Our first view of a black hole
They are considered as one of the most mysterious objects in the universe. We knew they existed, and that they swallowed up everything around them, but it was on April 10 that we finally got to see a black hole in a photograph.
According to the Guardian, the picture shows a halo of dust and gas at the heart of the M87 galaxy, 55 million light-years away from Earth.
As Time put it, the picture may "open one more tiny crack" onto the secret of the universe.
However, the photo doesn't show a black hole itself. That's because a black hole, with its great density, produces such a powerful gravitational field that nothing – not even the light – can escape its pull. It's only when surrounding objects, like gas, dust, stars and light are sucked into one, that it is possible to get a photograph.
但这张照片并未展现黑洞的样貌。因为密度巨大的黑洞能够产生强力的引力场，一切物质 —— 乃至光线 —— 都无法逃离其引力。只有当气体、尘埃、恒星、光线等周遭物质被吸入黑洞时，才有可能拍到一张黑洞的照片。
Though the picture just outlines the black hole, getting and showing it to humans are still not simple.
The first challenge lay in the remoteness of the black hole. Trying to get the photo was like "trying to spot an orange on the surface of the moon with the naked eye," Time reported.
In order to solve this problem, astronomers placed eight observatories in four continents. This global approach was key to getting the picture.
The collection of the data was completed in barely a week, but the analysis of it took the better part of the past two years.
Due to the telescopes in the different places, scientists couldn't share the information they collected with each other and only stored it independently. It wasn't easy to bring together these huge amount of data. The process involved transferring the data to different computer groups in order to produce the final image.
The final image is a big deal. As the Guardian noted, "it predicts a revolution in our understanding of the universe's most enigmatic objects."
One day, if we can uncover their secret, humans might "use black holes to time travel forward", according to National Geographic. We may be able to find out what the world will be like in the future.