Does the warp drive would ever ever become real

[Red Iron Crown]

Yes, you can have FTL travel or you can have causality, you can't have both.

[78stonewobble]

Yes, you can have FTL travel or you can have causality, you can't have both.

Unless Novikov's self consistency principle holds true right?

[Red Iron Crown]

Unless Novikov's self consistency principle holds true right?

Novikov strikes me as wishful thinking, a bit of handwaving to make FTL or time travel appear more possible.

[Seret]

Yes, you can have FTL travel or you can have causality, you can't have both.

You can also have neither. I'm highly sceptical that FTL travel is possible (if nothing else the Fermi paradox suggests it isn't), and we already know there's no such thing as universal causality.

[78stonewobble]

Novikov strikes me as wishful thinking, a bit of handwaving to make FTL or time travel appear more possible.

You may be right about the handwaving part. I'm very sceptical that either is possible, so I'd rather put the argument in the category of not making it impossible.

[78stonewobble]

You can also have neither. I'm highly sceptical that FTL travel is possible (if nothing else the Fermi paradox suggests it isn't), and we already know there's no such thing as universal causality.

Well I'm equally sceptical of the Fermi paradox. The universe is quite vast and we haven't been radiating EM for that long and have stopped with quite a bit of it allready again. We are only detectable within a sphere of space with a diameter of what? 100 lightyears? It's a very small sample all things considered.

[Seret]

Well I'm equally sceptical of the Fermi paradox. The universe is quite vast and we haven't been radiating EM for that long and have stopped with quite a bit of it allready again. We are only detectable within a sphere of space with a diameter of what? 100 lightyears? It's a very small sample all things considered.

The Fermi paradox is rhetorical, there are a lot of possible answers to it. We don't know the answer and it doesn't make sense to be sceptical of a question. It is after all a good question: "where are they?".

I don't think we should imagine our chance of being detected is limited solely by our RF transmissions btw. Astrospectroscopy could detect life on Earth at whatever range the aliens had the technology to image us at. They could possibly even detect our technology, especially if they were making observations over a long time period.

[78stonewobble]

The Fermi paradox is rhetorical, there are a lot of possible answers to it. We don't know the answer and it doesn't make sense to be sceptical of a question. It is after all a good question: "where are they?".

I don't think we should imagine our chance of being detected is limited solely by our RF transmissions btw. Astrospectroscopy could detect life on Earth at whatever range the aliens had the technology to image us at. They could possibly even detect our technology, especially if they were making observations over a long time period.

It is a good question.

And you are right about astrospectroscopy. However the same principle applies. Life might have been detectable on our planet for billions of years, but intelligent life would only have made it's presence known over the last few hundred years. Again only detectable from within a relatively small bubble of space.

If the latest guesstimates on the amount of planets out there are correct, then a single planet with life might be quite common and not worthy of investigation (yeah there are alot of if's in this).

[Guest]

Maybe we are a life form engineered by aliens on purpose, and they already know exactly when we will get ftl! Because they implemented the first bacteria on earth and knew the earth at that time and how it would evolve. But if we do blow ourselves with global warning it makes no sense then (except if we are actually terraforming the earth for them without knowing it because they breath co2 lol). I just mean that saying they can't observe us because we are out of reach is kinda stupid as we don't know anything about "them".

Edited March 12, 2014 by RevanCorana

[Seret]

And you are right about astrospectroscopy. However the same principle applies. Life might have been detectable on our planet for billions of years, but intelligent life would only have made it's presence known over the last few hundred years. Again only detectable from within a relatively small bubble of space.

The presence of life here would put us on the short list for observation, and our civilisation does release compounds into the atmosphere that would be somewhat anomalous if you had a decent baseline showing only the pre-technology processes. I'm quietly confident that an alien species at ours or higher level of technology would stand a good chance of detecting us. The limiting factor may be how long either civilisation lasts more than it is the distance. Who knows? As you say, too many "ifs" to be certain.

[78stonewobble]

The presence of life here would put us on the short list for observation, and our civilisation does release compounds into the atmosphere that would be somewhat anomalous if you had a decent baseline showing only the pre-technology processes. I'm quietly confident that an alien species at ours or higher level of technology would stand a good chance of detecting us. The limiting factor may be how long either civilisation lasts more than it is the distance. Who knows? As you say, too many "ifs" to be certain.

Signs of civilisation would still only be detectable within a very tiny area of the milkyway galaxy. If we say from the industrial revolution. It would only be a sphere with a diameter of 600 lightyears centered on earth.

If life, but not intelligent life, is widespread and common, then signs of life, which might have been detectable on earth for billions of years and thus theoretically detectable in a sphere measuring billions of lightyears. Then life would probably not be enough to merit a closer look.

But yes, too many if's. I'd feel more confident guessing if we had better sampling from atleast our solar system.

Ie. whether Earth is decidedly the only place life has ever existed versus that venus, mars, europa and some comets had life or has life.

Personally and purely speculative:

FTL: Highly unlikely.

Timetravel: Highly unlikely.

