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1 .This is Scientific American 60-Second Science. I'm Clara Moskowitz. Got a minute?
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2 .The universe is a dark, cold place.
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3 .But it has a strange region that's even colder than usual.
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4 .Seen from Earth, it's an area where the ambient cosmic microwave background light, the leftover thermal energy of the big bang is much chillier than expected.
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5 .Now astronomers say they've found in the same part of space a so-called supervoid, a large area mostly empty of galaxies.
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6 .And they think the overlap is no coincidence.
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7 .The supervoid extends 1.8 billion light-years across, making it perhaps the largest structure known in the cosmos, according to a report in the Monthly Notices of the Royal Astronomical Society.
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8 .The supervoid's relative lack of stuff could have drained energy from light that passed through it, explaining why the microwave background is colder there.
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9 .Here's how it works:
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10 .General relativity tells us that gravity bends spacetime, causing light to travel a curved path near massive objects, as if falling into a bowl.
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11 .The supervoid, then, with its lack of mass, is akin to a hill.
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12 .When light travels up that hill, it loses energy.
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13 .Normally it would regain the energy upon exiting the void—that is, when it comes down the other side of the hill.
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14 .But because the expansion of space is accelerating, the hill the light tumbles down is less steep than it was when the light climbed up.
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15 .And the flatter ride down means less energy recovered than was expended going up.
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16 .Which translates to a low-energy region, a big chill in the remnant of the Big Bang.
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17 .Thanks for the minute, for Scientific American's 60-Second Science. I'm Clara Moskowitz.
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