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

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1answer
54 views

Are residuals supposed to have error bars?

Hopefully I'm asking this in the correct section. So I've got a graph with a linear trend of data and a best fit line plotted. The data points on the main graph obviously each have their own error ...
3
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0answers
57 views

To what degree the probabilistic nature of quantum mechanics is tested?

I am not sure the question is well posed, what I mean is sort of an experiment in which one extracts some random, say, uniform distribution out of a quantum processes, and tests to what degree that ...
1
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2answers
66 views

Why so much electric charge?

I'm working on the Millikan experiment using the following apparatus: http://www.unitedsci.com/product-catalog/millikan-oil-drop-apparatus-0 when I compute the value of charge of the oil drops, the ...
2
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1answer
86 views

Michelson Morley experiment? [closed]

Its not that I question the conclusions reached concerning the Michelson–Morley experiment, however I would like to know how the following issue was addressed please? If I could pass bob through a ...
3
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2answers
48 views

Definition of atmosphere unit and relation to temperature and gravity

I've seem sometimes the atmosphere unit for pressure be defined so that $1\ \mathrm{atm}$ would be the mean atmospheric pressure at sea level. I've seem on the other hand the following definition: ...
0
votes
1answer
51 views

Choosing curves in data fitting [closed]

I have got a series of data points in experiments. And now I am trying to do some fitting job. What kind of curve should I select for this if I don't know what the exact expression is?
3
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3answers
256 views

How to measure an image's contrast?

I'm studying Fourier optics and Interferometry and I intend to determine the contrast of an image using computer software. My teacher of Experimental Physics didn't tell me how to do it, and so, I'm ...
2
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0answers
45 views

How is Spin experimentally determined?

I know what spin is and how theories determine it for particles. What I don't understand yet, is how people, through experiments and data analysis or whatever, reach to confirm/say that the $X$ ...
1
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1answer
68 views

Is the probability current an observable?

Is the probability current in Quantum Mechanics an observable? If so, how can it me measured (directly or indirectly)?
5
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1answer
46 views

Ideas for extending Muon-Life-Time experiment?

Background: I'm teaching a lab experiment for measuring the Muon lifetime. The experiment is a big tube of scintillator attached to a PMT. The muon entering the scintillator generates a reading in the ...
0
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1answer
30 views

Difficulty in dissolving scotch tape

The scotch tape peeling of graphene is the classical way to do it. But I am having difficulties in dissolving the scotch tape gum and it is giving noise in the Raman signal. How can I transfer the ...
1
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1answer
23 views

Finding natural linewidth's

I want to check whether my fit parameter for the width of a Lorentzian fit on my digital spectroscopy data for Helium (the 5875 Angstrom line) is what you would expect from the uncertainty principle, ...
0
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0answers
38 views

Inconsistencies in data: magnetic field in solenoid

In lab for our Calculus based Electricity and Magnetism course we are, for one portion of our lab, exploring the relationship between increasing the number of loops in a solenoid and the magnetic ...
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0answers
12 views

Ultrasound Transducers and Simulator [closed]

Presently I am working on Underwater Acoustic Wireless Transmission. I desire to measure water parameters at the bottom of the surface of the water and then pass it to the water surface using ...
0
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0answers
12 views

Where can I find Lorentzian values for the width of spectral lines for fitting XPS data?

I'm trying to curve fit my XPS data. I would like to start with known parameters to have an idea. Does anyone know of places the Lorentzian (and even the Gaussian) of elements is located?
0
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2answers
65 views

What is the Current Status of Measurement of the Gravitational Mass of Antimatter?

My current understanding is that it's generally expected (and has been predicted) that antimatter will fall down and not up in earth's gravity. But I haven't been able to locate any definitive ...
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0answers
26 views

Optical Parametric Amplifier performance compared to Optical Parametric Oscillator

I am trying to design a bright source of polarization entangled beams of photons so that it is visible to human eye. I have to decide between OPA and OPO. OPAs are cheap and simple to develop compared ...
1
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1answer
22 views

How to find the error of all the counts within the Full Width Half Maximum (FWHM)?

