Originally posted by adam warlock And I wasn't saying you were wrong I just didn't get what you meant. My first language isn't english and even though I normally understand things at first this was one of those times I didn't.

Ignoring that we need to rethink SR when taking into account QM I'd say that the gaps don't become any closer. Remember that you'd still have to [b]measure ...[text shortened]... ything would look the same to you.

Edit: Ignore my last paragraph because it is wrong.[/b]

Did you hear about the cosmic rays, particles with mass, going so close to C that after 300,000,000 years of travel the difference between a photon and these rays, in time traveled, would be one MICROSECOND behind. I would like to do the math but don't have enough digits in anything I have, like my trusty HP48. 300E6 years times 33 E6 seconds per year times 1E6 microseconds per second puts it about 25 digits or more needed to do the math properly. It must be a huge gain of mass and foreshortening and time has to go extremely slow inside the ray. Do you have something that can calculate it? Mathcad?

Originally posted by sonhouse Did you hear about the cosmic rays, particles with mass, going so close to C that after 300,000,000 years of travel the difference between a photon and these rays, in time traveled, would be one MICROSECOND behind. I would like to do the math but don't have enough digits in anything I have, like my trusty HP48. 300E6 years times 33 E6 seconds per year times ...[text shortened]... has to go extremely slow inside the ray. Do you have something that can calculate it? Mathcad?

Are you assuming that the cosmic rays come at a constant speed? If so there is no need to know the distance or how much time they have travelled. The equation that relates mass with speed in SR only depends on the rest mass and on the speed the particle has.

But if you give me the masses involved and a particular value for the speed they have I can calculate things with Mathematica that has the precision I want it to have.

Edit: By the way the concept of mass increasing with speed is becoming dated. Many of the high-energy physics I know don't like to use that concept and books that had it are being revised on the new editions. In one thread on the science forum this issue was somewhat discussed but if you want you can google things up and find out more about it.

Originally posted by adam warlock Are you assuming that the cosmic rays come at a constant speed? If so there is no need to know the distance or how much time they have travelled. The equation that relates mass with speed in SR only depends on the rest mass and on the speed the particle has.

But if you give me the masses involved and a particular value for the speed they have I can sue was somewhat discussed but if you want you can google things up and find out more about it.

I thought the mass increase was one of the underpinnings of SR.
Do you have links to why they question that? I don't know the mass, thats what I was trying to figure out. The only thing I know is some relate the kinetic energy of that single particle to a well hit tennis ball.
Well I found one such link:
http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html