X-Message-Number: 14002 From: Date: Sun, 25 Jun 2000 16:29:44 EDT Subject: FTL, a more palatable explanation After looking at my last posting, I find it not too clear for readers not acustomed to quantum strangeness. Well, all textbooks on electromagnetism write about the group and phase velocity of the photon, only the second may be larger than c. These textbooks say the phase velocity can't transport any information. This is true if informations are not in an entangled, hiden state and if we don't use teleportation to recover it. When the domain of nonzero amplitude of a photon is moved at phase velocity along the wave packet, ordinary information can't indeed be recovered. Now in "modern" quantum mechanics, we see that a quantum system is as an iceberg: a small part is above sea level and a larger part is under. Outside what we see in a quantum system, there is an socalled "entangled" part, this one is a copy of all the other quantum systems previously encountered. That "undersea" componment may be very big. To see it (or a part of it) we must first copy that part in a virgin system (a fresh quantum system similar to the first) and then erase the "above the sea" part with a destructive interference produced by a third quantum object. If you grind out the above the surface part of an iceberg, the hydrostatic push will bring out a part of the ice previously under the surface. I know, that explanation is at the level of the waterfall put for potential difference in elementary electricity, but floating ice remains simpler to see that entangled quantum states. (If you want the maths part, I can send you the reference of a paper on Los Alamos arXives -X is the grec letter chi-) Instantaneous interstellar communications will ask for an infrastructure similar to the one we see in large radio telescopes in the classical domain, this is not something a single person can build in its garage. There are simpler, smaller applications of the same concept more alike the simple radio receptor anybody can mount on a kitchen table. Yvan Bozzonetti. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=14002