The thing with black holes is that they have the same gravitational pull as the star that forms it. Yeah, it'd suck if Earth collided with a black hole, but it'd also suck if we collided with a star, and as far as I can tell there are a lot more stars than black holes.
If you have two entangled qubits separated by a large distance, and you make a measurement on one qubit, the state of the other qubit will change instantaneously. That is to say, the quantum information associated with both of the qubits will change instantaneously over a large distance. You're right in saying that "no actual information is conveyed by that change," if by information you mean classical information-- you certainly couldn't send a message faster than the speed of light. But quantum information is a very different concept.
What's with all of the physics time-travelers from the 1960s? Bell's theorem has repeatedly passed experimental muster, and has become a cornerstone of quantum information theory-- a field which has lead to any number of testable (and subsequently tested) predictions.
It depends on what kind of information you're talking about, classical information or quantum information. You most certainly cannot sent classical information faster than the speed of light. As for the logic behind this thought experiment, you may want to check out: http://en.wikipedia.org/wiki/Bell's_theorem
You fascinate me. Do you end all of your messages with "hahaha..." because you are laughing at your own jokes, because you want other people to know that you're being funny, or out of some sort of bizarre ritual? How old are you? I'm really not trying to offend, but I really just want to know why someone would chose to spend their time writing such inane comments on slashdot.
I should first mention that, although my view is the dominant (although not the only) view among quantum computation and quantum information theorists, it is still very controversial among other quantum physicists.
I'm really just talking about the many-worlds interpretation of quantum mechanics. http://en.wikipedia.org/wiki/Many-worlds_interpretation
It basically disagrees with the idea of the collapse of the wavefunction. After all, why should an atom behave differently when a person is looking at it? I can't really do MWI justice in a forum post (i highly suggest reading the wikipedia page). I should also note that, although i agree with the MW interpretation, i don't agree with the sci-fi interpretation of the MW interpretation, and i definitely don't agree with the pop-culture interpretation of the sci-fi interpretation of the MW interpretation!
I usually try to not feed the trolls, but your comment just confuses me. Whose ass am I kissing? I called the blog dumb, I disagreed with another critique of the blog, I'm currently disagreeing with you. The only people I mention agreeing with are a group of QC researchers who happen to believe in Everettian quantum mechanics. Sorry that I can't disagree with everyone.
As dumb as that blog entry is, it is correct in saying that the Schrodinger's Cat thought experiment was used to show that quantum mechanics predicts a result that Schrodinger believed to be impossible.
Currently, many people who study quantum mechanics (myself included) believe that not only is the cat in a superposition of both states before observation, but it remains in a superposition even after observation (although the scientist splits into a superposition of having seen a dead cat and having seen a live cat).
That blog entry made me giggle. I agree that DWave is most likely BS (most people in QC also agree). But the quantum weirdness that the blog doesn't believe in has been proven to exist (the author may just be behind in his reading; John Bell only proved it in 1966). Also, proof of concept experiments for both Shor's algorithm as well as Grover's algorithm have been done.
Your terminology is slightly off. Qubits can have an infinite number of possible states. 0 and 1 are called the basis. Also, a qubit is considered to be in a "pure state", not only when it's in a basis state, but also if it is in a superposition of the bases. A mixed state is something completely different. It occurs when we don't know exactly what pure state, so the state is represented by the sum of the possible pure states weighted by the probability of the qubit being in that state.
http://www.quantiki.org/wiki/index.php/Mixed_state
qubits have 3 possible states 1 0 and indeterminate.
Not true! Qubits have an infinite number of possible states. Imagine that your classical bit is represented as either an arrow pointing up for 1 and an arrow pointing down as -1. A quantum bit is like an arrow that can be pointed in the up direction, the down direction, or any other direction (it basically constrained to the surface of a sphere).
Slashdot Mirror
The thing with black holes is that they have the same gravitational pull as the star that forms it. Yeah, it'd suck if Earth collided with a black hole, but it'd also suck if we collided with a star, and as far as I can tell there are a lot more stars than black holes.
