Physics Help Forum tha mass of photon,a topic of both old and new

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Apr 25th 2018, 11:54 AM   #11

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 Originally Posted by htam9876 I hope that someone could give the answer that is the same with me .(X4 = ∞，what's the result?)
As X4 is a rescaling I don't see how you could say it can be arbitrarily large (a much better term than infinite here.) Your comment makes no sense unless you wish to share what you actually think X4 is. You still haven't done that yet, in your paper or otherwise.

-Dan
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 Apr 25th 2018, 05:02 PM #12 Banned   Join Date: Mar 2018 Location: Xinhui Guangdong Province China Posts: 118 this time this time , it will be right
Apr 25th 2018, 11:31 PM   #13
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 Originally Posted by htam9876 the mass of a photon ,either the static mass is M0 and the released mass is ∞，or the released mass is hγ and the static mass is zero, (the detailed calculation with Special Relativity omitted),but both are meaningless in physics. If photon has no effective mass, how to explain the Campton efffect. what is the mass of a photon?
Your mistake lies in this statement. The way that the velocity dependence of mass is derived is to require the conservation of the quantity of mv where m is the mass of a tardyon, i.e. a particle that always travels at a speed < c. It cannot be used for photons. I showed you how to get the mass of a photon. You use p = mv and with v = x and E = pc you get m = E/c^2.

So all your claims about the mass of a photon are wrong. The propr mass of any particle for v <= c is determined by E^2 - (pc)^2 = m_o^0 c^4

For a photon this gives m_o = 0.

 Apr 26th 2018, 05:44 AM #14 Physics Team   Join Date: Apr 2009 Location: Boston's North Shore Posts: 1,576 By the way. This is not just myself speaking but it reflects the Early Universe course given by Alan Guth at MIT. See http://www.newenglandphysics.org/other/guth.jpg You can watch him talk about it from this: http://www.newenglandphysics.org/com...an_Guth_01.mp4 topsquark likes this.
Apr 26th 2018, 12:59 PM   #15

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 Originally Posted by Pmb Your mistake lies in this statement. The way that the velocity dependence of mass is derived is to require the conservation of the quantity of mv where m is the mass of a tachyon, i.e. a particle that always travels at a speed < c. It cannot be used for photons. I showed you how to get the mass of a photon. You use p = mv and with v = x and E = pc you get m = E/c^2. So all your claims about the mass of a photon are wrong. The propr mass of any particle for v <= c is determined by E^2 - (pc)^2 = m_o^0 c^4 For a photon this gives m_o = 0.
Misspelling.

-Dan
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Apr 26th 2018, 01:53 PM   #16
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 Originally Posted by topsquark Misspelling. -Dan
Actually I spelled the wrong word correctly.

I meant to say tardyon.

Apr 26th 2018, 03:09 PM   #17

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 Originally Posted by Pmb Actually I spelled the wrong word correctly. I meant to say tardyon.
My bad. I have never heard of the term. Upon re-reading it I should have noted an inaccuracy of mine... tachyons have an "imaginary" mass.

-Dan
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Apr 26th 2018, 09:07 PM   #18
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 Originally Posted by topsquark My bad. I have never heard of the term. Upon re-reading it I should have noted an inaccuracy of mine... tachyons have an "imaginary" mass. -Dan
FYI there are three classes of particles:

v <c: Tardyon

v = c: Luxon

v > c: Tachyon

Apr 27th 2018, 10:29 AM   #19
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 Originally Posted by Pmb FYI there are three classes of particles: v c: Tachyon
Like Dan, I have not come across these terms before, but they admit a certain quaint charm (pun intended) don't you think?

You can learn something every day if you take notice.

Apr 27th 2018, 12:34 PM   #20
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 Originally Posted by studiot Like Dan, I have not come across these terms before, but they admit a certain quaint charm (pun intended) don't you think? You can learn something every day if you take notice.
This is one of my chosen fields. That's probably why I know them. I was probably a little insulting when it came to the various kinds of mass. My bad.

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