-5
votes
0answers
40 views

Quantization of electric charges [on hold]

As per charge quantization of charge $Q=ne \Rightarrow n=Q/e$. But there can exist some charge $Q$ such that $n$ isn't an integer (i.e if $Q/e$ is repeating or recurring decimal). This can prove ...
12
votes
3answers
807 views

How does the heat death looks like from inside the system?

As this answer points out, any human would first freeze rather than experience the heat death. However, assuming hypothetically that we could make some robot live at such low temperature (or even ...
-3
votes
0answers
29 views

Laser diode input and output power ratio [on hold]

I am a photo technician working in photographic labs to repair printing machines. I need technical help from you and from your technical team, as I want to know some basic information. May be it will ...
0
votes
1answer
63 views

Problem with quantum Hall effect and Berry curvature

I am having trouble proving that the Hall conductivity is equal to the integral over the Berry curvature in momentum space. In the TKNN (1982) paper, using the Kubo formula $$ \sigma_{xy} = \frac{ ...
0
votes
2answers
164 views

Origin of Universe [duplicate]

The universe is believed to have originated from absolutely nothing, and we know it is still expanding. Physics says "something can arise from nothing". I understand how mass and energy are related ...
-7
votes
0answers
33 views

Is there any absolute reality in our Universe [on hold]

Everything in the Universe is different for everything. So nothing is absolute real. Hence my question, is there any absolute real things in our universe?
0
votes
0answers
70 views

Spin 1/2 particle in rotating magnetic field [on hold]

So, I'm attempting a solution to the following problem: I am given a particle with spin 1/2 in a constant vertical magnetic field and a rotating field in the (x,y) plane. $$B(t) = [B_1\cos(\omega ...
0
votes
0answers
36 views

Does the uncertainty principle affect event horizons? [duplicate]

I was thinking about black holes. For a simple black hole the event horizon is given by a distance of 2 times mass (energy) of the black hole. (2m). But according to quantum mechanics, if you try to ...
0
votes
1answer
43 views

Why is the net work done in a pulley-string system zero?

In any pulley system, where the pulleys and strings are massless and frictionless, why is the net work done by Tension zero?
0
votes
0answers
29 views

Effect of orbifolding on gauge fields

A paper by Lalak et al, entitled "Soliton Solutions of M-theory on an orbifold", considers the brane solutions of 11 dimensional supergravity on a space of the form $R^{10} \times S^1/\mathbb{Z}_2$. ...
4
votes
4answers
1k views

Can we know if “all” physical laws are discovered?

Before Einstein, scientists believed that all physical laws to be discovered were already discovered. Of course, that was proven wrong. If we somehow manage to come up with the Theory Of Everything ...
0
votes
1answer
46 views

Is a non reflective display possible?

Can you think of a surface, that emits light, but doesn't reflect any light coming from outside (absorbs it)? Under what circumstances would this work?
-2
votes
0answers
31 views

solving an electromagnetic problem in the frequency domain

I study a course in electromagnetic fields and I don't understand why when I solve a problem in the frequency domain I lose the transient solution. can anyone show me mathematically why does it ...
-3
votes
0answers
37 views

What exactly is 'crosses of light'? [on hold]

when i looked two bulbs through my window it appeared as luminous crosses.i also took photoes.what exactly is this?
0
votes
3answers
97 views

The relation between mass and speed

Massless particles (or luxons) have no (rest) mass ($m = 0$) and a speed equal to the speed of light ($v = c$). Massive particles (or bradyons) have mass ($m > 0$) and a speed lower than the speed ...
10
votes
4answers
921 views

Do electrostatic fields really obey “action at a distance”?

In an electromagnetic theory class, my professor introduced the concept of "action at a distance in physics". He said that: If two charges are at some very large distance, and if any one of the ...
0
votes
0answers
21 views

How can electric and magnetic fields have any component in the direction of propagation of electromagnetic waves?

