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

learn more… | top users | synonyms (2)

0
votes
1answer
18 views

What do I need to calculate UV intensity?

I have a mineralogical UV lamp that I want to use for some research, I only know it's wavelengths. To calculate the µJ/cm3, what else is needed? Distance, time, wattage? Is the value I'm looking for, ...
0
votes
0answers
11 views

photometric redshifts - the origin of 1 / (1+ zspec) in photometric accuracy

i have a training sample of sources with known spectroscopic redshifts ($z_{\rm spec}$) and i run a photometric fitting code that uses a template to determine the photometric redshifts ($z_{\rm ...
5
votes
2answers
526 views

Evidence for quantum gravity from gravitational waves

The rumor spreads that physicists will make their big gravitational wave announcement this thursday. I am far from being an experimentalist, but I want to know if there is any chance that the ...
0
votes
1answer
29 views

Open Source Particle Tracing Software

I am fairly new to this forum. I am designing an ionospheric plasma testing environment in a thermal vacuum chamber and to do so I require some form of multi-physics package for simulations .. such as ...
2
votes
2answers
32 views

Why did James Chadwick use berryllium to discover neutrons?

In Rutherford's alpha particle scattering experiment he used gold foil because it's malleable and can be drawn into very thin sheet. Why did James Chadwick use Berryllium while discovering neutrons ...
1
vote
0answers
20 views

How to arrange a 3d cymatics experiment?

Various researchers have filmed levitating polystyrene using sound waves. If i were to take 3 speakers and attempt to visualize the standing wave fields formed by the three speakers, how would i do ...
1
vote
1answer
32 views

Single slit diffraction - choosing a wavelength?

For the classic experiment of determining the slit width of a single slit. If we assume the rough order of magnitude of the width is known. What factors determine the choice of wavelength? (Clearly ...
0
votes
2answers
51 views

Is the video “How to Reveal Subatomic Particles at Home”'s explanation of its experiment misleading?

https://www.youtube.com/watch?v=wN_DMMQEhfQ The video asserts that along the path of an electron or muon, a trail of condensation will appear. But from what I understand, if an electron or muon (both ...
2
votes
0answers
31 views

How to control a dc motor? [on hold]

I am in 8th standard and I am doing a project on 3d printing pens. I want to know how to control a dc motor, so that when I press a button it should increase its speed gradually till it reaches its ...
34
votes
2answers
3k views

Cause for spikes in trinity bomb test

In Richard Rhodes' book, The Making of the Atomic Bomb, I was reading about the Trinity nuclear test. High speed photos were taken and this one is from <1ms after the detonation. The book mentions ...
2
votes
1answer
45 views

publication ethics [closed]

What does it mean if somebody publishes the same concept of my paper with some changes without citing it although the paper has been published 5 years before his, and the concept was clearly first ...
0
votes
0answers
70 views

Gravitational waves: novel or confirmatory?

If the rumors are true and gravitational waves have been detected, would we learn any new fundamental physics from them? Or is this simply an important confirmation of a prediction of general ...
0
votes
0answers
13 views

Using thin needle for object and thick needle for image

I have performed an experiment to determine the focal length of a concave mirror in my school lab. It consists of an optical bench with two needles, one as object and one image. We basically try to ...
6
votes
1answer
81 views

Why is an airplane propeller so different from a boat propeller in shape? [closed]

Examples: Airplane propeller Source:http://www.sensenich.com Boat propeller Source:http://www.nauticexpo.com It is obvious that the airplane propeller is drastically different from the boat ...
6
votes
0answers
44 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 ...
0
votes
1answer
43 views

Why does quantum mechanics produce different predictions for Bell test experiments than classical mechanics?

I understand that experimental results from Bell test experiments have shown that measured correlation is a cosine function of the angle between the detectors. What I am struggling to grasp is why ...
1
vote
3answers
131 views

Is it correct to calculate the propagation of error in this way? [closed]

I conducted an experiment and measured the values of $R$ and $H$ to calculate $v_i$. The equation used is: $$v_i=\sqrt{{gR^2}\over{2H}}$$. My average values ($v_i$ is calculated only for the average ...
0
votes
0answers
33 views

Can 1km diameter ball of water preserve it's integrity before hitting the ground falling from 10km altitude?

