
Before posting anything, please review the Physics Forums Global Guidelines.
If you are seeking help with a...

Feb2313 08:38 AM
ZapperZ

1 
36,215 
If the uncertainity in position is equal to de broglies wavelength ..den is the uncertainity in velocity equal to the...

Apr1413 05:26 AM
darkfall

3 
338 
The photon as I understand it is a massless particle that "must" travel at the speed of light.
However I do not...

Apr1413 05:01 AM
tom.stoer

4 
486 
Greetings all. I'm a new poster here but have spent some time on philosophy forums previously. I subscribe to New...

Apr1313 08:58 PM
bhobba

220 
14,928 
I'm studying electron spin/magnetic field and I was taught electrons can have only 2 spin orientations, as seen in the...

Apr1313 08:12 PM
phyzguy

19 
1,366 
Currently doing AS physics and have come across De Broglie's equation: λ = h/p
Combining this with the idea that if...

Apr1313 05:57 PM
frankhawes

0 
398 
There is a type of exchange of particles which is generalised by a type of potential:
\frac{e^{\alpha\r}}{R} This...

Apr1313 03:19 PM
fzero

2 
472 
Me and my teacher have been arguing, whether photons have or don't have mass. I say that it's impossible for photons...

Apr1313 08:23 AM
medgalis

11 
1,270 
I'm curious, when an electron is bombarded by another electron or photon does the electron even jump at all if the...

Apr1313 05:59 AM
Fightfish

2 
564 
Hi,
Can anyone explain to me why the wave functions in QM must to be complex, other than to make it work when...

Apr1313 04:44 AM
akhmeteli

38 
2,757 
Sorry for the noob question, but is there a resource anyone can point me to for an easy to understand explanation of...

Apr1313 03:34 AM
Kulu

4 
1,696 
The position and momentum of a photon is uncertain. If that is the case, then shouldn't the speed of light be slight...

Apr1213 08:10 PM
fluidistic

30 
1,684 
I've been trying to wrap my head around spinors, and I think I'm beginning to understand the mathematical formalism,...

Apr1213 05:25 PM
samalkhaiat

10 
931 
Empirically, all known fundamental particles are either bosons or fermions. However, I understand that it is...

Apr1213 02:01 PM
Bill_K

6 
639 
Hello. In Molecular Dynamics simulations, the Newton's equation of motion is used to calculate the time evolution of...

Apr1213 11:23 AM
BacalhauGT

2 
418 
Hello everyone,
I'm going through Edmond's Angular momentum in quantum mechanics and I found a particular...

Apr1213 03:47 AM
Yoran91

4 
642 
In CM, p is the generator of translations.
On functions, exp is what translates.
So the relationship =i ...

Apr1213 12:45 AM
tom.stoer

1 
495 
Greetings,
I was trying to prove a theorem regarding degeneracy, and I succeeded. However, I also proved the...

Apr1213 12:13 AM
HJ Farnsworth

2 
455 
In classical QM, using a photon to measure the location or momentum of an electron collapses the electron's wave...

Apr1113 05:19 PM
mfb

1 
365 
I'm learning about NMR and it's been stated that deuteron has a spin 1 nucleus and so should exhibit different...

Apr1113 03:51 PM
Chopin

8 
827 
Most ideal light radiates uniformly in all directions. It means that for each photon, the probability of each...

Apr1113 12:42 PM
mfb

1 
369 
Hello,
In all information I see about quantum entanglement, it's stated that nothing travels faster than light,...

Apr1113 12:37 PM
DrChinese

4 
724 
Good evening fellas,
I'm in a bit of a conundrum: lately I've been considering a 2D array of atoms and the...

Apr1113 11:14 AM
SpinFollower

2 
431 
Hi, I'm a little confused by the selection rules for atomic transitions. In pretty much any standard QM text, they...

Apr1113 05:01 AM
andrien

3 
695 
I think I understand this only up to a point.
1. Photon spin is quantized to be +1 or 1 and these represent left...

Apr1113 02:30 AM
DrClaude

7 
987 
how does visible light carry with it?
does this energy increases with increase in number of reflection?

Apr1113 01:24 AM
Simon Bridge

1 
374 
Lets say we have a potential step as in the picture:
http://i.stack.imgur.com/HB3XI.png
In the region I there...

Apr1113 01:22 AM
71GA

8 
1,203 
There are few questions on an assignment (taken from an old exam, YIKES!) that are confounding me and I was wondering...

Apr1013 07:31 PM
ace1719

0 
520 
I'm not sure I know all that I should to understand it. I'm posting to try and determine if I do.
Knowing what I...

Apr1013 05:46 PM
BacalhauGT

4 
460 
When I was studying general relativity, I learned that to change a vector into a covector (or vice versa), one used...

Apr1013 04:04 PM
Trifis

14 
2,152 
Suppose I have a Schrodinger equation for two interacting particles located at x and y; so, something like
\left( i...

Apr1013 08:36 AM
DrClaude

1 
513 
If you have purely a coordinate transformation whose Jacobian equals 1, and your Lagrangian density has no explicit...

Apr1013 08:28 AM
geoduck

2 
493 
Hello All,
Here is the paper I'd like to ge opinions of.
As for interpretations of QM I am openminded agnostic.But:...

Apr1013 08:13 AM
Alexis1304

2 
543 
Hello, this is my first thread here and i have a question regarding coherent population trapping and the dark state. I...

Apr1013 03:11 AM
Zarqon

5 
837 
I am trying to understand the measurement of spin, in order to understand Bell's paper on the EinsteinPodolskyRosen...

Apr1013 01:08 AM
andrewkirk

2 
634 
Presumably a collider has some sort of pinhole out of which particles get ejected in a particular direction, and the...

Apr913 06:41 PM
jshrager

2 
536 
For fun (and classroom demos) we we regularly calculate the diffraction and time evolution dispersion of macroscopic...

Apr913 06:40 PM
jshrager

2 
479 
Why do electrons closer to nucleus have
Less energy than electrons first away?
Thanks

Apr913 09:06 AM
jtbell

3 
1,199 
Greetings,
I would like to find the commutator \left and prove that
\left=\left=\left I infer from the cyclic...

Apr913 05:35 AM
Septim

11 
1,198 
Hi guys,
I have a question which is probably stupid. I am studying angular momentum and I have found almost...

Apr913 05:32 AM
Einj

4 
623 
Lately, I've been wondering that the sum rule from probability theory applies in all fields of study, expect for in...

Apr913 02:00 AM
failexam

14 
1,374 