What is Digg?Sponsored by Threadless
The Threadless Holiday Sale view!
threadless.com - Share awesomeness with your family this holiday. Grab t-shirts for all Threadless.com!
155 Comments
- captaindan, on 10/12/2007, -0/+9I'm thoroughly convinced that everyone studying quantum computing is just ***** with us.
- ThadBoyd, on 10/12/2007, -0/+6A quantum physicist gets pulled over.
The policeman says, "Sir, do you know how fast you were going?"
The physicist responds, "No, but I know exactly where I am." - mage1129, on 10/12/2007, -0/+5I gave this a digg without even digging it
- nork, on 10/12/2007, -0/+5I am so getting a quantum laptop and buying me some lottery tickets.
- ggudggid, on 10/12/2007, -1/+6I didn't write this comment even though I did. But I didn't write it in this space even though it appears here.
- inactive, on 10/12/2007, -0/+4considering in quantum mechanics you can be 2 places and once and be nowhere I don't find this too surprising
what's also being said here is that the observer still has great influence over the outcome of the problem pumped into the quantum computer, thus it's really the observer who creates the answer anway
in quantum mechanics there is no safe observation point, if you want a quark to appear behind you, it will, if you want it in front of you, it will be right there, when in quantum 'reality' it's not in front of you or behind your
you basically know the answer before you get the answer, and knowing the answer means that's the answer - kowgod, on 10/12/2007, -0/+4This article invalidates my IQ test results. I'm going to start drinking now. *sob* digg *sob sob*
- Otto, on 10/12/2007, -0/+3The article is crap but if you understand the idea behind counterfactual computing, then it's at least interesting.
The idea behind counterfactual computing is to set things up in such a way that a certain thing can happen only if something else did not happen, sorta. Somebody linked to the bomb testing problem above, which is a good example.
The basic idea is that virtual particles travelling on virtual paths exist until the waveform has collapsed. And those virtual particles can interact. So the path that a particle *could* have taken will cause actual interference until such time as you actually measure it and determine what path it really did take. So you can setup an experiment where the result is dependant upon that interference in such a way that the result you're looking for only occurs when the particle did not travel the virtual path that you are actually looking at.
Now, this gives you probabilities, but you can make those probabilities as small as you like be repeating the experiment.
They applied this notion to the Grover's quantum search algorithim somehow. Basically, they set something up in such a way that they would get their answer when their particle did not travel the path they were actually interested in. So in that sense, they never actually ran the search algorithim. The algorithim was run only by a virtual particle on a virtual path. After getting their measurement and determining that the real particle went a different way, the search was complete. Basically, it's enough to have the algorithim setup and then send a particle off in a completely different direction, and still get your algorithim to run by a non-existent particle. The trick is in not knowing whether or not your particle actually went into the algorithim or not until after the fact.
Read the bomb testing problem entry on wikipedia. It explains the basic idea well: http://en.wikipedia.org/wiki/Elitzur-Vaidman_bomb-testing_problem - Brian48216, on 10/12/2007, -1/+4this would be an absolutely amazing read if I were high right now.
- toastgodsupreme, on 10/12/2007, -0/+3Everyone Digg this so Kevin and Alex have to talk about it on Diggnation. Should be hilarious. =)
- sonofagunn, on 10/12/2007, -0/+342 is the answer to the question about to be asked...
- modian, on 10/12/2007, -0/+3I didn't read it but I already know I won't understand it.
- thegreenarrow, on 10/12/2007, -0/+3so this is how my mom feels when i talk about computers
- dotwhynot, on 10/12/2007, -0/+2Quantum mechanics is the dreams that stuff is made of.
- cr3ative, on 10/12/2007, -2/+4*brain explodes*
- dink, on 10/12/2007, -0/+2Interesting. What really caught my attention more then anything was:
"We also showed theoretically how to obtain the answer without ever running the algorithm, by using a 'chained Zeno' effect."
for those not familar with Zeno paradox: http://en.wikipedia.org/wiki/Zeno%27s_paradoxes
Does this mean that they basically were able to jump from one limit to the next, therefore solving a concept before actually doing it?
