0
votes
0answers
7 views

Hurricane Emily

I need some help with my homework problem. In 1993 the radius of Hurricane Emily was about $350$ km. The wind speed near the center ("eye") of the hurricane, whose radius was about 30 km, reached ...
0
votes
0answers
10 views

The wavelength of EMR reaching an orbiting ship at .99 c

In this answer John Rennie says that, if a ship is orbiting the Earth at .99 c: .. observer on the Earth sees time moving slowly for the astronaut, while the astronaut sees time moving fast for ...
0
votes
0answers
6 views

Rainbow Black Hole

In the photon sphere of a black hole the photons are being trapped in orbit, pulled in and trajectories changed. Should we see color of the entire spectrum in the photon sphere? That a black hole ...
0
votes
1answer
17 views

Magnetic force on a charged particle doesn't affect total energy

So there's this sentence in a book I am reading. It states "When a charged particle is placed within a magnetic field, despite the magnetic force acting on the particle, there will be no change in the ...
1
vote
0answers
8 views

What are the Higgs masses for $SU(2) \times U(1)$ goes to $U(1)$ symmetry breaking with a complex triplet?

Consider an $SU(2)\times U(1)_Y\rightarrow U(1)_{EM}$ theory that is broken via a complex triplet with hypercharge 2. The potential is of the form \begin{align} V(\Phi) = -m^2\Phi^\dagger\Phi + ...
0
votes
0answers
9 views

Why can an electric chargeless Z-particle decay in three photons?

The Z-particle that is supposed to convey the weak force has no electrical charge. So how is it possible the particle can decay in three photons. Because the weak and e.m. force are more or less ...
0
votes
1answer
17 views

Principle of capacitor

It is said that second conductor reduces the potential of fist conductor and hence increases charge taking ability of first conductor My confusion... As per my limited knowledge it is electric ...
0
votes
0answers
11 views

thermodynamics tables

Steam is heated from 10 kPa and 50°C to 550 kPa and 500°C. Calculate the change in entropy: 1) If the steam is not considered an ideal gas 2) Discuss if it is appropriate to consider steam an ideal ...
0
votes
0answers
7 views

Contact Angle In Capillary

One Professor recently told me that in an insufficient length capillary, the contact angle doesn't change, its an inherent property which does not change. If the edges of capillary are extremely sharp ...
0
votes
1answer
5 views

Conservation of $C$-Parity and $P$-parity

Under what situations are $C$-Parity $C=(-1)^{L+S}$ and/or $P$-parity $P=-(-1)^L$ conserved? ( $L$ here is the relative angular momentum and S is the total intrinsic spin). It would make sense that ...
4
votes
2answers
157 views

Advantages of Lagrangian Mechanics over Newtonian Mechanics

Here, I'm going to pose a very serious list of doubts I have on Lagrangian Mechanics. Can we learn Lagrangian Mechanics without studying Newtonian Mechanics? Does Lagrangian help in solving problems ...
0
votes
1answer
28 views

Why does it matter which way I put a battery into an electronic device?

If I take a battery, some wire, and a light bulb and hook them all in a circuit that would create a current and light the bulb. If I turned the battery around so the terminals were switched then I ...
0
votes
0answers
17 views

How to understand the idea of functional renormalization group?

I have been looking at how to use the functional RG method in many-body systems, but I don't quiet get the idea of it, it look different from Wilson's RG approach (eg. why shall we integrate out the ...
0
votes
0answers
8 views

Does the irradience on a surface change as the length scale of the surface patch approaches the wavelength of the incident light?

Imagine an ideal, square, surface patch with sides of length l and area a that is a perfect absorber. Imagine this patch is being illuminated by a monochromatic plane wave. The irradient power on ...
1
vote
1answer
26 views

What do different frequencies in astrophysics data file mean?

I have a data file, with the first part looking like this. ...
0
votes
0answers
26 views

What would happen if a black hole merged with a white hole of the same size?

I learned about white holes a while back, this was the first question that came to mind.
0
votes
0answers
65 views

Could renormalization cutoffs be adjusted to explain absolutely any physical observation?

