With a mass equivalent to about 4 million suns, the supermassive black hole that resides at the center of our Milky Way Galaxy is the biggest and most mysterious object in the universe. Many still question whether it is really there.
Though its existence was predicted by Albert Einstein over a century ago, scientists have only been able to observe it very indirectly because it resides at the heart of our galaxy, meaning that light takes more than a few minutes to travel there.
While it is likely that black holes exist beyond our Milky Way, scientists have never been able to directly observe one due to the faint glow that is produced when a star is sucked in.
Now, however, a new research team has been able to do just that, unveiling a whole new side of the universe that we have never seen before.
Directly Observing a Black Hole For the First Time
In May 2019, a research team published new findings based off observations made with the Event Horizon Telescope (EHT), an international collaboration of radio observatories which work in concert to form a single, powerful instrument.
This remarkable feat of engineering and observation was made possible by leveraging the power of distributed computing, which enabled the EHT to make use of thousands of computing devices to analyze the data and bring it back for further study.
What we have here is something that astrophysicists have been striving to achieve ever since Albert Einstein first theorized the concept of a black hole in the early 20th century: a direct observational proof of the theory.
While light can take more than a few minutes to travel to the outside edge of our Milky Way Galaxy, the light from the central supermassive black hole is so bright that it takes only a few seconds for that light to reach the Earth. This effectively makes it possible for us to directly observe stars orbiting the black hole as well as light being emitted from the event horizon, the theoretical point of no return, where even light cannot escape the pull of the black hole’s massive gravity.
To achieve this, the EHT astronomers used the Very Long Baseline Interferometry (VLBI) technique to combine the signals from the 64 radio telescopes across the globe. VLBI is a term that is used for a type of observation that involves using baselines, or distances between two telescopes, that are hundreds of kilometers long, allowing scientists to see details on the scale of the solar system, or even smaller.
Black Holes And The Search For Extra-Terrestrial Intelligence
A significant portion of the paper outlining the EHT findings is dedicated to exploring the possible connections between the existence of black holes and the search for extra-terrestrial intelligence (ETI).
Since Albert Einstein first published his ideas on black holes more than a century ago, scientists have argued over whether or not black holes actually exist. One of the most ardent opponents of the theory, Dr. Clifford Hurst, wrote in 1921:
“I am, therefore, convinced that [black holes] are purely mathematical constructs, having no real existence in nature. It is, therefore, my opinion that the whole subject of black holes should be treated with great caution and skepticism; and although I believe that their mathematical definition is correct, I am almost afraid to assert that it applies to anything real.”
Despite his misgivings, Einstein’s theory stood the test of time and is still considered the defining theory of general relativity.
In recent years, however, new evidence has come to light that suggests that black holes might, in fact, be very real. In April 2019, for example, a study was published in which physicists analyzed the light being emitted by a black hole and concluded that it was, indeed, possible to infer the mass of the black hole from the pattern of light that was observed.
The connection between ETI and black holes is a fascinating one. As we have established, black holes are essentially the opposite of heavenly bodies: they are regions of space that are devoid of even the remotest trace of matter. It is generally accepted among astro-physicists that a location such as this would make for an ideal spot to settle down and start a new civilization. For centuries, scientists have theorized about the possibility of aliens building megastructures around black holes in order to establish themselves as a galactic society.
Certainly, that would be an interesting and unique environment for an alien civilization to conjure up. Perhaps, in addition to establishing contact with an alien intelligence, we could also glean important information about black holes and our own galaxy from this unique vantage point.
The Birth Of A New Science
As we have established, the existence of black holes was predicted by Albert Einstein over a century ago. In that time, scientists have been able to do a great deal of theorizing and observing about the relationship between black holes and the rest of the universe. In recent years, however, new evidence has begun to suggest that Einstein might have been exaggerating when he said that not even light can escape the gravity of a black hole.
What we have here is the result of an entirely new science called gravitational astronomy, which has enabled scientists to directly observe the effects of gravitational pull on celestial objects and to accurately measure the mass of those objects, including black holes.
Though it is often said that virtual astronomical tools have rendered traditional celestial observation obsolete, the truth is that gravitational astronomy is anything but virtual. It involves measuring the gravitational field of an object and using that information to deduce the mass of that object. Therefore, much like a DNA sequencing lab that observes the composition of an organism through the pattern of light it emits, gravitational astronomy sees matter through the pattern of gravity it creates.
The good news is that with gravitational astronomy, we now have an exact science that enables us to accurately measure the mass of black holes. The bad news is that this has effectively rendered Albert Einstein’s beloved theory of general relativity obsolete. The new science completely overturns Einstein’s work, demonstrating that his theory is, in fact, nothing more than a guesswork based on observational data gathered during a time when technology did not exist to enable astronomers to verify Einstein’s theory experimentally.
Though it will take physicists years to sort out all the contributions of Einstein’s great theory, we can already see the beginnings of a paradigm shift. For centuries, science has been conducted solely by men who viewed the world through a lens shaped by their own biases and subjectivity. Thanks to women like Catherine Chang, who pioneered gravitational astronomy, we now have a scientific toolkit at our fingertips that will allow us to look at the world through a different set of eyes. In the future, we might, just might, be able to see the universe as Einstein did his first time around: a cosmic pool surrounded by dazzling aquamarine skyspheres, a giant solar system, and a galaxy made up of billions of stars.