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

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1answer
110 views

Questions about MTW's _“thousand” tests of the Einstein principle_ (Box 16.4)

In Misner, Thorne, Wheeler (henceforth written as "MTW"), "Gravitation", Box 16.4, there's an experimental setup construction (or method) presented by which "Each geodesic clock is constructed and ...
2
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1answer
84 views

Quantum fluctuations in a classical domain?

"In the presence of chaos, even small fluctuations (including quantum fluctuations) can be amplified to produce large uncertainties in later behavior"(http://arxiv.org/pdf/gr-qc/9210010v2.pdf) Is there ...
2
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2answers
98 views

How do you measure proton's spin?

I've probably read it somewhere in Sakurai but I cannot recall it at the moment. So how does one really measure the proton's spin? I mean the proton's spin and not its constituents. Do you measure ...
0
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0answers
27 views

Elemental sensitivity factors for Auger electrons

Is there any open database of elemental sensitivity factors for Auger electrons? I'm trying to figure out graphite oxidation degree from AES spectra, so relative sensitivity of O to C is required. ...
6
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3answers
141 views

Are there any Meson colliders?

There are no stable mesons as far as I know. Are there any meson-colliders analogous to for example proton-proton colliders?
4
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1answer
105 views

How do I calculate the experimental uncertainty in a function of two measured quantities

I am performing an experiment where I'm measuring two variables, say $x$ and $y$, but I'm actually interested in a third variable which I calculate from those two, $$z=f(x,y).$$ In my experiment, of ...
2
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1answer
100 views

Evidences against Supersymmetry [closed]

Recently, some experiments show that the supersymmetry is not realised by Nature according to the simple models that we currently have. Nevertheless, it is far from saying that the "game is over" as ...
0
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3answers
148 views

Physically implementing quantum measurement of energy

If there were a particle in a box, how could one measure its energy? I understand the theory behind quantum measurements: the Hamiltonian operator represents the energy observable, so you perform an ...
0
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1answer
12 views

How can I determine a gas partial pressure knowing the flow?

I have a vacuum chamber with a pressure 10-8 Torr. Then I open an Oxygen valve with a set flow of 2 sccm from a tank with a pressure of 2 bars. The pressure in the chamber decreases to 10-2 Torr. What ...
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0answers
41 views

Exorbitant number of counts per sec. in the Rutherford Experiment

May someone kindly advise on the Rutherford experiment? I have created a Gaussian of dP$_0$/$\Delta$$\theta$($\theta$), where P$_0$ is the number of counts of alpha particles through a 1.05X19.86 mm ...
2
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2answers
97 views

Is Galilei's reasoning on free fall valid?

Galileo Galilei discovered by experiments that all bodies tend to fall with the same rapidity (I use it in an intuitive sense, you can replace it by 'acceleration' used in today's physics language), ...
0
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1answer
49 views

Can we make rigid floating helium spheres?

Is there any material that we can make rigid floating helium spheres out of without it collapsing? I have been playing with surface area and volume formulas and with a bit of trial and error have ...
0
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0answers
27 views

References on the LHC experiments

I'm looking for a references / short book which discusses what is going on LHC collider - specific experiments, collision processes, analysis of data, how exactly the facility is operating (not ...
2
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1answer
116 views

Rutherford Experiment - practical and theoretical questions

I performed the Rutherford experiment the other day, using Au thin foil of $2\,\mathrm{\mu{}m}$, a source/gun of α particles (241Am) and a detector/counter. α particles were shot from the source ...
1
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2answers
52 views

Can a broken light filter shift the wavelength of light exiting it?

I've measured the wavelength of light emitted from a red Helium–Neon laser passing through a red intensity filter (indirectly, by fitting a function to a single slit diffraction pattern, then forcing ...
-1
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1answer
122 views

Measure mass difference of an object without a scale

For a project i need to separate items based on their mass in real time. I like to explore measuring weight of an object (round metal ball) by taking photographs (several) during free fall and ...
2
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2answers
427 views

Is the Earth negatively or positively charged?

