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Matter Discovered Traveling at Near Light Speed
mcgrew writes to mention New Scientist is reporting that scientists have clocked matter traveling at 99.999% the speed of light. "The fastest flows of matter in the universe shoot out of dying stars at more than 99.999% the speed of light, new observations reveal. When a massive star runs out of fuel, it collapses to form a black hole or a neutron star. In the process, some of the matter from the star also explodes outward at blistering speeds, producing an intense burst of gamma rays and other radiation."
Much better subject line than what was found in The Firehose...
(The original subject line said "Matter found travelling at the speed of light", or something along those lines.
Close != At.
Given all the Complaints and BS the mods have to put up with sometimes, I think they should get complimented for a job well done as well.
We've known about gamma ray bursts for a long time. It's just that now we know how fast the matter is moving that causes these bursts.
It will be whatever the speed of sound is in the pole. Assuming a perfectly rigid material it would be instant, but there is no such thing and the actual speed will much less than c.
The "speed of force" as you put it, is not really a speed inherent to force. You would be measuring how fast a tensile or compressive wave passes through the pole, same as the speed of sound through it. It would be much slower than the speed of light.
Wow, I was hoping that there would already be an explanation answering this, but here you go: The speed of "force" as you put it, is actually quite slow. It's a actually the speed of sound through the object. Why? Because when you push the rod, you're bumping the molecules, they have to push the molecules in front of them, and on until you reach the end. This is actually a sound wave propagating the medium, you just usually can't hear it. Now, if you had a perfectly rigid pole (cue penis jokes here) it would seeming move instantly. However, no known substance is anywhere close to perfectly rigid. Even atomic nuclei, which are, far, far more rigid than bulk matter, behave like drops of fluid and can have waves propagate through them. So no, you can't forge a pole to another planet and communicate instantly, it would be hugely slower than normal radio.
I know you're joking, but even a perfectly rigid pole would be subject to the propagation of forces. Think about what forces have to propagate in order to tell the other end of the pole to move. One atom has to repel the next atom using electromagnetic force, weak and strong nuclear forces, which has to in turn repel the next atom, etc, etc. There is an elastic repulsive process which goes all the way down the pole until it reaches the other end. And we know the fastest that this can happen is the speed of light. So the pole will be momentarily compressed as the force propagates.
No information can travel faster than the speed of light, as a general rule.
Yeah, Gravity moves at the speed of light. That's all part of general relativity.
Actually, and believe you me I am no damn physicst (can't even spell it), a photon has no "resting mass", but does have momentum, which implies that there is an upper limit to is mass which cannot be zero.
WTF does that mean? Dunno. OK screw that. No more Wiki for me.
I am very small, utmostly microscopic.
What really happens is that velocities don't add like that. They seem to for everyday objects, but relativistic effects become important at 0.7c. You should add them according to the Einstein formula: v = (B+v')/(1 + Bv') where B is the speed of one ship relative to an observer at rest (0.7c), and v' is the speed of the other ship in it's frame (0.7c). So the speed of one ship relative to the other is just v = 1.4/1.49 = 0.94c. You can see that, for small speeds, the product in the denominator is small, so we have the usual addition.