I still argue with my friend over some big ball of water (1km in diameter) that is being instantly created 10km over the surface of the earth in perfect sphere form. I stated, that as it hit the Earth ...
1
vote
1answer
40 views

Will an Electrical Engineering Minor give me a significant advantage in experimental physics? [closed]

I'm currently choosing courses to complete in my university degree (science) and thought completing some basic electrical engineering may be useful if I go into academic experimental physics research. ...
0
votes
1answer
35 views

Wind resistance [closed]

You have a metal plate/sign (max weight $5\, \text{kg}$) $1200\, \text{mm}$ long and $400\, \text{mm}$ high pivot/hinge at its base. A windspeed of $90 - 100\, \text{km/h}$ is applied to one face of ...
0
votes
0answers
53 views

How to measure size of small particles of $mm$ level?

Is there any way to measure dimension of small particles (mm sized) such as rice grains accurately? I know there are techniques such as laser or x-ray diffraction, but the equipment needed are too ...
6
votes
1answer
54 views

Is there a tool to measure the chemical potential of a system?

Let's suppose I put you inside a room filled with a gas. You can measure its pressure directly with a barometer. You can measure its temperature directly with a thermometer. Can you measure its ...
4
votes
0answers
64 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 ...
0
votes
0answers
34 views

Obtaining an angular distribution from the Klein-Nishina formula

I'm having trouble on how one might obtain an angular distribution from the Klein-Nishina formula for compton scattering of polarised photons, more specifically on how this report is obtaining it. ...
0
votes
0answers
7 views

Circularly Magnetized Neodymium Torus With Minimum Flux Leakage

I'd like to conduct some experiments related to Aharonov-Bohm. In particular, I'd like to investigate the irrotational vector potential gradient. A simple geometry for this is the major axis of a ...
0
votes
0answers
13 views

magnetic field due to current carrying coils

In the Helmholtz configuration, why is the magnetic field between the two coils uniform (I know the mathematical expression)? Can anyone please explain this physically? When the distance between the ...
1
vote
0answers
67 views

How would you build a small cyclotron (particle accelerator)? [closed]

I heard Michio Kaku built a small cyclotron when he was young. I bought a book called "Principles of charged particle acceleration" where it explains the basic functioning of particle accelerators. ...
0
votes
2answers
20 views

i have a thin film deposited on a glass substrate, when i measure trasmittance for it ,should i use a reference glass or air? and why

i have a thin film deposited on a glass substrate, when i measure trasmittance (T) for it ,should i use a reference glass or air? and why regarding these points: for bare glass T=88 % for thin film ...
3
votes
1answer
102 views

Is it experimentally proven that photons travel at speed $c$ in vacuum?

Are there experiments which show that single photons (not classical em waves) travel exactly at $c$ in vacuum? What is the error bar in that case? The question is posed due to the fact that loop ...
1
vote
1answer
42 views

Experiment: releasing the copper bar above a permanent magnet

A classic experiment shows that when we drop a magnet through a copper coil long tube, there is eddy current induced in the coil. Then, due to lenz law, the motion of the magnet will be opposed and it ...
1
vote
0answers
20 views

Coupling into FC/APC fiber

I am currently attempting to couple a 405nm laser diode into FC/APC fibre. The fibre is mounted on a flexure stage approximately 15.3mm from an f=15.29mm lens. I have managed to couple into the core ...
5
votes
1answer
49 views

Will the speed of the wind produced by a fan increase continously to infinity with the propeller spin speed?

Imagine a scenario: On a stand, an $RC$ plane motor is mounted on a stand. The motor has a $8x4$ prop attached to it. In the theoretical model, if the spin of the motor can be increased infinitely ...
1
vote
1answer
36 views

Can the helium from a gas bottle lift the bottle?