The Earth carries a negative electric charge of roughly 500 thousand Coulombs. Does that mean the Earth is negatively charged?
1
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1answer
55 views

Conductive glue

I would like to use some conductive glue to contact a silicon chip's back gate. Any suggestions on what to use? Can I use thermal silver paste? I would be operating at cryogenic temperatures below 4K. ...
3
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1answer
79 views

Motion in a Paul trap: $2n$th harmonic with larger amplitude than $n$th harmonic

Using a Paul trap, we captured the motion of a light charged particle (based on a rotating potential applied by AC current). Our rotational frequency was 50 Hz, and so when used FFT on the data, we ...
3
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1answer
101 views

Is it possible to use the parabolic shape of a rotating fluid to measure the angular frequency of the rotation of the Earth?

A fluid in a rotating bucket will take on a parabolic shape (for example of some simple derivations of this result see http://en.wikipedia.org/wiki/Bucket_argument). The assumptions that play into the ...
1
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2answers
142 views

Observations in the cathode ray tube experiement

1.One of the observations I learned was that the glass tube begins to glow with a brilliant green light. Many websites I read through refer to a fluorescent material. However, as shown in the above ...
0
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1answer
96 views

LHC Experiments for finding parallel universes?

I watched this video featuring Michio Kaku explaining parallel universes. In the last two minutes he said that experiments in the LHC could reveal that there might be parallel universes and then he ...
5
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0answers
95 views

If time isn't continuous, what is the best-known upper bound on the length of time intervals?

There have been several questions about whether time is continuous or not and it seems like the answer isn't currently known. I know quantum mechanics treats time as continuous and any mathematics ...
3
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2answers
105 views

How to determine what an object is composed of?

Heads up: This question has never been asked (here) before the way I will ask it here, so let's shed some light on it a bit. Prelude and anecdote(can be skipped): The other day I was walking home, ...
0
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1answer
44 views

How long does it take to scan a typical scanning electron microscope image?

I suppose the answer depends on resolution and imaging area, but can you provide some ball park measures of imaging times with an SEM?
5
votes
3answers
451 views

Why are roofs blown away by wind?

Whenever there are high winds, such as in storms, thin metal roofs on sheds as well as concave roofs on huts are sometimes blown away. One explanation provided to me said that the higher velocity of ...
0
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0answers
136 views

Difference between Vernier constant and least count

What is the difference between the Vernier constant and least count of a Vernier caliper?
10
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2answers
707 views

Interpretation of “transition rate” in Fermi's golden rule

This is a question I asked myself a couple of years back, and which a student recently reminded me of. My off-the-cuff answer is wrong, and whilst I can make some hand-waving responses I'd like a ...
2
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0answers
21 views

What were the immediate consequences Yang-Lee work on Weak Interaction?

I am studying the history of Modern Physics and Yang-Lee earned their Nobel the next year after the Cobalt experiments. I am familiar with the chronology, but am not clear what those findings meant to ...
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0answers
20 views

Is there a difference in binding energy between a regular material and a doped one?

Say Silicon and boron doped silicon. Would the doping affect the binding energy? Could I see this in an XPS spectra?
4
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0answers
79 views

Textbook about the handiwork of a HEP analysis?

I'm wondering if there is a textbook that describes the handiwork of a particle physics analysis. There are a bunch of books about theory, about the experimental aspects like detectors, and about ...
2
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0answers
39 views

What is the requirements from an optical lab in terms of darkness

I am characterizing an optical lab and would like to know therefore what are the requirement from a standard optical lab in terms of ambient luminescence. In other words how dark should an optical lab ...
1
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0answers
74 views

Buoyancy Correction for a Kater Pendulum

Question: Consider a Kater pendulum: that is, a rod with two cylindrical masses at both ends, with a knife edge between the two masses and another between one ...
1
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1answer
95 views

How can one explain the Kelvin Water drop experiment without assuming the container to already possess a positive charge?

