Questions tagged [experimental-physics]
For questions about design, process, data, or analysis of experiments and observations.
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Has the curvature of space from GR ever been validated? [duplicate]
It is my understanding that at low gravitational potentials like we experience on earth that the time curvature dominates and that the curvature of space only becomes relevant within stronger ...
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Barrier layer photovoltaic effect (BLPVE) and Bulk photovoltaic effect (BPVE)
Ferroelectric materials typically exhibit the bulk photovoltaic effect (BPVE). My question is that if a material taken as an absorber in a device which works on barrier layer photovoltaic effect (...
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What is a CP number? In terms of CP-Symmetry and CP-Violation?
When researching the origins of CP-symmetry and CP-violation, and the Fitch-Cronin experiment demonstrating 'indirect' CP-violation, I came across these statements:
https://www2.lbl.gov/abc/wallchart/...
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Error analysis in measuring wavelength using diffraction grating [closed]
If $\alpha_m$ are the diffraction angles where the diffracted wave has maxima, then the wavelength is given by the following
$$d\sin{\alpha_m} = m\lambda.$$
In order to find $\lambda$, I've run a ...
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Is charge accumulated when two conductors of different resistivity placed in series in an electric circuit?
Let's say two long cylindrical conductors of resistivity ρ1 and ρ2 are joined together and a current I is flowing uniformly through the cross section
So if we consider this scenario two different ...
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When performing a fast likelihood fit (flavio) why can we assume the uncertainties are weakly dependent on fit parameters?
In the angular analysis of the $B^{0} \rightarrow K^{*}\mu^{+} \mu^{-}$, Wilson coefficients can be determined from experimental data of angular observables through the following (flavio - a python ...
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Why does the placement of a lens effect the shape of the interference pattern in the Michaelson Interferometer?
Consider the simple Michaelson interferometer configuration below:
I'm working with this apparatus in lab, where we add an additional component (a bi-convex lens placed either between the light ...
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Why are accelerator beam neutrino experiments built an angle off the beam direction?
Was reading some papers and review articles on accelerator based neutrino experiments and this came up a few times. Most of what I could find mentions "shrinkage in neutrino energy spectra" ...
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Will water be superconducting if add enough pressure?
Recently, room temperature superconductor has draw a lot of attention. Previous studies haven shown $H_2S$ is superconducting near room temperature given enough pressure.
I wonder if water $H_2O$ ...
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Does the Sun or Moon affect weight measurements on Earth?
The gravitational acceleration due to the Earth at its surface, $g_E$, is
$$g_E = 9.8\hbox{ m/s${^2}$}.$$
The gravitational acceleration due to the Sun at the Earth's position is
$$g_S = 5.9 \times 10^...
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Experiment Prediction: How much light can pass through an opening?
The flow of current through a wire is limited to the size of the wire. Water through a pipe is limited by the size of the pipe. What about light? Is it limited in a similar way?
Let's say I drill a 1,...
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Weight of magnet depends on its N-S orientation?
I weighed a Neodymium disc magnet and found that it weighs about $1$ mg more when the north pole is upwards than when the south pole is upwards.
Can this be explained by "conventional" ...
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How does the Kennedy-Thorndike experiment test for time-dilation?
From the Wikipedia page (as of 3/6/2023),
The Kennedy–Thorndike experiment, first conducted in 1932 by Roy J. Kennedy and Edward M. Thorndike, is a modified form of the Michelson–Morley experimental ...
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Negative constant values in Hartmann's Dispersion formula
Can the λo values become negative or smaller value compared to standard wavelength. I'm getting the correct values even though λo is negative. I believe λo is constant, it can be any value but my ...
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Structure functions for mesons
I was researching about structure functions and understand how it's a probability density function that describes the distribution of quarks inside hadrons. However, since mesons also have quark gluon ...
