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Quantum Setback For Warp Drives
KentuckyFC writes "Warp drives were generally considered impossible by mainstream scientists until 1994 when the physicist Michael Alcubierre worked out how to build a faster-than-light drive using the principles of general relativity. His thinking was that while relativity prevents faster-than-light travel relative to the fabric of spacetime, it places no restriction on the speed at which regions of spacetime may move relative to each other. So a small bubble of spacetime containing a spacecraft could travel faster than the speed of light, at least in principle. But one unanswered question was what happens to the bubble when quantum mechanics is taken into account. Now, a team of physicists have worked it out, and it's bad news: the bubble becomes unstable at superluminal speeds, making warp drives impossible (probably)."
Or is it *both* Impossible and not Impossible?
is this where the improbability drive comes in?
yeah, someone had to say it.
The SCI-FI buff in me holds out hope that physics will uncover a trick to FTL, but...
It doesn't really matter if we cannot travel faster than the speed of light so long as we can live long enough to get there.
Who cares if it takes 50 years to fly to Alpha Centauri if we can engineer ourselves to live for a thousand!
This is my sig.
We all know what happens when you try to travel that fast!
Just do what the Planet Express Ship does and use a Dark Matter drive to move the Universe around us instead... :)
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From the article... "strongly implies that such a bubble would be unstable." Sounds like proof to me! Right. Just like it was proved impossible for planes to fly. It might indeed - eventually - prove to be impossible, or impossible to do meaningfully / reliably, but it's pretty unlikely we're in a position to make that call at this time. That's why we do research.
=cjs
So you mean to say my brand spanking new SSDs have become obsolete already???
Faster-than-light travel always causes causality paradoxes, so a priori, FTL drives are impossible unless special relativity is wrong. (That's is a bit like saying that perpetual motion machines are impossible unless thermodynamics is wrong.) The proposed mechanism behind the FTL drive doesn't matter -- it'll still cause a time paradox.
Just like we know any proposed perpetual motion machine must have a flaw, any proposed FTL drive must also have a flaw. They belong to the same class of impossible device, and deserve the same degree of consideration.
Back before helicopters were successfully demonstrated, people dismissed the idea, saying basically they violated the laws of physics, too...
Any warp engineer knows that.
...The bubbles can't take no more Capt.
Please note the submission date:
Semiclassical instability of dynamical warp drives
Heck, after 8 weeks of army basic training none of the 50 or so people in my company were strangers.
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Hey its not like it hasn't been done before, I propose we call the new version Post-Modern Physics.
What Alcubierre did was prove that faster-than-light travel within a bubble of spacetime does not conflict with the laws of general relativity. What he didn't do was figure out exactly how to generate that bubble of spacetime. In fact I don't believe any laboratory experiments were involved.
In other words, he was pretty damn far from figuring out how to build anything. This is not to understate the importance of his work -- he never claimed to have invented anything practical or even to have set out to invent anything.
[Sir Garlon] is the marvellest knight that is now living, for he destroyeth many good knights, for he goeth invisible.
This is best guess at the moment. We don't have a unified theory of everything proven and in the bank. We are not yet even sure how many dimensions the universe is constructed out of (the total varies between 4 and some large number every month). So it is an improbability with current physics knowledge versus a distinct impossibility (a small but significant difference in argument)
A picture is worth exactly 1024 words.
now it's the good moment to start the reaserch for a superluminical speed Stabilizer! Maybe we can use the flux capacitor. :)
SOLVED!
In fact I don't believe any laboratory experiments were involved.
In other words, he was pretty damn far from figuring out how to build anything.
Sounds like Da Vinci and his helicopter to me.
That's it, cancel the Star Trek Movie. Now that I know it's all fake it just ruined it for me.
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relativity prevents faster-than-light travel relative to the fabric of spacetime, it places no restriction on the speed at which regions of spacetime may move relative to each other. So a small bubble of spacetime containing a spacecraft could travel faster than the speed of light
This whole proposition seems like flawed logic to me. It's like saying "air is odorless, so let's wrap a fart in a small bubble of air, so it won't stink up the room".
I have trouble believing the concept of a bubble of spacetime that moves relative to another without any interaction between the two, especially with mass inside the bubble. The other thing is, the whole idea seems to forget that everyday notions of relative speed (the "speed of a bullet shot inside a moving train" logic) don't work at relativistic speeds.
Or is this a late april fool?
Actually, it proves that there is no "Aether" that propagates light waves, analogous to air (or other matter) that propagates sound waves.
That does not discount the possibility of a space-time fabric, it simply states that it is not the thing that propagates light.
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Right. At about one G acceleration you can reach any point in the universe in a few years of ship time.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Oh wait...
Colorless green Cthulhu waits dreaming furiously.
Personally, I'm stocking up on Melange so I can fold space.
"Hyperspace ain't like dustin' crops, boy! Without precise calculations you could blast yourself into a star, or bounce of a supernova; and that'd end your journey Real Quick."
You can't be ahead of the curve, if you're stuck in a loop.
Don't they remodulate the shield frequency (or reconfigure the emitter array), and that keeps the bubble stable just long enough?
I thought we knew that combining these two theories resulted in answers we know to be nonsense. So the implication is one or both of them are wrong in some way. So I'm a little confused why we should trust results based on the combination of two theories that don't work together.
Granted I'm just a laymen, but does anyone else want to comment about the intersection of these two theories?
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Quantum would be an atomically short distance...
IE: a "Quantum leap" is just an electron jumping to another valence level in an atom... it's not a very large distance =)
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In fact there is a fabric of sorts, see Casimir Effect for an experimental result of that "fabric".
