Why is photographing the black hole such a special event?

This is the first time that physicists have been able to photograph with a telescope what the event horizon of a black hole looks like and the material that rotates around it and falls into it

On 10.4.19, for the first time, scientists managed to photograph the event horizon of a black hole and the accretion disk around it. To date, we have only seen black holes as computer simulations. This is the first time that physicists have been able to photograph with a telescope what the event horizon of a black hole looks like and the material that rotates around it and falls into it. But there is another reason why the first photograph of a black hole is such a special event.

Black holes are among the most interesting and mysterious bodies known to us in nature. They were predicted following Einstein's theory of general relativity about a century ago and many evidences of their existence have been collected over the years. But to date we have not seen a real photograph of a black hole. Seeing these interesting bodies for the first time is like seeing for the first time magic that becomes reality. But for that you need to know what a black hole is and what makes it such a strange and unusual body.

Black holes are a kind of tear in space - our time. A region of gravity so strong that not even light can escape it (and because the speed of light is the fastest it can be in nature, no body can escape a black hole). As you get closer to the black hole itself, the gravity gets stronger until you reach the point of no return, a certain distance that if you cross it, the gravity is too strong and you can't escape. Not even the light. This distance is called the event horizon of the black hole. If we continue to move towards the black hole itself we will be torn apart due to strong gravitational differences between our head and feet. But if we could somehow survive we would reach a point where according to the theory of relativity there is infinite curvature. This is the black hole itself. A kind of hole in the fabric of space - our time. A place where the laws of nature as we know them cease to exist. There is neither space nor time and it is impossible to describe the behavior of bodies. In other words, no one knows what happens when this point is reached. And yet these strange bodies exist in reality and now we have even photographed them.

According to the theory of relativity there is no such thing as gravity. What appears to us as a force that pulls bodies closer to each other is not a force at all but geometry. According to the theory of relativity, there is an infrastructure on which all bodies exist, space-time. It can be said that all the bodies are "drawn", if you will, in a four-dimensional infrastructure. Three dimensions of space and one dimension of time (for details see my series of articles "Einstein, the man who began to take us out of the Matrix" here). This infrastructure exists and is interrelated with the stars and the various masses that are depicted on it. Each mass slightly warps space-time. The interesting thing is that a curved space-time causes the material "drawn" in it to move in curved lines so that two bodies that are in the vicinity of a massive body that has strongly curved the space-time, will begin to approach it as if a force of attraction is exerted between them.

Einstein realized that actually there is no such thing as gravity, but there is a mass that distorts the space-time around it and therefore bodies seem to attract each other in this environment. This insight completely contradicts Newton's mechanics and what we are taught from a young age. We are taught that a stone we threw into the air will return to the earth because the Earth exerts a gravitational force on it, and here comes Einstein and shows us that there is no gravity at all. The Earth distorts the four-dimensional space-time around it and this causes the stone to return to the Earth. Einstein canceled the Gravity as a real force, in its place is a geometry of curved space where parallel lines approach each other until they finally meet. The more mass a body has, the more it curves its space-time and the space-time around it and we see it as if there is a force there. pulling harder.

The mass of the sun warps the four dimensional space-time around it. Space-time is represented in the drawing as a grid. The grid was supposed to have four dimensions and the stars are drawn on it, but we can't draw it.. Notice that a ray of light comes out from a distant star, but instead of continuing in a straight line, the ray curves because it passes through the curved space-time next to the sun and reaches the earth. This phenomenon was measured for the first time in 1919 and was the first confirmation of Einstein's theory of general relativity.

One of the strange results that comes out of this insight is that there can be stars with such a large mass that they will distort the space-time around them infinitely and actually tear the space-time (or the infrastructure) they are in! We call these strange stars black holes. Today it is known that there are many black holes and that there is even a giant black hole in the middle of every galaxy, including our galaxy (don't worry, it is very far from us). What happens inside such a black hole? What does it mean to reach an area where space-time is torn? Could such a rift take us to different regions of our space-time? Is it possible to go through it to a space-time different from ours and thus move to another universe with a different infrastructure? These are all excellent questions and we still don't have a solution for them. The theory of relativity does not know what happens inside the black hole and for that we will have to wait for the next theory in line that will know how to deal with the infinite sizes that appear in general relativity once we calculate what happens in the center of the black hole.

When Einstein saw the mathematical solution from the theory of relativity that predicts the invention of black holes, he did not think that they really exist and that this is just a mathematical result without physical reality. It took several decades before they were able to confirm this solution and discover the black holes throughout the universe. This is a wonderful example of the power of mathematics and why it is considered the language of nature and how it is more powerful than even those who developed it and found the appropriate mathematical solution. Every theory about nature starts with an idea, turns into the appropriate mathematics and from it emerges fascinating and new insights that we never thought about. The amazing thing is that all these mathematical games do describe nature and time and time again we see how mathematical solutions, no matter how strange, turn out to be correct in laboratory experiments. Stars with different mass densities warp space-time differently. According to the initial mass of the star, it is possible to know whether when the star runs out of nuclear fuel it will collapse and become a black hole or "stop on the way" and become small and very dense stars like a white dwarf or a neutron star. Today we know that stars with a mass density 6 times the mass of our Sun will collapse and eventually become black holes.

And now, for the first time, a European team using telescopes from around the world has photographed the event horizon of a black hole for the first time. They used a telescope called the Event Horizon Telescope. The telescope is made up of many telescopes that are located in different countries on Earth and photograph light at the frequency of radio waves. And with the help of images from all these telescopes they were able to construct this image:

So what do you see here?
In the center you see a kind of black circle surrounded by an orange ring. The circle is the event horizon, the limit up to which one can see. Because light cannot escape beyond it, no signal reaches our measuring devices beyond the event horizon and it is impossible to see what is happening inside (this is the black part of the black hole..). The shape of the event horizon is supposed to be spherical, but because this is a "top" shot we see the event horizon as a circle. Around the event horizon we see nearby stars swirling in a vortex around the black hole and falling into it, just like water falling as a vortex into our bathtub hole. This is the ring that the scientists painted orange. The black hole pictured is a massive black hole. It turns out that at the center of most galaxies in the universe there are black holes. These are massive black holes. The black hole in the picture has such a large mass that it is counted in units of how many times the mass of our sun enters the mass of the black hole. In this case the mass of the massive black hole is 6.5 billion times the mass of our sun!
And it is in the center of a galaxy called M87 which is 55 million light years away from our sun (when a light year is about 10,000,000,000,000 km). Trying to photograph the black hole from such a distance is like trying to see a tennis ball on the moon from Earth, yet we have enough advanced technology To do this, this image is just the first step in a new way to image black hole accretion disks. This is already further confirmation of the existence of black holes and some of the properties that black holes have, according to Einstein's theory of relativity.
To get some perspective on how huge this massive black hole is, take a look at the following image –

This is a very impressive achievement! Unbelievable that now you can actually see these amazing creatures that hold so many more insights into the essence of the reality we live in!

Nir Lahav is coming to visit Israel between Passover and Independence Day and will give two lectures to the general public:

On Tuesday, April 23.4.19, 0505903661, an experiential lecture - a journey into the recesses of the brain. The lecture is special for travelers in Mitzpe Ramon at Roni and Matti's guesthouse, eight o'clock in the evening. For details, call XNUMX
On Sunday 5.5.19 Is man's nature evil from his youth? The answer of social psychology. At Talkhouse in Tel Aviv. Details at the event

See you soon!