We've been doing Gamma ray spectroscopy and have peaks from various sources. We'd use Poisson statistics, but obviously the detector doesn't have a resolution of zero, thus we are summing the counts ...
0
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0answers
43 views

How can LIGO's measures be unequivocaly tied to gravitational waves? [duplicate]

I understand that there are 2 devices so that the signal cannot have a local stimulation as a source. But why couldn't it be seismic activity for instance? Given the accuracy of the devices couldn't ...
1
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0answers
64 views

LIGO detection statistic, SNR formula

According to B. P. Abbott paper published in Physical Review Letters, "Observation of Gravitational Waves from a Binary Black Hole Merger" http://journals.aps.org/prl/abstract/10.1103/PhysRevLett....
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0answers
14 views

What is the meaning of the minimum separation requirement?

In this work, BHsearch done by CMS, they reconstructed and identified objects using certain conditions. And finally, in Page 3, the last paragraph requires that the minimum separation between any two ...
3
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0answers
34 views

How to determine if a superconductor is type I or II?

What experimental measurements are available to determine whether a superconducting single crystal/polycrystalline sample is type I or II? I.e. BCS vs non-BCS? An answer would mention the ...
0
votes
1answer
40 views

Blue hues in Aluminum mirror

[][] When depositing Aluminium sometimes I end up with a bluish hue to my film especially when changing angle of view. I use a very high rate of deposition and low temperature. What would cause this?
2
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0answers
25 views

Ideas for experiments on the Beamline for Schools at CERN? [closed]

I'm thinking of participating in CERN's Beamline for schools competition. To those who do not know, they offer a batch from a school to conduct their own experiment on a small scale particle ...
5
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2answers
106 views

Can you simulate a Michelson-Morley experiment with sound?

Is it possible to make a MME with sound waves? Suppose we travel on a rail platform with two "mirrors" that reflect sound, what parameters would we need to simulate the light experiment? would it work ...
0
votes
1answer
137 views

SPDC and single photon production

In Spatial Parametric Down Conversion, incoming photons are split into entangled photon pairs by passing through a non-linear optical medium. Since I get a photon pair as an output then how can I say ...
0
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0answers
54 views

Generating Single photons

How can single photons be generated by making a coherent state weaker by attenuating it?(For reference please see, Quantum Computation and Quantum Information by Nielsen and Chuang, 10th edition,pg....
2
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1answer
273 views

Is Machine Learning a useful tool for analyzing experimental data? [closed]

Apart from being a student of Physics I'm also a developer and recently in the context of cloud development I've been hearing a lot about cloud based Machine Learning. After looking at some examples ...
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0answers
29 views

What is the highest upper limit on resistance of superconducting phase?

What is the highest precision achieved in the measure of the upper limit of the resistance of the superconducting phase (for any superconductor)?
0
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0answers
18 views

Please recommend a book about experimental instrumentation strategy

Some particular large scientific instruments prosper, reach their goals and develop over decades, while others doen't. The latter aren't experiments with negative results, but experiments with no ...
3
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1answer
68 views

Why does one use different materials for cathode and anode in the photoelectric effect experiment

All photoeletric lab experiments I have seen so far have a setup where you have different materials for cathode and anode. However this raises some experimental difficulties since you have to take ...
1
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0answers
31 views

Cloud chamber and observations [closed]

What are the best ways to use a cloud chamber to study particles. What would you gain from observations done in a cloud chamber.
1
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1answer
53 views

Measuring speed of sound in a solid specimen

Let's say I have real-life specimens of isotropic solid materials I want to investigate some properties of. Through my setup I'm able to send mechanical wave pulses into one cylindrical bar of the ...
2
votes
1answer
164 views

Does LIGO GW detection methodologically constitute discovery of two specific black holes (as astronomical objects)? [duplicate]

It is said that the gravitational waves (GW), recently detected by LIGO, correspond (according to Einstein General Relativity theory equations) to the effect of two black holes merging (with the ...
0
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1answer
14 views

Why does natural counting with a gamma spectrometer differ from Neutron activation analysis?

