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

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0answers
21 views

Can unexposed PMMA be reused (successfully exposed) after development?

Can unexposed PMMA be reused (successfully exposed) after development? To clarify, PMMA is exposed using an electron beam in an SEM, and then the exposed areas are removed using a developer solution, ...
1
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2answers
59 views

objects distorted by the earths curvature

We are doing a project where we hope to make people think about the fact that the earth is round. We want to imagine if we in London could see others places in the world and how the earths curvature ...
3
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1answer
195 views

How to compensate ray displacement caused by refraction in glass slab

I need a nudge in the right direction, i guess (this is not a homework question). I want to calculate the total length of a ray from an emitter to a target which passes through a slab with known ...
8
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2answers
577 views

Does a muon detector on Earth's surface correctly measure the mean lifetime of a muon?

Just a simple question. Does a muon detector on Earth's surface correctly measure the mean lifetime of a muon? I would think the answer is no because most muons detected are created about 15 km above ...
2
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0answers
39 views

Can a value of “length, in meters” be attributed to a pair of ends which are rigid (but not at rest) to each other? [duplicate]

The definition of the SI base unit "metre" [1] doesn't seem to rule out explicitly that a certain value of "length, in meters" could be attributed to a pair of ends which are rigid to each other, but ...
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0answers
29 views

What jobs can you get in the field of physics? [duplicate]

What good, fun and reasonably well paid jobs can you get in the field of physics?
6
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1answer
122 views

How would one experimentally prove AdS/CFT correspondence?

What would be an experimental test of AdS/CFT correspondence? Or it's extensions? I've heard that people are studying AdS/CMT (condensed matter) correspondence, but I don't know the details of it? ...
2
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0answers
71 views

If two ends were a certain “length” apart were they therefore at rest (or at least rigid) to each other? [closed]

Considering the definition of the SI unit of "length" [1] and [2 (" method a.")] I'm missing any requirements about the two "ends" of the required "path travelled by light" being "at rest to each ...
3
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0answers
47 views

Alternative ways to take particle tracks photographs in a cloud chamber

I know that the most common type of particle tracks photography is in photographic plates, but i'm using a cloud chamber and I would like to know if there are alternative ways to take photographs of ...
0
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1answer
171 views

Electrostatics-Coulomb's Law

Coulomb's Law is an experimental result $$F=k_e\frac{q_1 q_2}{d}.$$ How did or What did Coulomb do to verify this law as it is applicable for point charges at rest and in reality charges won't be at ...
2
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0answers
83 views

Reflector Klystron and Isolator for ESR/EPR Experiment

I am doing a lab on ESR/EPR, and I would like to know how the reflector klystron operates. It is very old and the company who made our model does not exist anymore and there are no operation manuals. ...
0
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1answer
39 views

Microwaves and metal poles

I have an experimental setup like so: And if one looks closer at the lens, there are metal poles near the bottom of the lens (the extensions of the stands beyond the clamps) that are obstructing the ...
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2answers
121 views

Backward Time Flow?

Physicists say that time is moving foward because entropy always increases. But have physicists considered that we might be mistaken? Since there is no ultimate reference frame, it could be possible ...
3
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1answer
123 views

Why did it take a long time to discover top quark?

In high school physics, I learned that it took a long time before the top quark was discovered. One of the reasons that was given in my book was that the top quark has a large mass, much larger than ...
7
votes
1answer
183 views

What Causes the Noise Floor of Modern CCDs?

CCDs are getting pretty good these days, but all systems are subject to noise. A typical value for a CCD seems to be 20 electrons RMS per pixel. This article from qsimaging.com says CCD Read ...
1
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2answers
714 views

Experimental proof for Conservation of Total Energy

In physics, the law conservation of energy states that the total energy of an isolated system cannot change—it is said to be conserved over time. (Source : wikipedia(conservation of energy) And ...
3
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3answers
82 views

Simple Experimental Laser Characterization Parameters Ideas?

