Mon Apr 30, 2012, 01:16 AM
MindMover (2,798 posts)
Quantum teleportation achieved over ten miles of free space
Last edited Mon Apr 30, 2012, 01:19 AM USA/ET - Edit history (1)
Quantum teleportation has achieved a new milestone or, should we say, a new ten-milestone: scientists have recently had success teleporting information between photons over a free space distance of nearly ten miles, an unprecedented length. The researchers who have accomplished this feat note that this brings us closer to communicating information without needing a traditional signal, and that the ten miles they have reached could span the distance between the surface of the earth and space.
As we've explained before, "quantum teleportation" is quite different from how many people imagine teleportation to work. Rather than picking one thing up and placing it somewhere else, quantum teleportation involves entangling two things, like photons or ions, so their states are dependent on one another and each can be affected by the measurement of the other's state.
When one of the items is sent a distance away, entanglement ensures that changing the state of one causes the other to change as well, allowing the teleportation of quantum information, if not matter. However, the distance particles can be from each other has been limited so far to a number of meters.
Teleportation over distances of a few hundred meters has previously only been accomplished with the photons traveling in fiber channels to help preserve their state. In this particular experiment, researchers maximally entangled two photons using both spatial and polarization modes and sent the one with higher energy through a ten-mile-long free space channel. They found that the distant photon was still able to respond to changes in state of the photon they held onto even at this unprecedented distance.
However, the long-distance teleportation of a photon is only a small step towards developing applications for the procedure. While photons are good at transmitting information, they are not as good as ions at allowing manipulation, an advancement we'd need for encryption. Researchers were also able to maintain the fidelity of the long-distance teleportation at 89 percentó decent enough for information, but still dangerous for the whole-body human teleportation that we're all looking forward to.
Poll: Is teleportation possible for humans ?
18 replies, 1799 views
Quantum teleportation achieved over ten miles of free space (Original post)
|Electric Monk||Apr 2012||#7|
Response to Zalatix (Reply #6)
Mon Apr 30, 2012, 03:52 AM
nilram (1,286 posts)
15. File the paperwork. It's gonna get used for either an expensive medication
(for eating disorders?) or for the name of an evil space alien in a sci-fi series. Either way, you and your lawyer will be rich.
Response to Zalatix (Reply #1)
Mon Apr 30, 2012, 02:53 AM
nadinbrzezinski (120,390 posts)
9. Star Trek has been using it since the 1960s
a lot of the science was worked up with NASA at the time. Why WARP is theoretically possible... as soon as El Cubierre solves the little problem with energy...
Response to Electric Monk (Reply #7)
Mon Apr 30, 2012, 03:03 AM
brettdale (7,178 posts)
10. Im more excited by Stephen Hawkings 2010 time travel thing
The doco thing, when he said, physics allows you to travel into the future.
If you build a train track around the globe, and put people in the train, and have them go at
a speed just under the speed of light, if they stay on the train for a week and then get off, it
will be 150 years into the future.
You just need to build a train to go that fast, so its a engineering and economic issue, not a physics one.
It is technically possible to go to the future.
Response to MindMover (Original post)
Mon Apr 30, 2012, 03:27 AM
cthulu2016 (7,946 posts)
12. No intelligible *information* can be sent faster than light
Last edited Mon Apr 30, 2012, 03:31 AM USA/ET - Edit history (1)
The entangled particles contain information about each other but the receiver of one has to know the initial state and transformations of the other... and that knowledge has to be sent at light speed tops.
The universe knows... which is creepy enough.
Response to cthulu2016 (Reply #12)
Mon Apr 30, 2012, 06:50 AM
2on2u (1,843 posts)
18. Faster than light?
Faster-than-light (also superluminal or FTL) communications and travel refer to the propagation of information or matter faster than the speed of light. Under the special theory of relativity, a particle (that has rest mass) with subluminal velocity needs infinite energy to accelerate to the speed of light, although special relativity does not forbid the existence of particles that travel faster than light at all times (tachyons).
On the other hand, what some physicists refer to as "apparent" or "effective" FTL depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal or undistorted spacetime. Although according to current theories matter is still required to travel subluminally with respect to the locally distorted spacetime region, apparent FTL is not excluded by general relativity.
Examples of FTL proposals are changing the "frequency" of mass to a higher state by applying high-frequency waves of energy, the Alcubierre drive, and the traversable wormhole, although the physical plausibility of some of these solutions is uncertain.
Response to MindMover (Original post)
Mon Apr 30, 2012, 03:39 AM
longship (17,711 posts)
14. Transwarp beaming is right around the corner!
I can hardly wait.
BTW, Simon Pegg was brilliantly cast as Montgomery Scott in Star Trek XI (except for the cartoonish, kids' toys to follow, alien companion). A definitive Scotty of which Doohan would be justly proud.