It is not at all like the aether that people were thinking of in the 19th century, but it does exist. One way of looking at it is that the vacuum is filled with particles that are constantly popping in and out of existence. Another way is to look as the vacuum as having a "zero point" energy. Either way, it is not truly "empty".
One component of most Sci-Fi "warp drives" is a forcefield/shield etc that would reinforce or protect the ship within that bubble.
So while the hyperspace bubble may be inherently unstable there could be a way given enough power (think fusion or matter-antimatter power) to stabilize it with a forcefield.
We're clearly at least a century if not more from having the technology to even think about building a warp capable space craft, and I believe that's largely because we need to get to the point of practical nuclear fusion or a practical way to manufacture antimatter in quantity.
Corporatism != Free Market
It always works.
While what you say may be very true, the problem is that we have yet to come up with a more feasible method of reaching distant planets in a reasonable amount of time.
The next closest idea that Science and Science Fiction have come up with is Wormhole/Space Fold travel. And unless you have some safe way of generating more power than a large star in a safe and contained manner, that's going to be even tougher than FTL or Warp Bubble drive.
So our best bet is to spend the time doing a full scientific inquiry into FTL/WB drive including actually attempting to BUILD something and testing it. If after that we can show that FTL/WB drive is the cosmic equivalent of a perpetual motion machine, then OK. But let's do the hard Science and prove it first. IANAQP, but it seems to me that your theory and TFA theory are as about as likely as the Mexican guy's theory. Let's find out, shall we?
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Obviously, they're missing a key ingredient...
The Science Directorate has stated that faster-than-light travel is not possible...
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Let's just hope that the time from original concept to working prototype is a bit shorter with this one.
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Ugh. Read this early in the morning, still haven't had my caffeine yet, and only after reading through all the comments did I realise this was about travel, not hard drives.
After skimming through it, I thought it was talking about a hard drive that stored data in a bubble of faster-than-light speed, using quantum mechanics or something. My first thought was that you'd probably end up with a hard drive where all your data is both there and not there at the same time.
Ugh. Need. More. Tea.
Sorry, but we already have faster-than-light communication trough quantum entanglement. The change in state happens instantly, without any delay, no matter what the distance is.
Of course in praxis, you would first have to fly a large mass of entangled matter to the other place at sub-light speed. But when it's there, you could communicate at FTL speeds, until the matter is used up.
I think with moving matter, you are basically correct. But even thermodynamics is just a theory of how things work. It can always happen that we find an exception to it. Pretty much all our scientific knowledge got refined more and more over the time, showing us how there are exceptions here and there (eg. superconductivity).
So it may be pretty unlikely, that searching for FTL drives will bring some results. But it is not per-se wrong or impossible.
Special relativity just has to hat so be a little tiny bit wrong.
Please stop acting as if theories were absolute unchangable laws. They may look, or be very close to that, but they never are exactly that.
(So I agree with you for 99.99999%. But not 100%! And say that there is a very important difference there.: )
Any sufficiently advanced intelligence is indistinguishable from stupidity.
If we want to treat Star Trek technology as something real, I seem to remember once reading that their warp drive involved many layers of shells of subspace, so that no superluminal travel was needed. Each layer was moving fast, but not superluminally with respect to the adjacent layers. The net result of all of those layers was added to be FTL. My impression was that Alcubierre suggested a 2-layer system.
OTOH, if you want to stick with the 2-layer system and are merely upset that it's "unstable", wire up a Conjoiner and ship him/her inside the drive. (Alistair Reynolds reference)
Other relevance... I went to CWRU, where Michelson and Morley did their experiments. Great to have your school's claim to fame being one of the most important failures in history.
The living have better things to do than to continue hating the dead.
We can still get hella fast moving at subluminal speeds.
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Wrong medium!
It ends with Sam Neill plucking out his own eyes and telling you, that you will not need them where you are going.
"Sounds like Da Vinci and his helicopter to me."
Well put. That's my point, and why I said "[t]his is not to understate the importance of his work." I am not so much putting down Alcubierre as I am putting down the summary, which asserts he "figured out how to build a warp drive." Not true, and Alcubierre would probably be the first one to tell you that.
[Sir Garlon] is the marvellest knight that is now living, for he destroyeth many good knights, for he goeth invisible.
That doesn't work. You can't transmit information faster than light; contrary to popular conception, quantum entanglement does not involve classical information transfer.
If you have one of a pair of dice, and the other is a thousand light-years away, one way to think of entanglement is to imagine that whatever number you roll is the number that shows up on the other die the next time it is rolled. Even if the two dice are linked, you can't control which number shows up, so you can't use the dice to communicate information.
I am completely hopeful for the sake of knowledge and experience that we get to into space like in Star Trek. However, I do note a bit of escapism in some of the hopes for a warp drive. I think people are a bit afraid of the idea that this Earth might be the only world humanity will ever live on. The cynic in me suggests that people want this world to be disposable.
We co-evolved with the planet all the way back to when we were microbes. This world is a part of us. Yes, let's try to break past the speed of light, for the sake of science and achievement. Are we existentially okay with our fate as a species being completely contained in this world? I think we can be.
There isn't any way to prove that the same rules apply at all scales. We sort of assume they do, but they might not.
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No we don't, and no you couldn't. I suppose you're thinking of the EPR paradox? Very well. Let us say that I have a set of electrons in equal spin superpositions, and you, at some distant location, have their entangled counterparts. What's the protocol for communication?
Well, if I measure the spin of my electron 0 about the x axis, then in doing so I will also establish the spin of your electron 0 about that axis. The superposition on your electron has vanished without you touching it. Terrific, that's communication, right? I collapse your electrons in sequence, this one on the x axis, this one y, this one x, and so on, a binary code?
