well, the ship actually does know u accomplished the mission or u failed, npcs are possibly transmitted the info as u enter the system or via Quantum Entanglement the ship transmits the data, tachyonic radio would cause a paradox of casuality as the signal is supposed to travel FTL which would cause the signal to be sent in the past , the problem is resolved by entangling particals which would instantly change their spin or position, u change one, the other change, it is actually technically possible as showed by experimental evidence, it is also called as Quantum Teleportation
How does information travel in ED universe?
- Thread starter Aella Fess
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I've heard on astronomic lecture "if you will ever see tachyon near the star - run away from there"
Something really bad is expected then.
I'm pretty sure that any FTL information transmission, regardless of method, has the possibility to create paradoxes. The crux of the matter is that breaking relativity (in any way) also breaks causality.
scientific theories say that anything passing the speed of light would cause a paradox of casuality , basically you would travel back in time, tachyons infact if it was found they exist for real they would travel FTL causing a paradox, that's why building such a machine traveling FTL would be impossible as it would break relativity, only way to bypass the issue is for information to be sent through Quantum teleportation and for matter to use an Alcubiere drive, infact I believe the ingame Frameshift drive actually use the same principle, u don't travel FTL infact, it's the timespace woven changing around u as u are in a bubble and spacetime is not affected, infact your perceived speed is influenced by masses around u.
That still involves sending information faster than light, which still breaks relativity and can thus enable time travel and thus the possibility of temporal paradoxes. In real life we can't actually use quantum entanglement to transmit information FTL, it's just that any science fiction which does use QE for FTL transmissions either handwaves away the causality breakage with more technobabble, or just flat-out ignores it.
Now of course, one is entirely free to suppose that something like the chronology protection conjecture applies in a fictional universe, but there's no good reason why such a thing couldn't also apply to tachyons as well as quantum entanglement and warped spacetime. But it's just that; a conjecture. If FTL travel does turn out to be viable, then it may well be the case that causality is something that only applies below light speed. Which would have a number of implications that I am nowhere near well-read enough in theoretical physics to work out the consequences. But given how causality underpins pretty much all of known physics, it would be one of the greatest paradigm shifts in the entire history of science.
Alcubierre drives and wormholes don't strictly speaking enable FTL travel on a local basis, but they most certainly do enable FTL travel on a global basis. There's nothing theoretically stopping a ship with a warp drive from heading off to a distant star, and then heading back home to arrive before it left in the first place. Similarly, an arrangement of wormholes known as a Roman ring can enable the FTL transmission of matter and information on a global basis.
Here's a great video by PBS Space Time that exposes the dirty great secret of FTL travel, namely that it allows time travel:
You can get up to about 1890c, I forget exactly what it is, but it's not 2000c
technically speaking , neither of those solutions break relativity, Alcubierre doesn't enable FTL as it would break relativity, infact u don't move at all, it's spacetime actually changing around u, quantum entanglement doesn't break relativity either as the communication between the 2 entangled particals happen instantly without any FTL communication involved, FTL travel is impossible, those 2 methods actually don't enable FTL , they use completely different principles not involving movement in 3D space in any way, infact if the Alcubierre drive involved movement the acceleration would be so crushing to kill u instantly and destroy the ship as well, since movement is not involved then relativity and standard physics are not broken, instead I'm more worried about the amount of energy you would need to cause the Alcubierre effect , I read somewhere you would need to consume an entire star to do that so it would be really unpracticle at current scientific knowledge to create such bubble around a vessel, quantum entanglement instead has proven it is possible in labs, they already transmitted long range data with it, what I see as a viable way to space travel are generational motherships which would achieve a fraction of light speed through solar sails , solar sails can be fed with a strong laser beam from earth to reach that speed and allow interstellar travel within a generation, it would take 20 years just to reach Alpha Centauri, it's not clear how theorically they would decelerate, as u can see even so there would be practical issues, so we are more likely to send probes to space rather than explore the cosmos ourselves , at least until we become a Type 1 and then a Type 2 civilization , at that point I feel like reaching Type 3 would become easier and we would resolve the Alcubierre problem.
Warp metrics don't break relativity locally, but they can be used in a way that breaks causality non-locally, as shown in the video I shared.
Quantum entanglement doesn't break relativity because the process cannot be used to transmit information faster than light.
The amount of energy required depends on the assumptions made. The real kicker for Alcubierre drives is that they require negative mass-energy in order to produce the required spacetime metrics, and negative energy is something that we have no idea how to generate, with the possible exception of the specific circumstances involved in the Casimir effect.
