[Pmb]

Any *fixed* region of space containing an energy E has a mass E/c².

Hi lightarrow! How goes it? I found this response from you to be unexpected. Normally in the passt you have used the term "mass" to mean proper mass. Here you use it to mean relativistic mass. Is there a reason for this that I'm not aware of? Thanks.

Pete

[lightarrow]

Any *fixed* region of space containing an energy E has a mass E/c².

Hi lightarrow! How goes it? I found this response from you to be unexpected. Normally in the passt you have used the term "mass" to mean proper mass. Here you use it to mean relativistic mass. Is there a reason for this that I'm not aware of? Thanks.

Pete

No, it's proper = invariant mass even here. If the region of space is fixed, then the total momentum is zero, so from E² = (cp)² + (mc²)² we can infer that m = E/c².

[Mr. Scientist]

Any *fixed* region of space containing an energy E has a mass E/c².

Hi lightarrow! How goes it? I found this response from you to be unexpected. Normally in the passt you have used the term "mass" to mean proper mass. Here you use it to mean relativistic mass. Is there a reason for this that I'm not aware of? Thanks.

Pete

No, it's proper = invariant mass even here. If the region of space is fixed, then the total momentum is zero, so from E² = (cp)² + (mc²)² we can infer that m = E/c².

You'd make this so much easier if you would just shorthand this to having gamma next to Mc^2.

[lightarrow]

Any *fixed* region of space containing an energy E has a mass E/c².

Hi lightarrow! How goes it? I found this response from you to be unexpected. Normally in the passt you have used the term "mass" to mean proper mass. Here you use it to mean relativistic mass. Is there a reason for this that I'm not aware of? Thanks.

Pete

No, it's proper = invariant mass even here. If the region of space is fixed, then the total momentum is zero, so from E² = (cp)² + (mc²)² we can infer that m = E/c².

You'd make this so much easier if you would just shorthand this to having gamma next to Mc^2.

Sorry?

[Mr. Scientist]

You know, relativistic forumla that come in the form E= \gamma Mc^2. No need for the messy definitions concerning mass.

[lightarrow]

You know, relativistic forumla that come in the form E= \gamma Mc^2. No need for the messy definitions concerning mass.

But I can't understand what exactly you mean. I proved that a system which is not moving in a specific frame of reference and which has energy, also has invariant mass. Relativistic mass is a different concept, that is, is just energy divided by c², *always*.

[Mr. Scientist]

You know, relativistic forumla that come in the form E= \gamma Mc^2. No need for the messy definitions concerning mass.

But I can't understand what exactly you mean. I proved that a system which is not moving in a specific frame of reference and which has energy, also has invariant mass. Relativistic mass is a different concept, that is, is just energy divided by c², *always*.

No, its not. reltivistic mass invokes M= \gamma m. This means that it has zero mass. A reativistic mass is never simply E/c^2=M.

[lightarrow]

You know, relativistic forumla that come in the form E= \gamma Mc^2. No need for the messy definitions concerning mass.

But I can't understand what exactly you mean. I proved that a system which is not moving in a specific frame of reference and which has energy, also has invariant mass. Relativistic mass is a different concept, that is, is just energy divided by c², *always*.

No, its not. reltivistic mass invokes M= \gamma m. This means that it has zero mass. A reativistic mass is never simply E/c^2=M.

Which is the energy E of a non-zero mass particle? Which is his relativistic mass? Is it different from E/c²?
Which is a photon's energy E? Which is his relativistic mass? Is it different from E/c²?

http://crib.corepower.com:8080/~relfaq/mass.html
http://w3.atomki.hu/fizmind/mag/photon_mass.html
http://crib.corepower.com:8080/~relfaq/light_mass.html

[Mr. Scientist]

You can either listen or not. But I can assure you one last time; relativistic mass is not correct under E=Mc^2, or any algebraic manipulation.

[Mr. Scientist]

Look into this: http://en.wikipedia.org/wiki/Mass_in_special_relativity

Relativistic mass is an outdated concept. Read especially : The relativistic mass concept
See also: Special relativity#Mass-energy equivalence
[edit] Early developments: transverse and longitudinal mass

[lightarrow]

Look into this: http://en.wikipedia.org/wiki/Mass_in_special_relativity

Relativistic mass is an outdated concept.