It seems like absolutely any observation can be expalined mathematically with no change to quantum theory except particular adjustments to renormalization cutoffs. Is this true? Example: Let there ...
-1
votes
0answers
11 views

Tsunami Modelling

In the coastal zone and seas, having relative small scales (up to 1000 km), the model of plane Earth with no rotation is applied $$ \frac{\partial M}{\partial t}+\frac{\partial M^2}{\partial ...
0
votes
1answer
16 views

Heisenberg Representation of Quantum Computers explain observable transformations

The Heisenberg Representation of Quantum Computers (Daniel Gottesman) http://arxiv.org/abs/quant-ph/9807006 Suppose we have a quantum computer in the state $|\psi\rangle$, and we apply the ...
0
votes
0answers
27 views

Is there a substitute for point particles other than strings?

In the Standard Model, QFT makes use of point particles. But are there models of elementary particles that are not pointlike? And I don´t mean the objects in string theory/M-theory.
-1
votes
0answers
13 views

Topics to learn, or books to be read for understanding physics goals of LHCb, and how LHCb detectors work

I would like to understand the physics behind the LHC experiment. I have some basic knowledge of modern physics, but have no knowledge of mesons, bosons, their decays and so on. I would like to know ...
0
votes
0answers
23 views

Photon Propagator in QFT

Please forgive my temporary split-brain, but I'm a little thrown off by something when considering units at the moment. In QED (depending on the guage), the photon propogator is written as ...
0
votes
1answer
69 views

Breaking Newton's 3rd Law?

I am having trouble explaining how the following experiment actually works, but it does.? Place a neodymium magnet on a piece of Styrofoam and a test tube of water next to it on the same piece of ...
-1
votes
0answers
13 views

non linear friction tsunami modelling [duplicate]

Deriving the following equation $$ \frac{∂u}{∂t}+u\frac{∂u}{∂x}+g\frac{∂η}{∂x}=\frac{−k}{2h(x)}u|u| $$ $$ \frac{∂η}{∂t}+\frac{∂[(h(x)+η)u}{∂x}=0 $$ equation (13) at ...
1
vote
0answers
18 views

Current rate of supermassive black hole merges

I think, it is probably not a very common event, and if it happens, it can be maybe one of the ...most interesting events of the Universe. Considering that the merge of two stellar blackholes were ...
-2
votes
0answers
24 views

Light and Magnets

Magnets affect EM field, tried that, know what it does. However, if light is a form of electromagnetic field, why is it not affected by a magnet?
0
votes
1answer
44 views

Is the time dilation experiment for real?

A popular experiment is described in books on special relativity, that claims that an atomic clock was flown at high speed and later compared with a similar atomic clock on earth, and it was found ...
0
votes
0answers
11 views

Biot–Savart law for a finite wire or the center of a square coil

I need to find the magnetic field inside the center square of a coil (I think this is the name, I'm translating, but if not, I'm talking about a loop of a wire, just 1 turn) of side $50cm$. So, I ...
-1
votes
0answers
61 views

Why are photons massless (quantum field theory)

I'm really trying to understand Quantum field theory and gauge in-variance, I'd like to ask a question about this to aid my understanding. The QED lagrangian as below has a kinetic term for this gauge ...
0
votes
0answers
11 views

Pion decay from chiral anomaly

I have to compute the decay rate of the process: $$ \pi^{0} \rightarrow \gamma \gamma $$ with 4-momenta $P \rightarrow K_{1}+K_{2},$ by the means of the following effective Lagrangian, coming from ...
-1
votes
0answers
23 views

Finding the initial conditions of a system

Find the initial condition $\:y(0)\:$ such that the response of the system described by $$ \dfrac{dy(t)}{dt}+3y(t)=x(t) $$ to the unit step input i.e., $\Bigl(x(t)=u(t)\Bigr)$ exhibits no transient ...
0
votes
0answers
19 views

what is there in qft which cannot be described by interacting wavepackets

What properties of qft are intrinsically "quantum" and cannot be reproduced in classical systems of interacting wave packets?
-1
votes
0answers
9 views

Singularity of $\Gamma(g) - I$

Let $\Gamma$ be a non-trivial irreducible unitary representation(also suppose of finite degree $d$) of a nontrivial group $G$. Consider the matrices $\Gamma(g) - I$, where $g\in G$ and $I$ is the ...
0
votes
1answer
18 views

Why are upthrust and normal reaction force not the same?

