp peaks at different ...
1
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0answers
45 views

Measuring expectation value in quantum field theory and in quantum mechanics

There is a way of calculating the vacuum expectation value $\langle 0|\hat\phi|0\rangle$ theoretically in a quantum field theory like there is a rule to compute expectation value of any operator A ...
1
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0answers
156 views

What is the origin of the Maxwell's wheel? [closed]

Tried to find it online, but nothing. Every refers to it and that it's named after the famous James Clerk Maxwell (of the maxwell electromagnetic laws and some other things) but it's like the ...
0
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0answers
54 views

Beta decay - Relative probability of electronic conversion for different disexcitations energies

I'm studying, experimentally, beta decay phenomena. Internal conversion of electrons happens when we have a sobreposition between a excited nucleus with it's electronic cloud. The colision between the ...
13
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4answers
943 views

The maximum distance for which Coulomb's law has been verified?

We know that Coulomb's law, $F_{12} = \frac{kq_1q_2}{r^2}$, was experimentally verified for small distances by Coulomb himself at the and of the XVIII century. The question is what is the maximum ...
1
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0answers
61 views

How to measure $\mathbb{L}^2$ and $L_z $ simultaneously

What does an experiment look like, in which both quantities are measured simultanously?
1
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1answer
94 views

Measure ball's acceleration down inclined plane

If I am asked to devise an experiment to find an expression for the acceleration of a uniform sphere (ball bearing) rolling down an inclined plane, as a function of the angle of incline. Hence deduce ...
1
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1answer
27 views

How does one build a framework of sensors from nothing? [closed]

I would like to understand how you can go from nothing to a framework of sensors you can use to try out things in physics/thermodynamics. That is, everything has to be bottoms up, nothing premade ...
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0answers
36 views

Simple Stern-Gerlach Apparatus Orientation

I have been reading Townsend(2012)A Modern Approach to Quantum Mechanics. In the first chapter, he introduces the idea of intrinsic spin angular momentum, and some of its strange quantum properties ...
0
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1answer
158 views

How do you calculate theoretical ratios of angular velocity final and angular velocity initial? [closed]

I'm asked to calculate the "Theoretical Ratio". ($\omega_f/\omega_i$) I have Inertia of the Disk = $I_{DISK} = .0094115713$, I have Hoop Inner Radius = $I_R = 55.725$ So I am supposed to use the ...
3
votes
1answer
33 views

Search for unpublished note on Magnetic Monopole Detection

Design of an electromagnetic detector for Dirac monopoles by Luis Alvarez This is an unpublished 1963 note from Lawrence Radiation Laboratory (Physics Note 470), and is heavily cited in all papers on ...
0
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1answer
42 views

Wu experiment beta decay

maybe it's a stupid question. But in Wu experiment she showed that parity in not conserved in beta decay. So how to say on general that this is true for any weak force interaction?
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0answers
22 views

Fiber holder with 'vacuum' holes.

I'm a student in my third semester and am currently working with workgroup in our physics department. Last week our lab got access to liquid nitrogen and we are fiddling around with fibers in ...
3
votes
1answer
80 views

Help me understand Pound and Rebka's experiment

I am a second year undergrad physics student and up until now have done some classical mechanics and some electrodynamics. For some reason I have always been really interested in light. A couple of ...
2
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1answer
37 views

How deep within the sample can the DOS(density of states) be detected by STM(scanning tunnel microscope)?

Using STM equipment, we can get the LDOS(local density of states) on the surface of a sample. I want to know whether the LDOS within the sample(not surface) can be detected by STM. what is the ...
1
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0answers
44 views

Why does stopping potential depend on intensity? [closed]

Yes, the stopping potential shouldn't depend on the intensity of the incident photons theoretically, but an experiment using a PASCO h/e apparatus shows that when we use a Variable Transmission Filter ...
0
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3answers
326 views

How do we know which direction heat flows? From cold to hot, or from hot to cold?

I'm trying to figure out which direction the heat flows. After many google searches I've determined it flows from hot (higher energy) to cold (lower energy). My question tho is, how do we ...
0
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1answer
13 views

Detection of the He-nuclei in the historical Rutherford scattering experiment

Which method did Rutherford use to detect the Helium nuclei in his scattering experiment?
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0answers
40 views

Hysteresis at low temperature [closed]

How will the hysteresis curve for a typical ferromagnetic substance change at low temperature(near 273K and near 0K) from its nature at room temperature ?
5
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3answers
117 views

What are the original papers on the hydrogen spectral lines?

I am trying to find original sources for experiments that had observed spectral lines from hydrogen or other gases. I am looking into experiments that motivated Niels Bohr to write his ideas on the ...
1
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1answer
101 views

Double slit experiment mechanism

Can someone explain the mechanism that sets in motion the electrons in the experiment? Is it an electro-magnetic force? If so, I think it's not right to describe the motion of the electron as a ...
3
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0answers
38 views

How did experiments affect the development of quantum mechanics? [closed]

What were some of the major experiments that helped to develop Quantum Mechanics? I've read about the Stern-Gerlach experiment and double-slit experiment. But what role did experiments play? Did they ...
1
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0answers
37 views

Sterile neutrino constraints (summary of results)

Constraints on sterile neutrinos come from an amazingly wide range of different sources. From astrophysical observations (review1, review2) to particle physics experiments (MiniBooNE, Daya Bay, LSND, ...
3
votes
1answer
140 views

Elementary graphical error analysis

Suppose you analyze experimantal data with pencil and piece of paper, one simple method is to plot the data in a linearized way with error bars. Suppose you are interested in the slope of this linear ...
2
votes
3answers
195 views

Is it possible to make a “wire-free” Bungee jump?

