My connection is that anyone who believes in 'Intelligent Design' or 'Creationism' is considered an idiot...
It is reasonable to consider X to be true if X is actually true.
whereas people who said things like "In 1980 there will be massive riots due to starvation" and who continue to make such claims are still given the time of day.
There have been food riots in all sorts of places before 1980, after 1980 and presumably in 1980. How many do you mean by massive? Is there a specific prediction that you're referring to?
And again I ask, are you actually trying to make a point?
Is there any connection between your two sentences? It seems about as relevant as saying "There have been people who play chess for years and yet French people will turn their noses up at British cooking."
When you're falling behind in the marketplace it can sometimes be a good idea to hide your identity. The point is, you make yourself more confusable with the market leader and hence make it easier for people to buy your product by accident when they intend to buy the market leader.
Interesting stuff. You've not convinced me that there is no doubt the other way - instead you have convinced me that there is quite a bit of doubt either way. I guess that if it ever comes to court it'll depend on who the judge's friends are. Just what does "any one time" mean anyway?
Here's a hint, when was the last time you heard "vector spaces" uttered on prime time TV
Here's another hint: when was the last time you heard "finite element methods" uttered on prime time TV? Yet nobody says that bridge building is "enigmatic". There is a deliberate conspiracy of mystery surrounding quantum mechanics.
I said I'd follow up. I found this paper on exactly what I was talking about. Note that the reference to Clebsch-Gordan is in a footnote because this is offtopic in quantum computing, and note that it appears in this paper because it is specifically about realising reliable qubits in physical systems based on spin. Clebsch-Gordan coefficients are in no way fundamental to understanding quantum computing, but may be useful for people actually building quantum computers (just as you can be an expert in classical computer science without understanding transistors).
At first I thought you were trolling, and you gave me a good laugh.
You know about the Bogdanov brothers, right?
my conclusion is that you know some quantum computing stuff, but you really don't have a decent understanding of the underlying quantum mechanics.
No, I understand the quantum mechanics quite well but you don't need the full power of quantum mechanics to do quantum computing.
Okay, don't just take my word for it. Take a look at this book . Notice in the description it says "A group theoretic abstraction of Shor's algorithms completes the discussion of algorithms."
Yes, because factoring integers involves group theory. In particular the integers modulo N form a group and modular arithmetic is pretty crucial to most factoring algorithms, including Shor's algorithm. But this is entirely separate from the usual use of group theory in quantum mechanics: studying the symmetry of physical systems. You don't need any of that Lie group and Lie algebra stuff to understand Shor's algorithm but you do need it to do particle physics, say, because when we study Shor's algorithm we're not studying symmetries of the system.
Okay, please demonstrate how to form the spin-singlet state by _adding_ the vectors of the two individual spinors.
You don't need to do this to understand quantum computing. To combine two spinors you look at the tensor product. Tensor products are the hardest bit of linear algebra in quantum computing, though they're obfuscated in many texts to make them seem even harder. But you're doing something in addition to forming the tensor product. You're considering a qubit to be an element of the 2D, spin-1/2 irrep of SU(2) and when you form the tensor product your're writing it as the sum of the spin-0 and spin-1 irreps (shorthand: 2*2 = 1+3). You need to do this to understand the total spin of the combined system. But this has nothing to do with quantum computing. In quantum computing you don't care what the total spin of the system is. In fact, you don't need to represent qubits using spin at all. You could use any pair of basis vectors you can physically construct. The vectors might represent energy levels of atoms or choices of wavefunction and have nothing to do with spin. So your talk of SU(2), while all very beautiful, has nothing to do with quantum computing. Combining two qubits is easy. The rule is |a>*|b>=|a,b>. The combined state has basis {|0,0>,|1,0>,|0,1>,|1,1>}. Eg. (|0>+|1>)*(|0>-|1>) gives (|0>+|1>)(|0>-|1>)=|0,0>+|1,0>-|0,1>+|1,1>. Easy peasy lemon squeezy.
Ie, you're increasing the size of your Hilbert space, so it's not basic addition at all.
Yes, it's multiplication. When you combine two quantum systems you multiply, not add. You don't need to know any group theory to do this. You just need to understand that a basis of the combined system is formed by taking pairs of basis elements, one from each system.
And while this might be relatively simple for two qubits, once you add many qubits to the system the complexity increases quickly.
Only if you're trying to compute the total spin of a combination of lots of qubits represented by spin. This has little to do with quantum computing.
Or you can talk about from a tensor point of view by including irreducible tensors, etc.
Yes, all very interesting, and nothing to do with quantum mechanics. You must be a particle physicist or something.
then you seem to be one of those scientists that just follow through calculations 'plug-and-chug', without any comprehension of the underlying concepts.
