So, apparently the scientists managed to succesfully teleport the states of the qubits, but fuck me, i have only very very misty idea, what that means and no idea, what are the implications of this discovery...
heres the link:
http://www.engadget.com/2011/04/18/first-light-wave-quantum-teleportation-achieved-opens-door-to-u/#disqus_thread
can somebody in laymans terms explain what happened and what it means for the future? Did they basically dicovered the Heisenbergs compensator from Star Trek?
You take a light particle (in this case) and then take the quantum information that identifies that particular particle of light--call it a vibration--and place another particle of light near it. You mix them until both particles are resonating exactly the same--which makes them into identical particles and then you take one of those particles across the room and make changes in the original. The particles are what scientests call "entangled"--each having the same information.
This is the sort of experiment that's been done successfully before.
Now they take a beam of light and shine it across the room to a fiber optic conduit or some sort of light storage medium and then turn off (destroy) the source of the light. On the other side of the room, the original light particles still exist and behave exactly like the original even though the original was destroyed.
They need this for quantum computers. Its like RAM memory sort of. Information is written, used and then overwritten for new information--but while still stored on the computer.
Sort of like your RAM and CPU do all sorts of processes which create a result and then that result can be saved to your hard drive.
They need light particles for quantum computing because quantum particles (qbits, etc.) are easily disturbed and interfered with and hard to see and read results from. A wire has impedance and molecular and atomic irregularities that would basically make quantum information too interfered with to be useful.
By being able to pass beams of light, no wires needed and by being able to turn them on and off while still saving them to a form of memory means you have the building blocks for quantum computers.
A lot more to it but this is a really dumbed down analogy. I've been reading on it for years and it still is near incomprehensible to me. As a comfort, Einstein had problems getting it too when it was first explained to him. That's where his, "God doesn't play dice with the universe!" quote came from.
This experiment used in part what Einstein defined as "spooky action at a distance".
Regarding the Heisenberg principle--it still stands. One day we might be able to get around it but it can't be violated. The same as nothing can acelerate to the speed of light but there are ways to go faster than it. Ukrainian scientists have actually taken a photo of the "electron cloud" around a carbon atom and it is just that--a cloud. All the places an electron could possibly be exist simultaneously and instead of seeing "an electron" you see a fuzzy cloud of their possible positions. It's enough to make you mad.
Here's Wikipedia's summary of the "double slit light experiment"...
In between times (from the light source across the distance to the double slot blind) it (the light particle) is completely out of sensible interaction with the things of our universe, out of sensible interaction with the macro world. What is going on in the apparatus is something that is not known.
It is perhaps not so astounding that one knows nothing about what a light particle is doing between the time it is emitted from the sun and the time it triggers a reaction in one's body, but the remarkable consequence discovered by this experiment is that anything that one does to try to locate a photon between the emitter and the detection screen will change the results of the experiment in a way that everyday experience would not lead one to expect.
If, for instance, any device is used in any way that can determine whether a particle has passed through one slit or the other, the interference pattern formerly produced will then disappear.
In layman's terms: If you watch the experiment and try to observe the light between the source and the target, it makes the light behave differently when it reaches the target. Go figure.
Easy, I do that everyday at lunch !
Lol....*slap.
This all means they will come a time when communication bandwidth won't matter, in the sense pings below 5 for all locations regardless of whether u r playing sins from pluto. This technology could connect ISPs all over the world and create a new lighting fast quantum broadband.
Thread necro aside , that won't work. Sinperium is mostly right, except for one important thing. Messing with the original particle does not directly change the other entangled particle. It actually breaks the entanglement. Likewise, you can't use quantum teleportation to communicate at the speed of light. For one thing, you need to get the 2nd entangled particle to Pluto (or wherever) in the first place. Once you do get it there, because of how quantum mechanics works, the 2nd particle can either be a negative or positive image of the 1st. You have no way of knowing whether it is positive or negative without finding out what the 1st particle looked like.
I probably did a poor job of explaining that, so I suggest you read this: http://io9.com/5584356/can-i-build-an-ansible-to-communicate-across-the-cosmos
It's two actually; you've got one, and here's the other one:
It can't be used for what would end up being FTL comm (ping of 5 between Pluto and Earth?!), as that would violate causality.
