I personally think CERN project is amazing,, and I appreciate the tidbit of explanation as it really does allow me to visualize that is happening.. I would never have thought of using a magnetic field as a mirror.
the whole project is amazing thank you Allan On Thu, Dec 1, 2011 at 1:39 AM, archytas <[email protected]> wrote: > I tend to like science that doesn't require building vast entities > like the LHC at CERN. Stuff I could do on the kitchen table is more > my scene and hopefully simple enough to show my grandson, at least in > principle. > Wilson, C., Johansson, G., Pourkabirian, A., Simoen, M., Johansson, > J., Duty, T., Nori, F., & Delsing, P. (2011). Observation of the > dynamical Casimir effect in a superconducting circuit Nature, 479 > (7373), 376-379 DOI: 10.1038/nature10561 > is an example - though I actually can't do this one. > > I went through undergraduate chemistry "knowing" about virtual > particles, though I mistakenly thought they were accounting devices > rather than real. I "knew" too that vacuums were full of such stuff. > The thought experiments all seemed undoable. Here's a description of > the plucking light from vacuum job. > > "In addition, there is also the dynamic Casimir effect. This occurs if > the mirrors are moving very fast so that the electromagnetic field in- > between has no time to adjust. Instead, the ripples in the field > caused by the fast mirror movement lead to the emission of a light > particle. Basically, the mirrors create light out of the > electromagnetic field in a similar way that a guitar player generates > sounds from plucking a string. The problem with the experimental > realization of the dynamic Casimir effect is that the mirrors need to > move seriously fast. Otherwise the system has time to adjust to the > new geometry of the mirrors, and no light will be excited. We are > talking about speeds close to the speed of light! > > Such fast mirror movements are simply not possible with mechanical > mirrors. What is needed is an analogue that changes the dimension of > the vacuum by other means. Fortunately, such systems exist in > superconducting circuits, where magnetic fields applied to a so-called > SQUID circuit on a chip achieve the same moving mirror function for > electromagnetic fields. Moreover, fast-changing magnetic fields are no > problem to create. In the present experiment the mirrors ‘move’ at a > quarter of the speed of light, which corresponds to a driving > frequency for the magnetic field of more than 10 gigahertz. The > dynamic Casimir is clearly observed, with light being generated at the > expected frequencies. > > This is certainly a beautiful study confirming the intriguing > properties of quantum mechanics. And what’s more, it doesn’t need > Hawking’s black holes to experiment with them, all that’s needed is a > table-top setup of superconducting circuits. This ease of > experimentation will make sure we will learn much more about these > virtual fluctuations in vacuum from future experiments." > > As a kid I used to hear that money could not be produced from thin air > and such - these days it seems more and more of what was nothing > actually is something. > > > > -- ( ) |_D Allan Life is for moral, ethical and truthful living.