Well, no, it doesn't work like that. How can you tell if I've done anything at my end? By making measurements of your electrons? No - because that will collapse the superposition too. Let's say I measure electron 0's spin around the x axis to be positive. Immediately and instantaneously, faster than light across the universe, the superposition on your electron 0 collapses and I know it to be positive about the x axis.
But you don't know that. You might pick the y axis to measure, which is still a superposition. Or you might pick the x axis, and certainly you'll get a +, but you might have got that anyway. You can measure each electron only once - you change its state in doing so - so you can't do a series of tests, build up the statistics and find that on the y axis it's a 50/50 shot but on the x axis it's + every time. That's what you'd need to do in order to determine that I'd chosen the x axis. That's what you'd need in order to communicate faster than light. But since you only ever get one measurement, you get no information about what I did at the other end.
Real Daleks don't climb stairs - they level the building.
Sorry, but we already have faster-than-light communication trough quantum entanglement. The change in state happens instantly, without any delay, no matter what the distance is.
Of course in praxis, you would first have to fly a large mass of entangled matter to the other place at sub-light speed. But when it's there, you could communicate at FTL speeds, until the matter is used up.
No. EPR does not allow FTL communication. FTL communication means causality violation: A causes B but B happens before A.
Tim.
God said, "div D = rho, div B = 0, curl E = -@B/@t, curl H = J + @D/@t," and there was light.
Liquid schwartz. Instant space tracks.
It will be better to purchase from an owner who is a good farmer and a good builder.
The only "somewhat" reliable theory we have so far that should work when both quantum and relativist thresholds are reached is the superstring theory (or it's advanced counter part or M-branes). Unfortunately nobody can tell if that theory is right or not since we don't have the means to measure any of the results that are predicted by that theory and are not in conformity with the general relativity or quantum physic.
Maybe with the LHC that with be possible, but that may not be the case. The maximum energy that LHC will be able to handle will in principle not be enough to put some of those principles in practice. BUT, perhaps we can observe a sub-"product" of superstring (M-brane) theory, the unfolding of extra spacial dimensions (6 or 11) and in that case, that should give us a pretty good idea that M-branes are the way to go.
Still, even if we don't see any of that with LHC, it doesn't mean the theory is wrong until we build a powerful enough particle accelerator that finally confirms or dismisses M-branes theory.
Since when does quantum physics make something impossible? Probably never.
Psychics aren't wrong - they just have a limited probability of success.
Scientists point out problems, engineers fix them
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Sorry, but we already have faster-than-light communication trough quantum entanglement. The change in state happens instantly, without any delay, no matter what the distance is.
You're mis-interpreting quantum mechanics and entanglement. The second sentence in that quote is right, but it doesn't imply the first sentence, which is wrong.
When a quantum entanglement collapses, both of the entangled particles will end up in states that are strongly correlated, even if the two particles are very far apart. So yes you could have two entangled particles that are separated from each other, have them collapse, and there would be "instantaneous" correlations between them.
However this cannot be used for faster-than-light communication. (It makes for cool sci-fi, but isn't correct when you really look into the details of quantum mechanics.) The reason it cannot is because the collapse is (at least to the local observers) random. Neither side can predict nor influence* what random state their end of the entangled pair collapses into. So if we have two streams of entangled particles (one on Earth and one at Alpha Centauri), both sides would read out a random stream of answers (up/down, yes/no, 1/0 ... or whatever). Only once you compare the two streams do you realize that they were correlated more strongly than random chance (and classical mechanics) would allow. A cool experiment, to be sure! But it can't be used to transfer information.
Many people have tried to devise ways around the rules of quantum mechanics, to allow entanglement to be used for FTL communication. But all such proposals (to date) have been found to have mistakes with respect to our current understanding of quantum mechanics. To date, there is no loophole that allows one to circumvent the (local) randomness of quantum mechanics to allow FTL. Of course it's possible that modern relativity and quantum mechanics are both wrong. But at least for now there is no evidence of any information ever being transmitted faster-than-light.
* Actually you can try to influence the answers you get from your stream by selecting a particular measurement method. And while doing so does influence the states of the distant particles, your faraway friend won't know what sequence of measurements you selected. So he will select his own set of measurements, and end up with what seems like a random stream, and no way to correctly interpret what the stream "means" without knowing the sequence of measurements you performed. Of course the two sides can pre-arranged what measurement sequence to use, but that's not FTL communication... that just becomes old-fashioned communication. The point is that "communication" means "transfer of information", and one cannot transfer information via entanglement (which may be FTL), because one has to additionally transfer the measurement information in a sub-luminal way. This may sound "contrived" to prevent FTL communication, but that's just what our best equations currently describe.
The very people who should be aware how little they know compared to what is possible. They come up with these statements, and they forget that for every problem, there IS a solution, even if they can not figure it out themselves.
The question their current "findings" should be asking is "what makes it unstable?". They may not know, but that is the key to solving the problem.
People forget that scientists used to think that it was impossible to break the sound barrier for various reasons. Then they came up with the idea that the speed of light could not be broken. Time has proven again and again that the only thing stopping ANYTHING is not having the knowledge to do it. Not having knowledge does not make something impossible, it just means a CURRENT inability to do something.
First of all it's worth remembering that quantum mechanics and relativity are not 100% incompatible. In fact "relativistic quantum mechanics" has been around for a long time. Quantum theory was greatly advanced when relativistic effects were included.
But you're right that we have good reason to believe that something is wrong with either quantum mechanics or relativity (or both), since they give contradictory predictions in a certain number of extreme cases. (Quantum gravity is not yet solved...)
