Loki Posted August 18, 2003 Share Posted August 18, 2003 I didn't know whether to put this under Relativity or Quantum mechanics... so hopefully it fits here... I was reading The Elegant Universe just now and one sentence stated that the theory of relativity and quantum mechanics cannot both be correct. I have heard this from many other sources too. What I want to know is why. In Bill Bryson's A Short History of Nearly Everything I read how some scientists sent two particles 6 miles apart from each other. After making one spin, the other spun in the opposite direction accordingly and instantaniously. This is how I understand this situation: The "data" (or spin) from the first particle was "sent" to the other particle to tell it to spin in the opposite direction. This mysterious "data" traveled instantaneously--faster than the speed of light, which leaves us with a paradox between two fundamentally sound theories. This is my understanding of the situation and I was wondering if I'm "right on" or "off-target." Also, this is the only condradiction I've heard of between the two theories, wouldn't there be more contradictions if all these sources claim that "they cannot both be correct?" I'm pretty uneducated in this field, so feel free to bash my argument to pieces =D Link to comment Share on other sites More sharing options...
Snorlax Posted August 18, 2003 Share Posted August 18, 2003 Nothing can travel faster than light, so it's impossible for "information" to travel from one place to another instantaniously. But relativity and quantum mechanics are not consistent at small scales, from what I understand. At small scales, at about the Planck length, relativity breaks down and quantum physics takes its place completely. I am not really good with physics yet also, so you maybe ignore my comments completely. Link to comment Share on other sites More sharing options...
JaKiri Posted August 18, 2003 Share Posted August 18, 2003 It's general relativity and quantum mechanics that have the problem, not special relativity. The effect you've quoted is called 'Quantum Entanglement', which is perfectly consistent with c being the upper limit for information exchange. The contradiction between GR and QM comes from the quantum fuzz that exists in all space; if we assume both are accurate and then work out what would be happening in the universe, we find out that we just get a chaotic array of gravitational forces all over the place, which obviously isn't happening. Link to comment Share on other sites More sharing options...
fafalone Posted August 18, 2003 Share Posted August 18, 2003 Also information can be transmitted at superluminal velocities through a group of particles... the group velocity can be faster than light; but none of the individual particles ever exceed c. Link to comment Share on other sites More sharing options...
YT2095 Posted August 18, 2003 Share Posted August 18, 2003 agreed, C cannot be exceeded rellative to imediate surroundings, but if the surounds are moving also then the combined speed may well exceed c. the space surrounding a black hole travels at near c, if you in your ship traveled at near c IN this space, no rules would be broken and your velocity would indeed exceed c to the outermost observer Link to comment Share on other sites More sharing options...
JaKiri Posted August 18, 2003 Share Posted August 18, 2003 c cannot be exceeded relative to any other object. Link to comment Share on other sites More sharing options...
blike Posted August 18, 2003 Share Posted August 18, 2003 loki, greene states, "On ultramicroscopic scales, the central feature of QM--the uncertainty principle--is in direct conflic with the central feature of GR--the smooth gemoetrical model of space (and of spacetime)." (page 129) If you check the notes section he talks of equations yielding infinite when GR and QM are merged. He also talks about (in the notes section) how some infinities (in physics) could be done away with a tool known as 'renormalization', but the infinities that arise when GR and QM are merged are "far more severe and are not amenable to the renormalization cure". Link to comment Share on other sites More sharing options...
JaKiri Posted August 18, 2003 Share Posted August 18, 2003 Ninja blike strikes again Link to comment Share on other sites More sharing options...
YT2095 Posted August 18, 2003 Share Posted August 18, 2003 Stir a cup of coffee that has some bubbles on top, what happens? centrifugal force SHOULD send them to the edge of the mug, but they fall in to the middle, the bubbles can`t move by themselves to the middle, the vortex pulls them in independant of gravity. flying at 90% c in space moving at 20% c will give you an outside velocity of 110% C, no laws are being broken! you`re still traveleing at 90%c in space your flash light on board would still not travel any faster than C either. that is the ONLY way C can be exceeded. it has also been done in lab tests using modulated HP lasers sending signals back in time by effectively breaking C, the beam was sent in a spiral and powerfull enough to generate its own gravitational pull (only slight) but enough to send signals back in time! Link to comment Share on other sites More sharing options...
JaKiri Posted August 18, 2003 Share Posted August 18, 2003 There's no such thing as 'centrifugal force'. Centripetal, yes. I also have no idea what that comparison is trying to say. I also have no idea how you think that argues with my last statement. Link to comment Share on other sites More sharing options...
Guest Syntax Posted August 18, 2003 Share Posted August 18, 2003 Has anyone ever 'really' done anything with quantum mechanics(probably a stupid question) or has it just been research? Do you want the question to stand (in which case 'most of electronics' would have to be my reply) or not? - MrL_JaKiri Link to comment Share on other sites More sharing options...
