View Single Post
November 16 2012, 04:03 PM   #157
Crazy Eddie

Re: Federation Law of restricting cloaking device

 blssdwlf wrote: You can see the light trail, aka reflected photons, as it reaches you if you're not FTL. When you are FTL with only LS sensors you are running into the light trail without the ability to see forward due to your LS sensors.
But you CAN see forward at FTL, precisely because you are still stationary in your own reference frame. This isn't even a trekism or a theoretical prediction; in the real world WE are already moving at FTL velocity with respect to distant galaxies 47 billion LY away (and they, in turn, are moving away from us faster than light). Not only do we have no trouble at all seeing what's "ahead" of us, but we can see the heavily distorted/redshifted images of those galaxies near the edge of our visual horizon.

 If that were the case, we wouldn't have people trying to come up with ways for SR to work in an FTL frame of reference. It's not complicated - it just doesn't apply.
You have it backwards: If it didn't apply, they wouldn't be trying to make it work. The reason they're still TRYING to make it work is because it is very complicated, and because we have very little data to work with on FTL reference frames (as I said above, the only ones we know of are about 47 billion light years away).

 Where are you getting this from? Are you trying to redefine FTL as STL? A ship going FTL is outrunning light.
You have a fundamental misunderstanding about how relativity works.

In relativity -- ANY flavor of it -- a reference frame is considered to be a mathematical coordinate system with the firsthand observer (Let's call him "Steve") at the center. Steve has an omniscient instant-information tool that can make measurements of velocity, distance and direction for other objects that exist within his reference frame with him. Since Steve is measuring from his own fixed position, there is no measurable quantity for "Steve's velocity." You can measure the relative velocity between Steve and an outside observer (let's call this observer "Joe"), but in Steve's reference frame, JOE is the one who is moving.

So Steve is happily humming along in his reference frame until he sees a flash of light, looks over with his omniscient godlike tool and sees Joe speeding towards him. Steve's tool will measure Joe's velocity by measuring the distance between them and recording how much the distance changes over a given time interval (Delta-D and Delta-T gives you V). He sees that in the space of one second, Joe has moved one million kilometers closer to him, ergo Joe is moving towards him faster than light. But Steve can also use his tool to measure the speed of the photons being emitted from Joe as he moves through space; again, measuring the distance changes in the rate of time, Steve's tool sees that those photons moved just under 300,000km closer to him in the same second. So in Steve's reference frame, Joe has outrun his own reflection and is moving towards him faster than his photons are.

So what if Steve uses his magical tool to measure his OWN photons? He will, of course, see them moving away from him at the speed of light. This is because Steve is in a stationary frame of reference measuring velocities and distances to other objects that happen to pass through that frame. The thing about special relativity is, Joe's magical tool would be able to make the exact same calculations at the exact same time and come to the exact same conclusions with regard to his own frame: from his point of view, STEVE is moving towards him at superluminal velocity and his own photons are uniformly moving outward at C. Both frames are equally valid, even when they contradict.

 That's why FTL in GR and SR can cause all sort of causality problems.
It can cause APPARENT causality problems, yes. What trips up alot of people is that relativistic time dilation doesn't ACTUALLY occur, it's an observational difference resulting from the extreme difference in those reference frames. Practically speaking, it's a bit like Schroedinger's cat: the magic tool I mentioned above is a mathematical abstraction, whereas in reality you cannot transmit or receive information faster than light and therefore cause and effect cannot exceed that velocity either.

 They were already feeling the FTL effects way before the visible shockwave reached them.
Indeed, they were feeling the effects BEFORE THEIR SENSORS DETECTED THE SHOCKWAVE. That, too, should tell you something.

 And again, SR still treats FTL as FTL and things at LS will still be slower than things at FTL.
You're still forgetting about the issue with their respective reference frames: in SR, you are always stationary within your own reference frame, no matter what speed SOMEONE ELSE measures between the two of you.

 And from where do you get this?
Special relativity. You're always stationary in your own reference frame.

 That's not correct. You're thinking of reference frames where the observers and objects are moving STL. SR makes LS constant across all reference frames but it also does not like FTL because it can cause a Causality violation.
And the REASON it causes causality violations is because of that very discrepancy: I see my photons moving ahead of me, and YOU see my photons falling BEHIND me.

So Steve moves towards Joe at FTL velocity for one second and then stops at a point 2 light seconds away and waits for Joe to see him. In Steve's reference frame, it takes that photon 3 seconds to reach Joe: the photon traveled 1 light second while he was moving at 2 light seconds after he stopped. Vice versa for Joe, whose photons cover the exact same distance in the exact same time interval. But if Joe measures STEVE'S photons (IOW, Steve's image) then he sees that Steve's photons take much longer than 3 seconds to reach him. That means that Steve and Joe will have two totally contradictory observations of reality: Steve will record that his photons reached Joe at the same moment that Joe's photons reached Steve, but Joe records that his photons arrived at Steve two seconds before Steve arrived at Joe. That cannot usually be reconciled because SR treats both reference frames as being mathematically valid (in reality, it is invalid to treat only ONE of them as the moving observer and therefore both of them would reach identical but contradictory conclusions). The only way to reconcile the contradiction mathematically is if Joe comes to the conclusion that one of the parameters of Steve's measurement device was skewed during travel: Steve thinks his photons were moving away from him because time was moving backwards for him while he was FTL (and vice versa for Steve, who will make the same contradictory observation of Joe's photons).

Hence the causality violation: in some interpretations of SR, Steve actually arrives at his destination before he actually left: Stargazer wouldn't merely APPEAR to be in two places at once, it LITERALLY WOULD be. The alternate interpretation is that the violation is only apparent and a consequence of the fact that information cannot travel faster than light; since you really cannot obtain information at a distance that quickly, there's no opportunity for a causality violation, only the kind of illusory afterimages like we see in the Picard Maneuver.

 Ok, I can buy the possibility that it was a complete accident that the weapons officer fired at the wrong target. So, the possibilities we have are: 1. Stargazer and Ferengi ship exchanged fire simultaneously. Ferengi chose the wrong target. 2. Ferengi fire first, but chose the wrong target. 3. Ferengi fired second but due to damage or confusion prior to its immediate destruction, fired at the wrong target.
In a nutshell, yes. And like I said, these are three possibilities separated in timing by three or four seconds at most. It really could go either way, but from the available information the second two seem the most likely.

 See above regarding FTL. The ship that is moving at FTL is moving at FTL speeds.
Simple question for you: you're in space, nothing around you, nothing no sensors, the most distant stars are too far away to accurately measure; IOW, you're in a reference frame that lacks any other objects other than yourself.

What is your velocity in this frame?
Now you fire your engines and accelerate forward at 3Gs for 30 seconds and then stop your engines. Still no other object in your reference frame and you are totally alone.
What is your velocity in this frame?
Then you go to warp 9. Still no other object in your reference frame and you are still totally alone.
What is your velocity in this frame?
__________________
The Complete Illustrated Guide to Starfleet - Online Now!

Last edited by Crazy Eddie; November 16 2012 at 04:38 PM.