Intelligent life: Quite quite rare, but not so rare as to make the earth the only intelligent life (if we can call it that), maximum of 50 in the milkyway.

Life: Depending on what we find in solarsystem either relatively widespred to quite rare (with a maximum of a few hundred to thousand places in the milkyway).

But it's all guesswork.

[DonLorenzo]

The Fermi paradox is rhetorical, there are a lot of possible answers to it. We don't know the answer and it doesn't make sense to be sceptical of a question. It is after all a good question: "where are they?".

I don't think we should imagine our chance of being detected is limited solely by our RF transmissions btw. Astrospectroscopy could detect life on Earth at whatever range the aliens had the technology to image us at. They could possibly even detect our technology, especially if they were making observations over a long time period.

Stephen Baxter wrote a book which was essentially like 20 short stories, all exploring different possible answers to Fermi. I quite liked it, I think it was the last of the 'Manifold' series

[Seret]

Signs of civilisation would still only be detectable within a very tiny area of the milkyway galaxy. If we say from the industrial revolution. It would only be a sphere with a diameter of 600 lightyears centered on earth.

Well, the relevance of this to FTL travel is that if interstellar travel became as easy and cheap as it's depicted in sci-fi there would be very little to prevent a civilisation from expanding should it wish to. Civilisations wouldn't occupy a point, they'd fill the volume of the galaxy. So they would be local to everybody. There's been abundant time for expansion, the main limiting factor would seem to be communication and the presence of other civilisations. The fact that technology doesn't appear to be ubiquitous in our galaxy suggests to me that even old civilisations (if they exist) aren't regularly plying the distance between the stars.

[78stonewobble]

Well, the relevance of this to FTL travel is that if interstellar travel became as easy and cheap as it's depicted in sci-fi there would be very little to prevent a civilisation from expanding should it wish to. Civilisations wouldn't occupy a point, they'd fill the volume of the galaxy. So they would be local to everybody. There's been abundant time for expansion, the main limiting factor would seem to be communication and the presence of other civilisations. The fact that technology doesn't appear to be ubiquitous in our galaxy suggests to me that even old civilisations (if they exist) aren't regularly plying the distance between the stars.

True, but it hinges on the following suppositions that:

A: That FTL is not only possible.

B: That FTL can become very easy and cheap.

C: That an alien civilisation wants to expand everywhere and devotes considerable ressources to do so.

Might as well assume that FTL isn't possible, or that FTL can never be cheap or that a civilisation developing FTL will most likely have evolved to the point where it is able to restrict any exponential growth and won't expand beyond a few "civilisation backups" (colonies), unless they are in direct competition with another civilisation.

They could be like us and only wanting to spend very limited ressources on seeking out life elsewhere.

[Seret]

True, but it hinges on the following suppositions that:

A: That FTL is not only possible.

B: That FTL can become very easy and cheap.

Indeed, that's my whole point. The fact we aren't overrun with little green men suggests that one or both of those are false.

C: That an alien civilisation wants to expand everywhere and devotes considerable ressources to do so.

That's also possible. But if both A and B are true, it seems unlikely that every civilisation that develops FTL would feel the same way.

Bottom line is we have strong reasons to think FTL is in fact impossible, and only weak ones to think that it might be possible. On the one hand you have proven physics, on the other you have wishful thinking.

[78stonewobble]

Indeed, that's my whole point. The fact we aren't overrun with little green men suggests that one or both of those are false.

That's also possible. But if both A and B are true, it seems unlikely that every civilisation that develops FTL would feel the same way.

Bottom line is we have strong reasons to think FTL is in fact impossible, and only weak ones to think that it might be possible. On the one hand you have proven physics, on the other you have wishful thinking.

I actually should have made another distinction too. Theoretically possible and practically possible.

So far I'd argue that we know too little as to whether FTL is any of the options.

If we suppose FTL is very hard and takes up alot of ressources, then allmost automatically that would disqualify a civilisation that expands rampantly on a planet with limited ressources. Basically they would expand themself into extinction before having the chance to use FTL. That would leave only civilisations that has mastered limiting growth to develop FTL.

Sure, we shouldn't "bet" on the development of FTL, but if you put it like: On one hand we have proven physics and on the other we have unproven physics... Then I think we should look into it (not necessarily with any high priority) until we have proven that it is indeed impossible.

Heck, just look at the time, energy and money spent on religion.

[Wahgineer]

wrong. The scientific community is overall more pragmatic than that. And so is the engineering community. They'd love to see it happen IF it were useful and feasible.

The Alcubierre drive has been shown to be neither.

The Alcubierre drive doesn't exist yet, so to say it is useless and unfeasible is rather ignorant.

What I find amusing is that people like you are so quick to refuse this kind of stuff just because it doesn't fit Einsteins almighty model of the universe. The Alcubierre drive can be classified as something that operates under quantum mechanics: stuff that shouldn't happen, but does any way. Stuff which has been proven to be true. The Alcubierre drive goes faster than light while, at the same time, not breaking any of the 'laws' in the theory of relativity. It does so by executing a loop hole in that 'law': it doesn't accelerate to the speed of light. Also, that 'law' only says you can't travel at the speed of light, yet doesn't say anything about going faster than it.

