0
votes
0answers
3 views

Proving charge on outer surface of parallel plate capacitor must be zero

If we have two conducting plates, with charge $Q$ and $-Q$, why is the charge on the outer surfaces of each conductor zero? I've been trying to wrap my head around the problem. Firstly, don't excess ...
0
votes
0answers
2 views

How does LIGO reduce noise below what it is detecting?

LIGO is designed to detect changes in length on the order of 10,000ths the scale of a proton. I know they are extremely well isolated from their surroundings, but how could we even approach isolation ...
0
votes
0answers
15 views

Why didn't 0.2A at 2V kill me?

I was recently connecting a circuit together like here, and I had the voltage set at 2V, with a 10Ω resistor. By Ohm's law, there was a current of 0.2A (and was confirmed by my multimeter). I ...
0
votes
0answers
20 views

Are gravitons affected by the force of gravity?

Every particle, including photons, is affected by gravity. Would this be true for gravitons as well? Gravitons should always move at the speed of light, so, if photons are red-shifted while moving ...
-2
votes
0answers
10 views

Capacitor charge [on hold]

It takes 14.8 J of energy to move a 13.0-mC charge from one plate of a 17.0-μF capacitor to the other. How much charge is on each plate? Assume constant voltage.
0
votes
0answers
4 views

Direct vs. indirect CP violation: theoretical foundations

I know very little about the difference between direct and indirect CP violation. I've been studying QFT from Peskin and Schroeder's "An Introduction to QFT", and they don't seem to address this ...
0
votes
0answers
8 views

Can I determine the maximum acceleration with frequency and magnitude?

Consider a mass oscillating up and down on a spring with negligible energy loss. If only the frequency and magnitude of the oscillation is known, how can one determine the maximum acceleration of the ...
0
votes
0answers
8 views

Higgs mechanism preserving supersymmetry

It is said that if supersymmetry was unbroken, masses of the superpartners would be equal. But at least for MSSM there are no SUSY-invariant terms that would allow the electroweak SSB, as far as I ...
0
votes
0answers
14 views

simulation probabilistic classical computation on quantum computers

Given an $N$-level quantum system with computational basis $\{|1> ,|2> , \cdots, |N> \}$, if we perform an unitary operation $U$ on a computational basis state $\{|j> \}$ and then measure ...
1
vote
0answers
19 views

Acceleration 4-vector in Schwarzschild metric [on hold]

I am working on A note of a paradoxical property of the Schwarzschild solution by Abramowicz M. A. and Lasota J-P It is a note on surprising cases in the context of the standard Schwarzschild ...
0
votes
0answers
19 views

Which requires less energy, complete mechanical breaking or vaporization of matter?

Let's say we have a one kilogram piece of rock. Now if we want to separate each molecule from the other molecules making this piece of rock, which method requires the least energy while neglecting ...
0
votes
0answers
35 views

Why are the arms of the LIGO interferometer so long?

The LIGO experiment consists of two interferometers, where each one of them has two 4 km long arms. Within these, light is further trapped via Fabry-Pérot cavities to achieve a total path length of ...
0
votes
0answers
9 views

Resonant Scattering and the Breit-Wigner Formula

Most of what I ask relates to the derivation found here: https://farside.ph.utexas.edu/teaching/qm/lectures/node91.html The basic idea is that we first consider zero energy s wave scattering from a ...
0
votes
1answer
13 views

Question about limit cycles and linear systems

In here http://users.isy.liu.se/en/rt/claal20/SysBio2015/Notes_SysBio_2015_partC.pdf it says: A limit cycle is however an intrinsically nonlinear concept: a linear system cannot have a limit ...
0
votes
2answers
43 views

Information can't travel faster than $c$

When we say that information cant travel faster than light, we mean that phase velocity can go beyond $c$ but the group velocity can't. Hence, we say that a plane wave carries no information. What I ...
-1
votes
0answers
9 views

Can Obstruction of EM waves itself obstruct change in field?

Let us continue to accelerate a particle P, up and down: between two points X,Y in space(and, say, always in a symmetric manner relative to X,Y). Now, as I know, we'll be continuously dragging the ...
-1
votes
0answers
14 views

Two Dimensional Momentum

A tennis player receives a ball of mass $60\ \mathrm g$ travelling horizontally at $55\ \mathrm{ms}^{-1}$ perpendicular to the net, and returns it at $28\ \mathrm{ms}^{-1}$ in a direction at ...
2
votes
0answers
36 views

Are gravitational waves dissipated and what is the mechanism?

