Moving mirrors create light from nothing - Polidicks

[img]http://www.nature.com/news/2011/110603/images/news346-i1.0.jpg[/img] [release] [h2]Moving mirrors create light from nothing[/h2] [b]A team of physicists is claiming to have coaxed sparks from the vacuum of empty space. If verified, the finding would be one of the most unusual experimental proofs of quantum mechanics in recent years and "a significant milestone", says John Pendry, a theoretical physicist at Imperial College London who was not involved in the study.[/b] The researchers, based at the Chalmers University of Technology in Gothenburg, Sweden, will present their findings early next week at a workshop in Padua, Italy. They have already posted a paper on the popular pre-print server arXiv.org, but have declined to talk to reporters because the work has not yet been peer-reviewed. High-profile journals, including Nature, discourage researchers from talking to the press until their findings are ready for publication. Nevertheless, scientists not directly connected with the group say that the result is impressive. "It is a major development," says Federico Capasso, an experimental physicist at Harvard University in Cambridge, Massachusetts, who has worked on similar quantum effects. At the heart of the experiment is one of the weirdest, and most important, tenets of quantum mechanics: the principle that empty space is anything but. Quantum theory predicts that a vacuum is actually a writhing foam of particles flitting in and out of existence. The existence of these particles is so fleeting that they are often described as virtual, yet they can have tangible effects. For example, if two mirrors are placed extremely close together, the kinds of virtual light particles, or photons, that can exist between them can be limited. The limit means that more virtual photons exist outside the mirrors than between them, creating a force that pushes the plates together. This 'Casimir force' is strong enough at short distances for scientists to physically measure it. [h2]From virtual to real[/h2] For decades, theorists have predicted that a similar effect can be produced in a single mirror that is moving very quickly. According to theory, a mirror can absorb energy from virtual photons onto its surface and then re-emit that energy as real photons. The effect only works when the mirror is moving through a vacuum at nearly the speed of light — which is almost impossible for everyday mechanical devices. Per Delsing, a physicist at the Chalmers University of Technology, and his colleagues circumvented this problem using a piece of quantum electronics known as a superconducting quantum interference device (SQUID), which is extraordinarily sensitive to magnetic fields. The team fashioned a superconducting circuit in which the SQUID effectively acted as a mirror. Passing a magnetic field through the SQUID moved the mirror slightly, and switching the direction of magnetic field several billion times per second caused it to 'wiggle' at around 5% the speed of light, a speed great enough to see the effect. The result was a shower of microwave photons shaken loose from the vacuum, the team claims. The group's analysis shows that the frequency of the photons was roughly half the frequency at which they wiggled the mirror — as was predicted by quantum theory. Capasso calls the experiment "very clever". He doubts that the effect has any practical use because it doesn't generate large numbers of photons, but he considers it a nice demonstration of quantum mechanics. He still hopes to see a moving piece of metal generate detectable light from the vacuum, and believes that micromechanical systems may eventually be able to reach such speeds. Pendry says that the result, if it stands up, is bound to generate excitement. "Work in this area stirs considerable passion in the breasts of physicists." [/release] [release] [h2]Abstract[/h2] [b]C.M. Wilson, G. Johansson, A. Pourkabirian, J.R. Johansson, T. Duty, F. Nori, P. Delsing[/b] One of the most surprising predictions of modern quantum theory is that the vacuum of space is not empty. In fact, quantum theory predicts that it teems with virtual particles flitting in and out of existence. While initially a curiosity, it was quickly realized that these vacuum fluctuations had measurable consequences, for instance producing the Lamb shift of atomic spectra and modifying the magnetic moment for the electron. This type of renormalization due to vacuum fluctuations is now central to our understanding of nature. However, these effects provide indirect evidence for the existence of vacuum fluctuations. From early on, it was discussed if it might instead be possible to more directly observe the virtual particles that compose the quantum vacuum. 40 years ago, Moore suggested that a mirror undergoing relativistic motion could convert virtual photons into directly observable real photons. This effect was later named the dynamical Casimir effect (DCE). Using a superconducting circuit, we have observed the DCE for the first time. The circuit consists of a coplanar transmission line with an electrical length that can be changed at a few percent of the speed of light. The length is changed by modulating the inductance of a superconducting quantum interference device (SQUID) at high frequencies (~11 GHz). In addition to observing the creation of real photons, we observe two-mode squeezing of the emitted radiation, which is a signature of the quantum character of the generation process. [/release] [url=http://www.nature.com/news/2011/110603/full/news.2011.346.html]Source[/url] [url=http://arxiv.org/PS_cache/arxiv/pdf/1105/1105.4714v1.pdf]Thesis[/url]

