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

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1answer
145 views

Inexplicable Results in a Vacuum Experiment

We've been doing the following experiment in our Physics Lab course and are coming up with some strange results which we're at a loss to explain. The purpose of the experiment is to determine the ...
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0answers
19 views

Mixing liquids when applying a voltage

I'm thinking in the following experiment: A) Two (non mixable (like water and oil)) liquids are going to lie in a container, in the extremes of the container there are two electrodes, those ...
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2answers
87 views

Does a Michelson-Morley experiment uphold mass-energy equivalence and special relativity?

If there is an experiment that best supports $E=mc^2$, is it the Michelson-Morley experiment?
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0answers
29 views

How is 2D spectroscopy able to show quantum coherent transport through networks?

For wave-like (quantum coherent) energy transfer in networks (eg. propagation of excitation in photosynthetic protein complexes of algae or FMO complex in plants) 2D electronic (photon echo?) ...
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0answers
13 views

Can “uniform motion” (or “mutual rest”) be determined intrinsically, by members of Synge's “five-point curvature detector”?

In his description of a "five-point curvature detector" [1], J. L. Synge exhibits a Cayley-Menger determinant in terms of "optical distances" between five distinct participants; and he states that the ...
7
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1answer
119 views

How legit is this paper claiming to have observed Hawking radiation? [closed]

I recently stumbled upon this paper. In it, the author claims to have found a signature for Hawking radiation in a condensed matter system. I know that experimentalists have been trying to find ...
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2answers
218 views

What is the experiment used to actually observe the position of the electron in the H atom?

Prior to observation, the electron can be found anywhere (from inside the nucleus to the ends of the universe), but once its position is determined the answer is precise (albeit its momentum is not ...
2
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1answer
63 views

What is $Q_p/Q_e$ experimentally? [duplicate]

What is the experimental value of the ratio between the proton and the electron charge? Or more generally, is there a table that lists the ratio of the different nuclei charges to that of the ...
0
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1answer
82 views

Why can't this flying swimming pool work in practice?

I was browsing a website with funny pictures and found this one quite interesting.
4
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1answer
73 views

Experimental determination of speed of light

How is the speed of light measured by the most current method i.e. using lasers and atomic clocks? Alternatively, is there a better method?
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1answer
27 views

Why is the decay time of the scintilator pulse of the gamma rays longer than the decay time of neutrons?

When you discriminate between neutrons and gamma rays (using a liquid scintillator) you use the fact that the pulse due to gamma rays have a longer decay time than the pulse due to neutrons. When you ...
3
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1answer
56 views

Why nano indentation is used to test bulk material?

I am curious why nano indentation is used? I can understand when material size goes to micros or below, conventional hardening methods can become difficult to use. However many papers say that ...
0
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1answer
63 views

Resolution of experiment is lower than the detector, so how to weigh the data?

I am attempting to create an atomic model based on data from a transmission electron microscope (TEM). Basically you shoot electrons at bunch of identical molecules stuck to a grid, and look at the ...
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0answers
90 views

A-level electromagnetism experiments? [closed]

Does anybody know any A-level experiments investigating electromagnetism that can produce good data relatively simply?
1
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1answer
40 views

Is there a rigorous, explicitly geometric, general characterization for whether a given clock had been “good”, or not?

In MTW, "Gravitation", there is a brief section (p. 26 and Fig. 1.9) discussing that clocks may be characterized, trial by trial, as having been "good" in the trial under consideration, or having been ...
0
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1answer
113 views

Simple pendulum is not so simple as it seems to be? [duplicate]

Does a simple pendulum come to stop due to the action of gravity ? Consider : No air drag, No change in place.
1
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2answers
108 views

Which error propagation equation to use for a function of 2 variables?