Funny, I was thinking the same about you. I think you need to stop and think about why you're so hu
I won't deal with everything you say but pick just one paragraph
Mathematically sophisticated. The details of quantum mechanics require infinite-dimensional Hilbert space theory, much of which has been developed during the 20th century. Things like the spectral theorem are mathematically very difficult and are necessary for quantum mechanics. It is not true that people learn what a Hilbert space is in the first year of undergraduate mathematics.
You can understand qunatum computing without infinite-dimensional Hilbert spaces (because quantum computers, at least the ones I know, live in finite-dimensional vector spaces, and plenty of interesting non-trivial quantum systems are finite-dimensional), you don't need the spectral theorem when dealing with finite dimensional systems, vector spaces are first year material even if Hilbert spaces aren't, and you don't need the full machinery of Quantum Mechanics to do Quantum Computing anyway.
No, this is very wrong, it's not simple vector space, it involves group theory, specifically that of Lie Groups. Additionally, spin states aren't in a vector space, but in a Hilbert Space.
I won't respond to all of this post. You clearly are unfamiliar with quantum mechanics and are just throwing around keywords to sound impressive. I'll just respond to this sentence. Your other sentences are just as much BS.
"It involves group theory". Clearly you don't know how or you wouldn't just say "it involves". The fact is, you can build up the theory of quantum computing without bringing in group theory. In fact, you need to know next to nothing about group theory to understand what a qubit is. An isolated qubit is represented by a 2D (complex) vector space. Where does the group theory come in? Read Shor's paper on factoring numbers. There's no special use of group theory above and beyond what you need to understand to do basic number theory and that applies just as well to classical factoring algorithms.
"spin states aren't in a vector space, but in a Hilbert Space" And now you're really making a fool of yourself. All Hilbert spaces are vector spaces. Infinite dimensional Hilbert spaces are interesting because the definition of "Hilbert space" requires it to be complete wrt its norm. Now every quantum computer I've ever seen discussed has states in a finite dimensional vector space. So completeness holds trivially. We're just dealing with ordinary vector spaces with norms.
And God only knows why you're lecturing me on Clebsch-Gordan coefficients (note the spelling BTW), interesting as the subject is. The representation of SU(2) really isn't very important to quantum computing and I've certainly never met any quantum algorithms that make use of intertwiners.
As far as I can see you're just part of the grand conspiracy to make Quantum Mechanics, and especially Quantum Computing, seem far more mysterious than it is. Shame on you.
What is enigmatic about adding two vectors in a vector space? I can't stand the way popular science press insist on making bizarre statements about the most trivial mathematics and science in an attempt to make it more interesting. States in a quantum computer are elements of a vector space. You learn what vector spaces are in the first year of an undergraduate course in mathematics. This is baby stuff. It's hard to realise physically but the underlying ideas are easy. This endless mystification is getting very annoying. Among other things it generates endless verbiage on/. where people have to keep clearing up other people's descriptions of what qubits are. This stuff isn't mysterious. I think it's time to write an idiot's guide to quantum computing.
No, it's just that the amount of excitement I have about something really needs to be in proportion to how good the thing is. Lost has resulted in a major recalibration of by excitement levels. I'll still enjoy Dr Who of course.
I really enjoyed the little 'hook' that the BBC used in Dr Who - "Bad Wolf". It was fun looking out for its appearance in each episode and the BBC created a bunch of "fake" websites tying into the series that added an extra dimension and helped to suck the viewer into the fictional world and suspend disbelief. What I enjoy about Lost is that it uses many of the sametricks - but on a grander scale that makes the little Dr Who games seem trivial by comparison.
Don't you think it is ironic? I'd say it fitted in with the notion of situational irony as described on Wikipedia. The story is about the media hype around Apple and there is a general implication on/. that hype is a bad thing and that geeks, and hence/., is above that sort of thing. The irony lies in the fact that despite such pretensions,/. is subject to hype just as much as any other media outlet. If the inclusion was a simple reporting of fact, without any kind of hint of judgement, then you'd be right that this was mere self-reference.
...being a big Dr Who fan 'n' all. I have downloads of the whole of the latest series and the Xmas Invasion. I've watched them all 2-3 times. And yet I'm not excited. The reason being, I've discovered Lost. "4 8 15 16 23 42" beats "Bad Wolf" any day. As an ex-pat I feel like such a traitor. But the Americans had to make a good TV series one day.
I hope there's a special place in Hell that they keep nice and warm for people who do things like that, right next door to the place where they keep people who put kittens in glass jars.
