QUANTUM TELEPORTATION has been experimentally demonstrated by physicists at the University of Innsbruck (Anton Zeilinger, 011-43-676-305-8608, anton.zeilinger@ uibk.ac.at; Dik Bouwmeester, Dik.Bouwmeester@uibk.ac.at). First proposed in 1993 by Charles Bennett of IBM (914-945-3118) and his colleagues, quantum teleportation allows physicists to take a photon (or any other quantum-scale particle, such as an atom), and transfer its properties (such as its polarization) to another photon--even if the two photons are on opposite sides of the galaxy. Note that this scheme transports the particle's properties to the remote location and not the particle itself. And as with Star Trek's Captain Kirk, whose body is destroyed at the teleporter and reconstructed at his destination, the state of the original photon must be destroyed to create an exact reconstruction at the other end. In the Innsbruck experiment, the researchers create a pair of photons A and B that are quantum mechanically "entangled": the polarization of each photon is in a fuzzy, undetermined state, yet the two photons have a precisely defined interrelationship. If one photon is later measured to have, say, a horizontal polarization, then the other photon must "collapse" into the complementary state of vertical polarization. In the experiment, one of the entangled photons A arrives at an optical device at the exact time as a "message" photon M whose polarization state is to be teleported. These two photons enter a device where they become indistinguishable, thus effacing our knowledge of M's polarization (the equivalent of destroying Kirk).What the researchers have verified is that by ensuring that M's polarization is complementary to A's, then B's polarization would now have to assume the same value as M's. In other words, although M and B have never been in contact, B has been imprinted with M's polarization value, across the whole galaxy, instantaneously. This does not mean that faster-than-light information transfer has occurred. The people at the sending station must still convey the fact that teleportation had been successful by making a phone call or using some other light-speed or sub-light-speed means of communication. While physicists don't foresee the possibility of teleporting large-scale objects like humans, this scheme will have uses in quantum computing and cryptography. (D. Bouwmeester et al., Nature, 11 Dec 1997; see also image at Physics News Graphics)

DO EARTHQUAKES HAVE ELECTRICAL PRECURSORS? The elastic waves measured by seismometers are transmitted by the flexing crust while an earthquake is doing its worst. But some scientists believe that flexing also goes on in the hours and even weeks before a quake. Too small to be detected seismically, the flexing might well be sensed electrically. As underground strata rearrange themselves before a quake, the thinking goes, pockets of water are squeezed into new configurations, changing local conduction properties, which can be monitored with buried electrodes. On this basis Panayiotis Varotsos at the University of Athens (011-30-1-894-9849, pvaro@leon.nrcps.ariadne-t.gr), has reportedly predicted certain quakes in Greece weeks ahead of time by triangulating voltage differentials at the level of 10 millivolts/km over distances of 100 km. (Some skeptics dispute this assertion.) In new research, Varotsos buttresses his claims with laboratory studies of another system under pressure which puts out transient electrical signals before it fractures, namely a crystal containing a variety of dislocations and defects. Conductivity patterns in the crystal convince Varotsos that analogous patterns (although on a much bigger distance scale) observed in the buried electrode arrays constitute a true earthquake precursor. (Varotsos et al., Journal of Applied Physics, 1 Jan, 1998; journalists can obtain the paper from physnews@aip.org.)