As is understood by current physics models. It's the same reason why FTL propulsion is generally considered a non-starter; it violates causality as it becomes time travel. One of the most basic ways to explain the brain-hurting problems of causality violations is the Grandfather Paradox.
Google/Wiki it.
That said..............there are theoretical manners in which one might be able to bypass causal violations via FTL devices (propulsion=communications for the purposes of causality). They generally hurt my brain.
Well, yes, that's what I tried to get into with the part about not being able to use quantum teleportation to communicate at the speed of light. Really, the two problems are interrelated, and that link I gave does a much better job of explaining it (and from a real physicist! ).
Well, yes, there are theories, in the sense that someone came up with an idea . Most serious physicists, however, regard them as little more than interesting thought experiments at best. Most of them require rewriting the laws of physics, when the current ones we have pass every test we throw at them, and are therefore much, much more likely to be correct.
Silly me for not reading the link then .
Well, yes, hence why I referenced "theoretical", "might", and "generally hurt my brain" when I wrote that.
I still think it's a pity that we're likely to never have FTL-anything. Oh well, I suppose.
I suggest that you do. It's very interesting. He does a semi-annual column where he answers physics questions. It's really cool.
Entanglement is a key part of quantum teleportation, and there is alot of uses for entanglement (not to mention it's wierd and worth studying on that note alone). However, I wouldn't really say that a quantum computer uses quantum teleportation (which is what the original post was about). Entanglement is a key to both, so studying entanglement in any form will be helpful for the understanding of the entire phenomena, which I think is what Sins-Imp was getting at.
The other point about using it for communications is valid, but as pointed out, cannot violate the speed of light. Which makes it a rube goldberg machine if used strictly for that purpose. However, if you do use it for communications, it is a very secure way of communicating, and that is the real benefit.
As far as teleportation, it might be possible, but that is a long, long way off and wouldnt be any faster than the speed of light anyhow. The general idea here is that you 'scan in' the object with entangled particles, which would destroy the original object. With the other set of entangled particles, you could then 'scan out' the original object. The entanglement is what is carrying the information about the original object to the new location. However, it does not violate the speed of light because if i 'scan' you in, i have to send a message to the guy on pluto to 'scan' you out. There are numerous clever ways to try to violate this, but theres always a catch that it does not work out faster than the speed of light. Also, if the guy on pluto trys to 'scan' you out before i 'scan' you in, he will destroy the entanglement that makes the whole thing work, and when i 'scan' you in, you will be destroyed. There have been some successful teleportations, but nothing approaching the level of a visible object. I think the best done so far was 1 atom and only a tiny distance.
The reason its so hard is that whenever something interacts with the entangled particles, it destroys the entanglement; and there is alot of particles going around that can do this destruction.
Here's an article about how much is possible to entangle at this point:
http://www.sciencedaily.com/releases/2011/04/110401085103.htm
entanglement cuts right to the heart of quantum wierdness, so dont be put off if it doesnt make sense. It doesnt make sense to anyone, some of us just understand that is the way the world works.
There is a limit to what you can do but you can "transmit" changes across unlimited (theoretically) distance. Doing so requires the destruction of the original entangled particle. Yes, you would have to get the particle out there in the first place.
There are some promising theories on using quantum entanglement for communication but recent research suggests it may be limited to the speed of light and it's possible that distance can corrupt the entangled information--either by degradation or interference.
I personally think it's more than a thought experiment--I really think these will be cornerstones of future tech.
Einstein was challenged by quantum theories and his initial response was to think the theories were incomplete and would be proven incorrect--i.e., "God doesn't throw dice".
Look back historically at all the "impossible" things that are now being done: invisibility, computers, space travel, etc., etc. Experts of their day wrote volumes in each case about how these things just could never be practical.
To quote the bible:
The LORD said, "Behold, they are one people, and they all have the same language. And this is what they began to do, and now nothing which they purpose to do will be impossible for them. Genesis 11:6
This has pretty much proven true throughout human history--except for the alchemy stuff.
That was a good summation up there SithLord. Curse yoooou! (I should have read it first...oops)
Do some reading on "entangling already entangled particles with other entangled particles"--you start seeing some potential.