I was amazed by the fact that we have been able to detect gravitational waves created thousands of year before they were observed. My surprise is that any wave phenomena I know it is always ...
0
votes
1answer
30 views

How much time distortion was caused by GW150914?

I understand (at least I think I understand) that LIGO used distortion of space to detect GW150914 (one arm grew longer, the other arm grew shorter, causing interference in the returning laser-pulse ...
-3
votes
0answers
13 views

Is wormhole time travel possible? [on hold]

I'm a student in the UK, doing an EPQ, I was wondering what your views are on wormhole time travel. Do you think it's possible, I understand that forwards time travel is more likely than backwards ...
-2
votes
1answer
11 views

Proper significant digits in terms of a characteristic scale

Suppose I have a defined quantity in a paper $$g = 20\ \mathrm{meV}$$ and I wish to express the following equivalence (where $k_{B}$ is the Boltzmann constant which easily has more than 3-digit ...
0
votes
0answers
6 views

Two-particle correlation function for Slater determinant

In a paper by Peschel, http://arxiv.org/abs/cond-mat/0212631, he writes: Consider first a system of free fermions hopping between lattice sites. The one-particle correlation function is ...
-3
votes
0answers
24 views

Can something made of atoms be subatomic?

Let's say there is an object made of atoms, this object is subatomic in scale. Can such a thing exists?
0
votes
0answers
18 views

Has Jaynes' argument for quantum mechanics as a possible theory of inference been debunked?

To my understanding, there is currently no scientific consensus on which interpretation of quantum physics is the correct one, if any. The most famous one, perhaps for historical reasons, is the ...
0
votes
2answers
44 views

What was the frequency of the gravitational wave recently detected, and why?

In one early Internet post there was a graphic that appeared to show the gravitational wave (pulse) at about 30 cps. And another video it was stated that the gravitational wave would be as high as ...
0
votes
0answers
7 views

Find total elongation problem?

The main question is like this The answer is total elongation = 4FL/AY But in the middle part wouldn't there be a compression . I think there will be a compression . Please clear my confusion
1
vote
1answer
15 views

Speed of pinewood derby car

If I drop a pinewood derby car from 4 feet I know it hits the ground in half a second at about 10.6 mph. If it rolls down the track (starting at 4 feet) it takes longer, but is it possible for it to ...
0
votes
0answers
26 views

Do gravitational waves interact with the Earth's magnetic field?

Do gravitational waves cause a minor vibration of the Earth's magnetic field, and therefore a minor (if undetectable) electrical inductance?
1
vote
1answer
27 views

What is meant by “surge” in fluid mechanics?

When reading about the action of opening a volume at vacuum submerged in a fluid at pressure, the fluid is said to "surge", i.e. to fill the void space (the vacuum). Per Google, surge is defined as a ...
0
votes
1answer
13 views

By which factors are tides and waves affected?

To my understanding, the tides and waves on Earth's oceans are caused by various factors such as the moon's gravity, the water cycle (rains, storms, evaporation), Earth's rotation, etc. Although the ...
1
vote
1answer
28 views

Could the LIGO in fact measure .. the expansion of the universe? What specifically is the numerical ratio of effects?

It would seem that LIGO measures wibbles in the metric (not manifold) of spacetime: How is it that distortions in space can be measured as distances? It would seem that the expansion of the universe ...
0
votes
0answers
12 views

Stokes law percentage error

I am supposed to find the % error in t , r and D this is for Stokes law to find the viscosity.I have tried to find the % error in t we used a stopwatch so I found the mean from my values for t and ...
0
votes
0answers
15 views

how does diffraction occur when laser beam is pointed on a steel ruler?

When a laser beam is pointed on a steel ruler with marking of the order of millimeter, why do we observe diffraction pattern at a distance? What is causing it to be diffracted?
0
votes
1answer
26 views

Plane waves intensity

Our professor said that a plane wave has the same intensity in the plane perpendicular to it's propagation. I can't really make sense of how that is possible. I mean, shouldn't the intensity decrease ...
0
votes
0answers
23 views

Does an electromagnet use more energy when it is repelling another magnet?

