Re: The Shalimar Treaty
 

You can use the doppler effect on the pulsar's frequency to measure your speed relative to the pulsar, and then only if you know the pulsar's actual frequency. This has absolutely no effect on the measurement of your speed relative to light.

Re: The Shalimar Treaty
 

I point my space ship at some pulsar, and count the rate, then I turn and point my space ship way from the pulsar and count the rate. The arrival of pulses at a stationary frame of reference is half way between the two rates.

Re: The Shalimar Treaty
 

Sorry, but just changing the direction you're ship is pointing won't change the measurements at all. You'd have to change your velocity for that, and you'd have to already know your velocity relative to the pulsar in order to tell when you had exactly reversed it, which renders the whole exercise pointless.

There's also another slight problem here. You know all these "stationary" observers we've been talking about? Technically whether something is stationary or not depends entirely on your frame of reference. There is no "absolute" or "superior" reference frame which defines what it means to be "stationary". The term "stationary" only really has meaning when you specify something like "stationary relative to the pulsar," which just means it's velocity is exactly the same as the pulsar's.

Re: The Shalimar Treaty
 

The term "stationary" refers to an object that does not move relative to some reference point. It has no meaning outside that context. Saying stationary with respect to blah blah is redundant.

The space ship, as you have surmized, is in fact moving relative to the pulsar. This is of course how come there is a difference in measurement between ingress and egress.

This conversation has lapsed into nit picking.

Re: The Shalimar Treaty
 

I think we're arguing different things. My point is that you can't violate cause and effect (and it seems you agree). Yes, you could contrive some situation where the light from the bullet was slowed to the point that you hear it before you see it (so in this case, I agree with you). You could also just close your eyes while the bullet was firing, then you'd never see it. That's the problem with using the term "speed of light". So just to be clear, when I say "speed of light", I mean the speed of light in a vacuum (which is the speed that information travels at).

A gun that shoots teleporting bullets would violate causality, since the bulletes would effectively be travelling faster than the speed of light. The victim would be shot, then later see the gun firing (we'll say that there is vacuum between the two people). The order of the two events would be changed in this frame. Causality requires that all observers observe cause and effect in the correct order.

Yep. That "incredibly -weird- physics" is called special relativity.

Re: The Shalimar Treaty
 

Anglewyrm, I loved you link to the time dilation page. What a blast from my past. It was fun to go over the formulas again. http://forum.shrapnelgames.com/images/smilies/happy.gif

The Lorentz contraction is now believed to really be a rotation, but the formula is a bit more complex I believe.

Thanks all for an interesting read!

Re: The Shalimar Treaty
 

Here is a paper on Experimental Evidence of Near-field Superluminally Propagating Electromagnetic Fields
http://xxx.lanl.gov/ftp/physics/papers/0009/0009023.pdf

And here is an article on a light pulse that was seen leaving a gas-filled chamber before it even entered
http://physicsweb.org/articles/world/13/09/3.

It's pretty funny watching the media squirm, redefining words and making exceptions and calling doesn't count. Like the universe as we know it will topple. So? We've had Black Holes, Superstring foam (or whatever they call that), spatial distortions of curved space, intangible aether, ftl tachyons, Heisenberg uncertainty principle, frame dragging, increasing entropy, and many other phantoms. The universe as we know it is in a constant state of redefinition. Life will go on, new professors will be hired.

Re: The Shalimar Treaty
 

Trimming quotes..

We're arguing different things.

You're confusing information with cause still. Both the bullet leaving the barrel and the sound are -effects-, not causes. Simiarlly, getting hit my the bullet is a effect. So is SEEING the bullet.

We've already established it doesn't matter what order you see the effects in. That was the point of the light-slowing barrier comment. In that scenerio, exactly the same thing happens- the observer sees the impact, THEN sees the shot. So, why does a FTC bullet violate causulity in a way this other example does not?

Re: The Shalimar Treaty
 

Which begs the question: What exactly is a cause?

Could we say that the explosion of the propellent is the cause of the bullet's motion? Or is that just an effect of a chemical reaction? Is the chemical reaction in the gun powder the cause of the bullet's motion towards the target? What about the barrel and the gunner?

Re: The Shalimar Treaty
 

What the cause is depends on what the effect is. http://forum.shrapnelgames.com/images/smilies/wink.gif

The trigger being pulled is a cause that causes the hammer fall.

The hammer is a cause that sets of the powder.

The exploding powder is a cause that propels the bullet.

The impacting bullet is a cause for whatever effect is has on the target.