[Seret]

The Alcubierre drive doesn't exist yet, so to say it is useless and unfeasible is rather ignorant.

That's not logical. Lots of things don't exist precisely because they're not useful or feasible.

The Alcubierre drive goes faster than light while, at the same time, not breaking any of the 'laws' in the theory of relativity.

Sure, but it does require a type of energy that we've never observed, have no particular reason to think exists, and have no technology to control. It's not a practical idea. It's purely a theoretical one. Calling it a "drive" is a misnomer, as the likelyhood of it moving from a theoretical toy, to proper science, to technology is pretty remote.

[Rakaydos]

That's not logical. Lots of things don't exist precisely because they're not useful or feasible.

Sure, but it does require a type of energy that we've never observed, have no particular reason to think exists, and have no technology to control. It's not a practical idea. It's purely a theoretical one. Calling it a "drive" is a misnomer, as the likelyhood of it moving from a theoretical toy, to proper science, to technology is pretty remote.

The same was said of the Hyperlense requiring a negative index of refraction. And nothing in nature HAS a negative index of refraction... but we can make microstructures that can mimic it well enough to fool light of long enough frequency.

[Stargate525]

Sure, but it does require a type of energy that we've never observed, have no particular reason to think exists, and have no technology to control.

Never observed, but the prevailing model of the universe, afaik, doesn't preclude it. And just because it doesn't exist doesn't mean it can't be fabricated. The elements in the islands of stability certainly don't exist in nature, but that doesn't mean we couldn't get our hands on some.

[Seret]

The same was said of the Hyperlense requiring a negative index of refraction. And nothing in nature HAS a negative index of refraction... but we can make microstructures that can mimic it well enough to fool light of long enough frequency.

Never observed, but the prevailing model of the universe, afaik, doesn't preclude it. And just because it doesn't exist doesn't mean it can't be fabricated. The elements in the islands of stability certainly don't exist in nature, but that doesn't mean we couldn't get our hands on some.

You're both making essentially the same argument here: "because unlikely concept A was shown to be possible, that means unlikely concept B must be likely". That's not really a strong argument if the two are unrelated.

Of course we revise what we understand to be possible, that's the cool thing about science. But that doesn't mean it reasonable to think that anything is possible. We do have to try and interpret the universe through what our best current understanding of it is. As fans of science and engineering (I assume) we have to take a realistic view of what the actual state of the art is. The Alcubierre metric is currently an interesting mathematical toy, but lacks certain essential crucial elements that would suggest we should invest a lot of hope in it. Speculative ideas like this get tossed around a lot by theoreticians, and the vast majority of them fall by the wayside without becoming useful technology.

Note that I'm not suggesting we should ignore it completely, the potential payoff is too large. But until we actual observe negative mass energy, or have a strong reason to think it does exist, then an Alcubierre drive should be considered an extremely long shot. Holding out hope for new data proving it possible is just wishful thinking, it's at least as likely that new data will erode the theoretical basis it's built on. It sounds like the LHC has been giving string theory a good kicking, for example.

[K^2]

But until we actual observe negative mass energy, or have a strong reason to think it does exist

Predictions of field theory partially verified with experiment aren't good enough for you?

[Seret]

Predictions of field theory partially verified with experiment aren't good enough for you?

I don't track the science as closely as you probably do. What level of confidence does "partially" represent?

[Ravenchant]

FTL travel may be possible on the atomic or subatomic level, and if there are any advances in that field, they will almost certainly start with that. But macroscopic objects, manned ones even? Highly unlikely, though I'm sure relativistic travel of one form or another will be possible sometime in the next few thousand years, if our species doesn't decline before that.

Perhaps we could probe the Martian poles for element 0, just in case

[Wahgineer]

That's not logical. Lots of things don't exist precisely because they're not useful or feasible.

Sure, but it does require a type of energy that we've never observed, have no particular reason to think exists, and have no technology to control. It's not a practical idea. It's purely a theoretical one. Calling it a "drive" is a misnomer, as the likelyhood of it moving from a theoretical toy, to proper science, to technology is pretty remote.

You can't say something is useless until you build it, and you can't gauge feasibility with just theorizing.

While we're on the subject of theory, who's to say the theory of relativity is true?

Supposedly, a theory is a hypothesis with some proof. Yet, the Theory of relativity say that nothing can reach the speed of light, while also saying that we can't see something traveling near that speed. It neatly contradicts itself: nothing can reach the speed of light, and since anything traveling near those speeds is unobservable, you can't prove that this theory is neither false nor true. Also, the theory of relativity was conjured to refute quantum physics, which has been proven to be true.

For all we know, ships approaching the light speed barrier don't experience time dilatation, or not as severely as we think. Since we can't observe these things, the Theory of relativity stands as a theory, though it should probably be called the Hypothesis of relativity, since the "proof" it stands on can't be verified as valid.