Summary of the European Commission Press conference on 10. April 2019.
FROM IMAGINATION TO THE IMAGE
Since childhood, we have all seen at least one image of the black hole. Let it be an illustration of an artist, a simulation of a scientist. But the image above is nor an animation nor a simulation. This one is real.
THE RING OF FIRE
The content of the image reminds us of the ring of fire with a dark region in the middle. It is created by the force of gravity, by the deformation of space-time, where the light goes around the black hole in almost a circle. It is true, that we can not really see a black hole, however, what we see, is its shadow and the light disappearing behind the event horizon, creating that dark region. It is hard to imagine that region being there, as it represents the edge of the universe.
The image was taken with the Event Horizon Telescope, a global network of radio telescopes around the world, back in the year 2017 and then needed two years to be processed with the help of advanced algorithms. The black hole in the picture is in the very center of the Galaxy M87 in the constellation of Virgo, 500 billion billion kilometers away from us. It is a giant black hole with a mass of 6,5 billion times the mass of the Sun.
HOW CAN WE BE SURE, THAT IT REALLY IS A BLACK HOLE?
Professor of relativistic astrophysics Luciano Rezzolla explains that black holes are very problematic subjects in physics due to the properties they possess. In the center of the black hole is a single one-dimensional point, with a huge mass and infinitely small place, where the laws of physics break down. The point is called the singularity. This singularity is covered by a mathematical surface called the event horizon. The gravity on that horizon is so strong, that nothing, not even light can escape it.
He gives us confidence that it really is a black hole since it coincides extremely well with the predictions from the Theory of Relativity. The analogy between theoretical predictions and the image is remarkable. The most extensive investigations with supercomputers were carried out and highly advanced numerical codes were used to calculate what happens to matter as it falls into the black hole in order to predict the picture. Thousands of possible synthetic images were made. This is how the scientists came to conclude that this is a black hole as predicted by Einstein.
WE ALL SHARE ONE MEANING OF THE DISCOVERY
We have predicted the existence of black holes before, so one might question the real importance of the image. Where many of us see the greatest meaning is that now "we have transformed a mathematical concept of the event horizon into a physical object. Something that we can test, measure and observe repeatedly. This is a fundamental first step in any scientific progress; the scientific method. Being able to make an experiment and deduce from it how nature works," as professor Luciano Rezzolla nicely put it into words.
THE IMAGE IS THE RESULT OF MANY PEOPLE WORKING TOGETHER
We have proven again, that science is not led by political interests. It is led by curious minds. The image is the result of many nations working together. Today, we are proud of astronomy. As European Commissioner for Research, Science, and Innovation Karlos Muedas said in his speech today: "We believe, deeply in the freedom of science, we believe, that scientists are the one to make the choices, that the choices of science are not done by politicians, we believe somehow in the intuition of science."