I read up on alot of this stuff. Physics is fascinating, especially quantum mechanics. I've been teaching myself calculus so that I can learn more about physics. Calculus is much easier than most people think, especially if you're teaching yourself. It gets hard in class when you have to work out a really intense problem. I didnt know any of this in high school, and I feel cheated now that I see how simple the concepts are.
It's interesting how people latch on to these things that are years away from making usable tech that they see in sci-fi shows; and dont really care about all the stuff we already know so well, that are equally complicated and mysterious. One thing I'm really hoping to understand at the fundamental level is magnetism. My general understanding is that it is a consequence of relativity and the electric force, but exactly how? I dont know. How is light propagating to cause this effect? Well, its not something you can just look up and understand. It requires looking at the equations and deriving meaning from it. If more people had this desire for understanding the cause of the effect, I think topics about the 'future tech' stuff could be more detailed and they could really contribute to the advancement of these topics. It also gives you an appreciation for the complexity of the world. As it stands, these articles are greatly 'dumbed-down' to try to explain it to people who come in with a bias that it will be extraordinarily difficult to understand. And it's too bad it has to go down that way.
If anyone is interested in learning calculus (or any math for that matter), I highly recommend www.khanacademy.org as a starting place. If you're interested in classical physics, I recommend MIT's Walter Lewin lectures. If someone has a link for a full-fledged quantum physics course online, I would be greatly intrigued.
Regrettably, I don't remember the exact source or substance, but a few months back I read about a breakthrough (possibly) theory on "what" exactly magnetism might be. It explained a lot of the conundrums. There have been a slew of breakthroughs regarding magnetic materials and the like lately.
I draw the line at pure mathematics. Tools of satan! Besides, my brain is too sharply honed in esoteric pseudoscientific genius to step down to mundane realities.
What's really neat about science fiction is it generally dispenses with the proven "how" and jumps straight to "what". Fascinating how routinely scifi has put the finger on future tech far before it was ever even considered to be practical or possible.
And since a mind is a terrible thing to waste and you like math (I think I threw up a little there) I wanted to make sure you knew that M.I.T. has opened up most of their curriculum as OpenCourseWare...which means you can take the classes online fre of charge (just no credits given and no help provided).
I think that's very cool though thinking about it makes my brain hurt.
On a purely narcissistic note, when I was sixteen, I worked out a pen-and-paper science fiction empire game and part of it was developing a rationale for jumping between stars. I didn't know until a couple of weeks ago that I duplicated (without math but rather intuitively) the very device used by Jerry Pournelle and S.M. Stirling for their CoDominium series stories.
To get theirs worked out, they asked a rocket scientist at JPL to develop a rational star drive for them. He came up with the "Alderson Drive" and my own invention was based on the same basic ideas--relative stellar luminosities and radii determined "jump points". I remember hating using luminosity as it seemed so unrelated to warping space but I just kept feeling it was 'the way to go".
Man, I am a pseudogenius.
When I was younger, I thought it would be a good idea to make a giant ring in orbit big enough to fly a ship through that would accelerate it via magnets when it flew through the center. obviously, you'd have to magnetize the hull as well, but since you're in orbit and the ring is in orbit, you'll circle around back to the ring again (this time in a higher orbit, obviously). I figured you could build up alot of speed that way before you leave earth orbit. I've never run the numbers though. Looking at this now, I'd guess that the mass of the ring would have to be very close to the mass of the ship in order to avoid mis-matching trajectories on the second pass and avoid as many corrections as possible. They could call it a 'stargate' just for kicks .
The math is not that difficult if you just want to get an understanding of what is going on. It's when you actually have to make a calculation that it becomes a difficult subject
You could build accelerator rings at carefully placed spots but the planets used to slingshot provide way more energy than a manmade ring would--and a lot cheaper too.
On the other hand, if you built a 15-20 mile long maglev track and angled it up the side of a high mountain at it's end, you could boost payloads into orbit every few minutes with ease.
My thought on all the "stimulus" money that was spent in 2008 is that it would have been better put into something like this and then take industry to space. Would have provided a new industry and jobs easily into the next century.
Nasa proposed years back a scheme that would allow solar collectors on the moon to beam energy back to earth orbit and then down to earth from orbital collectors. Now we can mass produce much more efficient or economical collectors cheaply and we could fill orbital space with them.