In case of waveguides we talk about E and H having non zero component in the direction of propagation of wave. But the entire basis of EMW is that E and H are perpendicular to the direction of ...
-7
votes
1answer
48 views
-4
votes
0answers
9 views

Suggest a material used in a specific product that can be improved by alternatives? [on hold]

such as the beverage cans, what materials can be used to replace the current packaging technology? or any other types of future development that may take place in the packaging technology? What other ...
-2
votes
2answers
33 views

Charge enclosed by a Gaussian surface inside an uniformly charged thin sphere [duplicate]

Why is the electric field due to a charge enclosed by a Gaussian surface inside an uniformly charged thin spherical shell, zero?
3
votes
2answers
83 views

Free rotation of a rigid body

So I am currently reading Fowles and Cassidy and there is something I'm confused about in the section about geometric description of free rotation of a rigid body. I will present the stuff first that ...
-4
votes
0answers
28 views

Circular motion physics [on hold]

Two automobiles of equal mass approach an intersection. One vehicle is travelling with velocity 13.0m/s toward the east and the other is travelling north with speed V. The vehicles collide at the ...
-1
votes
1answer
88 views

Can space be destroyed [duplicate]

Wikipedia says It appears that space was created in the Big Bang, 13.8 billion years ago This seems a little off to me: can we say something has been created if there was no before it had ...
0
votes
0answers
28 views

What is the kinetic energy of a proton as it is falling towards the core of the star?

Given: Star's mass = $1.99e10^{30}kg$ Type II supernova occurs (in a simple form: the outer layers of the star fall into the now inactive core at speeds of 126000km/s) $10^{44}$ joules of energy is ...
1
vote
3answers
94 views

Speed as the fifth dimension

In spacetime there are four general dimensions, three of space and one of time. Why is it that other dimensioned qualities seem to be rarely considered as part of spacetime? For example, why isn't ...
0
votes
0answers
27 views

Does a graviton impart negative momentum?

Picture a massive system on an axis. If a graviton is generated and emitted by a system in the positive direction, will that system also be accelerated in the positive direction? Another system ...
0
votes
1answer
28 views

How to know if a body is travelling with uniform acceleration or not?

One of the Example in my Textbook is A body travels a distance of 2 m in 2 seconds and 2.2 m in next 4 seconds. What will be the velocity of the body at the end of 7th second from the start. In ...
0
votes
1answer
45 views

Understanding the Carnot cycle

My textbook explains the Carnot cycle as follows: Heat is added to the boiler, where the steam inside expands isothermally at high temperature (T(High))--(both valves closed). The intake valve is ...
-2
votes
1answer
21 views

Torque-direction of rotation

Taking moment about $A$, the mass of 2.0g and 0.50g is rotated in the clockwise direction is because they are both directed in downwards position? while $R2$ is acted in upward direction, so it is ...
-2
votes
0answers
49 views

Maxwell said the dimension of charge is $L^3 T^{-2}$ and of mass is $L^3 T^{-2}$, is he right? [on hold]

If his right then, from Lorentz magnetic force, $$F= BQV$$ where $F$ is force, $B$ is magnetic flux density, $Q$ is charge and $V$ is velocity. Therefore, $$M L T^{-2} = B Q V \, .$$ Substituting for ...
-4
votes
0answers
43 views

Is the proton mass to charge ratio equal to the plank mass? [on hold]

Using a proton charge 1.602*10^-19 coulombs is equal to proton mass 1.673*10^-27 Kg. One coulomb = 1.673*10^-27 Kg divide by 1.602*10^-19 Therefore One coulomb is equal to 1.044*10^-8Kg. Therefore ...
-2
votes
1answer
59 views

Is gravity weak negative electric charge? [duplicate]

This could be true since the both have infinite range and other common properties. They both have fields.
0
votes
2answers
44 views

Can two artificial bodies be built in space and be made to orbit each other?

Would it be possible to make artificial constructs (satellites) orbit each other? I looked at the gravitational laws, and nothing seems to suggest that this is not possible.
0
votes
2answers
34 views

Can the anti-torque of a motor be used to spin a space vehicle about it's axis?

Imagine a huge electric motor together with it's power supply in space. What exactly will happen to it if it is suddenly powered, won't it spin about it's axis or it will experience no relative motion ...
2
votes
2answers
48 views

Why does transmission probability decrease, increase, then decrease again?

