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

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12 views

linear and circular polarization

Lets suppose we have some data collected from antenna measurement. For every theta and phi point in any coordinate system ( here refering to Ludiwg coordinate systems II and III) the data can be ...
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0answers
27 views

How to measure the spin of a particle?

How we can measure the spin of a particle from the angular distribution of its decay products? for spin zero particle the distribution is flat while for spin 1 particle the distribution is different, ...
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1answer
49 views

Is there a way to strip all the electrons from single atom with atomic number greater than 2

Please explain by what means electrons extraction can be done. How person can focus activity on single atom (from precision point of view) to do so? How at each step person can know how much electrons ...
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0answers
55 views

Detecting supersymmetry

What would scientists in particle colliders look for as evidence of supersymmetry?
6
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0answers
38 views

How extremely low temperatures (near absolute zero) are actually measured [on hold]

How do the industrial or laboratory thermometers for this purpose work like: what effects are based on, what are other alternatives how accurate they all are
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0answers
29 views

Can orbiting a black hole 99.99% speed of light make other object with relatively fast clock travel faster than light, relative to me?

If i orbit a black hole, 99.9% speed of light, time for me is moving slowly, relative to me, planet earth is aging fast, and i have traveled 10 years into the future(relatively) in 1 second, suppose ...
2
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1answer
36 views

propagation of error - sin^4

I am currently working on an analysis of a Rutherford scattering and encountered a somehow strange behaviour for the errors. It basically boils down to the behaviour of: $$\sin(\theta/2)^4$$ For ...
1
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1answer
27 views

looking for a technique for conducting experiment [closed]

I have used a servomotor and a controlling circuit to produce oscillatory motion for an experiment that involves flapping of a tiny metal plate (~few mm) inside liquid. I could not be very successful ...
1
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1answer
54 views

about the Pound-Rebka experiment and the answer to a second year undergrad student' s question 7 months ago [on hold]

The answer tells us about a specific subtraction of the doppler shift so as to obtain the net gravitational redsift. Can anyone explain all this thing about that subtraction?
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3answers
195 views

How do we know that an electron “spins”?

As far as I know, you can't necessarily isolate an electron to observe it, you can only observe its effects on other particles due to fields. Moreover, we can't know an electron's exact location or ...
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0answers
14 views

meaning of ISR and Heavy signal

I was reading a paper on particle physics and came across two undefined terms which are ISR and Heavy signals. I would really appreciate any help explaining what those terms mean. Thank you in advance....
8
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1answer
108 views

Experimental data for asymmetric Newton cradle

Using a "successive impact model" (as if each ball were seperated from the other ones), I produced the following animations: You can see any combination of balls with masses of 1 or 2 (left) or 1 ...
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1answer
68 views

Conservation of energy in the form of y=kx +b?

I am doing an experiment on method of mixtures and specific heat capacities. During my experiment I have to use the graph as a means of finding the SHC of the subject. So I did the experiment with ...
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0answers
27 views

Galileo's pendulum and any references

In some texts about the simple pendulum we use to see references about some "experiments" Galileo Galilei did realize and whereby he found some important results, including that the period of the ...
3
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1answer
132 views

How to read numbers reported in this LIGO paper?

I am not sure how to read the numbers in this excerpt from the abstract of GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence: Are the +/- small ...
2
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1answer
45 views

High $p_T$ and high $Q^2$ in deep inelastic hadronic collisions

When reading about high energy collisions (for example proton-proton collisions at LHC), I always find the relation $Q\sim p_T$, which, for me, is hard to demonstrate. Moreover, I found statements ...
1
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0answers
32 views

Cheap DIY Zernike-Phasecontrast: Optical Thickness of a inkjet/laser printed contour for phasering? [closed]

Rough guess: Optical Thickness of a inkjet/laser printed contour? Edit I was wondering if there is any research regarding the refractive index and the height of an inkjet or laser printed contour?  ...
0
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0answers
16 views

Comparison of electron deflection tube and Hall effect

Consider an electron deflection tube (something like this: http://www.ld-didactic.de/documents/en-US/GA/GA/5/555/555624e.pdf). Suppose you apply a magnetic field perpendicular to the screen. Then ...
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0answers
18 views

Liquid-vapor saturation curve

I am trying to draw the saturation curve for liquid-vapor region, but I don't have the exact equation. Can someone help?
1
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0answers
8 views

Why can we extract the oxidation state from XPS and XANES but not from XRF or EDX?

To my understanding it is possible to extract information about the valence/oxidation state of an ion in a material by using X-ray photoelectron spectroscopy (XPS) or X-ray absorption near edge ...
4
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0answers
90 views

A theoretical model for evaporation occurring when wind is blowing over the surface of water

I've recently done an experiment in which I was studying the variation of the cooling rate of hot water in a draft (wind). The air was blow directly over the surface of the water (kept in a ...
-1
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1answer
38 views

why do microscopic cracks happen?

2 weeks ago i asked a question about " Gas permeation through solid metal? " i have got a very good answer here .but microscopic crack was mentioned in the answer. i searched in Internet but i didnt ...
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0answers
14 views

Cathode Ray Tube: Nonuniform Magnetic Field

For an experiment, I found out that the charge to mass ratio of electron was 1.91x10^11 C*kg^-1. So, I overestimated from the theoretical quite a bit. I used a cathode ray tube with Helmholtz Coils ...
0
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0answers
26 views

Scanning Electron Microscopy on a smaller scale

Is it possible to sufficiently focus a ~1nm beam of electrons into a sample chamber in less than 10cm of vertical space, therefore reducing the volume of the entire vacuum chamber, and subsequently ...
2
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1answer
38 views

What do the terms “offline” and “online” refer to in the field of high energy physics data analysis?

