light is a measure of mass not velocity

Relativity is still a theory albiut most of the premises of the theory have been proven using current knowledge.
So you don't know what the word "theory" means. Well done.

If E=mc2 is true then an object that has zero velocity
You're hilarious. Really.

Though technically right. If an object doesn't exist it isn't going to be moving...

I'm not sure about all of the other "so called" physists/scientists out there who happen to live in the bubble of conventional science, but it does take someome outside of the sphere of "modern Science" every once in a while to ask questions.

Standard crackpot intro.

but it does take someome outside of the sphere of "modern Science" every once in a while to ask questions.

Diversity is good.

If E=mc2 is true then an object that has zero velocity must also have zero mass otherwise it would be possible for an object with mass to exceed the speed of light.

However not having a clue is bad!

Velocity (d/t) such as the speed of light, is based on space-time, which is an integration between distance and time potential. Time and distance work together in their reference proportions.

It is also possible to dissociate space-time into separated time potential and distance potential. For example, a quantum jump is distance potential without time potential, since distance is transversed without time.

It is not appropriate to calculate velocity from only distance potential, since velocity assumes an integrated space-time. Any movement in space in zero time would be infinite velocity. But since this is only distance potential, it is not velocity per se and does not violate C. Yet it can do things that appear to be faster than C.

This are also examples in nature of time potential without distance potential. If we have a twin pair, they can synchronize in time over a distance, without any time delay due to the space between. Time and information flows without any constraint of distance. This is not velocity either, since technically it is not integrated space-time so the speed of C is not violated.

The idea of dissociated space-time into time and distance potential takes a little getting used to. The dissociation allow us to do things that inertia and energy can't, since energy is based on integrated time and distance potential (wavelength/frequency). If we dissociated energy into separated wavelength (distance potential) and frequency (time potential), we can sequence the impact of the energy differently.

Is there any likelihood of you not posting your word salad in the near future?

This reminds me of a friend of mine who once told me that his brother said that relativity is wrong and the reason was that according to relativity c = 300000 km/sec is the largest velocity that can be reached, however in the formula E = mc^2 you have c^2 which is larger than c so there is a contradiction.
:bawl::crazy:

But since this is only distance potential, it is not velocity per se and does not violate C. Yet it can do things that appear to be faster than C.

Hey wellwisher, what the hell is C? Is that suppose to be a notation for crap. As in, "Whoa, that space ship is going faster than crap!":shrug:

This reminds me of a friend of mine who once told me that his brother said that relativity is wrong and the reason was that according to relativity c = 300000 km/sec is the largest velocity that can be reached, however in the formula E = mc^2 you have c^2 which is larger than c so there is a contradiction.
I LOVE it.
:roflmao:

I have a double sided laser pointer. I press both buttons sending two photons in opposite directions. How fast is photon A moving from photon B?

I have a double sided laser pointer. I press both buttons sending two photons in opposite directions. How fast is photon A moving from photon B?

c, the speed of light. If you measure the velocity of A from B, or B from A, you will always measure c.

So we have measured another photon while traveling at light speed?

I have a double sided laser pointer. I press both buttons sending two photons in opposite directions. How fast is photon A moving from photon B?

If you use the reference frame with you at rest, then obviously the distance between A and B is changing at 2c.

But the phrase "moving from photon B" implies a reference frame with B at rest... which is a problem, because there is no such reference frame (ie it's impossible to set up clocks and rulers that are at rest relative to B).

The formula for the relativistic addition of velocities is

w = u + v / 1 + (uv/c^2)

u and v, the velocities of the two photon are each c, so you have 2c/1 +(c^2/c^2), which is 2c/2 or c.

If you use the reference frame with you at rest, then obviously the distance between A and B is changing at 2c.

and we shatter the light speed barrier by twice what we previously thought! Woo!!

Tell Sylvester and his neutrinos to eat it.

and we shatter the light speed barrier by twice what we previously thought! Woo!!
Not really, no.
The speed of light barrier is a limit to how fast a single object can go relative to some other object considered to be at rest.

It doesn't apply to the speed of separation between two objects when you consider both to be moving, which can obviously be as high as 2c.

AlexG said:
The formula for the relativistic addition of velocities is

w = u + v / 1 + (uv/c^2)

u and v, the velocities of the two photon are each c, so you have 2c/1 +(c^2/c^2), which is 2c/2 or c.
Yes, that's the formula to get the speed of A in a reference frame with B at rest... but I'm not sure that it's valid when u=v=c.

Remember that the gamma factor when v=c is undefined (divide by zero). Can the velocity addition formula be derived without using a gamma factor?

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Work through it, Alex. You'll find at least one $$1/\sqrt{1-v^2/c^2}$$ term.

Work through it, Alex. You'll find at least one $$1/\sqrt{1-v^2/c^2}$$ term.

I've followed the derivation in wiki, and oddly enough, I don't see gamma in there anywhere. But the math is my weak point.

Hey Alphanumeric or rpenner, you guys reading this?

My bad, it's actually written as $$1/\sqrt{1-v^2}$$. The wikipedian used units in which c=1:
Wikipedia said:
To translate to engineering units, replace v with v / c everywhere.
...
Since the relativistic length of V is 1, $$V_0^2 - V_1^2 = 1$$ . So $$V_0 = 1/\sqrt{1-v^2}$$ and $$V_1 = v/\sqrt{1-v^2}$$ . The Lorentz transformation matrix which boosts the rest frame to four-velocity V is then:

That derivation is also done with four-vectors, which I don't understand well.

Try this one - it's the first Google hit for "velocity addition derivation":
Relativistic velocity addition law derived from a machine gun analogy and time dilation only
It clearly includes a 1/(1-u/v) term, and it also references a bunch of other derivations (that I haven't checked out).

So yeah, I'd also like clarification from the guys who know:

Is the relativistic parallel velocity addition formula valid when u=v=c?