The Student Room Group

TSR Physics Society

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Reply 40
I want to join plz. Gamow and Fermi were just as good lecturers as Feynman, it should be said. HEE HEE HEE.
AlphaNumeric
The thing is, can you definitely tell me they have annihiliated and then produced two entirely new photons, or have they just interacted, altering some of their characteristics? Given these characteristics are all you can know about photons, it doesn't matter which mechanism you think is true, the outcome is the same :smile:

How do you know that by interacting, the originally photons have not changed into new photons?
You don't, they are the same particle type and you can only define photons by their particle type, polarisation and momentum. Since the particle type doesn't change you have no method of differentiating between new photons and altered photons.

However, you might gain some insight into it by considering possible Feynman scattering. By conservation of spin I don't think you can have two photons combining into a single photon. Therefore lowest order scattering is photons interacting with one another. You can however get a infinitely many more complex fermion loops, where the photons turn into particle/antiparticle pairs, then back into new photons. In that case the photons were destroyed, then converted back.

It would seem we're both right, just it depends on the coupling force of electromagnetism :p: Your scatterings are O(e[sup]2[/sup), mine is O(1).
Is this ever going to be made into a proper society? as in with logos and the like... a lot of people probably don't know of its existence. :frown:
Reply 44
F1 fanatic
Is this ever going to be made into a proper society? as in with logos and the like... a lot of people probably don't know of its existence. :frown:


Yes, I agree, because I have been looking for a while, and only just found it. There seem to be plenty of people interested.

PK
Reply 45
I agree. Does jpowell still come on much?
Princess Ana
I agree. Does jpowell still come on much?

I haven't seen him on much... can't you check from his last activity/ posts etc?

Edit: last activity 1 day ago, so he's still about. Maybe someone should PM him or something. else set it up on his behalf
Reply 47
I've got 3rd year uni exams to worry about at the moment. I don't mind if someone else sets up the society though.
Reply 48
jpowell
I've got 3rd year uni exams to worry about at the moment. I don't mind if someone else sets up the society though.


Good luck then!

Alright, shall we do that?

Someone needs to find us a logo first....

...and then we should decide who other than jpowell should be leaders (you *can* have more than one, can't you?)
jpowell
I've got 3rd year uni exams to worry about at the moment. I don't mind if someone else sets up the society though.

yeah good luck with those!

Edit: Ana yes you can have as far as I am aware as many as you like.
My logo suggestions from last July (such is the length of time we have been meaning to do this!)

Galaxy

Nebula





Obviously they would need rescaling
Prefer Feynman to Einstein!
teachercol
Prefer Feynman to Einstein!

Find a pic of Feynman then :p:
oooh a physics society, i want in. (If no one minds of course :wink: )

EDIT: and i would vote for einstein if a vote is done
Reply 54
Just to see who would like a picture of what for the society, not deciding on a specific picture, after a short dispute about whether we should have Feynman or Einstein.

PK
Reply 55
Feynman for being one of the greatest physicists of all time.
Reply 56
suneilr
Feynman for being one of the greatest physicists of all time.


Don't you think that's a bit of a strange comment for voting AGAINST Einstein???
Reply 57
M1N1
Don't you think that's a bit of a strange comment for voting AGAINST Einstein???


Well Einstein was a good physicist however his rejection of quantum theory in spite of the evidence means that I see Feynman as a better physicist. Plus Feynman has really simplified our understanding of the physical world.
Reply 58
Ooh can i join please? And definately Feynman
Reply 59
BTW, in case anyone hadn't noticed, I've started a poll on the logo of the society.

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