scientific american - 1996 08 - the electronic wallet

... users of conven- tional cellular phones. SA MICHAEL GOODMAN Copyright 1996 Scientific American, Inc. The Stellar Dynamo 46 Scientific American August 1996 Copyright 1996 Scientific American, Inc. ... nature show at the Web site whose address the produc- News and Analysis30 Scientific American August 1996 CYBER VIEW The Notworking Computer DAVID SUTER Copyright...

Ngày tải lên: 12/05/2014, 15:14

... in Warsaw in 1 908. Turn-of -the- century Poland was a peas- ant nation with a veneer of sophisticat- ed city gentry. RotblatÕs parents were Jewish; his father was in the paper-trans- port business. ... transform their experiment into the quantum eraser, the researchers tagged one of the photons of the pair (speciÞcally, the one created by the la- serÕs direct passage through...

Ngày tải lên: 12/05/2014, 15:04

... Among the most com- mon mines in this group are the Italian scatterable mines TS-50 and SB-33 and the hand-laid VS-50 and VAR-40, the U.S made M14, and the Chinese Type 72. Typically, these weapons ... Space Adminis- tration unveiled the X-36 the first high-performance jet with no tail at all. Remotely controlled and powered by a cruise-mis- sile engine, the 5.4-meter-long, 600-...

Ngày tải lên: 12/05/2014, 15:08

... the impact of urban agriculture con- tinues to broaden, the notion of the gar- den city the turn-of -the- century dream of urban centers lined with trees and or- namental plants —may take on a new ... data from the probe’s 57-min- ute descent did not chal- lenge the prevailing hy- pothesis of the evolution of the solar system and its largest planet, according to Richard Young...

Ngày tải lên: 12/05/2014, 15:08

... protected under the executive order’s “state-of -the- art” tech- nology exemption to the bulk declassi - cation rule. But that introduces another concern. The issue is, what does state- of -the- art technology ... risk factors may affect the expres- sion of the disorder,” the group con- cludes in the Journal of the American Medical Association. The lead author of the s...

Ngày tải lên: 12/05/2014, 15:16

... forms the 0 and 1 of the de- vice the absence or presence of one ex- tra Cooper pair in the finger, which is then called a single-Cooper-pair box. The researchers test that their device has the ... peas- ant family to care for the three- and-a-half-year-old Mario. For a while, things went as well as they could in the mid- dle of a war. On the farm, the boy watched the whe...

Ngày tải lên: 12/05/2014, 15:58

... Utah Copyright 1996 Scientific American, Inc. T he turn-of -the- century stone building is rotting inside, floor- boards dusty and dilapidated, pigeons roosting in the eaves. There are no windows in the moldy ... leishmani- asis is being conducted, and the “pep- tideria,” where the synthesized peptides that form the basis of the malaria vac- cine are stored. He also points out...

Ngày tải lên: 12/05/2014, 15:18

... Oklahoma-northern Ark- ansas-southern Missouri, the north- ern part of the lower Michigan peninsula and most of the na- tion’s coastal areas. —Rodger Doyle (rdoyle2@aol.com) RODGER DOYLE The U.S. ... more malleable,” Owren theorizes. In the same way, when the men in the experiment laughed the most with other men, they were probably honoring the age-old tradition of the bu...

Ngày tải lên: 12/05/2014, 16:04

... 4,400 12-BILLION-YEAR- OLD AGE TRACK 15-BILLION-YEAR- OLD AGE TRACK NGC 288 NGC 362 Copyright 1992 Scientific American, Inc. means that within the halo the only re- maining main-sequence stars are the extremely ... declines as the reefs get farther away from two centersÑone in the Indo-Pa- ciÞc and the other in the Caribbean. The outlines of a map marking plum- meting dive...

Ngày tải lên: 12/05/2014, 14:48

... Witten com- ments. ÒThey also donÕt attempt to con- vey the importance of the ideas of phys- ics in mathematics.Ó JaÝe and Quinn have their support- ers. Richard M. Schoen, a mathematician at the Institute ... two infrared ones. The two photons are emitted si- multaneously, and the sum of their en- ergies exactly equals the energy of the parent photon. In other words, the col-...

Ngày tải lên: 12/05/2014, 14:50