# Questions tagged [measurements]

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### Quantum measuring simulation

Hi I want to understand a concept that I been thinking about. I'm trying to simulate the energy measurement of a system (a many body quantum system to be precise), and I'm trying to simulate a quantum ...
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### Error calculation for a relative difference with only one standard deviation (STD)

I have a quantity that is calculated with two measurements, but I only have a tabulated standard deviation for one of the measurements. How would I calculate the error on the calculated quantity? The ...
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### What can I give as an example for a dumb instrumentation system? [closed]

I've searched through many websites and textbooks but none of them have given an example for a dumb instrumentation device.
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### Is redshift an accurate method for measuring distances of distant galaxies and quasars?

I'm currently in 11th grade working on a science project about measuring distances using redshifts. I understand how the wavelength of a light wave increases when an object moves away from the point ...
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### How to add markers to IR photographs

I'm using an IR camera to identify thermal patterns. The thermal images are similar to this [LINK] image. I'd like to add markers to the area being measured to determine dimensions and normalize the ...
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### What is the cross-section area of an electrode when measuring electrolytic conductivity?

If we have two flat plates, then the area is understood easily. However, if our two electrodes are like this: then will we take the area of $S_1$ or $S_2$?
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### Heisenberg microscope for momentum

In the "Heisenberg microscope", the position of a particle is measured using a photon. The higher the photon energy, the better the precision in measuring the particle location is, but the ...
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1 vote
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### Hall sensor for electric(!) field?

Is it (in principle) possible to measure the strength of an electic(!) field with a hall sensor? I think so, for the following reasons: The hall sensor is a conductor. If we place an conductor in an ...
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### How can one measure the exact momentum of a particle in a quantum mechanical context?

According to quantum mechanics you can't measure both the position and momentum of a particle at the same time. A particle has an associated wave function. If you want to measure the momentum of a ...
• 1,359
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### Is Daredevil's superpower conceptually possible?

The Marvel superhero Daredevil is blind but has heightened senses, enabling him to perceive the world around him to a far greater extent than a regular person. In his depiction in the Netflix live-...
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### If a measurement has 5% error, can we say it has 95% accuracy?

Most often when, in a numerical problem, it is demanded that we calculate the accuracy of the final result, we write the final result in terms of the error. So I want to know if, in a measurement, ...
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### What materials will work for a Millimeter Wave Dosimeter?

Hi I'm trying to duplicate the experiment in this paper. However, I'm having some trouble sourcing the carbon loaded teflon described in it. What other materials would work? Specifically, would ...
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1 vote
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### Validity of power law fit (and analytical fit choice)

Context I am carrying out molecular dynamics simulations of trapped ions in a radio-frequency field of amplitude $U_{RF}$ + DC (see details https://arxiv.org/abs/2102.04098). I am studying radio-...
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### Can experiments show if there are real non-local hidden variables?

Local hidden variables are ruled out by experiment (Bell). Non-local ones are not excluded though. Are there experiments thinkable to discern if they really exist or if reality is intrinsically ...
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### Significant number and Measurement resolution

It would be kind if anybody could explain how many significant numbers do we have in 0.00034 if the resolution is 0.001? Without the special mention of "the resolution" my answer was 2, But ...
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### Minimum information required to measure your local physical environment

In Andy Weir's "Project Hail Mary" protagonist Ryland Grace wakes up in an environment and with a few physics experiments timing falling objects he relatively quickly determines that he is ...
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### Is there concurrency or is it just missing precision?

Imagine I measure the time of two balls hitting the ground. My stopwatch displays 5.5 seconds for both of them. Then I could say, that both balls hit the ground at the same time. But if I add a few ...
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### Some books write coulomb force is medium independent and some write it is medium dependent why so?

Some authors say coulomb force is medium independent others say it is medium dependent. I know value of universal gravitational constant does not depend on medium.But value of permittivity does depend ...
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### Are there any effects upon a proton an electron can impart when returning to its ground state after absorbing and emitting a photon?

Basically the title. When an electron and proton are bound say within a hydrogen atom, are there any measurable effects upon the proton when its electron goes through the process of absorbing, ...
120 views

### Can we measure the ground state energy?

If we consider a quantum harmonic oscillator, the ground state energy $\hbar\omega/2$ is typically stated to be not measurable, as energies are always measured as relative values (energy differences). ...
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### Is there data for natural background radiation measurement?

I am looking for raw data of alpha/beta/gamma particles natural background long-term measurement (preferably day by day or second by second for at least a few weeks), but cannot find any. I would be ...
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### Why does everyone keep using torsion balances for measuring the gravitational constant?

Most of the experiments aimed at measuring the gravitational constant use very complex setups involving suspended balls (Cavendish-like experiments). This is however not exactly the ideal setup – and ...
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### Calibration of a Pfizer type hardness tester

I am working on testing of hardness of pellets for their hardness and crushing strength. Currently I have a Pfizer type harness tester at my disposal. It came with a default spring, which we found was ...
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In the standard linear response theory, the variation of an observable $A$ at time $t$ due to the perturbing Hamiltonian $H'$ is \langle \delta A(t) \rangle = \int_{-\infty}^t dt' \langle [A(t), H'(...