Wireless bungee jump I think it could be possible with magnets, and the suit of the person has to have a different magnetic camp form the floor camp. But I don't know if the person can rebound. Is ...
0
votes
1answer
71 views

A confusion with solenoidal windings

I have seen in solenoids, toroids, transformers, electromagnets and machines that the core is pretty insulated. Over this the winding coil is wrapped but it is a bare coil (turns are not insulated to ...
3
votes
1answer
51 views

Have we observed sufficient extra-solar planetary systems to establish a planetary distribution pattern? [duplicate]

From Kepler And Extra-Solar Planetary Observations As of January 2015, Kepler and its follow-up observations had found 1,013 confirmed exoplanets in about 440 stellar systems, along with a further ...
1
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2answers
33 views

Gamma spectroscopy - Fitted Singlet

I'm using some gamma acquisition and analysis software. When I ask the software to do some sort of Nuclide Identification, almost every single peak in the generated output is marked with "F". ...
0
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0answers
86 views

I have some questions about reproducing Young's double slit experiment

I want to reproduce Young's double slit experiment for a school project. For the slits I am thinking making cuts in aluminium foil or maybe do something with pencil leads like this instructable ...
0
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0answers
232 views

What would be the limitations of this lab?

I was wondering what the limitations of this experiment would be. I found the static coefficient of friction between wood and sandpapaer by using a Newton spring scale and I believe that some of the ...
4
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1answer
44 views

How do space probes identify molecules?

How does a space probe identify molecules without actually obtaining the molecules? The common identification techniques I can think of are spectroscopy and magnetic resonance, but for both of them, ...
3
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0answers
70 views

Michelson–Morley experiment's aether; Why is the time gained from travelling downwind less than that lost travelling upwind?

From the Wikipedia article on the Michelson–Morley experiment, explaining one of the concepts behind the landmark experiment: "If the Earth is traveling through an aether medium, a beam reflecting ...
4
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3answers
70 views

Raw data acquirable from amateur astrophotography

What raw data can I possibly acquire from an 8" Classical Dobsonian Telescope, and a DSLR? Could anything eye-opening to amateur astronomers be computed or calculated first-hand with such equipment? ...
1
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2answers
276 views

Use of normal distribution in measurement error theory

When you study an experimental results you assume that normal distribution describe random error, specially in lab courses in K12. Is this true for every random component error treatment in physics? ...
0
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1answer
79 views

How do I measure speed accurately without any turning wheels?

Consider a pod (about 50 ft long and 15 square feet wide) that levitates using air pressure that shoots through the bottom and travels through a tube that's at low air pressure (about 100 Pa). It ...
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1answer
54 views

Graphing $E_p = E_k + E_{rot}$

I am measuring the moment of inertia of a flywheel and using conservation of energy to work out the value (I am ignoring friction). So for the experiment I have to roll the flywheel down a slope (I ...
0
votes
2answers
235 views

Magnetic flux density of a solenoidal electromagnet

I am designing an electromagnet which will be used to test magnetic sensors. So I used to formula found at hyperphysics which relates the magnetic field flux density to the number of turns, the ...
1
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1answer
36 views

Residuals are normally distributed

I did not know whether to post this question in the Physics or Statistics section of StackExchange, but the question involves the application of statistics to the analysis of experimental results. I ...
11
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3answers
338 views

Can someone clarify whether the recent experiment closing all remaining loopholes to Bell's Theorem really shut the door on local realism for good?

I saw this recent article on Phys.org that purports to close all remaining loopholes that previous experiments on violations of Bell's inequality left open. My question is, does this really close the ...
0
votes
1answer
111 views

Effects of massive magnetic field generated by operation of the large hadron collider?

I read an article about the CERN large hadron collider in which it talks about the magnetic field that is generated while the LHC is operating. A magnetic field more than 100,000 times more powerful ...
2
votes
1answer
36 views

What techniques are used in the Analyzer part of an Ellipsometer?

Specifically, what technique is used where the analyzer does not involve mechanical rotation? I assume it is a device to electronically rotate the plane of polarization of incoming light. Faraday ...
1
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0answers
24 views

LED characteristics to use in heating a material sample?

I am looking to be able to heat a sample of material, typically less than 500mg and sitting in a fused silica sample holder about 10mm diameter. Wondering about using (say) a 5W LED with narrow ...
0
votes
2answers
65 views

different energies for the same k vector for free electrons in a solid

when we use the nearly free electron approximations for electrons in a solid and get them as plane waves the energy becomes $E=\frac{\hbar^2k^2}{2m}$, which gives us a parabola. but when we see the ...
1
vote
1answer
51 views

Is there a beam splitter in time?

I have a train of pulses (with some known time separation between them) and I want to mix two of these (perform an XOR - beam splitter transformation - between them), leaving the rest alone. How do I ...
4
votes
4answers
211 views

What is the way to prevent the cream from settling on the surface of hot milk with least manual labour?

I have seen Cooling a cup of coffee with help of a spoon but that question has a restriction of using only a spoon. My problem is that I have to boil the milk before pouring it in the bottle for the ...