Even my own blog ran this story well over a month ago and I only posted the story because it was already well reported in the mainstream science press. Really. Slashdot could do with someone who reads a few science mags like New Scientist and so has a rough idea of what is and isn't news.
And, of course, this story has nothing to do with ID despite what the article suggests.
When will any of the/. editors learn to spell? You repeatedly demonstrate your inability to edit, even in your own posts. I spent about 20 seconds looking for errors in your article and found one that could easily have been caught by a spelling checker. I presume that if I'd read the whole thing I'd have found dozens more. Even magazines like National Inquirer have far higher editorial standards than Slashdot. I'm embarassed for you. You talk about agonising over a decision that might bring happiness to half a million people. Half a million people! Don't you think that makes it worth putting in that extra little bit of effort?
And when I say 'edit' I'm not just talking about spelling. You frequently post stories verbatim even when the original submission doesn't even contain sentences, or stories that make no sense out of context. These are very basic editing skills that you all appear to lack.
I sleep 5 hours, in average, per day...I lose my concentration
I whack myself on the head with a hammer 25 times a day. For some reason I now have a hammer shaped indentation in my skull. Do any other/. readers have any idea where this indentation might be coming from? It also hurts - I don't know if that is relevant.
Slashdot Mirror
It is reasonable to consider X to be true if X is actually true.
There have been food riots in all sorts of places before 1980, after 1980 and presumably in 1980. How many do you mean by massive? Is there a specific prediction that you're referring to?
And again I ask, are you actually trying to make a point?
Is there any connection between your two sentences? It seems about as relevant as saying "There have been people who play chess for years and yet French people will turn their noses up at British cooking."
When you're falling behind in the marketplace it can sometimes be a good idea to hide your identity. The point is, you make yourself more confusable with the market leader and hence make it easier for people to buy your product by accident when they intend to buy the market leader.
Interesting stuff. You've not convinced me that there is no doubt the other way - instead you have convinced me that there is quite a bit of doubt either way. I guess that if it ever comes to court it'll depend on who the judge's friends are. Just what does "any one time" mean anyway?
Is their any doubt over whether it is legal for someone in the US to purchase their mp3 data?
There are people who pay for music. There are people who steal music. But you're someone who pays someone else to steal music for you!
...disposable income to spend on legal downloads than owner of lesser^H^H expensive mp3 players.
I said I'd follow up. I found this paper on exactly what I was talking about. Note that the reference to Clebsch-Gordan is in a footnote because this is offtopic in quantum computing, and note that it appears in this paper because it is specifically about realising reliable qubits in physical systems based on spin. Clebsch-Gordan coefficients are in no way fundamental to understanding quantum computing, but may be useful for people actually building quantum computers (just as you can be an expert in classical computer science without understanding transistors).
You know about the Bogdanov brothers, right?
No, I understand the quantum mechanics quite well but you don't need the full power of quantum mechanics to do quantum computing.
Yes, because factoring integers involves group theory. In particular the integers modulo N form a group and modular arithmetic is pretty crucial to most factoring algorithms, including Shor's algorithm. But this is entirely separate from the usual use of group theory in quantum mechanics: studying the symmetry of physical systems. You don't need any of that Lie group and Lie algebra stuff to understand Shor's algorithm but you do need it to do particle physics, say, because when we study Shor's algorithm we're not studying symmetries of the system.
You don't need to do this to understand quantum computing. To combine two spinors you look at the tensor product. Tensor products are the hardest bit of linear algebra in quantum computing, though they're obfuscated in many texts to make them seem even harder. But you're doing something in addition to forming the tensor product. You're considering a qubit to be an element of the 2D, spin-1/2 irrep of SU(2) and when you form the tensor product your're writing it as the sum of the spin-0 and spin-1 irreps (shorthand: 2*2 = 1+3). You need to do this to understand the total spin of the combined system. But this has nothing to do with quantum computing. In quantum computing you don't care what the total spin of the system is. In fact, you don't need to represent qubits using spin at all. You could use any pair of basis vectors you can physically construct. The vectors might represent energy levels of atoms or choices of wavefunction and have nothing to do with spin. So your talk of SU(2), while all very beautiful, has nothing to do with quantum computing. Combining two qubits is easy. The rule is
|a>*|b>=|a,b>.
The combined state has basis {|0,0>,|1,0>,|0,1>,|1,1>}. Eg. (|0>+|1>)*(|0>-|1>) gives (|0>+|1>)(|0>-|1>)=|0,0>+|1,0>-|0,1>+|1,1>. Easy peasy lemon squeezy.
Yes, it's multiplication. When you combine two quantum systems you multiply, not add. You don't need to know any group theory to do this. You just need to understand that a basis of the combined system is formed by taking pairs of basis elements, one from each system.
