Big Head Press Forum

Online Comics => Escape From Terra => Topic started by: Sean Roach on November 15, 2008, 08:31:07 pm

Title: "Tanglenet"
Post by: Sean Roach on November 15, 2008, 08:31:07 pm
So...  just looking at the name of the network...do they have FTL communication?
Title: Re: "Tanglenet"
Post by: Leviathan on November 16, 2008, 09:09:52 am
Yeah, given their e-gold account was in panama, and the account transfer was virtually instantaneous, in the earlier strip?  I'd have to say the only way to negotiate an encrypted connection and process a transaction like that at interplanetary distances in less than probably twenty minutes depending on how far they are in their respective orbits (if they're on opposite sides of the sun, they'd need a relay and each phase of the networking handshake could take close to 20 minutes, talk about lag) is FTL.  Though I might suggest that "tanglenet" could both describe what a network topography would look like in a free market, and quantum entanglement.

We're actually not too far from FTL communication, right now.  I read an article some months back where a team had figured out how to induce entanglement in two particles, separate them, and then both input and read out the quantum states to transfer information truly instantaneously.
Title: Re: "Tanglenet"
Post by: KBCraig on November 17, 2008, 01:54:55 am
A-ha, "faster than light".

I was wondering what the heck FTL (http://www.freetalklive.com) had to do with this story line.  ;D
Title: Re: "Tanglenet"
Post by: Rocketman on November 17, 2008, 08:29:28 am
Leviathan:
     Makes me wonder if that could be the basis of telepathy?
Title: Re: "Tanglenet"
Post by: SandySandfort on November 17, 2008, 09:47:59 pm
So...  just looking at the name of the network...do they have FTL communication?
Tanglenet is short for Quantum Entanglement Network. Current quantum physics holds that quantum entanglement cannot be used to transmit classical information faster than the speed of light. But my mumbo-jumbo, hand waving and invocation of "Information Mechanics" says otherwise.
Title: Re: "Tanglenet"
Post by: enemyofthestate on November 21, 2008, 10:18:21 pm
Tanglenet is short for Quantum Entanglement Network. Current quantum physics holds that quantum entanglement cannot be used to transmit classical information faster than the speed of light. But my mumbo-jumbo, hand waving and invocation of "Information Mechanics" says otherwise.

OK.

Instantaneous communication (or any FTL communication for that matter) would enable the Cereans (Cereals :-) to send message back thru time.  Simultaneous is not objective.  It depends on the frame of reference.

We're actually not too far from FTL communication, right now.  I read an article some months back where a team had figured out how to induce entanglement in two particles, separate them, and then both input and read out the quantum states to transfer information truly instantaneously.

Unless John Cramer's assumption of non-linearity in QM is true (there is no evidence yet) it is not "communication" until you compare the state at both ends.  So you maybe able to change the state of the entangled system FTL but you decode any information sent STL.
Title: Re: "Tanglenet"
Post by: Leviathan on November 22, 2008, 10:39:54 am
*quickly moves around your quote tags*
OK.

Instantaneous communication (or any FTL communication for that matter) would enable the Cereans (Cereals :-) to send message back thru time.  Simultaneous is not objective.  It depends on the frame of reference.

Assuming similar relative velocity, and a position equidistant from both ends of communication, one would be able to establish what simultaneity is by having a station or something equidistant to two points transmitting lightspeed to the two points.  By the relativity, afaik.  I really don't understand why there's an insistence that FTL would allow time travel or temporal communication.  It'd just render two distant locations as in the same frame, or if one is moving at relatavistic velocity relatively the same frame.  And if the math says instantaneous communication would allow you to communicate "back in time", I'm relatively certain that's an artifact of the math.  Just because point B in frame B, assuming sufficient magnification, is observing a location with a time delay doesn't mean FTL communication to that location will occur to the point in time being visually observed.

Unless John Cramer's assumption of non-linearity in QM is true (there is no evidence yet) it is not "communication" until you compare the state at both ends.  So you maybe able to change the state of the entangled system FTL but you decode any information sent STL.

Not sure how that works.  Wouldn't it be possible to "filter" the quantum states for non-random patterns?  If the waveform consistently collapses into set oggledy for duration X, where "noise" would have it only collapse into oggledy only at chance, one could consider that, say, a zero bit.  Then a consistent collapse for duration X of doodly could be a one bit.  Even FTL dialup would be an improvement on lightspeed.

By the way, "preview" shows you if the tags are formatted right.
Title: Re: "Tanglenet"
Post by: enemyofthestate on November 24, 2008, 12:49:59 pm
First the disclosure.  My academic training is in engineering and telecommunications.  I've worked in one field or the other for thirty some years.  I am a dilettante at physics.  That said, I think that the experimental tests of Bell's Inequality disposed of the EPR paradox and there are no hidden variables.  I also think the Michaelson Morely, Kennedy Thorndike, Brillet Hall and some other experiments I cannot recall at the moment reliably establish that the speed of light in vacuum is isotropic and invariant in all inertial frames of reference.  Lately I tend  toward the transactional interpretation of QM but not strongly because it -- well -- feels a little contrived.  The advanced and retarded waves seem too convenient but that may be because I just haven't thought about it enough.  There are people who disagree with my interpretations and you might want to track a few down on Google to get a different take on the subject.

Quote
Assuming similar relative velocity, and a position equidistant from both ends of communication, one would be able to establish what simultaneity is by having a station or something equidistant to two points transmitting lightspeed to the two points.

I'm not sure what you mean here.  Is seems to me you are limiting FTL communication to frames where the difference between the classical and relativistic solutions are undetectable.