As stated in the title, why are the data from natural counting using s gamma spectrometer different than the data from neutron activation analysis using the same samples?
0
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0answers
23 views

Good books to read [duplicate]

I still regard myself as a beginner in the field of physics.. And there are a lot of information I should know, I am in my second year physics, and I need to read books which are not hard to ...
0
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0answers
22 views

What is the Best Electron Tube for creating X-Rays?

This is a question of Experimental Physics. I have seen that you can create X-Rays with a High Voltage Circuit using Electron Tubes. http://www.dangerouslaboratories.org/xray1.html. My question is, ...
1
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2answers
48 views

Problem with denoising BICEP2 data?

This question pertains to this article which talks about why the BICEP2 measurements of B-mode polarization in Cosmic microwave background radiation turned out to be noise from galactic stardust. They ...
7
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1answer
257 views

How does LIGO remove the effects of environmental noise?

Since LIGO is dealing with readings at nanometers, events such as vehicles driving nearby, and constant (but extremely minor) tremors of the earth can cause movement with the mirrors at nanometers. ...
0
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1answer
44 views

Practicality of measuring observables

In quantum mechanics Hermitian operators acting on the Hilbert space of a system are observables. From what I understand this means that there is some measurement we can do such that the eigenvalues ...
0
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2answers
43 views

Extending the reach of a crocodile clip for Kelvin Water Dropper experiment

We're doing a physics project that involves a version of the Kelvin Water dropper experiment. Everything is working great, and we have the following system: In the image: two plastic containers (...
10
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5answers
1k views

Do the LIGO observations constitute proof of a black hole merger, and what happened to the black holes?

Information says that the gravitational waves, recently detected by LIGO, correspond (according to Einstein theory equations) to the effect of two black holes merging (with the masses of both black ...
7
votes
1answer
179 views

How are LIGO mirrors cooled?

The recent LIGO announcement Observation of Gravitational Waves from a Binary Black Hole Merger has some technical details about LIGO. For example, LIGO is a modified Michelson interferometer. The ...
2
votes
1answer
173 views

What are the wave characteristics for the detected gravitational wave?

I'm curious to know what the amplitude and wavelength of the detected gravitational waves are? The paper mentions some characteristics of the detection event, but not what that means for the wave ...
8
votes
3answers
962 views

How are the 4 km arms of LIGO measured so accurately?

The arms of the LIGO interferometer are 4 km long. Now, LIGO functions by measuring phase difference between two beams of light comming (as in Michaelson's Interferometer) to a sensitivity of $10^{-18}...
3
votes
1answer
193 views

How thermal noise is avoided in LIGO?

I think I have understood properly the principle of LIGO, however the sensitivity is around $10^{-18}~\rm m$ of accuracy of distortion. That looks pretty small... just starting with simpler phenomena, ...
5
votes
0answers
92 views

How does LIGO reduce noise below what it is detecting? [duplicate]

LIGO is designed to detect changes in length on the order of 10,000ths the scale of a proton. I know they are extremely well isolated from their surroundings, but how could we even approach isolation ...
9
votes
1answer
921 views

G4v Gravitational Wave vs General Relativity vs LIGO Observation

CalTech emeritus professor Carver Mead produced an alternative prediction, to General Relativity, for gravitation wave observation which he published last year in anticipation of LIGO observations. ...
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4answers
260 views
3
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1answer
203 views

How does LIGO account for curvature of Earth?

Using an earth curvature calculator, I found that at a distance of 4 km (the length of LIGO's arms), more 1.26 m is hidden by the horizon. When constructing LIGO, did they account for the curvature of ...