| Submit your comments on this article |
| -Short Attention Span Theater- |
| Japanese Physicists Make Quantum Physics Even More Puzzling |
| 2009-03-06 |
| The good news is reality exists. The bad is it's even stranger than people thought "HOW wonderful that we have met with a paradox. Now we have some hope of making progress." So said Niels Bohr, one of the founders of quantum mechanics. Since its birth in the 1920s, physicists and philosophers have grappled with the bizarre consequences that his theory has for reality, including the fundamental truth that it is impossible to know everything about the world and, in fact, whether it really exists at all when it is not being observed. Now two groups of physicists, working independently, have demonstrated that nature is indeed real when unobserved. When no one is peeking, however, it acts in a really odd way. In the 1990s a physicist called Lucien Hardy proposed a thought experiment that makes nonsense of the famous interaction between matter and antimatter--that when a particle meets its antiparticle, the pair always annihilate one another in a burst of energy. Dr Hardy's scheme left open the possibility that in some cases when their interaction is not observed a particle and an antiparticle could interact with one another and survive. Of course, since the interaction has to remain unseen, no one should ever notice this happening, which is why the result is known as Hardy's paradox. This week Kazuhiro Yokota of Osaka University in Japan and his colleagues demonstrated that Hardy's paradox is, in fact, correct. They report their work in the New Journal of Physics. The experiment represents independent confirmation of a similar demonstration by Jeff Lundeen and Aephraim Steinberg of the University of Toronto, which was published seven weeks ago in Physical Review Letters. The two teams used the same technique in their experiments. They managed to do what had previously been thought impossible: they probed reality without disturbing it. Not disturbing it is the quantum-mechanical equivalent of not really looking. So they were able to show that the universe does indeed exist when it is not being observed. The reality in question--admittedly rather a small part of the universe--was the polarisation of pairs of photons, the particles of which light is made. The state of one of these photons was inextricably linked with that of the other through a process known as quantum entanglement. The polarised photons were able to take the place of the particle and the antiparticle in Dr Hardy's thought experiment because they obey the same quantum-mechanical rules. Dr Yokota (and also Drs Lundeen and Steinberg) managed to observe them without looking, as it were, by not gathering enough information from any one interaction to draw a conclusion, and then pooling these partial results so that the total became meaningful. What the several researchers found was that there were more photons in some places than there should have been and fewer in others. The stunning result, though, was that in some places the number of photons was actually less than zero. Fewer than zero particles being present usually means that you have antiparticles instead. But there is no such thing as an antiphoton (photons are their own antiparticles, and are pure energy in any case), so that cannot apply here. The only mathematically consistent explanation known for this result is therefore Hardy's. The weird things he predicted are real and they can, indeed, only be seen by people who are not looking. Dr Yokota and his colleagues went so far as to call their results "preposterous". Niels Bohr, no doubt, would have been delighted. Didn't they use Hardy's Paradox in one of the Pirates of the Caribbean movies? They could only find the island if they weren't looking for it? |
| Posted by:Anonymoose |
| #15 Perhaps not observing means that the universe doesn't need to waste time and effort creating alternate realities for those unobserved events. Conservation of effort and all that... |
| Posted by: 3dc 2009-03-06 20:52 |
| #14 If a woman says something in a forest and there are no men around, you are still wrong. |
| Posted by: Skunky Glins 5*** 2009-03-06 20:06 |
| #13 Of course, #11 BrerRabbit. ;-p |
| Posted by: Barbara Skolaut 2009-03-06 19:28 |
| #12 Okay, so some Big Brain came up with the idea that 'perhaps' nature doesn't exist if we're not looking and then years later, some other Big Brains prove that nature does indeed exist when we're not looking. That all these men earned (I use that term loosely) a living at something so absurd, is proof positive that these are extremely smart motherfuckers. Big Brains, indeed. |
| Posted by: Mike N. 2009-03-06 19:21 |
| #11 If a man says something in the forest, and there is no woman around to hear, is he still wrong? |
| Posted by: BrerRabbit 2009-03-06 18:37 |
| #10 AlanC: If you want to conceptualize reality from a quantum perspective, start with the idea that space and time are the same thing. Think traveling from "point 'a'" to "point 'b'". The further they are apart in space, the longer it takes to travel between them *at the same speed*. Reduce the space and you reduce the time. The next idea is to imagine that matter and energy are just different ideal states of the same thing, with all matter and energy being partly energy and partly matter to different degrees, somewhere in the middle between the two ideal states. Now imagine that space-time is more like 3 dimensional space, and that matter-energy is one of the three dimensions of that area. The second dimension is mass and gravity. One and a half of these dimensions are the more space and matter side of reality, the other half and third dimension are the more time and energy side of reality. So it is best to call the third dimension "causality". It is the middle ground between the two ideal extremes of stasis and change in reality. In a matter of speaking, from "outside", reality looks balanced and stable, but "inside" reality, it is inherently unstable, to maintain its overall stability. |
| Posted by: Anonymoose 2009-03-06 18:08 |
| #9 In Quatum Mechanics the particles are so small that in order to be observed some type of energy is either added or taken away. This energy changes the state of the particle and changes it inot something else therefore maybe you didn't see what you thought you did. Did the particle really exist before the observation? |
| Posted by: Deacon Blues 2009-03-06 17:24 |
| #8 #7, I would explain it but then you'd disappear. So, you understand why I hesitate? #7? Hello? #7? |
| Posted by: AlmostAnonymous5839 2009-03-06 16:34 |
| #7 What are the consequences of this not being true? What are the consequences of it being true? Are they the same or are they different? Please explain. |
| Posted by: Richard of Oregon 2009-03-06 15:04 |
| #6 Okay, my question is WHY?! Why does it act different if observed vs unobserved? What is it about observation that changes things? Is there an answer for that or is it one of those questions you're not supposed to ask? |
| Posted by: Silentbrick 2009-03-06 14:44 |
| #5 reality is weirder when not observed than when observed Veerily, the same has cows. |
| Posted by: .5MT 2009-03-06 13:38 |
| #4 There are many very weird descriptions at play in physics. I say descriptions because they are mathematical equations that purport to describe reality (and yes, that is what physics is). One of the items currently "understood" is that energy warps space (aka gravity) in a way similar to matter. Quote from a friendly NASA astro-physicist: "With respect to the curvature of space/time in the universe as a whole, the total warping of space/time comes not only from the "normal" mass, but from the total mass-energy density of the universe." Dark energy & dark matter, two other topics of my conversation, exist according to the mathematical models but have no experimental reality. At least not yet. I think I need a drink. |
| Posted by: AlanC 2009-03-06 13:37 |
| #3 It's things like this that persuade the ignorant that madness and genius are inextricably linked. This reminds me of a short story by Heinlein, an exploration of the idea that science only works because we all firmly believe that it does. |
| Posted by: trailing wife 2009-03-06 13:25 |
| #2 If I understand this article correctly (which is doubtful), the conclusion here seems to be that reality is weirder when not observed than when observed. |
| Posted by: mhw 2009-03-06 13:19 |
| #1 Physics seem SO cool, but I'm bad at math and unfortunately don't understand any of it! At least this article assures me that reality exists. I'm relieved to hear it.... Would the ghost of Decartes say "I told you that I think therefore I am? Then he could add "But you look therefore it isn't." |
| Posted by: Scooter McGruder 2009-03-06 12:34 |