[Firstdragon34]

That is why Mr. Einstein came up with the idea of wormholes. They exist in equations, but not in real life. You need Negative Matter  to open one up and the energy for that would be massive! It would be best to siphon a star's energy to do that.

[Davros]

I've just had a thought - yay me
I must be traveling at the speed of light relative to something in fact (or maybe not ) isnt everything
also if i shine a laser, imagine the first 2 photons emitted are they not moving relative to each other

[Mika]

Indeed, 1c, regardless of the velocity of the observer.  The speed of light in vacuum is constant and independent of the frame of reference of the observer or the motion of the source.

jr2:  Your example is based on a principle that sounds really weird and contrary to common sense, yet is demonstrably true.  Velocities are not linearly additive, which means you can't simply add the numbers together as you'd expect.  If I'm driving down the road at 60mph, and I throw a baseball out the window at 40mph (relative to me in the car), and I throw the ball in the same direction that I'm driving, then you'd expect to be able to say that the speed of the baseball relative to the ground is 60mph + 40mph = 100mph.  But this would be wrong!  It's actually 100mph minus a tiny little bit, that little bit is because of relativity.

If you examine the math behind this, the effect ends up being insignificant at small, every-day speeds that we're used to, but very significant at speeds close to that of light.

If somebody bothered me enough, I could brush up some relativity stuff from University times from my bookshelf dust bin and look if the relativistic observers will also agree on the frequency of the emitted light. My gut feeling is that they will not, but I cannot say this for sure. But nah, let's not go there yet, somebody has to ask first. Nicely.

EDIT: ...aaaaand by a brief look in Wikipedia brushed up my memory enough that this indeed happens, and got the nagging feeling that it should have been self-evident.

[Kolgena]

I've just had a thought - yay me
I must be traveling at the speed of light relative to something in fact (or maybe not ) isnt everything
also if i shine a laser, imagine the first 2 photons emitted are they not moving relative to each other

Well, everything is always moving at the speed of light in space time. That's why moving super fast or a lot actually allows you to live "longer", since you've used some of your velocity to move spatially and reduce the amount you move temporally. As for whether you are moving at the speed of light spatially relative to some other massive body? No. Not possible.

@ the laser question: A photon doesn't experience time. It is everywhere in its trajectory at once from its point of view (another way to think of it is that it's moving so fast that length contraction shortens the universe relative to the photon into a 2D plane, which is orthogonal to its velocity), so you can't really say that a photon looks at another photon and sees it moving at 0, since nothing moves relative to a photon.

[watsisname]

Today we have learned that relativity is mind bending just as much as it is...
space-time bending

YEEEAAAHHH 




edit: okay that was terrible, i admit

[Firstdragon34]

I will admit I can understand astronomy, but FTL just makes my brain melt. So, does anybody what to learn  the lifecycle of a Supergiant?

[Davros]

Wait till you study a Bistromathic drive

[Firstdragon34]

Bistromathic Drive, eh? Sounds interesting, be sure to post pics, they help, a lot!

[Davros]

Unfortunately a Bistromathic drive is usually encased in a sep field (Somebody Else's Problem Field)

"A SEP is something we can't see, or don't see, or our brain doesn't let us see, because we think that it's somebody else's problem.... The brain just edits it out, it's like a blind spot. If you look at it directly you won't see it unless you know precisely what it is. Your only hope is to catch it by surprise out of the corner of your eye.
The technology involved in making something properly invisible is so mind-bogglingly complex that 999,999,999 times out of a billion it's simpler just to take the thing away and do without it....... The "Somebody Else's Problem field" is much simpler, more effective, and "can be run for over a hundred years on a single torch battery."
This is because it relies on people's natural predisposition not to see anything they don't want to, weren't expecting, or can't explain.

[jr2]

So, I have a question:

A laser fired in the direction of travel from a spacecraft travelling at 0.25c, would an outside observer be able to measure the light travelling at 1.25c or would it end up being 1.00c??

OK, I got an answer on this, which was 1.00c

So, next question... will there be a sort of Doppler Effect for the light?  I mean, the light is being fired from a vessel travelling at 0.25c, and the light is travelling at 1.00c ... would the light accumulate or become more... dense, as it were or maybe intense is a better word, in front of the craft?