Slightly misleading title, they didnt create light from nothing, they separated pairs of virtual particles in a vacuum to create real photons.

[QUOTE=Icedshot;30246836]Slightly misleading title, they didnt create light from nothing, they separated pairs of virtual particles in a vacuum to create real photons.[/QUOTE] Virtual particles are usually instantly destroyed. This allows us to reflect them into real photons.

so many late articles today

So what does this mean? A mirror that can reflect virtual particles as light? Sounds like a way to take a peek at the world of virtual particles, see what lies behind this mysterious veil. Also, is there anyway to convert light into virtual particles, essentially a sort of cloak?

And they said making a house out of glass wasn't [i]bright.[/i] Take that interior decorators.

[QUOTE=ironman17;30249020]So what does this mean? A mirror that can reflect virtual particles as light? Sounds like a way to take a peek at the world of virtual particles, see what lies behind this mysterious veil. Also, is there anyway to convert light into virtual particles, essentially a sort of cloak?[/QUOTE] They are naturally pretty much real particles just with very limited lifetime due to appearing as a pair which is doomed to annihilate into itself, which makes their existence practically virtual, as they don't have time to influence anything. The mirror gives them the possibility to survive and become more "real" as it splits the antiparticles and prevents them from annihilation.

even in middle school when teachers told me that space between atoms was vacuum and vacuum was nothing, i didn't believe it, it had to be something

[QUOTE=DrBreen;30250964]even in middle school when teachers told me that space between atoms was vacuum and vacuum was nothing, i didn't believe it, it had to be something[/QUOTE] You can't really say there are there, filling the space. They just come out of nowhere and disappear again.

Virtual particles like to hang around the event horizon of black holes from my understanding. Maybe if this technique is employed properly, we can take a gander of what was pulled into the black hole using this method.

Somethig from nothing? DOES NOT COMPUTE- :psyboom:

[QUOTE=ironman17;30249020]So what does this mean? A mirror that can reflect virtual particles as light? Sounds like a way to take a peek at the world of virtual particles, see what lies behind this mysterious veil. Also, is there anyway to convert light into virtual particles, essentially a sort of cloak?[/QUOTE] Here's an easier cloak. Turn the light off. [editline]5th June 2011[/editline] [QUOTE=Madman_Andre;30253918]Somethig from nothing? DOES NOT COMPUTE- :psyboom:[/QUOTE] Just think of it as something from vacuum energy and quantum foam. [editline]5th June 2011[/editline] [QUOTE=Master117;30251374]Virtual particles like to hang around the event horizon of black holes from my understanding. Maybe if this technique is employed properly, we can take a gander of what was pulled into the black hole using this method.[/QUOTE] Virtual particles pop in and out of existence everywhere man, literally everywhere, it's just that the gravity of the black hole has an effect on some of the pairs that form around them.

[QUOTE=ironman17;30249020]Also, is there anyway to convert light into virtual particles, essentially a sort of cloak?[/QUOTE] it wouldn't make a cloak it would make the object appear pitch black

Making an object appear pitch black would still be a quite useful camoflage.

So, if you're not allowing those particles to anhilate themselves with some other particles, that means other particles appear, besides those photons. Right?