So I have been taught two formulas for error propagation: For $Z=A+B$, $\sigma_Z=\sqrt{(\sigma_A^2+\sigma_B^2)}$ and for Z=AB or Z=A/B ...
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3answers
286 views

Correction factor for standard deviation

I have conducted an experiment, from which I obtained a finite amount of values for the gravitational acceleration. The amount of values ranges from 6 up to ~150 values. I have the unbiased sample ...
0
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1answer
189 views

Orifice Jet Flow experiment

I am writing up a report on Orifice jet flow experiment in which I am required to find coefficient of flow velocity, $C_v$, and the Coefficient of discharge, $C_d$. There are couple of things that I ...
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3answers
204 views

How do we physically apply the operators of quantum mechanics on a particle?

What do we have to perform physically that is equivalent to applying those quantum mechanical operators on a state $|\psi\rangle$? Edit: I have removed the part I was asking regarding measurement ...
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1answer
75 views

Error in standard deviation and variance from error in data

I have a set of datapoints $x_i$ which have known upper bounds for absolute errors $\delta x_i$. (To clarify, this means each $x_i$ is actually $x_{i_0} \pm \delta x_i$). For simplicity, assume that ...
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0answers
257 views

Do these photographs depict the Higgs Field?

[PHOTO 1] Colter Dallman wrote in his paper - Space, Density, Relativity and Higgs Field Occupancy - (available online): ...
7
votes
1answer
181 views

Is it THE Higgs?

Can anyone brief me, about the status of the Higgs boson discovery and verification at CERN? Specificaly is it A higgs or THE higgs? If it is A higgs, where exactly does it differ from THE higgs? ...
3
votes
2answers
161 views

Is a wave packet physically realizable as a Fourier series?

In QM a wave packet is modeled as an infinite, or almost infinite, Fourier series, and the Fourier transform provides a transformation between momentum space and position space. To what extent is ...
0
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1answer
201 views

2 vacuum pumps in parallel [closed]

I have a problem with a vacuum pump that cannot generate enough vacuum to grip an uneven item. There is a spare vacuum pump in parallel which I will turn on and run at the same time to try and get ...
0
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1answer
67 views

Can this type of graph be analysed to produce any meaningful data?

The above is a graph of pendulum length on the x-axis measured in metres, and pendulum period on the y axis measured in seconds. The pendulum period is not squared. If I square the pendulum period, ...
4
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1answer
1k views

Is it possible to use “negative sound waves” to “cancel out” a sound to create silence?

I saw youtube videos that claimed to do this, although I'm quite certain the videos just excluded sound and lied. However, I am wondering if the physics of this is actually possible - to create a ...
1
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1answer
270 views

What is logical way to calculate percentage error?

I wish to know logic behind percentage error formula. Say, $A$ is measured or calculated quantity, $B$ is theoretical or known or benchmark quantity. Then, what should be the formula for percentage ...
3
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0answers
91 views

Did these scientists actually detect dark matter?

I came across an article in The Guardian (definitely not the best source for science, but that's why I'm asking this question) that said that a team of scientists may have detected dark matter ...
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0answers
39 views

Scintillator Length Calculations

This is sorta homeworkish, yet it still relates to my understanding of the physics behind it as well. Does anyone know how you determine t_98 (aka the length to contain 98% of the energy) for a ...
6
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2answers
623 views

How is antimatter made?

How is antimatter made in laboratory? Can anyone explain, at the particle level, specifically how anti-protons and anti-electrons are made?
3
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0answers
52 views

How could we find preons?

If I understand correctly, scientists were able to find strong evidence for the existence of quarks by using deep inelastic scattering. If quarks (hypothetically) are composed of preons, could we use ...
2
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1answer
91 views

Stimulated emission in Nd:silica glass, energy levels broadening and lasers

It is known that due to absence of uniform crystalline structure in Nd-doped glasses (comparing to Nd:YAG and Nd:YVO4 crystals) energy levels of Nd+ are significantly broadened. This means that we ...
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1answer
68 views

Reason behind the train remaining intact to the Train track

I was wondering why trains moving at such hard speeds remain intact to the railway track even while turning. Is it because of friction ?
4
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2answers
96 views

Does measuring the air temperature near a 21 lane asphalt highway impact measurements?