However we also have ample evidence that quantum mechanics and relativity are incredibly accurate and predictive theories in a vast range of circumstances. We have every reason to believe that the correct "Theory of Everything" will reduce to conventional quantum mechanics and conventional relativity in the appropriate limits. And thus we have every reason to continue using those theories to make predictions all over the place.
Now a warp bubble is one of those extreme situations where the two theories might be expected to give contradictory results, in which case only the hypothetical theory-of-everything would give the correct answers. But it is certainly still useful to ask what our current theories would predict for these extreme situations. It helps us better understand the theories. And, again, we have reasons to believe that many of the things our current theories predict (even in extreme situations) will be right. Absent the theory-of-everything, quantum mechanics + relativity will give us the "best guess" about how such objects would behave
Hah... it's probably just my engineering background, but I always found "atomic" as a description of a quantum unit to be funny.
æeee!
My people are taught that it's a fluid, not a fabric. When particles pop into existance, or exist as matter, in our dimensional space their probability function becomes highly localized and creates a "void" between dimensions and a pressure density gradient at that point in space. This pressure forces the fluid of space to flow into these voids and it's this flow of space fluid that creates and explains the drag known to us as gravity.
We are also taught that if enough matter is brought together in a region of space the flow of space fluid into other dimensions becomes so strong that nothing, not even light, can escape the currents. We call these objects deep blue holes. Technically they are black because no light escapes, but we're smurfs and we think we're cool, so since cool blacks are bluish blacks we call them deep blue holes.
I'm pretty sure I got that explanation right. Brainy lectures on and on about it but it's hard to pay attention when the discussion is about deep blue holes... Smurfette sits next to me... droooooool....
I smurf everything and everything I smurf is perfect.
Everything is impossible until proven otherwise - don't they know better?
I am Jack's smirking revenge.
I canna change the laws of Physics!
Impossible only means "Everyone else gave up"
We are not capable of faster than light communications based on quantum entanglement since to be able to decode the information you may transmit with quantum entanglement you need to transmit beside the information in the entanglement also a classic channel and that puts everything back in the slower than light (or as fast as light) domain.
One of the nice things about the universe is that it's actually pretty hard to hide phenomenon. We, for instance, have been making no attempt to not blatantly broadcast our location and existence - while the sample size is small, do you really think any other civilization is going to have their first thought upon discovering radio waves be "Damn, better be careful about using lest an impossibly distant alien race finds out where we are!"?
No, far more likely is that if there is life out there, it's simply far enough away (or, correspondingly, too young) that we haven't had the chance to see any evidence of them. But to assume that 'if there is life, of course they see us', is entirely illogical.
[Ego]out
There is no causality violation if you travel FTL to some point in the expanding universe that is beyond our light cone, as long as expansion never reverses. In other words, FTL is "causality safe" between two reference frames that can never come in contact with each other.
Additionally, within a local reference frame, causality violation presumes the existence of free will. Dr. Robert L Foward posited that the instant one transmits information FTL (i.e. time travel), restrictions begin to be placed on free will such that causality can not be violated, and thus preventing paradoxes.
You might be able to go back in time, but you can't go back and kill your own grandfather.
Forward saw this as essentially the inverse of forward causality, i.e. if I'm going to break my leg tomorrow skiing, I don't really have any choice in the matter.
Are they talking about Quantum Hard Drives or Tape drives? I thought they stopped making hard drives.
A 'failure' in science is an erroneous result. A valid negative result is still a scientific success (even if it's not as publishable).
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That's sounds like a circular argument:
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You have a good point: we cannot definitively rule out warp drive until a theory of quantum gravity becomes well-established. Of course, that doesn't mean there aren't clues that tell us that the universe behaves a certain way. Unfortunately, both quantum mechanics and relativity predict that information can't be transferred faster than the speed of light, so I wouldn't get your hopes up.
Arthur C. Clarke formulated the following three "laws" of prediction:
1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
3. Any sufficiently advanced technology is indistinguishable from magic.
(http://en.wikipedia.org/wiki/Clarke%27s_three_laws)
I assume then, a statement about superluminal travel being impossible, is actually good news.
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And if we could collapse a specific area of the universe in the same way the particles pop out of existence, we could connect the space around the collapsed part.
Forgive me for being stupid, but why can't you just "roll" until you get whatever you want?
I'm looking at this Particle on Earth, you're looking at it's Entangled Twin somewhere in the Delta Quadrant, and beforehand, I told you "If I roll a six and stay there, bring me back Anti-Matter. Otherwise, bring me back dark matter."
I then roll my particle dice until I get a six, then perform no more rolls. Otherwise, I roll until I _don't_ get a six, then perform no more rolls.
Why doesn't this work?
Well said :)
But even if it's proven impossible, it could at least be usable to travel at light speed! Much better than our current max speed... no?
I can't call that English
the transporter
both are currently ridiculous notions
but to disassociate matter, transport it instantaneously, and then reassociate exactly as it was- alive and thinking, somewhere else without any type of confinement in that other place... this brings to mind even more impossibilities than just the singular major problem facing us with a warp drive
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You can only roll the dice once. After that they are no longer entangled.
Yeah it is funny hearing people say they have made a "quantum leap" which would mean "the smallest possible discreet leap". I mean even the show with that name wasn't implying huge leaps, so I don't know how it came to mean that in their heads. Or maybe they mean it's an advancement worthy of Scott Bakula?
