The Black Hole Picture
By Abby Beddow
A few weeks ago on April 10, 2019, a major scientific breakthrough was released to the world. Scientists announced that they were able to capture, the previously thought to be unobservable, a black hole, a void so deep and dense that not even light can escape it. Due to Hollywood movies like Interstellar black holes have become common knowledge for most people. However, up until recently, nobody knew what they actually looked like.
Einstein was the first to speculate their existence in his general theory of relativity. His prediction was that when too much matter is condensed into a singularity it creates a point of infinite density, effectively trapping any matter or light that enters its vicinity. Because a black hole is such a destructive power it is impossible for humans to observe what is in the center of a black hole. However, it is easily identifiable by the ring of bright light surrounding it called the Event Horizon.
To take a picture of a black hole that is around 55 million light years away and about 6.5 billion times as massive as our sun, it took worldwide effort from a team of approximately 200 people scattered across four continents aiming eight radio telescopes that had to be kept perfectly in sync with atomic clocks. Doing that task is essentially the same thing as making a telescope the size of the Earth. This gargantuan project was called the Event Horizon Telescope (EHT).
To start with, the EHT team had to find a black hole. Locating a black hole was more difficult than it sounds. First, they had to find a black hole that was big enough and close enough to photograph. In addition, the radio waves had to be in the correct frequency. here also had to be a way for light to escape through the clouds of dust surrounding it. The black hole they settled on was a supermassive black hole located in the Messier 87 galaxy (M87). Furthermore, to capture an image, the weather had to be clear and the Earth had to be in the correct orientation for all eight telescopes to see the black hole at the same time for about four days of observation. With all these factors combined, there was really only one time of the year that everything aligned perfectly for the telescopes to gather information.
Because there was so much data gathered everything had to be stored on hard drives and shipped on airplanes. They had to wait six months for the data to arrive from the south pole because it travels to Antarctica closes in the winter. This method is called very long baseline interferometry which works by correlating data from telescopes at very long distances to boost the signal and help filter out the noise.
After gathering all this information there were four teams working for months in complete isolation from each other in order to see if each one would develop the same image. The result of this long journey is the first ever photograph of a black hole. However, the picture is far from the most important product to come out if this investigation. The data gathered is indispensable, among other things scientists can now see that whether it be the black hole itself, the ring of light surrounding it or both, something is spinning in a clockwise motion around the black hole.
For the first time in history, humans have been able to reach beyond the stars and capture an image of a supermassive black hole. This amazing feat has further proved Einstein’s theory of relativity and has stretched the limits of observation to new heights.