If they really did, then they did not do it faster than light. The idea that QE can be used for FTL communication is pure fiction. If you disagree, then please provide evidence.
well technically speaking Quantum entanglement doesn't provide FTL comm simply cause it's not how it works regardless of distance so theorically distance doesn't matter , communication would happen instantly even billions light years away without breaking GR or SR, as for the Alcubierre drive, the warp bubble would cause spacetime to warp around the ship causing a contraction in front of the ship, causing an apparent FTL while the ship is actually not moving at all in any conventional way not breaking GR or SR in anyway , causuality would not be violated as events would still happen in proper order, anyways that's just speculation, we are more likely to space travel like in 2001 space odyssey rather than like in Star Trek, at least until we find the way to produce negative energy and prove the Alcubierre drive can actually be built, as for Quantum teleportation, it is already being experimented in labs, they already sent data up to a satellite and back.
Did you even watch the video? You can totally violate causality with a warp drive.
the video talks about FTL travel in normal 3D space, not the Alcubierre Drive which works in a completely different way , you would actually not move at all, your speed relative to the 3D standard space would be 0, it's the space around u warping around the bubble, that's what basically passing through a theorical wormhole would do, it's a shortcut , no acceleration of movement of any kind needed .
Wrong, the video is talking about four-dimensional spacetime, and warping around will produce the same effects as described in the video.
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this one a kinda explain my point but it also explains the difficulty of producing dark energy
I get that warp drives don't actually involve acceleration. My point is that it doesn't matter in terms of producing time travel effects, because a warp drive would still be changing the position of the ship relative to everything else in the universe. Time and space are both unified under relativity, and a warp drive can change the position of a ship in spacetime faster than it would take for a beam of light to get to same location. In other words, the warp drive can move the ship to a region outside of the top cone in the below diagram:
The warp drive equipped ship can do the same thing when returning to the planet it left from, and in doing so it can arrive at a point in time before it first left. This causality-breaking behaviour is independent of whatever FTL method you can think of, because it's a consequence of changing position in spacetime, not of warp drives.
The warp drive equipped ship can do the same thing when returning to the planet it left from, and in doing so it can arrive at a point in time before it first left. This causality-breaking behaviour is independent of whatever FTL method you can think of, because it's a consequence of changing position in spacetime, not of warp drives.
I get that warp drives don't actually involve acceleration. My point is that it doesn't matter in terms of producing time travel effects, because a warp drive would still be changing the position of the ship relative to everything else in the universe. Time and space are both unified under relativity, and a warp drive can change the position of a ship in spacetime faster than it would take for a beam of light to get to same location. In other words, the warp drive can move the ship to a region outside of the top cone in the below diagram:
The warp drive equipped ship can do the same thing when returning to the planet it left from, and in doing so it can arrive at a point in time before it first left. This causality-breaking behaviour is independent of whatever FTL method you can think of, because it's a consequence of changing position in spacetime, not of warp drives.
No, I don't agree, the Alcubierre drive doesn't produce movement at all not you don't travel faster than light, the speed is only apparent , that's why you don't risk timetravel and a casuality paradox as events are still in the same order, you actually don't move, that's why.
The Alcubierre drive still changes your position (otherwise it would be pointless to use one as a means of travel), and doing that faster than it would take a photon to reach the same location through normal space is what matters in terms of allowing time travel. FTL warp drives mean that those regions outside of the future light cone in the above diagram are just as valid a destination as any regions within the future light cone. That's what it means to travel faster than light. It doesn't matter if you do it by warping space. It doesn't matter if you do it by making your mass imaginary and riding a beam of tachyons. It doesn't matter if you do it by donning a pair of ruby slippers and clicking your heels three times. Space and time are unified under relativity, so any device which allows for the FTL changing of position in space also allows for time travel into the past.
"Events are still in the same order" - But according to whom? Relativity explicitly forbids a universal frame of reference, that's how it got the name. An astronaut taking a trip to a distant star in his FTL warp ship will experience events within his warp bubble occurring in the expected order, but while he's warping FTL, he is to all intents and purposes isolated in his own little pocket universe, outside of which no object can reach him, or indeed any information whatsoever travelling through normal space, not until the bubble is dismantled. So there is no causal chain of events requiring that the time one emerges from a warp journey is in a future direction from the time one entered it.
FTL travel = time travel. Relativity demands it, and doesn't care about the means by which you accomplish it.