Quote
By the relativity, afaik.  I really don't understand why there's an insistence that FTL would allow time travel or temporal communication.  It'd just render two distant locations as in the same frame, or if one is moving at relatavistic velocity relatively the same frame.  And if the math says instantaneous communication would allow you to communicate "back in time", I'm relatively certain that's an artifact of the math.  Just because point B in frame B, assuming sufficient magnification, is observing a location with a time delay doesn't mean FTL communication to that location will occur to the point in time being visually observed.

This comes up periodically in the Physic forums.

The communication backwards in time is a consequence of time dilation which is pretty well tested for both special and general relativity.  The GPS calculations take both into account (http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html) and GPS is used millions of times per day.

To construct a simple scenario for illustration:  Observer A is on Ceres.  Observer B is a relay satellite that simply resends any message it receives to A.  To keep is really simple, the Cereans also have a laser launcher that can push the package from 0 to .866C in a very short time.  The on board drive can produce enough thrust to to maintain the relative velocity against the resistance from interstellar hydrogen and the whole thing is hardened against radiation.  So far it's all engineering

Next add superluminal communication using quantum entanglement meaning the range is, in theory, infinite.

Now they have a time dilation factor of 2 and the clocks have been running that way since shortly after the launch a year ago.

A sends a message at +31,536,000s in his frame of reference. It arrives "instantly" in the B frame where only 15,768,000s have elapsed.  B resends the messages back to A where it arrives instantly at +7,884,000 in the A frame.  The difference is 31,536,000s - 7,884,000s  = 23,652,000. 

The message returns about 273 days before it was first sent.

This is not just an artifact arising from a photon arriving at one end of train before the other in a particular frame.  It is an inevitable consequence of superluminal communication and relativity.

Wayne Throop has some explanations on time dilation that may be helpful.

http://www.sheol.org/throopw/sr-ticks-n-bricks.html
http://www.sheol.org/throopw/sr-twin-01.html

Special Relativity may be incomplete (it is) but it has been tested to several decimal places. In fact, it is probably one of the best tested theories in modern physics.  General Relativity may be incomplete (probaby is) but it has also stood up to intensive testing.

Quote
Not sure how that works.  Wouldn't it be possible to "filter" the quantum states for non-random patterns?  If the waveform consistently collapses into set oggledy for duration X, where "noise" would have it only collapse into oggledy only at chance, one could consider that, say, a zero bit.  Then a consistent collapse for duration X of doodly could be a one bit.  Even FTL dialup would be an improvement on lightspeed.

The states are entangled and undetermined but existent.  So, when you measure a quantity in an entangled system you cause the state to collapse but do not determine what that state will be.  It is randomly "selected" from the possibilities.  If QM is linear, this means the state changes at the "receiving" end will appear to be random too.

Randomness alone doesn't means there is no information.  For example, a perfect one time pad encryption system will generate results indistinguishable from randomness.  There may be information in the gobbledygook but you cannot extract it without the key.  In the entanglement scenario, the "key" is effectively being generated as the encryption is being done. 

BTW, that last characteristic can be exploited for cryptography.

I am one of those who think QM is incomplete and not just because a workable theory of quantum gravity is missing.  There may be be a loophole that will allow for FTL communication.  I read somewhere that John Cramer is working on an experiment to test if "complementarity" can be exploited to send information.  However, so far, the evidence is that nature does play dice with the universe and reserves any FTL telegraph for her own use.
Title: Re: "Tanglenet"
Post by: Leviathan on November 24, 2008, 06:49:14 pm
EotS:
My statement of lightspeed simultaneity between two points was in regards to trying to establish what is and isn't simultaneity.  Not restricting communication to it.  Basically kind of like having a simultaneity arbiter capable of establishing a common referent so both could figure out what "realtime is" in relation to each other.  A hypothetical observer that doesn't even need to be there, just to say that there is a frame capable of observing both at the same time, with the same delay to both, and figuring out from there what that observer would be telling you about what time it is in both locations, heh.  Nothing to do with how you'd carry FTL communication out.

The next bit is I really, really, really don't understand how that works with time dilation if that's the proposed way it works.  What I'd think would happen is the communication from A at +31,536,000s would arrive at elapsed +15,768,000s for B, but communication at elapsed +15,768,000s from B would arrive at A's elapsed +31,536,000s.  Sort of like a temporal doppler effect.

Though if the entanglement were to "drag" rather than keeping the two in the same frame (and thus to cause collapsures in the entangled states to occur at seemingly doublespeed as far as the relativistic travellers are concerned, or half-speed as far as homebase is concerned), this would allow an odd form of backwards communication.  Basically, B sets out at dilation factor 2, travels 80 years round trip subjectively.  160 years would've passed back home.  The FTL node then should then be sending to 80 years earlier back home.

My question is, has anybody actually tried subjecting one pair of an entangled set to relativistic speeds while the other is not, and seeing whether collapsure is still simultaneous from the dilation 1 frame perspective?

The last bit, I could've sworn I read somewhere that somebody'd figured out how to control the quantum collapsure process, to cause collapse to happen in a specified manner with a specified outcome rather than a random outcome.  Probably an outgrowth of the quantum computing efforts if it's happened.  That basically if you performed a quantum computing "calculation" on entangled particle A, its entangled partner B should be experiencing the entangled version of it, and so reading the states out in a similar manner as you would read out the results of a "calculation" would tell you pretty close to exactly what A had been up to.  Thus giving you communication.  Like I say, I have no clue how either are carried out.  Just that I thought I'd read that some working theory had been managed, and when combined with the team that figured out how to induce entanglement pretty much at will that should allow communication.