If you have two entangled qubits separated by a large distance, and you make a measurement on one qubit, the state of the other qubit will change instantaneously. That is to say, the quantum information associated with both of the qubits will change instantaneously over a large distance. You're right in saying that "no actual information is conveyed by that change," if by information you mean classical information-- you certainly couldn't send a message faster than the speed of light. But quantum information is a very different concept.
What's with all of the physics time-travelers from the 1960s? Bell's theorem has repeatedly passed experimental muster, and has become a cornerstone of quantum information theory-- a field which has lead to any number of testable (and subsequently tested) predictions.
It depends on what kind of information you're talking about, classical information or quantum information. You most certainly cannot sent classical information faster than the speed of light. As for the logic behind this thought experiment, you may want to check out:
http://en.wikipedia.org/wiki/Bell's_theorem
A completely valid arguement-- until 1964:
http://en.wikipedia.org/wiki/Bell's_theorem
Why is subatomic decay probalistic?
The probabilities can derived in MWI using work done by Everett and DeWitt in the '50s and by Deutsch and Wallace in 2007.
quantum computing is based on wishful thinking and ignorance.
Actually, proof of concept experiments have already been done for both Shor's algorithm as well as Grover's algorithm.
You fascinate me. Do you end all of your messages with "hahaha..." because you are laughing at your own jokes, because you want other people to know that you're being funny, or out of some sort of bizarre ritual? How old are you? I'm really not trying to offend, but I really just want to know why someone would chose to spend their time writing such inane comments on slashdot.
I should first mention that, although my view is the dominant (although not the only) view among quantum computation and quantum information theorists, it is still very controversial among other quantum physicists.
I'm really just talking about the many-worlds interpretation of quantum mechanics.
http://en.wikipedia.org/wiki/Many-worlds_interpretation
It basically disagrees with the idea of the collapse of the wavefunction. After all, why should an atom behave differently when a person is looking at it? I can't really do MWI justice in a forum post (i highly suggest reading the wikipedia page). I should also note that, although i agree with the MW interpretation, i don't agree with the sci-fi interpretation of the MW interpretation, and i definitely don't agree with the pop-culture interpretation of the sci-fi interpretation of the MW interpretation!
I usually try to not feed the trolls, but your comment just confuses me. Whose ass am I kissing? I called the blog dumb, I disagreed with another critique of the blog, I'm currently disagreeing with you. The only people I mention agreeing with are a group of QC researchers who happen to believe in Everettian quantum mechanics. Sorry that I can't disagree with everyone.
As dumb as that blog entry is, it is correct in saying that the Schrodinger's Cat thought experiment was used to show that quantum mechanics predicts a result that Schrodinger believed to be impossible. Currently, many people who study quantum mechanics (myself included) believe that not only is the cat in a superposition of both states before observation, but it remains in a superposition even after observation (although the scientist splits into a superposition of having seen a dead cat and having seen a live cat).
That blog entry made me giggle. I agree that DWave is most likely BS (most people in QC also agree). But the quantum weirdness that the blog doesn't believe in has been proven to exist (the author may just be behind in his reading; John Bell only proved it in 1966). Also, proof of concept experiments for both Shor's algorithm as well as Grover's algorithm have been done.
NSA and Army wants quantum computations researchers to do exactly what they have been doing for the last 15 years.
http://en.wikipedia.org/wiki/Quantum_error_correction
Your terminology is slightly off. Qubits can have an infinite number of possible states. 0 and 1 are called the basis. Also, a qubit is considered to be in a "pure state", not only when it's in a basis state, but also if it is in a superposition of the bases. A mixed state is something completely different. It occurs when we don't know exactly what pure state, so the state is represented by the sum of the possible pure states weighted by the probability of the qubit being in that state. http://www.quantiki.org/wiki/index.php/Mixed_state
that -1 should have been a 0. Sorry.
qubits have 3 possible states 1 0 and indeterminate.
Not true! Qubits have an infinite number of possible states. Imagine that your classical bit is represented as either an arrow pointing up for 1 and an arrow pointing down as -1. A quantum bit is like an arrow that can be pointed in the up direction, the down direction, or any other direction (it basically constrained to the surface of a sphere).
I know-- it's not _really_ a physics book, but Hofstadter is (was) a physicist. And the book is amazing.