I actually liked how the last Bond movie, "Quantum of Solace", used the term correctly. Though this probably confused some people. My roommate thought the name was stupid till I told him what "quantum" really meant and then he thought it was cool. :)
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This doesn't seem like it could be the right explanation. Suppose you measure 2^10 of your electrons on the x-axis. Some time later, I come along and measure the equivalent electrons in two groups of 2^9 each, half on the x- and half on the y- axis. One of those two groups won't be correlated, and one will. (If the probability isn't high enough, use more electrons.) That gives me one bit of classical information with an arbitrary degree of confidence.
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People forget that scientists used to think that it was impossible to break the sound barrier for various reasons.
No they didn't. Some idiot writing for a news paper may have however.
If information wants to be free, why does my internet connection cost so much?
From the headline I thought they were talking about OS/2!
I hope IBM doesn't do anything rash.
Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
Paradoxes sometimes have explanations that aren't immediately obvious. Take, for instance, the twins paradox, which can be explained by the fact that one of the twins suffered accelerations and changed his velocity, therefore using two different frames of reference. Likewise, the site you linked has two different frames of reference, moving relative to each other. There are two different "ansible" communications, sharing one common event "B". Perhaps one event cannot have two ansible communications.
Let's say somehow an ansible is invented, based on entangled photons. In order to transmit instantaneous communications between two observers a source of entangled photons should be positioned exactly midway between both observers. If both ansibles send a message to event B, the sources of entangled photons should be physically positioned in a line between Me and Alice, the A-B source closer to Alice than the B-C source.
At event B, Alice and Carol are receiving photons from both sources at the same time coming from the same direction. Maybe that causes interference into the ansible communications? Without knowing how that "ansible" works, no one knows, but one can imagine an instantaneous communication system that has limitations that will not let it violate causality.
Also, it's important to note that, at a microscopic level, causality does not exist, only correlation exists. Causality, i.e. the "arrow of time", is a macroscopic phenomenon, microscopic effects are reversible. Maybe someday we will find limitations to causality that will permit some violations to the no-FTL rule. It will be a strange world, but no stranger than quantum mechanics seem to us now.
I've been around long enough to see this as a serial communications synchronization issue.
Simply guarantee that the collapses will happen at a given time frame, then check them at any time thereafter.
Sure its inefficient, but its simple serial binary transmission -- we've been doing it a while now.
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While I think achieving superluminous speeds may certainly be possible as our understanding of physics develops, it seems like it could be a moot point.
The idea for traveling large distances within the universe which involves folding space/time into a higher dimension seems both more efficient and generally better understood today. As was noted above, working with something like superluminous velocities is going to inevitably require analysis involving two of our most powerful models of physics, relativity and quantum mechanics, which at this point still don't play well with each other (at least not in every circumstance).
However, it seems like the general trend towards the theory of everything research continues to lean to higher dimensions as an accurate model. That being said, ideas that have been expressed that involve folding and or dropping out of the space/time continuum and reentering at a different location/configuration in the universe seems like it might still be a more viable option for traveling large distances.
Still though, superluminous speed does seem like it would be cool...
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but neither person can alter the probability distribution, you can only measure it.
when i see
110111010001000100000
i know that you have
001000101110111011111
but that doesn't help me comunicate with you in anyway, switching axis and what you collapse makes the situation more complex, but there is still no way to write a message, just for both of us to read the same random message (that's why this is useful for cryptography).
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So: I measure 2**10 electrons on the x axis and get a random string of + and -.
You then measure 2**9 electrons on the x axis and get a random string of + and - (which happen to be identical to the first half of my string), and then another 2**9 electrons on the y axis and get another random string of + and - (which bear no particular resemblance to the second half of my string).
Until you get my slower-than-light email telling you what values I measured at my end, how can you prove which of the two strings is correlated? You can't tell whether I chose the x or the y axis, so no information has been transferred.
Real Daleks don't climb stairs - they level the building.
Sustaining 1G for several years isn't magic. It's just advanced technology.
James Powell, the co-inventor of super-conducting maglev, described a mechanism to build a 1G rocket to travel to the stars. His basic idea was to use Mercury as a solar collector to manufacture a few tons of anti-matter. When you react the anti-matter, you get both power and ejectable mass moving at very high speed. A sci-fi author, Charles Pelligrino, wrote up the idea in the appendix to his book, Flying to Valhalla.
The Orion designers were thinking that once they got the first version working to ferry between the planets, they could build a star ship that would get to Alpha Centauri for $100 Billion in 1960 dollars. The cost was so far out of reach, the idea was almost forgotten.
The point is, you don't need magic to travel at 1G, you need resources.
Whatever, I'm going to try it tomorrow, if I get ripped apart in my unstable time bubble I'll piece myself back together and try again next week.
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Yet another thing that will somehow managed to be blamed on Barack Obama and the Democrat Congress.
Where's Zefram Cochrane when you need him?
Oh yeah - likely passed out.
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
It is believed that during the big bang areas of space expanded faster than the speed of light, so does this disprove the big bang theory also?
You can only roll the dice once. After that they are no longer entangled.
So Joe carries 1000 particles, which have twins back home, to Joe's Space TV/VCR Repair Center, which is out near Betelgeuse. I want to send him a message: "Pound pastrami, can kraut, six bagels--bring home for Emma."
I "roll" particles to encode a 1 and leave 'em alone for 0. Sez I:
01010000 01101111 01110101 01101110 01100100 00100000 01110000 01100001 01110011 01110100 01110010 01100001 01101101 01101001 00101100 00100000 01100011 01100001 01101110 00100000 01101011 01110010 01100001 01110101 01110100 00101100 00100000 01110011 01101001 01111000 00100000 01100010 01100001 01100111 01100101 01101100 01110011 00101101 00101101 01100010 01110010 01101001 01101110 01100111 00100000 01101000 01101111 01101101 01100101 00100000 01100110 01101111 01110010 00100000 01000101 01101101 01101101 01100001 00101110
Nobody seems to take into account time dialation. You don't need to travel faster than light when it only takes you 4 months to get to Alpha Centauri from your perspective.
