The Event Horizon Telescope Update 02/19/17

One of the strangest and most mysterious phenomena in science today is the black hole. So strange in fact that once you go through one, which would most certainly kill you, you will have left our universe entirely and entered some place else that can only be described as ambiguous at best. It's a place where the laws of physics as we know them break down and if someone were watching you fall in time itself would appear to stop.

At the center of most galaxies, you will find supermassive black holes. The Milky Way is no exception. Called Sagittarius A, this supermassive black hole lies hidden in the shadows of the galaxy's central core. And while we've known about its existence for some time, the one thing we've never been able to do is take a picture of it, or for that matter any black hole.

Now, we can theorize what they might look like close up but even this has been subject to change. But the current theory is that it should look like a black dot surrounded by a halo of light which represents the black hole's glowing accretion disk. A good representation of this view, and one of the few scientifically accurate parts, was the recent movie "Interstellar" which featured Gargantua, a black hole that humans intended to colonize.

But from our perspective, Einstein predicted that it may be more of a crescent than a ring due to one area of the disc appearing brighter than the rest due to a dramatic doppler effect on the light that's being emitted. But to really know for sure what they look like we must photograph a black hole.

This has never been done. For good reason, they are impossible to photograph. The reason for this is that they swallow light itself, leaving nothing but black. But a radical, new telescope will be coming online in April of this year that may change that.

The Event Horizon Telescope isn't really a single instrument, but a network of radio telescopes scatted across the world as an array. Known as Very Long Baseline Interferometry, or VLBI, this technique promises to provide unprecedented resolution. The telescope will go live from the 5th through the 14th of April and intends to photograph the black shadow of Sagittarius A superimposed over its accretion disc.

This is hard to do. Black holes, for their mass, are very, very small. Even though Sagittarius A is millions of times more massive than our sun, it's compacted very tightly and as a result the diameter if its event horizon is comparatively small. It's also very far away, at 26 thousand light-years. And to top it all off, it's obscured by dust and gas.

Hoping to peek through the gas and dust the telescopes will look at radio emissions from the black hole at a wavelength of 1.3 mm, or 230 GHz. Because there are so many radio receivers focused on the black hole, the resolution will be extraordinarily high allowing scientists, hopefully, to glimpse in the radio spectrum the event horizon of the black hole. Think resolutions that could spot a softball at the distance of the moon.

In addition to imaging the black hole in radio, Einstein's theory of General Relatively should predict the exact size of the black hole based on how much it bends space-time around it. This will either create yet another validation of General Relatively, or throw the world of physics into chaos if the prediction ends up being wrong.

So there you have it. At the end of this year or the beginning of 2018, if all goes well, we may have our very first direct image of a black hole.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently very excited because an image of a black hole is one of the top items on my astronomy bucket list to see within my lifetime and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live.