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Photons increase in mass?

Posted: Wed Apr 21, 2010 7:31 pm
by Isaac
So when momentum is changed, by a mirror or by a black hole's gravity, a photon will have more mass? Is it really that simple? And, when light particles combine, into a bond state, they also increase in mass?

I'm trying to understand how light particles gain mass, while at the bottom of the math physics learning curve.

Posted: Wed Apr 21, 2010 7:50 pm
by Top Gun
I can cut you off right here by stating that photons have zero rest mass, no matter what they're doing. :P

Re: Photons increase in mass?

Posted: Wed Apr 21, 2010 8:51 pm
by AlphaDoG
Isaac wrote:So when momentum is changed, by a mirror or by a black hole's gravity, a photon will have more mass? Is it really that simple? And, when light particles combine, into a bond state, they also increase in mass?

I'm trying to understand how light particles gain mass, while at the bottom of the math physics learning curve.

Dude if you are indeed old enough to study such things, why make ME do YOUR research?

Git-r-DONE!

Re: Photons increase in mass?

Posted: Wed Apr 21, 2010 9:11 pm
by dissent
AlphaDoG wrote:Dude if you are indeed old enough to study such things, why make ME do YOUR research?

Git-r-DONE!
Yeah.


Google "do photons have mass",
get stuff like this -
http://imagine.gsfc.nasa.gov/docs/ask_a ... 60731.html


Have fun, my little mathematical flounder.

Posted: Wed Apr 21, 2010 10:43 pm
by Verran

Posted: Wed Apr 21, 2010 11:18 pm
by Kilarin
Photons have Mass? I didn't even realize they were Catholic!

Posted: Thu Apr 22, 2010 8:01 am
by Foil
To say the least, there's a lot of misunderstanding about this topic.

Here's the fundamental thing to understand: There are two 'types' of mass being talked about here.

One is \"rest mass\" or \"invariant mass\" or \"intrinsic mass\". Being very un-technical, you can think of this as the classic \"mass\" we all learned about in grade school.

The other, and usually the source of the confusion, is something called \"relativistic mass\". It's essentially a term which acts like mass in the equations for relativistic motion. It's described and taught different ways (and there's still debate about the terminology), but when physicists say things like \"mass increases near light speed\", they're talking about relativistic mass.

So... do photons have zero mass? Depends on what you're talking about. They have zero rest mass, but nonzero relativistic mass.

... Does that help?

Re:

Posted: Thu Apr 22, 2010 10:04 am
by Isaac
Foil wrote:To say the least, there's a lot of misunderstanding about this topic.

Here's the fundamental thing to understand: There are two 'types' of mass being talked about here.

One is "rest mass" or "invariant mass" or "intrinsic mass". Being very un-technical, you can think of this as the classic "mass" we all learned about in grade school.

The other, and usually the source of the confusion, is something called "relativistic mass". It's essentially a term which acts like mass in the equations for relativistic motion. It's described and taught different ways (and there's still debate about the terminology), but when physicists say things like "mass increases near light speed", they're talking about relativistic mass.

So... do photons have zero mass? Depends on what you're talking about. They have zero rest mass, but nonzero relativistic mass.

... Does that help?
I think so. Thanks.

Re:

Posted: Thu Apr 22, 2010 10:21 am
by dissent
Kilarin wrote:Photons have Mass? I didn't even realize they were Catholic!
Jesus did say "I am the light of the world ..." :P

Posted: Thu Apr 22, 2010 12:08 pm
by Floyd

Posted: Thu Apr 22, 2010 1:02 pm
by Isaac
Paper converted pages? How innovative!
http://en.wikipedia.org/wiki/Books