Only if you're trying to compute the total spin of a combination of lots of qubits represented by spin. This has little to do with quantum computing.
Yes, all very interesting, and nothing to do with quantum mechanics. You must be a particle physicist or something.
Funny, I was thinking the same about you. I think you need to stop and think about why you're so hu
You can understand qunatum computing without infinite-dimensional Hilbert spaces (because quantum computers, at least the ones I know, live in finite-dimensional vector spaces, and plenty of interesting non-trivial quantum systems are finite-dimensional), you don't need the spectral theorem when dealing with finite dimensional systems, vector spaces are first year material even if Hilbert spaces aren't, and you don't need the full machinery of Quantum Mechanics to do Quantum Computing anyway.
I won't respond to all of this post. You clearly are unfamiliar with quantum mechanics and are just throwing around keywords to sound impressive. I'll just respond to this sentence. Your other sentences are just as much BS.
"It involves group theory". Clearly you don't know how or you wouldn't just say "it involves". The fact is, you can build up the theory of quantum computing without bringing in group theory. In fact, you need to know next to nothing about group theory to understand what a qubit is. An isolated qubit is represented by a 2D (complex) vector space. Where does the group theory come in? Read Shor's paper on factoring numbers. There's no special use of group theory above and beyond what you need to understand to do basic number theory and that applies just as well to classical factoring algorithms.
"spin states aren't in a vector space, but in a Hilbert Space" And now you're really making a fool of yourself. All Hilbert spaces are vector spaces. Infinite dimensional Hilbert spaces are interesting because the definition of "Hilbert space" requires it to be complete wrt its norm. Now every quantum computer I've ever seen discussed has states in a finite dimensional vector space. So completeness holds trivially. We're just dealing with ordinary vector spaces with norms.
And God only knows why you're lecturing me on Clebsch-Gordan coefficients (note the spelling BTW), interesting as the subject is. The representation of SU(2) really isn't very important to quantum computing and I've certainly never met any quantum algorithms that make use of intertwiners.
As far as I can see you're just part of the grand conspiracy to make Quantum Mechanics, and especially Quantum Computing, seem far more mysterious than it is. Shame on you.
These are the three best known quantum algorithms.
What is enigmatic about adding two vectors in a vector space? I can't stand the way popular science press insist on making bizarre statements about the most trivial mathematics and science in an attempt to make it more interesting. States in a quantum computer are elements of a vector space. You learn what vector spaces are in the first year of an undergraduate course in mathematics. This is baby stuff. It's hard to realise physically but the underlying ideas are easy. This endless mystification is getting very annoying. Among other things it generates endless verbiage on
I really enjoyed the little 'hook' that the BBC used in Dr Who - "Bad Wolf". It was fun looking out for its appearance in each episode and the BBC created a bunch of "fake" web sites tying into the series that added an extra dimension and helped to suck the viewer into the fictional world and suspend disbelief. What I enjoy about Lost is that it uses many of the same tricks - but on a grander scale that makes the little Dr Who games seem trivial by comparison.
Don't you think it is ironic? I'd say it fitted in with the notion of situational irony as described on Wikipedia. The story is about the media hype around Apple and there is a general implication on /. that hype is a bad thing and that geeks, and hence /., is above that sort of thing. The irony lies in the fact that despite such pretensions, /. is subject to hype just as much as any other media outlet. If the inclusion was a simple reporting of fact, without any kind of hint of judgement, then you'd be right that this was mere self-reference.
...being a big Dr Who fan 'n' all. I have downloads of the whole of the latest series and the Xmas Invasion. I've watched them all 2-3 times. And yet I'm not excited. The reason being, I've discovered Lost. "4 8 15 16 23 42" beats "Bad Wolf" any day. As an ex-pat I feel like such a traitor. But the Americans had to make a good TV series one day.
I hope there's a special place in Hell that they keep nice and warm for people who do things like that, right next door to the place where they keep people who put kittens in glass jars.
Even the lowliest of machines can run a spelling checker that spells 'arguement' correctly. Then again, maybe you're bluffing.
As long as you keep the buzz alive my stocks are just going to go up and up...
And in my book you need to spout more than common platitudes and trite cliches to make a good reviewer.
And, of course, this story has nothing to do with ID despite what the article suggests.
But I'd hardly describe as "chatter" any sound that can be masked by the low frequency sounds lost by poor earphones.
And when I say 'edit' I'm not just talking about spelling. You frequently post stories verbatim even when the original submission doesn't even contain sentences, or stories that make no sense out of context. These are very basic editing skills that you all appear to lack.
I whack myself on the head with a hammer 25 times a day. For some reason I now have a hammer shaped indentation in my skull. Do any other