Does a gas bottle full of helium contain so much helium that, if the helium can expand into a baloon, can lift the empty gas bottle? And input on this question highly appreciated...
1
vote
1answer
29 views

Cryogenic (LN2) gas vs liquid for cooling

For cooling, would you recommend using gas over liquid or vice-versa? What is the temperature differential between gas and liquid? In other words, at standard volumes and pressures from a gas ...
3
votes
1answer
30 views

Sound attenuation when holes size less than wavelength

The actual problem is as follows. There is a gap between a transducer and its circular mounting collar that is about half the wavelength of the incoming sound. What I do not want is for the incoming ...
3
votes
2answers
97 views

How mass is determined in dynamics?

Mass is one of the most core and complicated concepts in dynamics. I have tried many books but I still don't have a good idea of how the mass of any object is determined relative to another. In The ...
3
votes
0answers
53 views

How do we know what happens to stars during their life cycle?

It is common knowledge than Sun-sized stars will eventually become red giants, and later they will get gradually smaller again until they cool down into a brown dwarf, and that bigger stars can ...
1
vote
1answer
68 views

Holographic universe experiment?

I heard a passing news story which a satellite employed to prove or disprove the Holographic Universe theory came back disproving the Holographic Universe Theory. I searched for recent news reports ...
0
votes
1answer
28 views

Where can I find the Auger emission spectra of the most common chemical elements?

I am looking for an online resource where I can find the Auger emission spectra of (most common) chemical elements, i need them for AES (Auger Emission Spectroscopy). Thank you.
0
votes
1answer
44 views

The confusion of fractional error calculation

I need to find the focal length of a lens by using equation 1/u + 1/v=1/f I have: u= 50+-3 mm v= 200+-5 mm I calculate the value of f as 40mm. Now i need to find the uncertainty in this value. ...
1
vote
0answers
19 views

Is it possible to make a capacitor of required specifications using aluminium foil? [closed]

I wanted to make a FM radio transmitter but I was not able to get a capacitor with the exact rating of certain micro farad and pF. But I live in a poor country and I can not find them in the local ...
3
votes
1answer
131 views

Wavelength of electromagnetic waves [closed]

How can you determine experimentally the wave length of an electromagnetic wave having wave length in the visible range and that in the ultra violet range?
0
votes
1answer
130 views

Fusion, Magnets and Quantum Generators [closed]

I cannot even play like I'm even at this level, but this is the fusion reactor in Germany called the Wendelstein 7-X stellarator. These doughnut-shaped magnets (often seen on Physic Exchange) are ...
1
vote
1answer
66 views

What is an Unbalanced Interferometer

I have read in some papers about a so-called unbalanced interferometer. This appears particularly in the context of Experimentally verifying the Englert-Greenberger-Yasin Duality Relation. However, I ...
0
votes
0answers
14 views

Book Recommendation for relativistic scattering theory [duplicate]

I am looking for books on relativistic scattering theory with particular emphasis on application to experimental high energy physics. Does anyone have excellent recommendation?
0
votes
2answers
34 views

Question about Cavendish experiment

I got a question. In Cavendish experiment was used lead in both of spheres. Can we repeat that experiment with balls made from stone or anything else. Because lead could be a byproduct of radioactive ...
0
votes
0answers
26 views

Sum rule in X-ray Photoelectron Spectroscopy (XPS)

What is the sum rule in X-ray Photoelectron Spectroscopy (XPS)? how can I derive it? Can anybody explain the principle of sum rule in XPS or in spectroscopy in general? How can I apply it to a ...
0
votes
1answer
35 views

Perfect vacuum in experiment [closed]

When conducting experiments to determine the speed of light in a perfect vacuum does that vacuum(?) replicate outer space?
1
vote
0answers
24 views

How can one induce rapid temperature changes in a controlled environment?

What kind of processes are there using which it is possible to change the temperature of a material as fast as possible. You are allowed to use any material you want. Constraints - It should ...
1
vote
0answers
26 views

Single Photon Counting Module [closed]

I have a single photon counting module from Picoquant (tau-SPAD) . When it is powered on, the TTL output has a constant value of around 4 volts (as opposed to occasional TTL spikes indicating photon ...