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  • NARRATOR: Of the billions of stars twinkling overhead,

  • one may be a scourge to life on Earth, an evil twin

  • to the sun named Nemesis.

  • Some scientists suspect that Nemesis

  • is a dark, still undiscovered star orbiting our sun.

  • And every 26 million years, it triggers a disaster.

  • We know that the solar system is

  • surrounded by this enormous cloud of comets.

  • And so these successive passages of the sun's companion

  • would send comets into the inner solar system.

  • Some of them would hit Earth.

  • NARRATOR: What follows is death on a colossal scale.

  • It is now widely accepted that a rock from space

  • caused the end of the age of dinosaurs 65 million years ago.

  • But astronomer, Richard Muller, has proposed

  • a revolutionary theory to explain

  • why that space rock crashed to Earth

  • at that particular moment.

  • The Nemesis theory postulates that

  • there's a star orbiting the sun at a 26 million-year period.

  • That's about it.

  • Almost no other assumptions need to be made.

  • NARRATOR: Muller believes that as Nemesis nears the sun,

  • its gravitational disturbance sends comets flying

  • through the solar system.

  • The resulting impacts have been the source

  • of many major extinction events in Earth's history.

  • Muller explains how the theory came about.

  • RICHARD MULLER: Two paleontologists,

  • when looking at patterns of extinctions,

  • came across something that seemed utterly insane.

  • They said that similar extinctions

  • were taking place every 26 million

  • years on a regular schedule.

  • NARRATOR: The discovery of a 26 million-year pattern

  • of extinctions seemed impossible to explain by any process

  • native to the Earth itself.

  • RICHARD MULLER: This is the sort of thing

  • you dream about in science.

  • It means there's something we don't understand.

  • It means there's a discovery waiting.

  • So I set about trying to figure out what that was.

  • NARRATOR: Muller made an astonishing proposal.

  • The only logical cause of these periodic extinctions

  • is a cosmic stalker that orbits our sun every 26 million years,

  • disturbing the comets on each approach.

  • In short, a Death Star companion to our sun.

  • RICHARD MULLER: If this star is discovered, it is so important.

  • It was a major player in the evolution of life on Earth.

  • Without this, perhaps the dinosaurs would still be here.

  • NARRATOR: If Muller is right, humanity

  • itself could owe its existence to the Nemesis Death Star.

  • After all, each mass extinction wiped out vast numbers

  • of species, but each also cleared the way for new species

  • to arise, including, ultimately, humans.

  • RICHARD MULLER: Now why haven't we found it yet?

  • Actually, there are quite a few astronomers

  • who don't pay very much attention to this

  • and simply assume that if it existed,

  • it would have been found by now.

  • We believe this thing can be found

  • within the next few years.

  • What it takes is a survey of dim stars.

  • NARRATOR: Enter WISE, the orbiting Wide-field Infrared

  • Survey Explorer, a powerful new tool that just might

  • crack the Nemesis mystery.

  • The reason that WISE is going to be so good

  • is because it operates in the infrared.

  • It sees heat, basically.

  • NARRATOR: By measuring heat instead of light,

  • infrared scanners can make warm but dark objects easy to spot.

  • The nice thing about looking in the infrared

  • at the heat of it is, you don't care how

  • far away you are from the sun.

  • NARRATOR: Jupiter provides an example.

  • The temperature on the surface of Jupiter

  • measures 230 degrees below 0 Fahrenheit.

  • But that's blazing hot when contrasted

  • with the 450-degree below 0 temperature of space.

  • So even in the absence of sunlight,

  • a distant Jupiter-like planet would

  • glow brightly in the infrared.

  • The hot spots of the race car are sort of

  • like warm, glowing objects out in the cold depths of space

  • far from the sun.

  • This is a whole new way of discovering objects, objects

  • too faint to be seen through a normal optical telescope

  • but bright enough to be detected in the infrared.

  • NARRATOR: The WISE telescope completed

  • its sky survey in early 2011.

  • But in the search for Nemesis, the results

  • are still inconclusive.

  • The WISE survey is going to take a long time to analyze,

  • simply because there's a huge amount of data that had

  • been gathered by this craft.

  • RICHARD MULLER: About half of the Nemesis candidates

  • have not yet been studied.

  • But in the next few years, we expect the theory will be

  • either proven right or wrong.

  • Until that time, it is and should be controversial.

NARRATOR: Of the billions of stars twinkling overhead,

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太陽がくれた双子の悪魔|宇宙(シーズン6)|歴史 (THE SUN'S EVIL TWIN | The Universe (Season 6) | History)

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    林宜悉 に公開 2021 年 01 月 14 日
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