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23 July 2010 Last updated at 15:33 ET By Paul Rincon Science reporter, BBC News, Paris
Time in space has always been an elusive issue for scientists who have long struggled to find a constant standard.
- Scientists manage to teleport information nearly 10 miles with unprecedented precision. - The team used quantum entanglement to teleport the information. - The feat could lead to a global, impenetrable communication network and powerful quantum computers. Scotty won't beam anybody anywhere anytime soon, but a new report by Chinese scientists shows that it is possible to transmit information over long distances using quantum entanglement.
Scientists previously have measured the light from distant exploding stars to show that the universe is expanding at an accelerating rate. They assumed that these supernovae are spreading apart faster as the universe ages. Physicists also assumed that a kind of anti-gravitational force must be driving the galaxies apart, and started to call this unidentified force "dark energy".
At this Web site you can study aerodynamics at your own pace and to your own level of interest. Some of the topics included are: Newton's basic equations of motion ; the motion of a free falling object, that neglects the effects of aerodynamics; the terminal velocity of a falling object subject to both weight and air resistance ; the three forces (lift, drag, and weight) that act on a glider ; and finally, the four forces that act on a powered airplane.