Kelvin Water Dropper experiment refers to the electrostatic generator invented by Lord Kelvin, which uses falling water to generate a voltage by electrostatic induction occurring between ...
-4
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1answer
60 views

Free 'fall' on an Inclined Plane

I guess we can say that two identical balls on the same inclined plane with different heigths reach the ground at the same time. So, who was the first one to observe it? ...
4
votes
1answer
120 views

Can force be transferred through objects in a chain to the last object without any displacement of objects in the middle?

sorry for terrible graphical representation, I did an experiment, i took 6 coins fixed 4 of them in one place by placing some real heavy objects on them , then i took a 5th coin placed it in the ...
5
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1answer
76 views

Determining source of neutrinos

An article in Science, Evidence for High-Energy Extraterrestrial Neutrinos at the IceCube Detector, claims to have detected 28 neutrinos from an unidentified extra-solar location that has yet to be ...
4
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2answers
54 views

How to realize long-range interaction of colds atom in an optical lattice?

In the Bose-Hubbard model of cold atoms in an optical lattice, we consider only the short-range interaction or on-site interaction. Is it possible to realize long-range interaction similar to Coulomb ...
1
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2answers
138 views

Are there moments in particle collision experiments where the particle beam is in open air?

I keep encountering the story of Anatoli Bugorski, who apparently got hit in the head by a proton beam at the U-70 PS in Protvino, Russia. I find it difficult to believe that this is actually ...
3
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4answers
245 views

how long do large hadron collider experiments take?

This travel stackexchange answer has kinda got me wondering... how long do experiments involving the large hadron collider usually take? I'd expect you run it for a few seconds and bam - higgs boson ...
2
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0answers
117 views

Problem with (grad school) physics education? [closed]

(Just to anticipate, having looked at other closed threads about physics education, I don't think this question should be too opinion based or broad.) Since being in a lab now for a couple years, ...
2
votes
3answers
197 views

The cooling curve of tin during solidification

I'm going to measure the freezing point of tin by recording the cooling curve. It sounds like a dull experiment because all I have to do is to heat up the tin, wait for it to cool, and the computer ...
8
votes
4answers
377 views

Doesn't the use of a thermometer alter the temperature of the system?

If I place a mercury thermometer in hot water, heat energy will transfer from the water to the mercury inside the thermometer. Will this continue until thermal equilibrium is reached and thus the ...
1
vote
2answers
66 views

what could generate a high-pitched whine in electronics where the frequency depends on the current?

So I was operating a Laue machine recently which generates x-rays and fires them at a sample, and I noticed that there was a high-pitched whine coming from the instrument (nothing abnormal, just ...
6
votes
1answer
123 views

What are the different ways to measure the spatial curvature of the universe?

Just what the question asks. Assuming the Friedmann-Rovertson-Walker (FRW) metric, what measurements can be performed to determine the spatial curvature of the universe.
4
votes
1answer
145 views

Propagation of uncertainty when integrating or differentiating

Lets say I have a polynomial $ax^4 +bx^3 +cx^2 +dx +e$ and the uncertainties on each coefficient. Now I need to calculate the tangent at some points as well as some areas under this curve. How would I ...
4
votes
2answers
419 views

Understanding the Eötvös experiment

The aim of the Eötvös experiment was to "prove" that for every (massive) particle, the quotient $\frac{m_g}{m_i}$ is constant, where $m_g$ is the gravitational mass and $m_i$ is the inertial mass. ...
3
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0answers
42 views

Converting impact speed to pressure magnitude

In explosive safety and stability testing, a drop test is commonly used to determine the sensitivity to impact. In the test, an impactor of known mass is dropped. The initial height varies throughout ...
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0answers
55 views

Long range repulsion in anomalous solids

As far as I know things like rocks, walls, rubber balls, polished tables etc. exert a short range repulsive force on other everyday objects that is responsible for hardness, softness, collisions, ...
2
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1answer
62 views

Dark matter detection

In the detection of weakly interacting massive particles (WIMPs), which is the basis of dark matter, what is the use of the tank filled with liquid xenon? I mean, how does the releasing of photons ...