How is this not a violation of Zeno paradox... I'm Still trying to figure this out. - mbwilliamson, on 10/12/2007, -0/+2Think of it this way... A problem already has a solution before you solve it.
- kowgod, on 10/12/2007, -0/+2Seriously, I just tried re-reading this article, and at certain points, I got that funny "brain tickle."
I mean, I kinda understand it all. But I dunno. It makes me feel all sad and empty inside. - lbeaty1981, on 10/12/2007, -0/+2I wonder if I could use this to get out of going to work? Maybe I could send this article to my boss and explain to him that while I may appear to be goofing off at home, I'm actually at work too (at least on a quantum level).
- jimmyM, on 10/12/2007, -0/+2that is comically over the top hard to understand it is almost like it was written by the onion, mocking the absurdities of quantum physics.
- theGimpboy, on 10/12/2007, -0/+1I'm just waiting for my computer to tell me there maybe was an error.
- chimona, on 10/12/2007, -0/+1i hear they tried to use it to make the ultimate warrior...that's why chuck norris already exists.
- I8PP, on 10/12/2007, -0/+1You're not necessarily stupid if you don't understand this, rather you're just ignorant about this aspect of science. I'm both though.
- smooshy, on 10/12/2007, -1/+2I think they took this from the dialog in Ghostbusters
- ryanknapper, on 10/12/2007, -0/+1Hell, they should ask the thing how to make a quantum computer. By the time they hit the switch it'll already be on and controlling our lives.
- Inkling, on 10/12/2007, -0/+1This is how it really works: the device, through the clever use of fecal regurgitators, galvanizes the smartonium particles emitted in the quinine frequency range while simultaneously refluxing the bit map of the photon's wanton burrito meal.
In layman's terms, just THINKING about the device can, in a very strange way, negate the need for the search algorithm to run. Quantum mechanics doesn't get any more mysterious than this. - BuddyDoQ, on 10/12/2007, -0/+1I think I get it. They have 2 photons, and they're used to search a 4-item database. Using Quantum voodoo they fire them, they don't appear to move because they exists in both places at the same time anyway, (does that just depends on where you want to see them?) So in essence the damn thing doesn't need to be "on" from our end because it's already "on" at the other end. We just need to look and see what the results were in "dimension X," after all they have the same database.
Ok, I quit! - Empyrean, on 10/12/2007, -0/+1Super digg. First digg article Ive seen where people arent bashing each other over it in the comments lol.
- theonlybigboss, on 10/12/2007, -0/+1this kinnda reminds me of another story
http://digg.com/science/Getting_email_before_it_s_sent_
cool lol - jonathan4465, on 10/12/2007, -0/+1I'd like to think that I am a pretty bright guy, but that article was hard to follow! Digg though...
- inactive, on 10/12/2007, -0/+1My God.
I'm not even geek enough for this story. - timewarrior, on 10/12/2007, -0/+1original story http://www.news.uiuc.edu/news/06/0222quantum.html
- toomuchgreentea, on 10/12/2007, -0/+1I hope someone else can explain it better. This is all I've got from the article.
As far as the duality of photon concern, my guess is that you can look at the wave properties of photon as the distribution of probability of where the photon is likely to be detected. The tricky part is, once the photon is detected (i.e. its position is known), the probability map no longer exists, which means the wave properties for that particular photon disappear.
In a sense what quantum superposition does is to split the probability map of one photon into two paths. Keep in mind that just because a photon can move along one path doesn't mean it'll take that path. And there was no requirement that the photon has to travel in a straight line either. There is no way of knowing which path the photon took unless you can detect it, but once again the detection will destroy the probability map for that photon.
So if you setup the experiment such that by interference photons can only be detected along a particular path if the experiment failed, then in contrast the experiment must have succeeded if you cannot account for all the photons along that path. (If the search failed, all photons must appear along a certain path. Thus missing photons must mean the match is found.)
It's not that the quantum computer didn't run, my guess is that they just didn't know whether the quantum computer ran at all. - manano, on 10/12/2007, -0/+1Infinite Improbability Engine anyone?