I am currently studying IGCSE Physics, and have the following question: Why aren't upthrust and normal reaction force not the same. I understand that upthrust only occurs in fluids, and normal ...
0
votes
0answers
15 views

The Electric Grid: if AC load/generation causes frequency to change, what happens in a DC circuit where there is no frequency?

I've been trying to understand why, in the AC electric grid, frequency changes when there is imbalance in load and generation. Why doesn't voltage, or current, or power factor change? Why does ...
-3
votes
0answers
20 views

What one is better to use to build stuff clay, silly putty or play dough? [on hold]

I need to know which one of these can shape and hold its place better for a project im doing i need to know before 5/9/16 that when it is due please help me thank you sorry i dont know what type of ...
-2
votes
2answers
56 views

What particles travel near the speed of a photon?

I know photons travel at the speed of light. How does the size of a particle determine its maximum velocity? Phonons, Preons, Electron ect. Is there a scale in from the smallest particle's maximum ...
0
votes
0answers
5 views

How to derive Q-factor from damped beam resonator?

Starting with free load ($q=0$) homogeneous beam with damping coefficient $\xi$ $$ EI\frac{\partial^4 w(x,t)}{\partial x^4} +\xi \frac{\partial w(x,t)}{\partial t} +\mu\frac{\partial^2 ...
-4
votes
0answers
19 views

Does travelling faster in time slows one in space?

Why it is said that if one travels faster in time then he will travel slower in space and vice-versa too ? I have made some approach but is it right ? What object wants in space-time trajectory is to ...
0
votes
1answer
48 views

Can the following baryon exist?

I am trying to find out whether the following baryons can exist: $$ |X\rangle = \frac{|u u u\rangle + |d d d\rangle + |s s s\rangle}{\sqrt{3}} $$ $$ |Y\rangle = \frac{|u u u\rangle + |d d d\rangle - ...
0
votes
1answer
19 views

Why is force negative if PE increases?

I'm looking at the PE vs force graphs for gravity, and it doesn't make sense to me. As potential energy increases (and the object goes higher above the ground), F=-mg. But if I'm raising an object up, ...
-1
votes
0answers
13 views

3d wave packet form of a free particle

Consider the 3d wave packet of a free particle moving along the x-axis. The wave packet will have components in the y and z dimensions as well as the x dimension. What form do they take? Are they ...
1
vote
1answer
40 views

Is there anything comparable to many-body localization in classical physics?

I've only just started looking into many-body localization, so this question may come off as a little vague. But my understanding is that it relates to how some quantum systems do not thermalize, as ...
-1
votes
0answers
18 views

In universal units, should E-Planck, an t-Planck should be one?

Al units are made to fit the human measure. But are the truly elementary units the Planck length and the Planck time (and Planck's constant, the Planck energy, the gravitational constant and the speed ...
0
votes
0answers
27 views

Interpreting group velocity of free particle wave packet

I am trying to understand the concept of group velocity of a free particle wave packet: $$\Psi(x,t) = \frac{1}{\sqrt{2 \pi}}\int_{-\infty}^{\infty} \phi(k)e^{ikx}e^{-\frac{i \hbar k^2 t}{2m}}dk.$$ ...
-1
votes
0answers
21 views

Telegraph process [on hold]

Wikipedia article on telegraph process This is all I know about telegraph process and want to calculate the mean and correlation. But I can't do it. Please help or suggest me some material.
-5
votes
0answers
22 views

Gravity and vibrational suppression

My question(s) relate to the source of gravity. Is it at all possible that the universe has a vibrational energy and that localized suppression of that energy by a mass acting upon it causes a force ...
0
votes
1answer
27 views

Invertibility of Dirac matrices

Suppose we have Dirac equation in the following form : $i\partial_t\psi = (-i\vec{\alpha}\cdot \nabla +m\beta)\psi$ and assume that the Klein-Gordon equation is satisfied, i.e. $\partial_t^2 \psi ...
1
vote
1answer
20 views

shock waves generated by ultrashort laser pulses

I am reading about shock waves and their origin. During my study i have found that the long pulse lasers (nanosecond-miliseconds duration) are used to generate the shock waves in the materials, ...
3
votes
0answers
10 views

Supersymmetrizing bosonic actions at higher orders

Given only the bosonic terms of a supersymmetric action, using a knowledge of the (local) supersymmetry transformations, is there a systematic way of reconstructing the fermionic terms? More ...

15 30 50 per page