If you can do one Impossible thing after breakfast but before lunch why not stop by at Millyway's and have Lunch at the Restaurant at the end of the universe?
Tsukasa: All I really want, is to be left alone...
>Warp drives would become rapidly unstable once superluminal speeds are reached
So invent a warp core stabilizer.
[where's my easy button?]
Don't kid yourself. It's the size of the regexp AND how you use it that counts.
Going out on a limb here but I think the problem is that if you observe the dice roll then it's disentangled. And nobody is actually rolling the dice. We are simply rattling the dice in a an overturned cup. Once you remove the cup you can see the result the entangled die is set to the same thing. But the guy on the other end doesn't know how many dice you have looked at and when to stop looking at the dice on his end. In order for him to know that you've stopped he'd have to look at the others but doing so sets the ones on your end.
I'm not really sure what you're getting at, but you definitely can't transmit information using entanglement. You can only know that both parties have them same *random* data.
It is effectively the same as writing a random number down on two bits of paper. Each party goes off and can now look at the paper if they like. Obviously there's no way to transmit information because they can't affect anything the other person sees or does.
I agree with your caution against scientists over-stating their knowledge. But...
Time has proven again and again that the only thing stopping ANYTHING is not having the knowledge to do it.
I don't think that's right. If that were true, it would imply that the physical universe has no immutable laws. That every physical law can be somehow circumvented. But such a universe is de-facto a universe without actual laws. What I'm saying is that if you accept that the universe operates based on some set of rules/laws (and this is a basic assumption in science), then this means that there are some things that simply cannot be done, no matter how smart you are.
Now we can't know for certain that the "speed of light limit" is one of those laws. But all the evidence we have so far (and this includes a boatload of experiments and all of our most predictive theories) is that matter/energy/information cannot travel faster than light.
for every problem, there IS a solution, even if they can not figure it out themselves.
A romantic notion, but one without any particular evidence. The idea that technology can become arbitrarily powerful, that "anything" can be done if only one knew how, is completely at odds with a universe having a specific set of physical laws. The physical laws define a set of possible and impossible behaviors... and there is no guarantee that a given problem has a solution falling into the "possible in this universe" class.
The construction of your argument is sound, but the foundation is not. Obviously, communication protocol is something that requires a predetermined agreement between both parties. Just sending someone out into space with no agreement as to what axis to analyze is equivalent to sending someone out into space with no agreement on which radio frequency to listen on; only with a more ludicrous selection of possibilities. The real trouble is this, you have a limited amount of bits that can be transmitted that must be transported from the source to the destination... This is not a practical solution until we can remotely entangle (or at least re-entangle) these elements. My quantum physics, quite frankly, sucks, so I have no idea if this is even a remote possibility.
Dude, just turn on the quantum instability compensators.
For a thorough discussion of QM vs SR you may read my thoughts on it in the following thread: http://www.sciforums.com/showthread.php?t=91001
A lot of 'qualified' and 'educated' scientists said that it was impossible to break the speed of sound 60 years ago. Yet here we are with spaceships and research vessels travelling thousands of miles per hour in space. We '_CAN_' go faster than the speed of light - we just need to figure out a way to bend space to make it so.
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You're absolutely right about the impossibility of transmitting information FTL using quantum entanglement, but I have a small nitpick about this:
It's effectively the same if you're only talking about the ability to send information FTL; but not when talking about other things (like channel capacity). For example, you can use entanglement to double the capacity of a classical channel:
http://www.quantiki.org/wiki/index.php/Enhancement_of_channel_capacities_with_entanglement
(and also http://en.wikipedia.org/wiki/Superdense_coding)
This could never be done with the two bits of paper.
People forget that scientists used to think that it was impossible to break the sound barrier for various reasons
There was no physical law prohibiting going faster than the speed of sound, ie, "the sound barrier", it was mostly a engineering issue as compared to the speed of light which is a physic's issue.
Does this moving region of spacetime or warp bubble or whatever it is actually exist? Either I am misunderstanding something or this is a theory using a theory that is possibly flawed. Why research what would happen to a bubble that has not been proven to exist? Wouldn't it help to figure out if it is possible for the bubble to exist before guessing what would happen to the bubble. It seems to me like this team of physicists have put alot of time and effort into figuring out what might happen if someone elses day dream is correct. Wouldn't it make alot more sense to research whether or not the foundation is there before you build the house on it?
That doesn't work either because Joe doesn't know if you have rolled the dice or not.
Entangled particles are like dice that are already rolling, and they stop rolling the moment that either particle is observed.
So you and Joe each have a dice that, say, always roll the same number as each other. You look at your dice to cause it to stop rolling, and see that it rolled a 6. Joe can look at his dice too, and will also see a 6, but he doesn't know if he was the one that caused the dice to stop, or whether it was you who stopped it.
You both see a 6, but no actual information was transferred.
You are missing the point. All you can do is observe the particle, and thus learn something about the distant particle. You don't get to choose what you observe. You cant force the particle to have +y spin. You just observe it. The other observer would see the same thing as you, but that doesn't help you transmit data. It is like you are both looking at the same random set of data.
If we have one space ship moving at 70% the speed of light and another one from the opposite direction moving towards the first ship also at 70% the speed of light... then they're both moving above light speed relative to each other. So it looks possible.
