Questions tagged [experimental-physics]
For questions about design, process, data, or analysis of experiments and observations.
849
questions with no upvoted or accepted answers
16
votes
0
answers
250
views
Why do flux qubits have to be micrometer-sized?
Flux qubits are made using micrometer sized Josephson junctions. They exploit superconducting properties to create and interfere with the magnetic flux between them.
My question is that I've seen ...
- 261
11
votes
0
answers
295
views
Experimental Hopf fibrations
Recently I read a paper where the authors experimentally constructed a Hopf fibration - that is, they created a quantum system where the nematic vector field of the system had a non-zero Hopf ...
- 751
8
votes
0
answers
172
views
Large Hadron Collider 2015 upgrade, what may we discover?
I realise that the initial answer to my question that may come to mind is, "we don't know yet, obviously" But my question is hopefully not opinion based.
For example, does this upgrade have a ...
user81619
8
votes
0
answers
153
views
Experimentally diminishing random errors for low wavelength UV observations
Part of the work that I do involves observations of solar low wavelength UV observations, specifically UV-B and UV-A II (up to 340nm). I have noticed that when I observe responses on a CCD or CMOS ...
user60063
8
votes
0
answers
247
views
Is there a cheap way I can do a Bell inequality experiment?
My work is almost completely theoretical/computational. But I'd really like to do a Bell inequality experiment just so I can personally see this (the best way to learn something is hands-on, right?)
...
- 2,859
8
votes
1
answer
305
views
Does this method of predicting the ratio of translational diffusion coefficients for a sphere and a sheet, work?
Imagine that I have a spherical particle of molecular weight $M$, volume $V$, and some experimentally observed center-of-mobility translational diffusion coefficient $D_{sphere}$ in water. I take ...
MorningCoffee1998
7
votes
0
answers
142
views
What is required for a minimum viable Bell test experiment at home?
My objective is to create a tabletop Bell test experimental setup generating data of suitable quality for undergraduate education or satisfaction of personal curiosity; remaining free from loopholes ...
- 283
7
votes
0
answers
211
views
Measuring the Dirac field
If the Dirac field $\psi(x)$ is to the electron as the Electromagnetic field is to the photon, why is it that we can measure the Electromagnetic field, whereas the Dirac field we cannot?
- 335
6
votes
0
answers
247
views
Experimental time-series for quantum particle-in-a-box or simple harmonic oscillator?
I would like to see experimental results for repeated measurement of a single-particle, quantum system that is approximately either particle-in-a-box or simple harmonic oscillator. If particle-in-a-...
- 4,787
6
votes
0
answers
312
views
How to cleave a perovskite single-crystal in vacuum?
I am trying to cleave the lead-halide perovskite in vacuum to study its intrinsic electronic properties using photoelectron spectroscopy, since it is difficult to remove surface adsorption without ...
- 171
6
votes
0
answers
62
views
Sterile (4th) neutrino and cosmological bound
Recent results by MicroBoone seems to give support to old LSND experiment in favor of a fourth neutrino (sterile). How does it fit with the current cosmological bound for neutrinos?
- 6,175
6
votes
0
answers
192
views
How can I estimate meta-uncertainty?
A type A uncertainty estimate is derived from repeated measurements. For example, I may estimate the uncertainty on a measurement by repeating the measurement $N$ times and then calculating some ...
- 2,987
6
votes
0
answers
589
views
On the right-angled fork track of alpha particles
In high school we were told that the idea "alpha particles are actually helium nuclei" came from observing the right-angled fork track, produced by placing an alpha source in a diffusion cloud chamber ...
- 61
6
votes
0
answers
89
views
Experimental tests of Cluster Decmposition
How tight are experimental and astrophysical tests on whether Cluster Decomposition is satisfied at various space-like separations?
Is there a review paper or a standard reference on the question?
I ...
- 9,832
5
votes
0
answers
68
views
Does 5G affect your physics experiment?
Our institution wants to lease a nearby roof for a 5G mast. Has anyone experienced the installation and operation of telecoms infrastructure - particularly 5G - significantly affecting physics ...
- 527
5
votes
0
answers
320
views
Lightning through helium gas
Assuming that some distant planet had an atmosphere of helium and(due to extremely cold temperatures) a "water cycle" of neon, what would happen if the theoretical neon clouds acted in a ...