Instead, we'll stay down here and just play until the next planet killer lands on us.
Here's the link to the 2000 free M.I.T. courses online which include physics courses: http://ocw.mit.edu/index.htm
... I linked the MIT open courseware in my post . I just specifically pointed out Walter Lewin's physics section (name of the course should be re-named "The Force of Walter Lewin").
The setup I explained only used one ring for the reason that once you get to a high enough orbit, you can use a gravitational slingshot as well. Having multiple rings, the best method is a railgun approach, as you explained. I thought it would be pretty shaky to try to thread so many needles, so having 1 ring that orbits in the opposite direction would minimize this problem to twice per orbit. This strategy could definitely work, the question is do you get enough propulsion to make it worthwhile? And my thinking is no. While it would save having to carry a bunch of fuel, the propulsion is probably very small and would take too long. You would probably still have to carry some massive batteries to get the magnetic field to a high enough strength
They did? I'd like to see a book about computers being impossible . I'm not really sure that space flight was considered impossible either (well, after the invention of gunpowder). I think the general assumption was that with a rocket big enough you could go to space. I mean, there's that legend of the ancient Chinese Emperor who strapped a bunch of rockets to his chair to try to go to space.
In any case, the "people at one time thought technology X was impossible, but now we have technology X" isn't an argument to say that faster than light communication or teleportation or whatever will be possible. Unless you can see the future, you can't possibly know which technologies will pan out and which will never happen. Just because sometimes past theories are wrong doesn't mean that they always are wrong.
I'm confused about your confusion . For one, I'm not sure what you think light has to do with it (aside for light being part of electromagnetism). Essentially, most subatomic particles have a quantam mechanical property known as spin. The spin of a particle determines it's magnetic (dipole) moment. The electron dipole moment is what causes the magnetism of permanant magnets and such.
The other way to get magnetism is to move electric charges. Usually, that means electrons in a current-carrying wire. This is where you get into electricity and magnetism being linking. The spinning of electrons create a magnetic field. Essentially, all magnetism is the product of moving/rotating charges.
I suggest you read these:
http://io9.com/5620547/ask-a-physicist-what-ever-happened-to-magnetic-monopoles
http://io9.com/5713560/what-the-hell-is-spin?
The first is primarily about magnetic monopoles (only a south pole, or only a north pole, not both like other magnets) and the second explains spin much better than I can. Of course, neither the articles or my explaination deal with the math and stuff, but it should help you out.
i dont think your getting the idea that both the ring and the ship are moving at the same speed in opposite directions so that they meet back up every half-orbit. But its okay... I can't build it and it wouldn't work very well.
Anyone want to talk about teleporting? eh?
Well, ultimately magnetism has to boil down to electrons and light. Yes, spin is the 'magnetic' part of the electro-magnetic force. My understanding is that magnetic fields look and behave just like electric fields from a moving frame of reference. However, this alone doesnt tell you how a magnetic field arises.
My guess based off this understanding is that the electron, moving in particular fashion, propages a shift of some kind in the electro-magnetic field (which is just light due to vacuum fluctuations). It seems to me the topology of this shifting is what makes the field a magnetic field instead of an electric field, but I don't know for sure.
Magnetism so far as I can tell is just an expression of the movement of electrons... Of course, my high school physics teacher didn't like dealing with anything subatomic, so he skimmed the sections more than I'd have liked...
If you go by the theory that all mass is simply light that has locked itself into effectively chasing its tail, then so far as I can tell, that's the field given off by the compression of the electric field coming straight out of the photon as it chases itself (or vice versa, I don't really know). Electromagnetism is never something I've completely understood...