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How can I make a toboggan to study projectile motion? [closed]
I'm currently working on an experiment due in a month in which I have to recreate this toboggan :
I would drop a ball at the top of it on the left and let it slide. I would then study the trajectory ...
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Problem with the Fisher information matrix in case of $N$ measurements of two observables
Let consider two observables, $x$ and $y$. Suppose that $y$ depends on the independent variable $x$ through the model $m(x; \boldsymbol{\theta})$, where $\boldsymbol{\theta}$ is a vector of model ...
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How to understand measurement uncertainty (error) from scientific papers in this form 6.67430(15)?
My question is very practical and is about real physical value measurements and related uncertainty.
As I understand now most scientists work with Student's t-distribution when they are estimating ...
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Best configuration of double slit experiment in a ripple tank?
I'm carrying out an experiment about interference and diffraction with double slit (multiple slits in a future) in a ripple tank.
I have the chance to 3d print the slits so I'm thinking about the best ...
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Where can I find sources on a QED partial reflection experiment?
In "QED: the strange theory of light and matter" Richard Feynman describes a thought experiment where a glass block and two photomultiplier tubes are set up so that he can calculate the ...
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How can a meson beam be created?
I was reading this thread where the answer states that to use deep inelastic scattering on mesons, we have to
"generate a meson beam (which is a bit of a trick in and of itself) and direct it ...
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How do scientists attempt to break quark confinement?
From what I understand, when energy is supplied to quarks, it elongates the gluon tube and when enough energy is put in, new quarks are formed, keeping quark confinement. However, I am inquisitive ...
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Damped oscillation experiment - damped harmonic motion
Does anyone know of any easy experiments to do that involves damped spring harmonic motion? Preferably an experiment in which I vary variable A and examine how it affects variable B.
I was thinking of ...
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Can a beam splitter be used to measure Earth's absolute motion through space?
Let say the Earth is not moving through space...Then a beam splitter that refracts the beam into 2 new created beams at an angle of 90° towards reflectors which will reflect the beams at 180° again ...
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Quantum physics book linking experimental data with theory
Kindly recommend book or resource which links quantum physics experimental data with theory. Any suggestion will be highly appreciated.
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How to convert bandwidth from wavelength to energy?
I have an x-ray emission spectrum obtained using wavelength dispersive spectroscopy (WDS), the spectrum gives us the number of counts (intensity) as a function of wavelength. I measured the bandwidth (...
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Experimental searches for magnetic quadrupole moment
My professor mentioned that a particle with an intrinsic magnetic quadrupole moment would be CP violating in an analogous manner to how a particle with an electric dipole would be evidence for new ...
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Are there any efforts to measure the ratio of the circumference of a circle to its diameter? [closed]
There is a mathematical constant $\pi$ that is known to a gazillion decimal places. Based on the usual axioms of geometry this value is coincident with the ratio of the circumference of a circle to ...
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Force supplied by oscillation generator: is there a way in finding the amplitude of the force?
In a mass-spring system with an oscillation generator, a force is supplied by the generator that causes the mass to oscillate. I know that the force is periodic/harmonic and I have defined it as $F=f\...
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Sagnac effect and active ring laser gyroscope
I have to help with some lab classes soon and for that I will be tutoring an experiment where the students will use an active ring laser gyroscope and measure the beat frequency that occurs when the ...
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How would you experimentally determine the damping coefficient of a system?
We have a suspended beam that we need to determine the natural frequency, and more importantly the damping, of. To avoid resonance.
The geometry of the beam is a little too complex to rely on theory ...
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Why the low mass resonance $K(1270)$ can decay into higher mass final states $K^*(1400)\pi$?
I’ve seen same explaining that the mass of a decaying particle must exceed the sum of the masses of its daughter particle.
But Why the processes like $K(1270)\to K^*_0(1400)\pi$ and $K_1^*(1400)\to K^*...
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Current bounds on the value of $g$ for antimatter
In 2011, the ALPHA experiment showed that the gravitational acceleration for antihydrogen was between -65 and 110 times the normal gravitational acceleration. Has there been any improvement on the ...