Guest Syntax Posted August 18, 2003 Share Posted August 18, 2003 wtf... someone delete that last message, that isn't even me... any messages from this name in the last week or so isn't from me so ignore them. Link to comment Share on other sites More sharing options...
YT2095 Posted August 18, 2003 Share Posted August 18, 2003 yeah ok, my spelling maynot be upto snuff today, my bad. C cannot be eceeded, this is a true statement. However without breaking any of Einsteins laws, it is possible to travel faster than C in using a coupled effect in high grav circumstances (a black hole or the likes) time and space are rellative, if SPACE is moving at near c and you`re moving WITHIN that space at near C the net effect is greater. but ONLY where space itself is warped! hope that makes some kinda sense a bit? Link to comment Share on other sites More sharing options...
JaKiri Posted August 18, 2003 Share Posted August 18, 2003 I can't remember my GR enough to comment. Link to comment Share on other sites More sharing options...
Loki Posted August 18, 2003 Author Share Posted August 18, 2003 Does YT always ramble on about relativity even if it has nothing to do w/ the original topic? Link to comment Share on other sites More sharing options...
Sayonara Posted August 18, 2003 Share Posted August 18, 2003 Originally posted by Loki Does YT always ramble on about relativity even if it has nothing to do w/ the original topic? Thread title: "Relativity and Quantum Mechanics Condradictions" Link to comment Share on other sites More sharing options...
alt_f13 Posted August 19, 2003 Share Posted August 19, 2003 Question. If space was travelling at near C, as was the ship inside, how would we view the ship? Edit - I think what I mean to say is, how would the ship be moving relative to us? Like a boat in a river going below the speed of light reletive to its current but faster relative to the shoreline (us)? Link to comment Share on other sites More sharing options...
newbie Posted August 20, 2003 Share Posted August 20, 2003 An interesting thing to note here would be the impulse of electricity. It is at least to be said as fast as c--or even greater. Also there is such a think as Centrifugal force. It is similar to Centripetal Force but is a measuring of coordinates with respect to a rotating coordinate system. Link to comment Share on other sites More sharing options...
Sayonara Posted August 20, 2003 Share Posted August 20, 2003 Iirc the average velocity of electrons in a circuit is usually quite low. Actually, you'd think I'd know the exact calculation by heart considering who I ultimately work for. In physics at school they beat the word centrifugal out of us with canes Link to comment Share on other sites More sharing options...
Dudde Posted August 20, 2003 Share Posted August 20, 2003 figures those UKers would just try to hide the existance of it from their people... Link to comment Share on other sites More sharing options...
YT2095 Posted August 21, 2003 Share Posted August 21, 2003 Loki, I`m sorry that you perceive it as rambling my point was merely that there need not be any contradiction between the "faster than light occurance" in your original post. I beleive this faster than light (reverse time travel) was 1`st acomplished at a university somewhere in Australia last year. A research institute in Germany did a limilar thing using lasers to accelerate particles that "broke" light speed also. An there is also another man (a Black guy, forgot his name) that has actualy built a working "time machine" nothing is contradicted though! Light speed is still a constant! the movement of space (hi grav) isn`t however (not that we know to as yet anyway). the catch with these machines is that a "message" can only ever be sent back to the time the machine was 1`st switched on. anyway, If it pleases, I`ll leave this thread now. Link to comment Share on other sites More sharing options...
swansont Posted October 4, 2003 Share Posted October 4, 2003 Loki said in post #1 :I didn't know whether to put this under Relativity or Quantum mechanics... so hopefully it fits here... I was reading The Elegant Universe just now and one sentence stated that the theory of relativity and quantum mechanics cannot both be correct. I have heard this from many other sources too. What I want to know is why. In Bill Bryson's A Short History of Nearly Everything I read how some scientists sent two particles 6 miles apart from each other. After making one spin, the other spun in the opposite direction accordingly and instantaniously. They didn't cause the particles to spin - they already had spin. What they did was measure one particle, and instantly knew, because the particles were entangled, what the spin orientation of the other particle had to be. This is because the spins had to add up to some value. Link to comment Share on other sites More sharing options...
swansont Posted October 4, 2003 Share Posted October 4, 2003 fafalone said in post #4 :Also information can be transmitted at superluminal velocities through a group of particles... the group velocity can be faster than light; but none of the individual particles ever exceed c. I think that's phase velocity you mean. The phase relation between individual waves can exceed c, because there's no information there. It's the group, or wave packet, that cannot exceed c. The popular phrase that "nothing can exceed c" is a simplification to the point that it's wrong. Link to comment Share on other sites More sharing options...
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