If you don't understand what I mean, think of a garden hose firing water.  Now imagine the garden hose moving forward, but only at 0.25x the speed that the water is being fired at.

[The E]

That would result in the light sent out being blueshifted for an observer in the ships' flight path.

Conversely, if a ship travelling at fractions of c was travelling away from you, it's emissions would be redshifted from your perspective.

Yes, this is an application of the Doppler effect.

[jr2]

Interesting.  So, this blueshifting will occur?

Yes/No

And
    will appear blueshifted to:
     a) source
     b) target
     c)  observer from sidelines
       OR some combo of a, b, and/or c?

[The E]

For the source, and an observer on the sideline, the laser will not appear blueshifted.

For the target, yes, blueshifting will be visible.

Addendum: For the source, any emission source in its flight path will appear blueshifted, while every emission source behind it will be redshifted.

[jr2]

  Interesting.  Would be rather cool to have some sort of mod where the FTL isn't subspace based, maybe not even real FTL, just like 0.95c.... have subspace walls basically be a filter for the starfield, and blue / redshift them, depending on what stars are in front / behind the direction of travel.  Maybe make it an escort mission.

SO,

Idea for a mod:

You are travelling at 0.95c, and you must do escort duty for a top-secret diplomatic envoy from Earth, as hostile aliens have subspace FTL tech and can jump in out of the blue.  (haha, no pun intended)  You are equipped with the latest experimental weaponry that still needs to be fine-tuned and have the bugs shaken out of them.  You might have shields that are of the same type, not really reliable, but the tech improves as your techs work the bugs out. You are travelling to reach another FTL tech capable alien race that is rumored to be benevolent (or at least, has a sense of fairness) and request assistance defending from hostile alien race.  However, you must neutralize ALL hostile alien patrol craft that jump in, or else they will contact their superiors and you will be found out.  (Of course, since being overrun by hostile alien race, all contact with other races is strictly forbidden.)  Sympathizers from the hostile alien race informed members of the government(s) on Earth about the existence of benevolent race(s) (maybe alliance)  that you are attempting to contact.

Along the way, maybe you try to capture alien craft to attempt to reverse-engineer their FTL drives (whereas, on Earth, of course, that's verboten and shooting down alien craft would be capital offense, but out here, you might as well).  That's another objective, you also have research craft / or research station on main diplomatic craft that will attempt this... maybe make for interesting missions where you attempt to test experimental FTL drives with the risk that something might go wrong.

Aaaand... that's my little thread hijack. 

[The E]

Presupposes magic drive tech that can accelerate/decelerate from and to near c without requiring a near-infinite amount of energy, and can maneuver at those speeds.

Also presupposes that your little fleet can actually get valuable sensor data while travelling at those speeds; purely light-speed sensors won't work very well when all you see forward of you is blueshifted into insane frequencies.

Also note that your theoretical FTL-capable craft will not be able to catch something travelling at near c, supposing that the FTL works similar to FS (meaning that ships exiting FTL do not conserve momentum from when they entered FTL).

And finally, an observer in the craft's flight path will not have much time to react to detecting it on lightspeed sensors, as the ship will be shortly behind the photons announcing its presence.

[Astronomiya]

Add to all that relativistic beaming, and it would be very difficult to play, unfortunately, although it is a very cool thought exercise.  In our ship traveling at .95c, if you were to look behind you, you would see nothing.  If you look forward, you'd see everything around you concentrated in a cone in front of you.  Yes, this includes stuff that is actually behind you.  What you would actually see is a blueshifted region directly in front of you, and a redshifted annulus around that.

More info, pictures, and movies here.

[jr2]

Great.    I guess it'd have to be rule-of-cool then.   But, it is interesting knowing how these things would actually work / appear.    Thanks for the replies!

[MR_T3D]

http://www.bbc.co.uk/news/science-environment-15017484
DUN DUN DUNNN
neutrinos going too fast for light, it appears.

Well, possibly, they're looking for another reason

[Mongoose]

oh sweet

[Nuke]

hopefully they will use this discovery anomaly to make warp drive, or at least a cool new way to blow ourselves up.