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Calibrating an inertial measurement unit (IMU) to zero/flat surface
I am building a digital spirit level using an inertial measurement unit (IMU), and I want to calibrate the device so that it shows the angle correctly. Does anybody here have experience with this kind ...
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Why would there be a larger data dispersion at minimums than at maximums in a graph of intensity against path difference?
I'm doing a rather simple experiment concerning the superposition of two waves and the impact that path difference of 2 identical waves has on recorded intensity at that point. However, there is ...
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Current through a solenoid: magnetic field gives a staircase graph
We were running current through a solenoid coil with an iron core, and measuring the resultant magnetic field strength. We expected a purely linear relation for the "current-field strength" ...
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Optical theorem verification
The optical theorem states that
$$\left.\frac{d\sigma}{dt}\right|_{t=0}\geq\frac{\sigma_{tot}^{2}}{16\pi}$$
where $\left.\frac{d\sigma}{dt}\right|_{t=0}$ denotes the elastic cross section for ...
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Bernoulli and direct-air jet when using overhead vents
There is this famous experiment to demonstrate the Bernoulli effect, where you try to very rapidly inflate a loose air balloon of sorts, like shown for example in this video. Here's a still image so ...
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By what experiment is the vacuum energy density actually measured?
I have heard that the actual vacuum energy density which is up to 120 orders smaller than the predicted QED value can be measured in experiments or cosmological observations?
What are these ...
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Do I need knowledge of fluid mechanics to do the ripple tank experiment? [closed]
I have to design and do an experiment for a course of my physics bachelor.
I have thought about ripple tank in order to study diffraction, interference and maybe Doppler effect.
As far as I read from ...
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Motor efficiency experiment
I want to try and measure the efficiency of the motor by varying voltage. So my independent variable will be voltage and dependent variable will be power. However when i actually am doing the ...
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How can we detect gravity phase-shift in quantum mechanics?
I have been searching for a satisfying answer on how we can detect the predicted phase shift due to the gravitational potential in quantum mechanics. Specifically, Sakurai, describes in his book the &...
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Reliability vs Accuracy vs Precision vs Validity [closed]
I am trying to distinguish the difference between Validity, Accuracy, Precision and Reliability. I understand that accuracy is a measure of how close something is to the true value and precision is ...
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How damping constant of pendulum varies with length of wire? (experiment result confusion)
I'm a high school student doing an experiment for my physics course. The experiment aims to find out the relationship between the damping constant and the length of the wire. The constant is ...
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How to rule out that the speed of light was different in the past?
The constancy of the speed of light is a fundamental principle in modern physics, and it is supported by a wide range of current experimental evidence.
There is no evidence to suggest that the speed ...
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Do lower frequency sound waves penetrate through materials better than high frequency waves
I was doing a physics experiment today where we played different frequencies at the same volume and a sound recorder at the other end with a sheet of cardboard in the middle. We found that the higher ...
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Changing cube splitter's reflection% with paint
Hi folks, I need beam #2 to be reflected as close to 100% as possible, while ALSO allowing beam #1 to be transmitted through as close to 100% as possible.
Will black paint on side 3 alow this? Or is ...
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Would a Magnet Weigh More on a Metal Scale than a Plastic One
If you had two scales, one made of metal one made of something like plastic (not magnetic), and weighed the same magnet on both scales would it read heavier on the metal scale rather than the plastic ...
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The DOS effective mass
If we consider the spin-orbit coupling in semiconductors, it is known that the degeneracy of the valance band is lifted up and we got 2 sub-bands the light hole and the heavy hole that are still ...
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What is the smallest entropy value ever measured?
Entropy is measured in J/K or in J/K/mol.
What is the smallest value ever measured in an experiment?
Google Scholar does not seem to help.
In other words, how good are scientists at measuring small ...
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