Color me unconvinced. 1) What "fuel" is there to mine on the moon? 2) If you intend to do all this mining, manufacturing, assembling, and so forth in space... that means you have to launch lots of large, heavy factory components up there to do all that stuff. Plus lots of life support equipment, buildings, food, etc, for the people who do the building. 3) No one has the first clue what it would cost to construct said factories, etc... but because of 2), it would be hideously expensive. 4) We don't have the technology to "robotically assemble in orbit" a giant telescope.
If you did some math that shows anything different, I'd really be interested in seeing it.
Just for the sake of argument, we know about .000000005% of how space/time works.
Anyone that says, "impossible" needs to clarify that with the word "today".
You are missing the real problem here.
When observer A measures the electron at his side to be X-aligned, he will measure that 50% electrons are aligned and 50% are not. He has no control over what he will measure. He can just setup the test an observe that electrons are aligned or not.
Observer B will setup the same test on her side. Suppose she checks the same alignment as observer A, then she will also observe that 50% of the electrons are aligned and 50% are not.
When A measures an X-alignment, B will measure a non-X-alignment for the same electron. But because B doesn't know what A measured, because that's random, there is no way to use this to exchange information. Only when A and B later meet and discuss their results, they will find that A observed a sequence of alignments, and B observed the opposite sequence.
The only thing quantum entanglement tells you is that there is a correlation between the observed states of the two particles. It does not tell you if the other particle has been observed or not.
You and I both have a quantum particle, and neither of us knows the state.
I check my particle. It has spin 1/2. I therefore know that if and when you observe your particle, it will have spin -1/2. I do not know whether or not you have actually done so. You may have already done so and observed -1/2. You may not yet. Therefore I know nothing about your situation other than what I already knew when I gave you your particle -- that you will observe a result that is correlated with mine. That's it.
The enemies of Democracy are
But, the other side needs to be able to measure the change in order for it to be useful. Doesn't the act of measuring change its' state, also? I must be missing something, as I'm by no means an expert.
Just reverse the polarity of the plasma manifolds and re-route power from the shields relay, and it should hold up fine. It's so easy a vulcan child could do it.
--
Stay tuned for some shock and awe coming right up after this messages!
The entanglement usually occurs to conserve some physical quantity, such as spin or momentum. So for the dice example, let's say that every pair of entangled dice must add up to 7.
The problem is that they can only become entangled while they're still in luminal communication range - so you have to roll all the dice before the ship leaves.
If neither of you looks at your dice, then the number rolled remains undefined. As soon as one of you looks at a given die, both it and it's twin instantly take on their respective values (or you spawn 6 universes identical in every way except for the values rolled, if you like the multi-universe theory.) But when you look at a die, all you see is a number. You know that the number on the previously entangled die must be 7-#, but you have no way to tell whether you looked first or your counterpart on the ship.
All we need is Wesley Crusher. Can't he do anything?
The days of the digital watch are numbered.
wow the quality of the comments from the 99 article are better then todays comments they have grammar complete sentences and paragraphs
No, I will not work for your startup
And if there were only some way of contriving that a state or an army should be made up of lovers and their loves, they would be the very best governors of their own city, abstaining from all dishonour, and emulating one another in honour; and when fighting at each other's side, although a mere handful, they would overcome the world. For what lover would not choose rather to be seen by all mankind than by his beloved, either when abandoning his post or throwing away his arms? He would be ready to die a thousand deaths rather than endure this. Or who would desert his beloved or fail him in the hour of danger? The veriest coward would become an inspired hero, equal to the bravest, at such a time; Love would inspire him. That courage which, as Homer says, the god breathes into the souls of some heroes, Love of his own nature infuses into the lover.
Apollodorus, in The Symposium by Plato.
Gotta love those Greeks
The English word fart is one of the oldest words in the English vocabulary.
...because the Stupid Humans don't get that it's EXACTLY that instability that makes FTL possible. You CAN'T go FTL UNLESS it's unstable.
Of course, Gragnar forgets it took him and his multipodia brethren a hundred years and 892 "chunky salsa" incidents before they figured out how to make a "mostly stable" instability...
He put his boots up on the table and made a face. "The sig," he smirked. "You can waste your life in search of the sig."
Alternatively, you could just increase the speed of light, which scientists did in 2208.
Yeah. You see that star that's 45 light years away from here? You ain't getting there unless you can become energy and not die. Then it'll take 45 years or so, lord knows what it's like being pure energy, and everyone who remained as matter will be long since dead when you get there.
Get it? Good.
We have a better shot at traveling into "inner space" as gods than we do "outer space," as waveforms. Get out the microscopes, colliders, and deep sea environment suits, there's lots of exploring to be done *right here*, and we aren't getting away from *right here* if we don't solve the problems *right here, right now*.
--
Toro
If the "bubble" is unstable at superluminal speeds, would this still work as a sublight propulsion system? What properties would that have? Would it still be immune to the effects of relativity?
Give a man fire, and you warm him for the night. Set a man on fire, and you warm him for the rest of his life.
Ask Franz Embacher and his team from the university of Vienna. They do exactly what I described and transferred information over half the city. I think he can control which number shows up.
Any sufficiently advanced intelligence is indistinguishable from stupidity.
This whole conversation isn't practical anyway. The only way we can even practically travel around even our own solar system is with nuclear power and too many people are trapped in 50's monster movie world to let that happen any time soon.
This is my sig.
Don't forget about time travel ;)
~ awaiting spiritual enlightenment ~
It looks like his warp field is wrong, but his image is unclear so I can't read it properly. I guess it breaks down after warp speed 2,2 has been reached. Warp speed is calculated like this, light speed is equal to Warp 0.
What needs to be done is to create a stable field. However, I do not know how to do this. As I don't know what basics he used. to create this theoretical warp field.
