The proposal to send the ultracold atomic clock on the International Space Station (ISS) might get delayed and therefore physicists have to wait to test the predictions of Einstein's theory of relativity, said Physics Nobel Laureate Claude Tannoudji here. | |
| "The International Space Station is a great place for atomic clocks because the station is freely falling around the earth," he said at a lecture jointly organised by the Department of Physics, Indian Institute of Technology, and Indo-French Centre for Promotion of Scientific Research here. |
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| When boarded on the ISS, slow-moving atoms in a cooled weightless clock can be observed for a longer time, and they are less likely to hit the walls of their container in mid-oscillation, he said. |
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| If all goes well (with space shuttle) , a laser-cooled (ultracold) atomic clock named PARCS "" the Primary Atomic Reference Clock in Space "" will be installed on the ISS by 2008-9, Tannoudji said. |
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| "We expect it to be the most stable clock ever, keeping time within 1 second every 300 million years," he said. |
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| According to Einstein's theory of gravity and space-time "" called "general relativity" "" clocks in strong gravity tick faster than clocks in weak gravity. Because gravity is weaker on ISS than at earth's surface, PARCS should accumulate an extra second every 10,000 years compared to clocks ticking on the planet below. |
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| PARCS would not be there that long, but the clock is so stable that it will reveal this effect in less than one year. |
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