Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

So? I'm talking about the observer frame. This is simply an assertion that there exists a frame from which all FTL is forward in time. This can actually be true without the special frame being privileged by anything but coincidence, the wormhole network with virtual particle collapse create a preferred frame that matches the wormhole network.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

I don't think you have that right. "No special frames of reference" is one of the postulates that you derive relativity from. Relativity is never going to contradict one of its own postulates.

In your example the satellite is constantly accelerating, and the ground server is supported in a gravitational field, both or which bring General Relativity into play. You're talking about accelerating frames of reference, and unlike straight-line motion acceleration is absolute. The statement that there are no privileged frames of reference is more strictly that no inertial frame of reference is privileged.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

There is no "observer" frame. The problem necessarily involves two observers in different frames - neither of which is necessarily stationary with respect to the ship.

FTL travel is by definition forward in time in the frames it is FTL in, that's inherent in the definition of the word "faster", which assumes you can define velocity sensibly somehow. The problem is that if some observer can see something move FTL, some other observer can see it arrive long enough before it departs to send a signal to abort the departure.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

Like I said, I'm pretty sure I don't understand how it works, but satellites being affected by Special Relativity in the form of time dilation is a problem in the real world.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

Of course it is. And it is corrected for using General Relativity, without having to posit any privileged inertial frame of reference.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

Not a lightspeed signal. And if the FTL mechanism has properties that are not invariant between frames of reference it can work out that an FTL signal won't do it either. That's why you can choose "causality" and "FTL" out of the "causality, relativity, FTL: choose only two" trilemma.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

Of course you can. You can select a preferred frame in which the physics are defined. That works fine, but you have to abandon the notion there is nothing but coincidence that's special about that frame.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

Time dilation and the frames of reference issue mean that you can observe something before the event that causes it occurs, from your point of view. However, the cause will always be outside the future light cone of any observer of the effect. Without FTL, such causality violations are cosmetic.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

Agreed. I'm just saying that if you do (abandon the Postulate of Relativity) you can end up with a case in which travel occurs along a space-like interval (FTL in some inertial frames of reference, backward-in-time in others, instantaneous in boundary cases) but it is not possible for any signal from the arrival event to get back within the past-ward light-cone of the departure event.

Re: [Spaceships] Real Life Non-Super Science Reactionless Engines
 

Can you? If you have a special frame (and hence can define an absolute clock, the one that runs in it) aren't space-like and time-like intervals cleanly separated?