Warp field and warp speed is a subject that I have been looking into for a long time now. The biggest problem with warp field is the power. The need for anti-matter engine is clear.
original poster:
Problem:
The bubble isn't moving relative to itself. It would be "us" that is unstable? The bubble can't destabilize because in its frame of reference it is not moving -- we are, thus wouldn't we equally likely to be 'unstable'?
Implication: a field moving through our universe faster than speed of light would cause instability of entire universe? Something seems wrong with some assumptions somewhere (could be FTL can't happen, but claiming instability seems an unlikely paradigm on the surface).
The guy's name is "Miguel Alcubierre", not "Michael Alcubierre".
Pretty stern word for a science we know so very little about. I would rather state that there seems to be a problem that needs to be overcome, and I assume it is neither the first, nor will it be the last. Remember, there was the large assumption by scientists that the problems that occur when approaching the sound barrier would tear a ship apart when it gets to that speed. This didn't pan out. I think that these are likely just more problems that need to be overcome. Not that I know much about it. Quantum mechanics is NOT my strong suit!
Open Source: Eroding the Digital Divide
Looking over the findings presented I have a difficult time agreeing with their model. It would appear they assume a static structure. A static model of a helicopter, or snowboarding session, or rifled-bullet would not work. It's the counterintuitive stability-through-dynamic adjustment thing that I suppose still hasn't caught on yet.
If one were to look it over it appears as though that if they were to assume a non-periodic, elongated-toroid-bubble, with the hawking radiation in the middle bit and the instability happening on the outer-and-inner shells, they'd have nary a problem: the weather inside stays peachy.
A "quantum leap" refers to any change which is not continuously incremental, and therefore includes advances which are qualitative differences.
Never mind, Seven. You can get dressed now.
That is in fact a great analogy. Without a car! Mind if I use with my physics teaching?
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
1) We agree ahead of time that we use the x-axis spin of two atoms (each) for communication.
2) I only manipulate two atoms of my set of 4, and only observe the other two.
3) You only observe the pair entangled with my 'write' set, and only manipulate to the pair entangled with my 'read' set.
Ok.
4) I continuously toggle the spin of one atom from my 'write' set back and forth between two previously agreed upon states, and change (or don't) the state of my other atom between two agreed upon states.
No. You measure the spin of one particle from your write set. The entangled particle from my read set silently agrees to return the complementary value when I measure it. The entanglement is now broken. You continue to "toggle" the spin on your particle, where "toggle" means "measure and receive non-deterministic, random, unpredictable results". I can measure my particle's spin at any time after your initial measurement and will find the random counterpart to your random first value. I have no way of knowing whether I've received the random result of your having measured, or if I've primed your first result by measuring before you did.
5) By continuously observing your 'read' pair of atoms (the pair entangled to my 'write' pair), you can see the one is constantly flipping states, and use that to determine the binary pattern I am sending. (1bit parity, 1bit data)
By continuously observing my read pair of particles, I can see that I get a stream of random results. Coincidentally, the first random value from each particle correlates with the first random value you get from each of your particles.
GENERATION 25: If you haven't yet, copy this into your sig on any forum and add 1 to the generation. (Social experiment)
I think the article is using the term literally in its quantum mechanics meaning. The paper discusses a theory stemming from quantum mechanics that would defeat this theory of faster-than-light travel. In this regard, it is literally a setback coming from quantum mechanics.
A NYC lawyer blogs. http://www.chuangblog.com/
Well, if you consider the Universe a bubble of space time, it at one point had to expand faster than light to grow from it's smaller than a pea size to what it is now. Quantum mechanics is the alchemy of physics and should be taken with large grains of salts.
Say I had 50 electrons, all of which I chose x, and you measure those 50 electrons, 70% of which come up x.. pretty good measure of x, no?
Just because we haven't figured it out yet doesn't mean its impossible.
I thought that was a core principle of science, that we can never really know anything with certainty. Especially in such a young field.
Sometimes, you can, you go to hell for the rest of your life! That's a true thing.
Ah, but here is an odd way to look at things, if there is an edge to the universe(the universe is expanding), then there must be something beyond the edge of our universe. This means that there must be some set of laws that govern what is outside of the universe, and there is the possibility that in time, humanity COULD make use of those laws, which may circumvent the laws of this universe.
My own feeling is that people spend too much time accepting conventional wisdom, rather than looking for the reasons why things either work or do not work.
As with programming, the majority look at how to make something work. A smaller number look at how things may break. Then you have those who accept that things may break, so try to figure out WHY things may break. So, you have people trying to prove a theory, you have those who try to disprove a theory, but there are a small number trying to figure out why something "can not be done".
Now, keep in mind that by the time humanity is able to answer certain questions, humanity will have evolved into a much more advanced form of life, and solutions may be obvious to those "future humans". Thinking in four dimensions, perceptions that extend beyond the current five senses, and so on may be possible for some forms of life, and once your perceptions go beyond the three, who knows what laws may be governing the universe?
The problem is that I can't control what the dice will roll. So if I roll my dice and get a 7, then I know that your dice will also show a 7. But if I wanted your dice to show a 9 - which would be a form of communication - I would need to force my dice to roll a 9 somehow. However, there is no way to do this, hence no way to communicate. Keep in mind that with entanglement, you only get one dice roll then the number is set - so I can't just keep re-rolling until I get the desired number to show up like I can do with real dice.
I'm not a physicist, so bear with me here.
So why can't you have a protocol agreement and a clock?
We both agree that electrons 0-15 are for sending, electrons 16-31 are for receiving (for a single message only), on the x-axis. All electrons must be set to + or - to eliminate any default state.
Then you say that at clock time t, we assume the message has been sent.
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