Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.

If in it's rest frame a mass is measured as x, then
all frames must agree.

If in it's rest frame a mass' energy is measured as x,
then all frames must agree.

***What the above is saying is that a measurement is performed
which will always involve relative motion between, the mass
or it's energy, and the measuring devices.
If another observer whizzes by, he cannot measure
different results.***

Rod Ryker...
It is reasoning and faith that bind truth.

Dear Rod Ryker:

"Rod Ryker" wrote in message
...
Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.

No. The correct formula is:
E^2 = (pc)^2 + (mc^2)^2

If in it's rest frame a mass is measured as x, then
all frames must agree.

Yes.

If in it's rest frame a mass' energy is measured as x,
then all frames must agree.

No. Wrong formula.

***What the above is saying is that a measurement is performed
which will always involve relative motion between, the mass
or it's energy, and the measuring devices.
If another observer whizzes by, he cannot measure
different results.***

No. It is saying you made a mistake.

David A. Smith

Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.


E=mc^2 is only for massless particles. You should add the gamma factor for
kinetic energy.
Result: E=(mc^2)/sqrt(1-(v/c)^2). or for total energy E=sqrt((pc)^2+(mc^2))

(formerly) wrote:

Dear Rod Ryker:

"Rod Ryker" wrote in message
...

Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.


No. The correct formula is:
E^2 = (pc)^2 + (mc^2)^2

Rod: Why is that?
I'm not arguing pro relativistic effects.
E=mc^2 need not be relativistic at all.


If in it's rest frame a mass is measured as x, then
all frames must agree.


Yes.


If in it's rest frame a mass' energy is measured as x,
then all frames must agree.


No. Wrong formula.

Rod: Elaborate.


***What the above is saying is that a measurement is performed
which will always involve relative motion between, the mass
or it's energy, and the measuring devices.
If another observer whizzes by, he cannot measure
different results.***


No. It is saying you made a mistake.

David A. Smith

Rod: Elaborate.

Rod Ryker...
It is reasoning and faith that bind truth.

F. Kuik wrote:

Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.



E=mc^2 is only for massless particles.

Rod: Nope. Not to me.

You should add the gamma factor for kinetic energy.
Result: E=(mc^2)/sqrt(1-(v/c)^2). or for total energy E=sqrt((pc)^2+(mc^2))

Rod: No need for relativistic effects.

Rod Ryker...
It is reasoning and faith that bind truth.

Dear Rod Ryker:

"Rod Ryker" wrote in message
...
(formerly) wrote:

Dear Rod Ryker:

"Rod Ryker" wrote in message
...

Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.


No. The correct formula is:
E^2 = (pc)^2 + (mc^2)^2

Rod: Why is that?
I'm not arguing pro relativistic effects.
E=mc^2 need not be relativistic at all.

It is based on your context above. "The energy of a mass or mass less
particle also remains
unchanged regardless of relative motion."

Obviously "relativistic".

David A. Smith

Rod Ryker wrote in message ...
F. Kuik wrote:

Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.



E=mc^2 is only for massless particles.

Rod: Nope. Not to me.

You should add the gamma factor for kinetic energy.
Result: E=(mc^2)/sqrt(1-(v/c)^2). or for total energy E=sqrt((pc)^2+(mc^2))

Rod: No need for relativistic effects.

Rod Ryker...
It is reasoning and faith that bind truth.

As I understand it, E=mc^2 is only true for total energy of a particle
if it is at rest, since the equation does not include kinetic energy,
only the potential energy of nuclear forces, etc. So it is true that
if you measure potential energy, you will always get a constant
(mc^2), however, the particle's kinetic energy is free to change in
spite of E=mc^2.

AaronB wrote:
Rod Ryker wrote in message ...

F. Kuik wrote:


Rod: If of course we think E=mc^2 to be correct, then:
Mass remains constant regardless of relative motion.
The energy of a mass or mass less particle also remains
unchanged regardless of relative motion.



E=mc^2 is only for massless particles.

Rod: Nope. Not to me.


You should add the gamma factor for kinetic energy.
Result: E=(mc^2)/sqrt(1-(v/c)^2). or for total energy E=sqrt((pc)^2+(mc^2))

Rod: No need for relativistic effects.


As I understand it, E=mc^2 is only true for total energy of a particle
if it is at rest, since the equation does not include kinetic energy,
only the potential energy of nuclear forces, etc. So it is true that
if you measure potential energy, you will always get a constant
(mc^2), however, the particle's kinetic energy is free to change in
spite of E=mc^2.


Rod: Ahhh, but kinetic energy _IS_ potential energy.
It is different for every relatively moving frame.
Like momentum, it is frame dependent.
So, how does potential energy change a
homogenous rest mass/energy?

Rod Ryker...
It is reasoning and faith that bind truth.