Question about photons

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aplefka

Lifer
Feb 29, 2004
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I realize this isn't a hardware related question, but back when I used to look at HT I remember the questions being about anything so I figured I'd post here rather than in OT for better quality of answers.

My question may be stupid/simple but I didn't get a chance to ask yesterday in my physics class. My professor stated that the average time it takes a photon to get from the center of the sun to the surface is 10,000,000 years. I was wondering if as the sun gets closer to burning out, will the photons be able to make that journey faster, and if so does this have anything to do with why stars burn brighter before they're about to burn out?
 

Cogman

Lifer
Sep 19, 2000
10,286
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http://en.wikipedia.org/wiki/Sun

my guess is no. they won't make the journey faster (I'm no quantum/star expert). If anything it will take longer because the layer of plasma (the primary slowdown.) will be thicker. The fact that the star gets brighter doesn't mean that the photons are necessarily moving faster (though they could be), rather, it more likely means that more photons are/have been produced.
 

sjwaste

Diamond Member
Aug 2, 2000
8,757
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I've always wondered this, too. Is it really the same photon? I always thought that photons were being absorbed in the plasma, exciting an electron, which emits a photon. Is that the case, and if so, is it really the same photon, or a chain of these events whereby some photon eventually gets to us?
 

silverpig

Lifer
Jul 29, 2001
27,703
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Originally posted by: sjwaste
I've always wondered this, too. Is it really the same photon? I always thought that photons were being absorbed in the plasma, exciting an electron, which emits a photon. Is that the case, and if so, is it really the same photon, or a chain of these events whereby some photon eventually gets to us?

Well that's the thing about identical particles. If a photon is absorbed and re-emitted, even though it may be identical, you can't really say it's the same one.

It's sort of like adding a drop of rain to the ocean.
 

WildHorse

Diamond Member
Jun 29, 2003
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well obviously your beloved dual particle / wave theory is inadequate since when traveing at light speed, that little photon's mass (particle theory) didn't increase toward infinite mass after all

what boggles me, and this is the O N L Y thing in life I don't understand, the atom throws out a hapless photon, perhaps from an inner valence shell. That little guy travels out & away, passing right through other electron shells further out.

Those electrons, under the dual theory, can be thought of as particles or waves of stochastic position at any instant. They're so fast they're everywhere at once, instantaneously, around that entire shell. Yet that lonely little photon travels right on out through the "solid" electron shell(s).

In other words, at the moment your photon is piercing the valence shell, two physical objects (photon & electron both as particles) occupy the same identical position in space at the same instant....which supposedly can not happen. It does.
 

sao123

Lifer
May 27, 2002
12,653
205
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Originally posted by: scott
well obviously your beloved dual particle / wave theory is inadequate since when traveing at light speed, that little photon's mass (particle theory) didn't increase toward infinite mass after all

what boggles me, and this is the O N L Y thing in life I don't understand, the atom throws out a hapless photon, perhaps from an inner valence shell. That little guy travels out & away, passing right through other electron shells further out.

Those electrons, under the dual theory, can be thought of as particles or waves of stochastic position at any instant. They're so fast they're everywhere at once, instantaneously, around that entire shell. Yet that lonely little photon travels right on out through the "solid" electron shell(s).

In other words, at the moment your photon is piercing the valence shell, two physical objects (photon & electron both as particles) occupy the same identical position in space at the same instant....which supposedly can not happen. It does.

at this point they are both waves... and waves can sum or cancel as they pass through each other.

actually, I thought it was that particles with the same quantum values cannot exist in the same space at the same time.
 

silverpig

Lifer
Jul 29, 2001
27,703
12
81
Originally posted by: sao123
Originally posted by: scott
well obviously your beloved dual particle / wave theory is inadequate since when traveing at light speed, that little photon's mass (particle theory) didn't increase toward infinite mass after all

what boggles me, and this is the O N L Y thing in life I don't understand, the atom throws out a hapless photon, perhaps from an inner valence shell. That little guy travels out & away, passing right through other electron shells further out.

Those electrons, under the dual theory, can be thought of as particles or waves of stochastic position at any instant. They're so fast they're everywhere at once, instantaneously, around that entire shell. Yet that lonely little photon travels right on out through the "solid" electron shell(s).

In other words, at the moment your photon is piercing the valence shell, two physical objects (photon & electron both as particles) occupy the same identical position in space at the same instant....which supposedly can not happen. It does.

at this point they are both waves... and waves can sum or cancel as they pass through each other.

actually, I thought it was that particles with the same quantum values cannot exist in the same space at the same time.

Fermions with the same spin cannot exist in the same state. There is no such restriction for bosons, and thus the bose-einstein condensate is observed.
 
Sep 12, 2004
16,852
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Originally posted by: firewolfsm
that's new...interesting...why?
It's interesting because each small question and answer helps to give us further insight into the inner workings of the universe we live in.
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
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Originally posted by: scott
well obviously your beloved dual particle / wave theory is inadequate since when traveing at light speed, that little photon's mass (particle theory) didn't increase toward infinite mass after all

what boggles me, and this is the O N L Y thing in life I don't understand, the atom throws out a hapless photon, perhaps from an inner valence shell. That little guy travels out & away, passing right through other electron shells further out.

Those electrons, under the dual theory, can be thought of as particles or waves of stochastic position at any instant. They're so fast they're everywhere at once, instantaneously, around that entire shell. Yet that lonely little photon travels right on out through the "solid" electron shell(s).

In other words, at the moment your photon is piercing the valence shell, two physical objects (photon & electron both as particles) occupy the same identical position in space at the same instant....which supposedly can not happen. It does.

The electrons are not everywhere at once. The wavefunction is indicative of the probability density of finding the electron(s) within a specific volume. The electron is not spread out over a cloud or a surface. When you solve for these probability densities, you still assume that the electron is at a single point in space. It is just that for a specific energy, the electron can be found in almost any position (there can be instances where wavefunctions do reach zero, don't know off hand if that is the case for electrons though), but the probability of finding the electron within a given volume does vary.
 

firewolfsm

Golden Member
Oct 16, 2005
1,848
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Originally posted by: TastesLikeChicken
Originally posted by: firewolfsm
that's new...interesting...why?
It's interesting because each small question and answer helps to give us further insight into the inner workings of the universe we live in.

I meant, why does it work out like that (the restriction on fermions but not bosons,) I really have no idea.
 

KIAman

Diamond Member
Mar 7, 2001
3,342
23
81
Originally posted by: scott
well obviously your beloved dual particle / wave theory is inadequate since when traveing at light speed, that little photon's mass (particle theory) didn't increase toward infinite mass after all

what boggles me, and this is the O N L Y thing in life I don't understand, the atom throws out a hapless photon, perhaps from an inner valence shell. That little guy travels out & away, passing right through other electron shells further out.

Those electrons, under the dual theory, can be thought of as particles or waves of stochastic position at any instant. They're so fast they're everywhere at once, instantaneously, around that entire shell. Yet that lonely little photon travels right on out through the "solid" electron shell(s).

In other words, at the moment your photon is piercing the valence shell, two physical objects (photon & electron both as particles) occupy the same identical position in space at the same instant....which supposedly can not happen. It does.

That's easy, you wanna know what boggles me about photons? The fact that a single photon (particle) can interfere with itself (wave).
 
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