Kind of a strange question. Is the amount of energy used to power an electromagnet directly proportional to the amount of work an electromagnet does? That is, if I were to power an electromagnet ...
-1
votes
0answers
24 views

Path of light and gravitational waves

Now that gravitational waves are detected, the way they are detected was using laser beams and they were out of phase when the return from the same trip distance. Does this means it is based on ...
0
votes
1answer
24 views

How would a galaxy “bathing in radiation” behave?

For the sake of understanding mass and radiation interaction, I hope somebody could explain how this hypothetical situation would look. A spiral galaxy is subjected to such high levels of cosmic ...
1
vote
0answers
19 views

Is there any issue/concern for a slight wavelength shift of the laser light in the LIGO experiments?

A friend and I were having a discussion about the LIGO experiments and were wondering if there is any issue with the laser light undergoing a wavelength shift as a result of the gravitational wave? ...
0
votes
0answers
30 views

Producing an audible sound from the gravitational waves of the GW150914 event

As is said in the latest LIGO press realease, the detected gravitational waves vary with a frequency that is audible for us. The audio one can obtain from the detected data is actually plaied during ...
3
votes
1answer
51 views

Do the photons emitted along with the gravitational waves take more time to reach earth than the ones emitted after them?

I'm puzzled because the gravitational waves do warp the spacetime locally. They do it continuously as they propagate. So the photons travelling in tandem with these waves must be constantly following ...
1
vote
0answers
8 views

Spring constant and a spring's decompressed length

I wonder why the decompressed/free length of a spring doesn't change the spring constant $k$. I'll give the equation for $k$ here: $k = \frac{Gd^4}{8nD^3}$ For a fixed number of coils, if the free ...
1
vote
0answers
12 views

Special conformal transformation of stress-energy

Consider a 2d CFT, e.g. a single bosonic degree of freedom. The $TT$ OPE is $$ T(w) T(z) = \frac{c/2}{(z-w)^4} + \frac{2 T(w)}{(z-w)^2} + \frac{\partial T(w)}{z-w} + \text{regular terms}. $$ Does ...
1
vote
0answers
11 views

Charge distribution on a line

Given a conducting line segment from -a to a, with a total charge Q distributed by the continuous charge density $\lambda(x)$. I can write this system of integrals. Since the charge must total Q: ...
1
vote
1answer
34 views

General Relativity, Curvature, and extra dimensions

Setup of idea I had somewhat of a thought question regarding general relativity. Consider a simple situation of a sphere and arrow. You hold the arrow and walk from the equator to the north pole. ...
3
votes
1answer
30 views

Orientation of the LIGO Arms

The orientation of the interferometer arms at both sites are approximately Northeast-Southwest and Nortwest-Southeast, though I assume that, on account of the Earth's curvature, no pair of arms is ...
0
votes
0answers
12 views

Calculating the solar produce the right way

I am not quite sure on how to calculate the following. We've got solar panels on the roof and a data logger in the heating's room. The data logger is returning every 10 seconds the current energy ...
1
vote
3answers
31 views

How can I calculate how high an arrow goes when all I know is its initial speed?

I'm not familiar with English physics terms so bear with me. If I shot an arrow straight up and it went off with a speed of 21 m/s, how high up would it go? (air resistance is insignificant). My ...
0
votes
2answers
42 views

How to find the current source Is and the voltage V1 of this circuit schematic?

I have Vs= 1.5V, R1=1 Ohm, R2 =6 Ohms, I got the equivalent resistance to be 7 Ohms. Then I set equal Req to Vs for 7I=1.5 and got my current source to be 0.214A. Since it is only Vs and Req in the ...
1
vote
0answers
16 views

Calculate ballistics using Pejsa method (bullet physics)

I'm not sure if it was already asked, but, could someone please explain the Pejsa method of ballistics, specifically the velocity and trajectory (no energy, wind or lead etc.) (just drop drift and ...
-1
votes
0answers
14 views

What is the isochronic law of pendulums? [on hold]

I think the Isochronic law of pendulums is related to law of isochronism in thermodynamics: //physics.stackexchange.com/

15 30 50 per page