I have 2 months to do a project on characterization of a laser parameter. We have typical optics lab equipment (DFB Lasers, oscilloscopes, random number generator, etc.). I was told to choose a laser ...
0
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0answers
81 views

Problem with experiment results on drag force

I am trying to investigate the relationship between velocity and drag force of falling object in air. I used video analysis from logger pro to determine the displacement of the falling object at ...
10
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4answers
168 views

Observed composition of UHE cosmic rays

How much is known about the composition of ultra high energy cosmic rays (say $E>10^{20}\text{ eV}$)? I get the impression that the particles are often assumed to be protons or other heavier ...
3
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1answer
130 views

How to determine the order of indications of a clock?

Given the description of a clock $\mathcal A$, as (1) a set $A$ of all (more than 2) distinct indications of this clock, in no particular order (where the individual indications contained in set ...
0
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0answers
319 views

Does the Delayed Choice Quantum Eraser experiment prove consciousness causes collapse?

https://www.youtube.com/watch?v=H6HLjpj4Nt4 This question comes from the video above. If you don't want to watch the video, I'll cut to the chase. Essentially, it claims the Delayed Choice Quantum ...
0
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1answer
89 views

Issue with running a Van De Graaff generator

I am following this online video: http://www.youtube.com/watch?v=fsT69XnjxgU but my Van De Graaff generator is not working. I am using pvc pipes for the body, nylon and electrical tape as two rollers, ...
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2answers
243 views

Oil drop experiment and quantization of charge

How to systematically show that the resulting charges in oil drop experiment are integers multiplied by $e$ in other word how to extract $e$ from the data?
0
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2answers
182 views

does the rate of change of height varies for different fluids?

I decided to experiment for the rate of flow of liquids (like water, oil, acid, etc) from a burette. I decided to use Torricelli's law $v=\sqrt{2gh}$. When experimenting, the time taken for a viscous ...
3
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0answers
83 views

Did Penzias and Wilson need such a large horn antenna to discover the CMB?

Penzias and Wilson discovered the 2.7K Cosmic Microwave Background (CMB) Radiation using a 6 meter horn antenna, along with a cryogenic low-noise detector measuring at 4 GHz: ...
1
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1answer
44 views

Experimental methods for finding London penetration depth

I have been doing some readings on superconductivity and have come across the London penetration depth. I somewhat understand how it comes into play with the London equation and Ampère's law. Right ...
2
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2answers
154 views

Can we have light through out the house with out light being switched on for all the time?

Optical fibres are used to transmit light from one place to the other along curved path in a more effective manner. The optical fibres consist of thousands of strands of a very fine quality glass or ...
1
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0answers
55 views

Weighted average whenever a variance is 0? [closed]

So I have data for the number of times a certain event happens. Each column is a different event and each row is one trial. A sample of data would look like \begin{bmatrix} 1& 4& 7& ...
0
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5answers
325 views

Can we create invisible things?

We are able to see this beautiful world because of light. When light gets reflected from the object, the reflected light enters our eye retina and thus we are able see that particular object from ...
2
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2answers
331 views

Measuring background radiation

We tried to measure background radiation using a geiger counter for a experiment at school. The meter showed $0.12$-$0.21$ microSv/h during the day averaging at about $0.14$ mcSv/h. As we tried to ...
0
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1answer
75 views

How magnets create electricity in conductors?

what are the reasons for current appearing in a wire when wire is in a changing magnetic field?
1
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0answers
99 views

Do I understand measurement of dispersion relation in a solid correctly?

I'm currently doing an introduction to solid state physics course and have a quick question about measurement of the dispersion relation of phonons in a solid: The way I understood it is the ...
0
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1answer
152 views

Is there a way of measuring the spin along an arbitrary direction of a spin 1 particle?

I am familiar with the expression for spin 1/2 but haven't seen one for spin 1.
1
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1answer
231 views

Questions about MTW's “thousand” tests of the Einstein principle

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
votes
1answer
113 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 ...
3
votes
2answers
131 views

How do you measure proton's spin? [duplicate]

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
85 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
180 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
151 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
votes
1answer
131 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
162 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
49 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 ...
1
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0answers
55 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 ...
4
votes
2answers
146 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
86 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
35 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
votes
1answer
194 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
68 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
375 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 ...
4
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3answers
5k 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?