"Randy Poe" wrote in message oups.com...
On Jun 22, 4:54 pm, John C. Polasek wrote:
On Fri, 22 Jun 2007 16:02:51 GMT, "Dirk Van de moortel"



wrote:

"Matt Hickman" wrote in glegroups.com...
Recent gamma-ray burster observations have clocked matter being
expelled at 99.999% light-speed. This is said to give a Lorentz
factor of 400.

Does this mean that time for the speeding matter has slowed down by a
factor of 400?

Sort of, yes. It means that we would observe decaying particles
of that matter with a normal half-life time H, to have a half-life
time of 400 H.

And what does this mean for the mass of the matter?
How much as this increased?

It hasn't. See for instance
http://math.ucr.edu/home/baez/physic...y/SR/mass.html

Dirk Vdm

To the contrar;y, If you study that reference you will find only
obfuscation.

Where "obfuscation" means "perfectly clear statements that I
either don't understand, choose not to read, or disagree with."

"Physicists dont talk about relativistic mass anymore".

They talk about invariant mass, what was formerly called
"rest mass". Why is that "obfuscation"?

and even Einstein said "avoid gamma" (just do something else).

No idea where you think you read that whopper.

That's why I didn't bother replying.
Leaving the room with the door open is much more
effective than slamming the door on your way out.

Dirk Vdm

"Dirk Van de moortel" wrote
in message ...

"Matt Hickman" wrote in message
ps.com...
Recent gamma-ray burster observations have clocked matter being
expelled at 99.999% light-speed. This is said to give a Lorentz
factor of 400.

Does this mean that time for the speeding matter has slowed down by a
factor of 400?

Sort of, yes. It means that we would observe decaying particles
of that matter with a normal half-life time H, to have a half-life
time of 400 H.

And what does this mean for the mass of the matter?
How much as this increased?

It hasn't. See for instance
http://math.ucr.edu/home/baez/physic...y/SR/mass.html

In reality it depends on which "school" you adhere to and people like to put
up a fight about it. ;-)
For some people time doesn't slow down and mass doesn't increase, but for
others the mass increased by a factor 400. See for instance the Feynman
lectures of physics or T. R. Sandin, Am. J. Phys. 59 p.1032 (1991).

Cheers,
Harald