The official temperature in Sydney is measured at the Sydney Observatory. This is located near the city side of the Sydney Harbour Bridge - which is a major highway. My question is Does ...
21
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3answers
978 views

Has the gravitational interaction of antimatter ever been examined experimentally?

I know that the gravitational interaction of antimatter is expected to be the same as normal matter. But my question is, has it ever been experimentally validated? I think it would not be a trivial ...
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2answers
176 views

Outcome from this experiment with solid hydrogen?

Let's say that we have two solid hydrogen blocks (or at least two solid hydrogen lattices) in a vacuum. Both blocks have perfectly smooth surfaces which are later put together. Before putting blocks ...
0
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1answer
59 views

How was phase randomly changing in CHSH test (M. A. Rowe and others)?

Measuring phase of photon should always be random while checking CHSH inequality, but i can't explain this: http://qudev.ethz.ch/content/courses/QSIT08/pdfs/Rowe01.pdf (the most clear experiment i ...
2
votes
1answer
101 views

Experimental set up of vertical circular motion

We are trying to do the following experiment: http://farside.ph.utexas.edu/teaching/301/lectures/node90.html. At the moment, here is the experimental setup: We have a rod 0.4 m long which rotates ...
2
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0answers
104 views

Formulas for Haitz's law?

The Nobel Prize in Physics 2014 is for LED. There is a related Haitz's law: ...every decade, the cost per lumen (unit of useful light emitted) falls by a factor of 10, and the amount of light ...
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3answers
141 views

Is a gapless system always conducting and a gapped system insulating?

In an answer to this question, @user566 mentioned that there is a qualitative difference between gapped and gapless systems; that gapless systems are conducting and gapped system are insulating. Is ...
3
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0answers
77 views

Clarification about Bragg's law explanation

The Wikipedia has this illustration of Bragg's law and then says The two separate waves will arrive at a point with the same phase, and hence undergo constructive interference, if and only if ...
0
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1answer
42 views

How much measurements are usually done to test CHSH inequality?

How much times particle is measured during experiment? How much times sub-experiment (state of detector) is randomly changed? Where i can find such statistic?
3
votes
1answer
98 views

How do we perform transverse measurements in a two level system?

In quantum mechanics any two level system can be mapped onto effective spin variables. If the system is defined by two energy levels, $|E_1\rangle$ and $|E_2\rangle$, the Hamiltonian is $$ H = ...
2
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0answers
154 views

Odd experiment results (electromagnetics)

Okay, a bit of background. So I'm working on a linear accelerator (you might know it as a Gauss rifle), and I had worked through the equations I thought I needed (Magnetic force, displacement, etc.) ...
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0answers
37 views

Why can't we use the Neyman-Pearson likelihood ratio directly?

If you have a bunch of events and would like to choose a cut to distinguish background and signal, you can take the likelihood ratio $$ \lambda(\vec x) = \frac{f(\vec x| s)}{f(\vec x| b)} $$ and the ...
4
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2answers
120 views

Is fluorescence from a single atom/ion visible with the naked eye (e.g. in a strongly coupled trap or cavity)

I remember sitting in on a conference talk by a person (possibly Rainer Blatt) doing research with trapped ions (or single atoms strongly coupled to light in an optical cavity), and the person showed ...
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0answers
50 views

What sort of things do condensed matter experimentalists measure and how?

What sort of things do condensed matter experimentalists measure and how? Do they do scattering experiments? If voltages are measured then how? I want to know what specific experiments are done. The ...
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0answers
48 views

Functional relationship of pressure and position(1d)

so today I started doing my research on oscillations in a course on advanced mechanics. The experiment was to mathematically model the speed of sound in air and experimentally prove the usability of ...
1
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1answer
57 views

Ideal gas law in open volumes

I often find in text books that the ideal gas law given by $p\cdot V=m\cdot R\cdot T$ is applicable in a closed system, still, some use it for open systems (like freezing the system at a given ...