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This post was edited by CeciliaQ at 2019-4-12 17:58|
Humanity's first image of a black hole, which offers a glimpse of one of the weirdest spectacles in the universe, thrilled the world on Wednesday.
However, as people were amazed by "seeing the unseeable", many are wondering why the glowing donut is so blurry.
As a matter of fact, the image isn't really a photograph.
When we take a selfie, the light from the sun shines upon our faces and reflects into the smartphone camera. But a black hole is so dense that it sucks light in, leaving nothing visible reflected.
With that said, there are still things we can capture -- namely the objects around the black holes. When they are being sucked in, they rub with each other, creating light, radio waves and other things.
So we used eight radio telescopes on Earth to capture the radio waves and get an understanding of the black hole's shape.
So why it's so blurry? Just like taking a photo, the distance matters.
Try taking a photo of a cat from 100 meters away. It will appear so small that you can't recognize it no matter how you zoom in.
Though the M87 black hole is gigantic with a radius of 60 light years, it's 55 million light years away from us. That means the "cat" is about 23 million meters away. Try picture that and zoom in. No wonder it's blurry.
The scientists working at those eight telescopes have tried hard to take the picture back in 2017. The telescopes were combined to form an Earth-sized "lens" to capture the radio waves emitted from the M87.
As you may have realized, that also means what we captured was an ancient moment of the M87, literally a moment that happened millions of years ago. And it took almost all the latest technology we have right now to get it.
So, does that mean the black holes in sci-fi movies are fake? Not 100 percent. Since the real picture serves as another proof of the relativity, our previous artistic guessings are still vaguely valid.
Don't call filmmakers liars. At least they made you interested in seeing the blurry reality in the first place.
(Source: CGTN, by Gong Zhe)