- 51
5
votes
0
answers
162
views
How do measurements of $G$ account for variations in the local gravitational field?
One of the notable discrepancies of modern physics is the current disagreement of measurements of the gravitational constant $G$, well beyond reported uncertainties (and agreeing only to about 1 part ...
- 1,002
5
votes
2
answers
1k
views
Explanation of formation of Newton's rings
I was asked to do a lab report in my University about Newton's rings experiment that we made in lab. I understand that the aim of the experiment is to measure the wavelength of a light after the ...
- 163
5
votes
1
answer
2k
views
Do a floor tile or dry sand conduct electricity?
If you touch an electric wire while standing on a ground made of soil or floor tile, you will get electrocuted. So, electricity passes through it. Right? Shall I conduct an experiment by passing ...
- 49
5
votes
0
answers
236
views
Quantum (spin/thermal) Hall v.s. (Spin/Thermal) Quantum Hall effects
Are the following concepts defined correctly, as I understand:
Quantum Hall effect is a quantum-mechanical version of the Hall effect, observed in two-dimensional electron systems subjected to low ...
- 7,600
5
votes
0
answers
114
views
Is it caustic reflection or hyperbolic projection?
actually last night I noticed a strange form of light rays on the wall of my room which were reflected off a CD. Here is its photo:
Please let me know what is it exactly? A caustic projection or ...
5
votes
0
answers
153
views
How can one confirm creation of magnetic graphene?
Recently my high school physics teacher contacted me looking for an expert to ask about this situation. I am paraphrasing his correspondence below:
I just had a a student accidentally create magnetic ...
- 333
5
votes
0
answers
349
views
Selecting an epi-illuminated objective for optical microscopy
I am currently trying to improve my silicon microphotography. To provide context: this is what I get with a 10x epi plan objective¹:
This is what I get with 40x epi plan objectve with NA=0.65:
I can ...
- 151
5
votes
0
answers
254
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:
http://en.wikipedia.org/...
- 326
5
votes
0
answers
399
views
Is there precision experimental evidence for Furry's theorem -- that only even degree VEVs are non-zero?
Is there precision experimental evidence for or contradicting Furry's theorem -- that only even degree VEVs are non-zero, specifically for the EM field?
- 9,832
4
votes
0
answers
44
views
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 ...
- 694
4
votes
0
answers
289
views
How do you weight a chi square for uncertainties in $x$ and $y$ (different units)?
So I have experimental data for energy vs angle with uncertainties in both the $x$ and $y$ direction for every point. I am comparing this to a known curve/data points. Is it possible to calculate a ...
- 41
4
votes
1
answer
93
views
Is there any experiment to check discreteness of space?
This article from 2015 seems to suggest that there will be experiments to check discreteness of space:
If space-time is discrete, there should be imperfections. And even if
rare, these imperfections ...
- 385
4
votes
0
answers
85
views
Principles and methods of measuring the orbital angular momentum of $\rm H$-atom
When we talk about the orbital angular momentum (OAM) of the $\rm H$-atom, we mean the eigenvalues $l(l+1)\hbar^2$ of the OAM operator of the electron $\hat{L}^2$ defined from its classical ...
- 477
4
votes
0
answers
55
views
Splashing of Falling Sphere does not depend on Sphere Size
I am reading through a Nature article where the authors study whether a sphere dropped from height into a body of water has enough velocity to splash and form the classic effect where air is pulled in ...
- 894
4
votes
2
answers
126
views
Operationally, how do I choose between measuring position or momentum?
First a simple example to illustrate the essence of the question: If we have a spin half particle in the $S_z+$ state and if one wants to choose from either measuring $S_z$ or measuring $S_y$, which ...
- 155
4
votes
0
answers
115
views
Experimental challenges of increasing the size of a Bose-Einstein condensate
My question is partially inspired by this question. I know that BECs have been created whose side lengths are on the order of microns, while others have managed to make a side length of approximately $...
- 573
4
votes
0
answers
1k
views
What is the third peak in the spectrum of Sodium-22?
I collected this spectrum from a sodium-22 sample in an instructional laboratory. The sample was set in front of a germanium detector which sends a signal into a pulse height analyzer and plots a ...
- 990
4
votes
0
answers
381
views
How can I test whether my cloud chamber is supersaturated or not?
