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If you are seeking help with a...

Feb2313 08:38 AM
ZapperZ

1 
36,451 
I suppose that momentum of virtual photons is known precisely and energy of them is uncertain. But how uncertain?...

Sep510 05:07 AM
exponent137

4 
1,058 
I am new to quantum physics and mostly self taught. Please forgive me for what is probably a very naïve question.
...

Sep410 08:59 PM
Wanderbiker

2 
2,360 
In QFT given a Lagrangian L=\partial_a \phi^* \partial^a\phi, how do you take this derivative \frac{\partial...

Sep410 07:42 PM
strangerep

14 
1,440 
\Delta E \Delta t \geq \frac{\hbar}{2}.
If I understand well, if I measure the energy of a particle (or system of...

Sep410 07:18 PM
jcsd

11 
1,778 
Hypothetical device:
Vacuum Tube
Two tungsten electrode plates at each end
The work function of tungsten is...

Sep410 04:54 PM
AshsZ

2 
980 
If the electron of the hatom is not moving in a classical orbit (like a circular orbit) why is the reduced mass used...

Sep410 12:33 PM
Bob S

9 
3,366 
hi,
when an electron stays in the same electronic orbitals with principal quantum number n, with a constant energy...

Sep410 03:30 AM
AshsZ

2 
952 
Hi,
This is has been bugging me a while in regards to quantum physics and I figure this would be a good place to...

Sep410 01:47 AM
AshsZ

1 
804 
Simple, ingenious, and effective.
http://www.nature.com/news/2010/100829/full/news.2010.436.html
...

Sep310 06:52 PM
Kidphysics

4 
1,356 
http://physicsworld.com/cws/article/news/43275
...and in another famous magazine:...

Sep310 02:19 PM
unusualname

13 
4,725 
Changes spotted in fundamental constant
Sep 2, 2010
Billions of years ago the strength of the electromagnetic...

Sep310 12:43 PM
bcrowell

1 
831 
hi,
the following question is extremely important so please reply!
in an atom, the energy levels of the...

Sep310 12:39 PM
alxm

1 
2,852 
I want to talk to a scientist cuz this is pissing me off. >:(
So, I'm learning about CARS and Raman spectroscopy....

Sep310 05:20 AM
alxm

1 
786 
I wanna simplify something like
\Gamma^{\mu\nu\rho}\Gamma^{\alpha\beta\gamma}\Gamma_{\nu\rho}
in a given...

Sep310 03:12 AM
ismaili

0 
1,113 
Hi
I would like to know how you get from the classical 4vector polarization
to the two component quantum...

Sep210 07:34 PM
strangerep

3 
836 
In David Tong's QFT notes (http://www.damtp.cam.ac.uk/user/tong/qft/qft.pdf p. 43, eqn. 2.89) he shows how the...

Sep210 06:59 PM
The_Duck

3 
1,304 
Ok is this article as silly as it seems to me?
http://www.physorg.com/news202539967.html

Sep210 02:06 PM
TheRealTL

1 
683 
Hey guys.i have heard it has been experimentally proved that even atoms can tunnel through a metal surface.I tried...

Sep210 10:27 AM
alxm

3 
801 
In Srednicki (ch14 say), he looks at integrals of the form \int\, \frac{d^{d}l}{l^4}.... This is of course diveregent...

Sep210 04:21 AM
humanino

3 
837 
In this experiment wave particle duality is shown. Without observation the wave function is used. With observation the...

Sep210 02:28 AM
arkajad

35 
3,790 
Is it possible to capture photons within a perfectly spherical/reflective ball by aiming a faraday isolator within the...

Sep210 02:28 AM
bscfrnd

34 
5,284 
Hello
Here is the known formula for the spin: S=0.5*h*\sigma
is this formula correct also to the orbital Angular...

Sep110 10:35 PM
strangerep

1 
632 
Photon has momentum but is massless.Doesn't that seem strange?

Sep110 09:40 PM
Bob S

7 
1,293 
I watched a lecture that derived the properties of the angular momentum operators J and J3 using two QHOs and a bunch...

Sep110 08:15 PM
nateHI

0 
574 
I'm relativly new to quantum ohysics and have only read a few books, please can people explain some of the equations...

Sep110 06:00 PM
DevilsAvocado

1 
983 
\Delta x \Delta p \geq \frac{\hbar}{2}.
Say I want to measure the best I can the position of an electron, in...

Sep110 04:49 PM
fluidistic

3 
848 
Hi,
Movement of an electron in constant magnetic field, according to semiclassical QM, give rise to Landau levels ...

Sep110 03:36 PM
xepma

1 
1,410 
Alright, so I am new to the whole "Quantum Physics" thing, so please don't jump down my throat. I have seen this...

Sep110 02:56 PM
tom.stoer

7 
1,452 
Hi,
I have been looking into the phenomenon of Zitterbewegung which is a high frequency oscillatory motion of the...

Sep110 02:56 PM
johne1618

7 
2,581 
We use the antisymmetric Fock space ( "fermions"). We denote by c(h) a creator operator.
I need to evaluate the...

Sep110 12:01 PM
Boby37

6 
1,043 
We had a test a week ago, it asked for Acceleration Potential of an photon to achieve wavelenth of 0.005 picometer....

Sep110 09:58 AM
Smarty7

4 
1,484 
Hello Everybody,
I am trying to understand the concept of symmetric and antisymmetric wave functions in QM.
Now...

Sep110 09:10 AM
silverwhale

6 
2,110 
I was reading about this, but I'm unclear on something. Does the Heisenberg principle arise due to limitations in...

Sep110 07:29 AM
tom.stoer

49 
4,702 
Hi, I'm currently working through some exam papers from previous years before an upcoming module in Quantum Mechanics....

Sep110 04:23 AM
dcuk86

3 
699 
Hi, my dad is quite old and i had a big arguement about some completely stupid concept that he made up, ok what his...

Sep110 03:56 AM
nickthrop101

21 
2,576 
What physical force or property makes it so that atoms 'want' to achieve noble gas configuration of electrons? It...

Sep110 01:19 AM
alxm

1 
637 
Feynman very clearly presented QED in his book The strange theory of light and matter. He tried also with quantum...

Aug3110 11:23 PM
humanino

1 
1,029 
from my reading to DFT I constructed this algorithm
V ex....>\rho ....\varphi.....SCF....new\varphi>>>new\rho...

Aug3110 11:50 AM
Karrar

2 
964 
I have a question regarding quantization.
In most cases one never starts with a quantum theory, but always writes...

Aug3110 11:20 AM
Fra

23 
2,216 
Wigner's representation theorem says that any invertible transformation between rays of a Hilbert space that preserves...

Aug3110 02:48 AM
arkajad

3 
1,209 