We did a quantum tunneling lab online. We used a Java program to model the electron wave function and show what happens when there is a step potential (U is less than E). Our value for the ...
0
votes
1answer
50 views

How is light slowing down in a medium thought of in the photon picture? [duplicate]

The speed of light in any medium besides vacuum is smaller than $c$. In a classical way, I just look at that as a wave that propagates less fast, the change in EM-field is passed on slower. How should ...
3
votes
2answers
136 views

Is the Legendre transformation a unique choice in analytical mechanics?

Consider a Lagrangian $L(q_i, \dot{q_i}, t) = T - V$, for kinetic energy $T$ and generalized potential $V$, on a set of $n$ independent generalized coordinates $\{q_i\}$. Assuming the system is ...
1
vote
0answers
41 views

How do the renormalization enter the actual amplitude calculation in QFT?

I have studied QFT from Peskin and Schroeder and from a few other books and lectures and I think I understand the procedure of renormalizing various parameters in the Lagrangian like mass, coupling ...
1
vote
0answers
22 views

Mass and wave function renormalization In chiral perturbation theory

Before I put forward my actual question, I think it will be useful to set the context in a clear way and that involves my understanding of a few very basic things of Chiral Perturbation Theory. ...
3
votes
3answers
198 views

Constructing solutions to the time-dependent Schrödinger's equation

The following question is from David Griffiths' Introduction to Quantum Mechanics: Problem 2.13 A particle in the harmonic oscillator potential starts out in the state $$\Psi(x,0) = A[3 ...
0
votes
1answer
37 views

Water enclosed in a vessel

Suppose I am taking water in a glass or metal or even something else. It s air tight and (so it is water tight). Now imagine, if I keep it heating and none of its molecule escapes from it, what am I ...
1
vote
0answers
41 views

Gravitational “acceleration” and frequency change of a photon?

For massive particles, force translates into acceleration which again is a change of the velocity vector in direction and/or magnitude. For a photon, the velocity magnitude cannot change, only the ...
0
votes
1answer
26 views

Two glass bottles of water warming by different temperatures

A friend posed a question to me yesterday: if I have two glasses of 60 F water, would they heat at a different rate if one were in a 70 F room and one were in a 90 F room. Myself having some ...
0
votes
0answers
28 views

Is interaction a relevant perturbation for 1d Anderson localization of fermions?

Disorder is a relevant perturbation in 1d, which drives the system to Anderson localization. My question is if I am already at the Anderson localization fixed point, how to analyze the scaling ...
2
votes
1answer
31 views

In a lens the image formed by the first surface serves as the object for the second surface.What is the reason?

When deriving the lens maker's equation I faced the problem of understanding the logic behind this reasoning "image formed by the first surface of a lens serves as the object for the second surface."
0
votes
1answer
38 views

Why is my Lyapunov exponent similar for single and double pendulum?

This is my first question here on stackexchange. I hope that I can be understood. If not, tell me and I will reformulate and fill in with details. I have simulated a single pendulum and a double ...
-1
votes
0answers
31 views

Point View and the relativity of everything, also regarding seemingly neutral pen and paper formulas - also, the nonexistence of black holes [on hold]

I am just a programmer with a love for math/physics and ... science fiction, haha! Anyway, to state it right in the beginning: This question is related to the following postulation (of mine, but ...
0
votes
0answers
72 views

Problems with Maxwell density Lagrangian [on hold]

I want to expand the right-hand side of $$\dfrac{1}{4} F_{\mu\nu}F^{\mu\nu} = \dfrac{1}{4}\left(\partial_{\mu}A_{\nu} - \partial_{\nu}A_{\mu}\right)\left(\partial^{\mu}A^{\nu} - ...
-1
votes
1answer
30 views

Refrigeration and thermal science [on hold]

What happens to the weight of the vegetable after keeping it in fridge for few hours? Does it gain the weight or lose the weight?
0
votes
1answer
54 views

Fillings of dispersion bands (E-K diagram)

I struggle in understanding why in some references the bands filling by electrons in the E-k diagram is shown as an area delimited below by the dispersion curve and above by the Fermi energy (if in ...

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