As for FTL, I'm assuming its possible in some bizarre way, so FTL communication is probably possible somehow (so long as its on the nano scale). As for actual trasportation, that's another thing entirely... The book I'm writing (which is science fiction) depends on the idea of multiple universes and the ultimate ability for humanity to create smaller ones which can travel exterior to the primary universe. Think bubbles in a bathtub. If you pinch one bubble off, it can join another bubble or reattach to the first one. According to an extension of string theory, if you were to focus enough energy into a small enough area, you would rip space-time. What happens after that is anyone's guess. My book says FTL Now of course, this leads to all sorts of weapons (if you can rip space-time, you can start doing all sorts of fun things to your enemies). Alas, this isn't a speculative physics thread, so I'll stop now. The point is, in the book, I mention how since the present day, there have been three major physics overhauls (discounting the theory of quantum gravity which I have pegged at happening sixty years from now). The first allows for bussard scramjets (2500's), the second allows for more or less a warp drive (3000's), and the third allows for the FTL I just mentioned (3300's).
Physics overhauls aren't that unlikely if you think about it. As instruments become more and more precise, it may happen that data points don't line up. For that reason, I see no reason why FTL should ultimately be ruled out.
To Sinperium's comment regarding the stimulus money... I actually did my term paper on that, and after a couple months of research, I can definitely say some sort of linear accelerator would have worked better for the country in the long run.
Sorry about jumping around... I love threads like this because of their topic, but hate them because of their continuity, so I tried to stay mostly on topic...
@kygore...pfft!
JK. Quantum tunneling is what really makes computers possible. The idea of a particle potentially existing on either side of a barrier simultaneously and be "told" where to be would have been roundly laughed at a century ago.
I forget the exact year but the head of the British Academy of Science around the turn of the century proclaimed space travel, "impossible" and it was precisely because of gunpowder that he assumed this.
My point isn't that scifi picks the winning bets and the law of averages is what always makes it pay out--its that scifi often invents the very thing that ends up being bet on much, much later.
I claim this topic as my own anyway! The guy asked the question, I was the only one who answered and he never came back--then after sitting with only my reply, other people dug it up. Victory is miiiiiine and all your thread belong to us now.
I have returned to claim my right over this very thread!
I am sorry for not responding to your answer, as i visit the boards only sporadically recently...and then it got lost under lots of other threads, until i rediscovered it now. Anyway thanks for your response, it cleared a few things to me. Now i need to read the rest of the thread, seems quite interesting reading.
BTW recently i read, but cant get the link right now, there has been another breakthrough made in regard to quantum computer, i reckon it had to do something with discovery of the means of storage of entangled particles without breaking them...
EDIT:
so i think i found it, it was probably this:
http://www.sciencedaily.com/releases/2011/07/110720142123.htm
its probably not quite the same what i described, but it does not matter now
The above article is indeed a big breakthrough for quantum computers. What they are talking about is they found a way to resist decoherence with large collections of particles, which is essential to scaling up to a full computer. You can't really compute much with just 1 particle and the more you add, the harder it is to prevent the breaking of entanglement. This is useful for a teleporter as well, as to teleport any large object you would need a ton of entangled particles.
For an electron to change its direction/speed, it has to emit/absorb a photon. With that qualification, things are 'magnetic' due to the way the electrons move in the electro-magnetic field (which is a sea of photons).
Actually, concentrating energy to rip spacetime is a consequence of Einstein's General Theory of relativity, String Theory is just consistent with GR. Mass = energy, through E=mc^2; So when you concentrate alot of mass in a small amount of space, what do you have? A black hole.
Now, there are actually several different ways of creating a multiverse; the bubble method is the idea that the expansion rate of the universe is based off a value. As space expands, it 'copies' this value to the new space created. However, due to quantum fluctuations, it's not always uniform. So, a new value might appear that then 'copies' itself into new space, which spreads this new expansion rate around. Assuming there are a couple different expansion rates going on, 1 universe is the space at a particular value of this expansion rate, which is separate from other values.
Like I said, I've never really understood electromagnetism.
I was referring to one specific case where they think you wouldn't just create a black hole, but yes, under normal circumstances, you would create a black hole. Which brings me to a question...
What actually happens with spinning or electrically charged black holes? Whenever I've read articles describing black holes, the physicists always conveniently say, "we'll talk about non-spinning, uncharged black holes because they are simpler." What actually happens when they are those things? I heard once that if spinning, the singularity will actually turn into a circle. Whether they meant a ring or a two-dimensional object, I wasn't sure, but.. I've just always wondered. I've also wondered how a black hole can even be magnetic because some show on the discovery channel (I think it was Through the Wormhole) actually said they even eat magnetic fields...
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