On April 10, scientists from a global collaboration announced that they had pieced together the first-ever photograph of a black hole. The black hole photo captures a mass that is several billion times more massive than the sun and 55 million light years away. The photo represents the culmination of decades of research, hard work, and collaboration between scientists all over the globe.
The Daily had the opportunity to sit down with professor Eric Agol of the UW department of astronomy. Although not currently involved in the project, Agol played a significant role early on in the process of building the picture of the black hole.
When did you first get involved with black hole research?
My involvement came early on, about 20 years ago, when I was giving a talk down in Arizona and was approached by two scientists who had the idea of an event horizon telescope. At the time, I had been doing some calculations related to black holes and I was able to calculate the approximate shadow of a black hole. My prediction and the actual photo are in pretty good agreement. We published a paper at the beginning of 2000 of the simplified model.
Who did you work with on the project?
One of the things I'm very proud of is that my former graduate student Jason Dexter did some modeling with me about what the event horizon of a black hole should look like, and our models matched the picture very closely. Our goal was to model the radiation as it orbits around the black hole. We took a model of the gas flowing into the black hole and followed the radio waves back out into space to create a simulation of what the observer would see, which ended up being very similar to the simulation recently published. The model we used was simple, but a good description of the black hole shadow.
How were scientists able to get a picture of something 55 million light years away?
A good metaphor is how your ears work. When you hear something with both ears, your ears figure out where the sound is coming from. The [global network of] telescopes work similarly through timing. They were able to measure how intense radio waves were at a specific spot in the sky. Depending on exactly where the waves were coming from the sky, they arrived at each telescope at slightly different times. Recording the times allows you to pinpoint where the waves came from in the sky.
What impacts do you think the black hole picture will have on our understanding of science and technology in the future?
One [impact] is technological development. [Computer scientists tasked with creating the black hole image] used half a ton of hard drives to build digital correlators to mimic this digitally. There was a lot of computer science and algorithm development. Some of these developments were made for this problem specifically but ended up having applications elsewhere, such as medical imaging.
Another aspect is increasing our understanding of black holes and their effect on the universe, which might affect the distribution of life in the universe if we're not the only life out there.
Black holes hold this conundrum for the laws of physics, specifically general relativity. They seem to contradict quantum mechanics, which gives very specific constraints on the properties of matter. Nobody knows the resolution, but there are some ideas out there, and some of these ideas could be tested by looking at this photo of the event horizon of the black hole.
Reach writer Divya Rajasekhar at email@example.com. Twitter: @divraj16
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