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Description:
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Here's some exciting space news.
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Astronomers have used the Hubble Telescope
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and a technique pioneered by
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Albert Einstein to weigh a white
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dwarf star for the first time.
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So in 1916, Einstein said that
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a massive object like a star would
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actually warp the fabric of spacetime
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and what that means is that a ray of
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light going past the star would actually
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get bent and move in different paths
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as it was before.
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In 1936, a Czech engineer named Mandl
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came knocking on Einstein's door and asked
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him to do a little calculation.
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He said what would happen if a star passed in front
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of another star, and Einstein really
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didn't want to do it. He was kind of busy but
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he felt sorry for him and he did the
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calculation and wrote a paper for Science,
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very short paper saying if one star passed
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in front of another star, the distant star
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would be magnified and distorted by this
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gravitational lensing effect. And today,
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gravitational lensing is one of the most
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powerful tools in astronomy. People use
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it to measure the size of the universe and
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to map out dark matter and to find distant
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galaxies they couldn't find otherwise
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because they were too dim. What people in
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space telescope have done is watch as a
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distant ordinary star passed behind a
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white dwarf. It was distorted just as
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Einstein said it would. And by looking at
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the exact distortion, they were able to
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calculate how much the white dwarf was
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distorting spacetime and therefore,
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what its mass was, which turned out to be
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two-thirds of the mass of the Sun (more or less), which
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is what the theory has said. But still,
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it's good to know. So once more, we have
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Einstein to thank for yet another discovery
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even though he died way back in 1955.
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This is Mike Lemonick for Scientific American.
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