The title says it - I've encountered these terms several times but have never found an explanation anywhere. An example of use is this ATLAS note. If I may hazard a guess: Data rate is high at the ...
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2answers
50 views

How to calculate energy loss in a rotating shaft?

Please help me with proper formula for below example. Imagine a rotating shaft 'X' with 2 gear wheels 'a' and 'b' of same dimensions. If energy applied to gear 'a' on the shaft through source A ...
3
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1answer
38 views

Why does a CfBe neutron source not exist?

Sources such as AmBe take advantage of Beryllium's $(\alpha,n)$ process to produce high energy neutrons. Sources such as Cf utilize spontaneous fission. Why not combine the two? Such a source would ...
2
votes
1answer
52 views

GR Verification for a Charged Black Hole

For a charged ($Q$) rotating ($L$) mass ($M$), the Kerr-Newman equations give the angular deflection of light. Has there been observational verification (I would prefer to use only the angular ...
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0answers
20 views

Online rotation curve data search

I would like to know how to find rotation curve data online. I know there are online data bases like hyperleda, ned, simbad, etc. but how to look inside those projects for the rotation curve data?
0
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1answer
57 views

How are the standard model and the Higgs boson actually confirmed experimentally in practice?

This is my mental picture on how we can make predictions from a theory (I'm not a physicist so this might be quite wrong) : Typically, we solve a partial differential equation (analytically if we can,...
2
votes
1answer
33 views

What will happen if we establish a physical connection between ground and ionosphere?

https://en.wikipedia.org/wiki/Ionosphere The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about 50 km (31 mi) ...
1
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1answer
29 views

Verify Faraday's law of induction [closed]

I need to design a procedure for an experiment to verify Faraday's law of induction. I'm given: A Helmholtz coil of radius 15 cm Three plastic spheres of radii 1 cm, 1.5 cm, and 2 cm. A spool of ...
1
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3answers
33 views

How to determine the concentration and sign of the charge carriers in copper

I need to design a procedure for an experiment to determine the concentration and sign of the charge carriers in copper. I'm given: A slab of copper 2.0 mm thick, 1.5 cm wide, and 4 cm long One very ...
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0answers
29 views

Effect of shielding on a miniature Helmholtz coil

So a bit of background... I'm a university graduate student with primarily digital signal processing and embedded experience. However I've managed to get myself involved with a project that requires ...
0
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1answer
32 views

Basic high school physics question, on measuring voltage from CRO screen:

My textbook says 'this represents a voltage that varies from +300mV to -300mV. If this voltage were measured using a meter a value less than this would be displayed since the meter gives an average ...
0
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1answer
33 views

How to interpret these gravitational lensing data?

The data I am trying to understand this gravitational lensing data in the link above. However, unfortunately I don't have an extensive knowledge in physics. Could someone please tell me what each of ...
0
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0answers
20 views

How is a frequency comb used to stabilize other lasers?

So I am currently in the process of writing my bachelors thesis which partly concerns frequency combs. I have read that some of the applications is: Optical measuring tool. (by detecting beat-note) ...
0
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2answers
73 views

How are laws proven in general?

This may be a bad question, but what are the ways that laws are proven? I would expect that some ways would include by proving them mathematically or through experimentation. My biggest question about ...
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0answers
137 views

What is the significance of the possible new 17-MeV “protophobic X boson?”

Krasznahorkay et al ...Possible Signature of a Light, Neutral Boson published results in 2015 of a possible new particle at 16.7 MeV+/-0.35. The researchers suggest "such a boson might be a good ...
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0answers
27 views

High pressure deformation of metals

Does copper undergo elastic recovery after being exposed to high pressures (above 30 GPa in a diamond anvil) at room temperature?
2
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2answers
71 views

Muon lifetime determination

My colleagues and I performed several experiments to determine the lifetime of the muon (from secondary cosmic rays) using scintillator detectors coupled to multi-channel analysers. The results ...
0
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1answer
50 views

Are pure Dirac fermions (electrons, quarks, …) allowed to have effective Majorana mass?

Charged particles such as electrons and quarks are not allowed to have a hard Majorana mass (see here). With 'hard' I mean an explicit mass term in the Lagrangian which would break the corresponding ...
47
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4answers
4k views

Why does LIGO do blind data injections but not the LHC?

The LIGO group has a team that periodically produces fake data indicating a possible gravitational wave without informing the analysts. A friend of mine who works on LHC data analysis told me that ...
2
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2answers
75 views

Experimental confirmation of the textbook explanation for local entropy reductions

Clarification: In my original wording of this question, regrettably, I did not make it clear that I am interested in the the Boltzmann/Gibbs/statistical (BGS) interpretation of it, as opposed to the ...
4
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2answers
136 views

Why do we learn only two computations, cross sections and decay rates, in such a fundamental theory as QFT?

When I learned Newtonian mechanics I found a vast variety of computations that I could do and that was so interesting. And it was so when I learned Maxwell theory. When I started learning QFT I hoped ...
2
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2answers
56 views

Why don't reflector telescopes place their reflectors at an angle?

To avoid placing a secondary mirror in front of the objective mirror, why not tilt the objective and design the eyepiece in such a way that comatic aberration is minimized?
3
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1answer
41 views

How can I determine whether balloons inside a balloon are filled with the same gas?

We recently awarded ourselves some helium balloons to celebrate something, and they came with about a dozen little balloons inside, filling it to just under half way. I was discussing with a ...