For those avoiding registration, the BBC also has an story.
My favorite part was the response of John Preskill, the other side of the bet. From the BBC article,
Later, Preskill said he was very pleased to have won the bet but added, "I'll be honest, I didn't understand the talk." He said he was looking forward to reading the detailed paper that Hawking is expected to publish next month.
Physics is a wonderful place, where not even the physicists know what the hell is going on!
They're not the RIAA, but the MPAA does definately look at Bit Torerent. To be blunt, using BT for anything the MPAA has a copyright on while a college network is fairly dangerous. The MPAA seems to run robots which, as best I can tell, find BT servers and check the owner of the network. If it happens to be a school, they generate a nastygram and send it to the computer department, with not so pleasant consequences. This happened to me a few weeks ago, where I was getting a few episodes of Firefly (and uploading at a whooping kB/s, too!)
No, you have to send what the result of the joint measurement was. The result can't be determined beforehand, so there can't be anything faster than light.
The trick is a little more subtle than everyone's making it out to be. There is a sort of faster than light transmission here, what Einstein called "spooky action at a distance" (this is the topic of the somewhat famous EPR paper.)
Quantum teleportation is, however, not faster than light. In the case of the simplest way of preforming teleportation, which uses a singlet state, the process is as follows
1) Two particles (photons, atoms, etc) are put into a state with zero angular momentum or its optical equivalent, polarization.
2) One of these particles is shipped from Alice to Bob. They haven't been measured, so they're still in the zero angular momentum state, called a singlet state.
3) Alice takes a new particle, the one she wants to send, and makes a measurement on both it AND her half of the singlet. By measuring both at the same time, she changes the state of both of then, yet does not collapse the wavefunction.
4) This measurement transfers the state of Alice's particle to be teleported onto Bob's particle. Almost. There are four outcomes of Alice's combined measurement, and there are four possible rotations of Bob's particle. In order to recover the state of the original particle, Bob much preform a certain rotation on his oarticle. Without doing this, the state of the particle, when measured, is the same as if no teleportation had taken place.
So, in short, Alice has to send Bob the results of the measurment which teleported the state in the first place, which is slower than (or equal to) the speed of light, or else no information is transmitted.
Slashdot Mirror
They're not the RIAA, but the MPAA does definately look at Bit Torerent. To be blunt, using BT for anything the MPAA has a copyright on while a college network is fairly dangerous. The MPAA seems to run robots which, as best I can tell, find BT servers and check the owner of the network. If it happens to be a school, they generate a nastygram and send it to the computer department, with not so pleasant consequences. This happened to me a few weeks ago, where I was getting a few episodes of Firefly (and uploading at a whooping kB/s, too!)
No, you have to send what the result of the joint measurement was. The result can't be determined beforehand, so there can't be anything faster than light.
The trick is a little more subtle than everyone's making it out to be. There is a sort of faster than light transmission here, what Einstein called "spooky action at a distance" (this is the topic of the somewhat famous EPR paper.)
Quantum teleportation is, however, not faster than light. In the case of the simplest way of preforming teleportation, which uses a singlet state, the process is as follows
1) Two particles (photons, atoms, etc) are put into a state with zero angular momentum or its optical equivalent, polarization. 2) One of these particles is shipped from Alice to Bob. They haven't been measured, so they're still in the zero angular momentum state, called a singlet state.
3) Alice takes a new particle, the one she wants to send, and makes a measurement on both it AND her half of the singlet. By measuring both at the same time, she changes the state of both of then, yet does not collapse the wavefunction.
4) This measurement transfers the state of Alice's particle to be teleported onto Bob's particle. Almost. There are four outcomes of Alice's combined measurement, and there are four possible rotations of Bob's particle. In order to recover the state of the original particle, Bob much preform a certain rotation on his oarticle. Without doing this, the state of the particle, when measured, is the same as if no teleportation had taken place.
So, in short, Alice has to send Bob the results of the measurment which teleported the state in the first place, which is slower than (or equal to) the speed of light, or else no information is transmitted.