It's certainly one explanation that I've seen.

Bah, I came up with this idea years ago. Shoulda patented it.
You would be better off with banks of 8(bits) or more per channel and with 2 channels per transmitter/reciever pair.

IIRC the real problem is that the atoms would change their spin pair partner to one physically closer over time.
Well that and if you get the incantation wrong, demons accidently pop out.
Science-it's more magical than you think.

Card talks about this idea at some length in the "Ender" series.

Yes.

The bitch, though, is keeping track of which particles are paired up and figuring out how to manipulate the correct ones.

The further problem is figuring out what to say to the Andromedans.

At the moment, the plan is to identify Earth as the 4th planet from Sun and see what happens.

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At the moment, the plan is to identify Earth as the 4th planet from Sun and see what happens.

I'm not liking that plan very much. I say we identify Earth as the 5th planet from the Sun and see what happens. If its all good, then we can say oops, we meant...

The catch here is that the instantaneous EPR linkage involves the collapse of an indeterminate quantum function through measurement--sort of a Schrodinger's Cat situation. However, the function collapses randomly; if you measure the spin of particle A and get a value of +1, then particle B's spin will necessarily, and instanteously, be -1. But there's no way to decide beforehand whether that initial measurement will be positive or negative; observers light-years apart measuring the spins of Particle Stream A and Particle Stream B would be looking "simultaneously" (whatever that means) at a random string of pluses and minuses, one of them the converse of the other.

The EPR effect is instantaneous in a way that makes the whole notion of physical distance look a bit notional, and there are several other phenomena that are known to travel faster than light--much faster, in some cases. The problem is that all of them seem to forbid transmitting information, even in principle.

Didn't Star Trek use "subspace radio" or some similar piece of gobbledegook? I always assumed that involved the use of wormholes, a whole different idea that also doesn't look like it can work. No question, quantum physics makes subjects like tax law seem absolutely pellucid by comparison.

Hokey Science and Spooky Action are no match for a good blaster at your side, kid.

BTW, Ace, nice segue into quantum physics from the Big Genitals Round-up. You're definitely exploring the studio space.

Does this mean that one can have two entangled particles, separated by light years of space (one on earth, one on, say, Andromeda-5) and change the spin of one (therefore instanteously changing the spin of its partner) and therefore have the makings of an instanteous communications system?

No.

That kind of FTL communicator is often called an "ansible" in SF for some reason. More often though, they use some kind of modulated tachyons, or they use a term like "hyperwaves", the implication of which I believe is that it's like radio waves through hyperspace, or they just radio through a wormhole. Of course, a lot of the good hard SF goes ahead and assumes that communication is limited to light speed.

You know what happens when matter and antimatter meet? A TREMENDOUS EXPLOSION

Like I've been saying for years, I'll be there when I get there!

Bell's inequality showed that entangled particles do not carry hidden information about each other. Aside from the idea of instantaneous action at a distance the other way of looking at it is that there are a set of possible outcomes (realities). The reality you resolve to by measuring the spin removes that outcome from the possibilities your distant cohort can measure.

IOW if you get spin=up, the alternate reality cohorts who measures spin=up are blocked off from the future timeline you chose by measuring spin=up.

Therefore only the cohorts who measure spin=down are left in your reality. But your measurement had no effect on them at the distance, you just removed the set of timelines from your possible futures that included them.

Either way seems to work the same for transmitting uninterceptable random numbers faster than light. What good is that? Large random numbers can be used for crypto keys.

Boy,I wish I ahdn't been sipping Scotch all evening.Then I could really impress peopul. Wheeler and Feynman touched on this by pointing out that a positron can be
the equivalent to an elctron going backwards in time. (I
don't know what this means.)

I think that string theory says that this "action at a distance" is nothing of the kind -- the two particles are simply endpoints of the same "string", but most of the string is "curled" into higher dimensions.

I suppose if you want to extract a sci-fi FTL communications device out of this idea, you could propose something like a propagating wavefront that vibrates the "strings" at a given "frequency" and thereby transmits information instantaneously over vast three-dimensional distances.

Keep in mind, this is just the beginnings of exploration. Attempting to measure often ends in failure, until the right question is posed; except that you have to pose a bunch of wrong/inadequate questions first. Still, attempting to measure is the precursor to measuring, measuring is the precursor to random influencing, random influencing is the precursor to deliberate influencing, deliberate influencing is the precursor to consistent influence, and this comment is the precursor to an insomnia cure.

Bottom line: we'll get there, someday; even if this turns out to be a blind alley, as it seems right now. But even blind alleys need to be fully explored to make dang sure it is, in fact, a dead end; and much can be learned in the process of exploring dead ends.

This topic was covered completely, correctly, and ata level suitable for any high school graduate in this book:

http://tinyurl.com/crzse

Highly recommended, and the answer to Ace's question when all is said and done is "sort of". I spent a lot of late nights working this problem when I was getting a Physics PhD long ago, and I still remember that you had to work the math -- intuition didn't help very much.

Who else thinks quantum mechanics would not be so weird if someone went back in time and killed Aristotle, so that the ancient Greeks would have stayed on course and arived at it through sheer deductive logic, instead of leaving it to be stubled upon by Germans messing with radioactive stuff?

If I were to measure the mass, velocity, etc, of one particle in such a manner that it spookily acted at a distance upon another particle in a mosque, would that violate someone's civil rights?

Utron implicitly answered this but not clearly:

Does this mean that one can have two entangled particles, separated by light years of space (one on earth, one on, say, Andromeda-5) and change the spin of one (therefore instanteously changing the spin of its partner) and therefore have the makings of an instanteous communications system?

No. You can measure one particle but you can't control what you'll find, which means you can't use it to purposefully transmit information to someone in the presence of the other entangled particle.

Andromeda-5?? Andromeda is a galaxy (M31, about 3 million light years away), not a star; it won't have a "fifth planet."

"Spooky action at a distance" has already been used for untappable communications, but not FTL. Even if it would work, you'd have to get one of the paired particles to the other end, which presents certain practical difficulties.

(Sorry, didn't mean to post anonymously; 12:23 AM message is from me.)

Wheeler and Feynman touched on this by pointing out that a positron can be the equivalent to an elctron going backwards in time.

M-theory. The expanding universe is nearly large enough for dimensions 5, 6, 7 and maybe 8 to uncurl explosively. Sproing! That is why the expansion is accelerating. Quantum entanglement isn't very interesting when you consider what will happen to property values after the extra dimensions uncurl.

From what I've read, you can't transmit meaningful information by quantum entanglement.

Now open up a tiny wormhole and shove a few particles through it, and you've got a communications link that'll work anywhere in the universe. Open it big enough to shove more particles through it, and you can use it to move power around. Then you can do neat things like build and launch cheap rockets with the propellant being water or something and the energy coming in from a large bulky power source (that doesn't have to be lifted) through the wormhole.

Supposedly you'd need to turn the mass of Jupiter into "exotic matter" to open up one big enough to walk through, but even tiny ones would be amazingly valuable...