Good news! I thought to be the only one to say this!

[lightarrow]

You can either listen or not. But I can assure you one last time; relativistic mass is not correct under E=Mc^2, or any algebraic manipulation.

Ok. So, can you please give me the definition of relativistic mass of a photon?

[Mr. Scientist]

You can either listen or not. But I can assure you one last time; relativistic mass is not correct under E=Mc^2, or any algebraic manipulation.

Ok. So, can you please give me the definition of relativistic mass of a photon?

The mass of a photon in relativity is zero but has itself, a non-zero energy:

E=M^2c^4+p^2c^2

Plugging in the appropriate values, one finally assumes that for Mc^2, we actually have:

E= \gamma Mc^2

Which reduces its mass total to zero; this is the mass of the photon.

[lightarrow]

You can either listen or not. But I can assure you one last time; relativistic mass is not correct under E=Mc^2, or any algebraic manipulation.

Ok. So, can you please give me the definition of relativistic mass of a photon?

The mass of a photon in relativity is zero but has itself, a non-zero energy:

E=M^2c^4+p^2c^2

This is correct.

Plugging in the appropriate values, one finally assumes that for Mc^2, we actually have:

E= \gamma Mc^2

This is *not* correct for photons. What does infinite multiplied by zero means?

[Mr. Scientist]

You can either listen or not. But I can assure you one last time; relativistic mass is not correct under E=Mc^2, or any algebraic manipulation.

Ok. So, can you please give me the definition of relativistic mass of a photon?

The mass of a photon in relativity is zero but has itself, a non-zero energy:

E=M^2c^4+p^2c^2

This is correct.

Plugging in the appropriate values, one finally assumes that for Mc^2, we actually have:

E= \gamma Mc^2

This is *not* correct for photons. What does infinite multiplied by zero means?

It is correct for photons, because M is the rest mass, and \gamma makes the value of matter to zero. That is why the rest energy of a photon is given by: E=\gamma Mc^2. You can learn this stuff quite independantly and easily on web sites spralled all over the place.

[Mr. Scientist]

You can either listen or not. But I can assure you one last time; relativistic mass is not correct under E=Mc^2, or any algebraic manipulation.

Ok. So, can you please give me the definition of relativistic mass of a photon?

The mass of a photon in relativity is zero but has itself, a non-zero energy:

E=M^2c^4+p^2c^2

This is correct.

Plugging in the appropriate values, one finally assumes that for Mc^2, we actually have:

E= \gamma Mc^2

This is *not* correct for photons. What does infinite multiplied by zero means?

Also, where i have bolded; what infinite value? There is no infinite value in question here. ts a simple case of algebra.

[lightarrow]

It is correct for photons, because M is the rest mass, and \gamma makes the value of matter to zero. That is why the rest energy of a photon is given by: E=\gamma Mc^2. You can learn this stuff quite independantly and easily on web sites spralled all over the place.

And how much is gamma for a photon?
You shouldn't base your knowledge on internet sites only, you should also go to school, at least...

[Mr. Scientist]

It is correct for photons, because M is the rest mass, and \gamma makes the value of matter to zero. That is why the rest energy of a photon is given by: E=\gamma Mc^2. You can learn this stuff quite independantly and easily on web sites spralled all over the place.

And how much is gamma for a photon?
You shouldn't base your knowledge on internet sites only, you should also go to school, at least...

Talking about ''infinities'' did nothing for the conversation. And I dont need more school. I've had a shitload of it so far; i have education and certificates in physics too.

[lightarrow]

Talking about ''infinities'' did nothing for the conversation. And I dont need more school. I've had a shitload of it so far; i have education and certificates in physics too.

Well, so you should know that m*gamma is meaningless for a photon.
At high school they call it "Indeterminate form":
http://en.wikipedia.org/wiki/Indeterminate_form

[Mr. Scientist]

Talking about ''infinities'' did nothing for the conversation. And I dont need more school. I've had a shitload of it so far; i have education and certificates in physics too.

Well, so you should know that m*gamma is meaningless for a photon.
At high school they call it "Indeterminate form":
http://en.wikipedia.org/wiki/Indeterminate_form

M alone is meanngless, not to mention incorrect.