At, like, the center of the Milky Way is, like, a supermassive black hole that the galaxy rotates around or something. I dunno.
Sagittarius A*, I think it’s called, but like, no one knows much about it. No one really knows much about black holes at all. They, like, are one of the biggest paradoxes in space. Sure, they appear to suck things in, but what happens when they do? Does time stop? Does Matthew McConaughey enter the fourth dimension? No idea.
But, like, hopefully, that, like, is gonna change, like, next year, with the launch of the Event Horizon Telescope.
It’s going to, like, point its lenses at Sagittarius A* and hopefully figure out what the fuck it is going on at the point where it sucks everything in. Its event horizon, to be precise.
Hence its really uninspired name.
A network of nine radio telescopes, dotted around the globe, is set to take the first ever picture of a black hole’s event horizon in 2017.
The project, called the Event Horizon Telescope, has completed most of its technical preparations as well as extensive theoretical calculations.
With it, they hope to get the best ever, most extensive look at our galaxy’s black hole. Although it is going to be no small feat to spot in the sky.
Supermassive though it may be, the heart of the Milky Way’s black hole is not as big as you might think; the event horizon of Sagittarius A* is just 24 million km across – 17 times bigger than the Sun.
At 25,000 light years away, that makes it a pinprick. From the surface of the Earth, Prof Ozel explained, it takes up about as much of the sky as a CD sitting on the moon.
And surrounding this mysterious, spherical frontier are roiling clouds of gas and dust, which blaze with energy as they are sucked and squeezed furiously towards it.
Hell, finding it in space isn’t even half the problem. Harder still is figuring out what kind of light to observe it with.
One of their most important decisions was choosing which wavelength of light they would use. Radio waves were an obvious place to start, because they are scattered much less by this material than visible or infra-red light.
Then it took a lot of theoretical calculations to settle on the specific wavelength of 1.3mm, as Prof Ozel explained.
“We’ve run upwards of a million simulations, for many different configurations of what that gas might look like. And in all cases, we think that the 1.3mm wavelength is the right choice to see down to the event horizon.”
What they see and find could prove or disprove one of the most fundamental tenets of physics.
Einstein’s theory states that a mass – especially one as big as a black hole – bends space-time. And that curvature can be calculated mathematically.
So the size of the shadow cast by Sgr A* will either match what is predicted by general relativity, or it won’t.
“We know exactly what GR predicts for that size,” Prof Ozel said – making this observation what scientists call a “null hypothesis test” of the theory.
Astronomers rely on general relativity all the time, making use of the way masses bend the path of light. But it has never been tested on this scale before.
Heady fucking stuff, indeed.
[Via The BBC]