- kindrobot, on 10/12/2007, -0/+1Grover's search? Is that the near and far thing, or something more complex?
- Pselus, on 10/12/2007, -0/+1dugg just for the comments :)
- jeolmeun, on 10/12/2007, -0/+1Blame the writer.
- Archimboldo, on 10/12/2007, -0/+1I concur with those who said the article is poorly written. They didn't really give enough details to know WTF they were talking about.
BTW, Physorg.com is generally laughed at in the physics community. - nuxx, on 10/12/2007, -0/+1"Seems a bit Kafkaesque to me... "The computer thought, therefore it was.""
Bleh! that's not Kafka, you ninny! That's Decartes!
no digg for you...just 'cos you called something Kafka-esque when it isn't. - CaughtThinking, on 10/12/2007, -0/+1Is this like the Art of Fighting Without Fighting?
(with apologies to Bruce Lee!) - Vill4no, on 10/12/2007, -0/+0I'm not digging just bc this article made my head hurt...owie...
- theredfist, on 10/12/2007, -0/+0>>I'm thoroughly convinced that everyone studying quantum computing is just >>***** with us.
>>posted by captaindan
Agreed - TheyWillKillUs, on 10/12/2007, -0/+0'I had to read, reread, and rereread again. I like to think I have a very logical mind and can put things together fast but this... ugh. Dugg for sheer unreadability."
It really wasn't that hard to follow. Digg - jhuebel, on 10/12/2007, -0/+0@chimona: it must be true, how else would Chuck Norris exist?
- acontorer, on 10/12/2007, -0/+0A much clearer explanation was posted on Slashdot. Go to http://science.slashdot.org/article.pl?sid=06/02/23/1325253 and search for the posting (partway down a long page) by SirBruce.
Here is an excerpt:
----------------------------
In this case, you have a quantum computer composed of mirrors that runs on photons. The mirrors are pre-set in a certain configuration to run a certain "program". No electricity is needed to "run" the program; you just inject photons into it and it spits out results when you measure it.
What they've done here is then place that computer in a certain location in an existing quantum mechanical system, the one which the photon comes from. This photon is associated with its own set of mirrors and detectors, and because of where and how the computer is placed into it, it effects the larger system.
Thanks to QM, you can then tweak the exterior system so that the chances of a photon ever actually getting to the quantum computer are infinitessimally small. But because there's still a small chance, the very nature of the computer in that location allows you to determine the results it would generate, even though a photon never actually gets into it to "run" it.
So, it's not to misleading to say the program never actually "runs". And you could say the computer isn't "on", but since it's just a mechanical-optical construct it's always "on". More importantly, though, is that exactly where the "computer" is becomes blurred; while it's true that it's particular programming is self-contained, by hooking it up to the external quantum system, you're sort-of making it a part of the computer as well. The "work" is being done by the photons outside the computer; remove them and you don't get anything. - doant, on 10/12/2007, -0/+0its not that hard as people think. OK its hard but not that confusing and totally over the top interesting . its about possibilities go and watch what the bleep do we know. ignore the god stuff the rest is really interesting. there is also a nice movie on http://www.whatthebleep.com/ check the trailer of in to the rabbit hole. it explains it a bit.
- MikeCampo, on 10/12/2007, -0/+0Just along as my computer doesn't evolve and decide to kill me, I can't wait to have this technology.
- SnakeO, on 10/12/2007, -1/+1In Soviet Russia, Quantum Physics learn You
- Mysidia, on 10/12/2007, -0/+0The technique they describe has another name: Jedi Mind Trick.
The fact that they can't scale it up should be telling. This "performing the search" without the computer is no more special than you can solve any computer algorithm for small data
sets with pencil and paper.
Of course you can sort the list of numbers {5,8,10,2}, without running a real sorting algorithm on a computer.
It would be more disturbing if quantum algorithms were so complex that you couldn't find simple answers without the quantum computer. - funkytaco, on 10/12/2007, -0/+0If you cut a sphere exactly in half, do they have the same mass?
Yes. -
Show 51 - 100 of 155 discussions
© Digg Inc. 2009
— Content created and posted by Digg users is