Me and my friend are building a diffusion cloud chamber for a school project. In stead of using dry ice or a peltier, we have used the phase changer of a freezer to cool our plate. We were able to ...
- 78
4
votes
0
answers
146
views
What experiments confirmed Poynting's Theorem?
Actually, I have two related questions. The fist is the above question. The second is, what experiments confirmed that $\varepsilon_0\left(\frac{E^2}{2} + c^2 \frac{B^2}{2}\right)$ is the ...
4
votes
1
answer
129
views
How is Spin experimentally determined?
I know what spin is and how theories determine it for particles. What I don't understand yet, is how people, through experiments and data analysis or whatever, reach to confirm/say that the $X$ ...
- 3,687
4
votes
0
answers
99
views
How can I precisely measure the intensity of the Hydrogen Alpha (Balmer) line at low intensities?
I assume that I will need some kind of very precise filtering, but how is that accomplished? After that, photon counting at worst, but I am expecting millions of photons per second.
The background is ...
user56903
4
votes
0
answers
103
views
Experimentally realizable states for bosonic quantum fields
I would like to know which type of quantum states of a bosonic field, that have an explicit analytical expression as vectors/density matrices in a symmetric Fock space, can be prepared in an ...
- 11.8k
4
votes
0
answers
81
views
How can the effects of temperature be accounted for in-situ electrical resistance corrosion monitoring?
In reading the Berkeley Lab's article Rust Never Sleeps, where research is underway investigating the use of iron oxide rust as a photovoltaic, they state:
Rust – iron oxide – is a poor conductor ...
user77400
4
votes
0
answers
193
views
How to express Allan variance without neglecting clock drift
Allan variance, $\sigma^2[ \tau ]$, or its square root (Allan deviation, $\sigma[ \tau ]$) is a quantity (as function of parameter $\tau$) which is said to be a measure of (or related to) "stability ...
- 4,133
4
votes
0
answers
217
views
Baryonic density in collision experiments
Does anyone know any way of estimating the net baryon density in collision experiments, e.g. in LHC, RHIC, or the upcoming ones at GSI-FAIR?
I have comes across many hand-waving arguments, sample -
...
- 3,144
4
votes
0
answers
63
views
Experimental results regarding non-extensivity in small systems
From a statistical mechanics point of view, the extensivity of thermodynamics arises from the fact that we can neglect interaction terms in the Hamiltonian. This allows us to infer that when we put ...
- 33.3k
4
votes
2
answers
63
views
4
votes
2
answers
203
views
Neutrino Nuclei Coherent scattering and the Dark Matter lower wall
Suppose that current and new forthcoming dark matter direct detection experiments find no evidence of Dark matter events and exclude interactions of hypothetical DM particles (like LSP or similar) in ...
- 6,175
4
votes
1
answer
255
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"(https://arxiv.org/abs/gr-qc/9210010)
Is ...
- 5,565
3
votes
0
answers
32
views
What is the meaning of "Dual Accuracy" on this datasheet?
I'm trying to determine the uncertainty in some of my measurements, and one of the variables I measure is temperature, using a Tenma 72-7715 thermometer. I looked up the datasheet to find the ...
- 87
3
votes
0
answers
52
views
Quasiparticle interference experiment - why backscattering is usually dominant?
I am reading Avraham et. al (2018) Quasiparticle Interference Studies of Quantum Materials about quasi-particle interference (QPI) experiments. In the simplest case where they use QPI to study the ...
- 726
3
votes
2
answers
150
views
Cloud Chamber Failure
Me and my friend are trying to build a working cloud chamber to find muons.
We’ve built the chamber more than six times, and only the first one worked.
In our latest cloud chamber we used a big ...
3
votes
0
answers
807
views
Relationship between resonance frequency of a cup and amount of water filled
For a science project I chose to investigate the relationship between the resonance frequency of cups and the amount of water filled in it. I filled the cup with 10 grams of water each time, and used ...
- 31
3
votes
1
answer
148
views
What is the reason for keeping the mercury bulb in a Callendar's compensated constant pressure thermometer in an ice bath?
The following statement explains the main source of error in a constant volume gas thermometer:
Figure 1 : Constant volume gas thermometer
In constant volume gas thermometer, the gas in the capillary ...
- 5,148