The intricate palaces of the black holes faced two fundamental theories describing our world. Are there any black holes really? It seems that Yes. Is it possible to resolve the fundamental problems that emerge upon closer examination of black holes? Unknown. To understand what we’re dealing with scientists, have a little to take in the history of the study of these unusual objects. And we start with the fact that, of all forces that exist in physics, there is one that we don’t understand at all: gravity.
Gravity — the point of intersection of fundamental physics and astronomy, boundary where you face two of the most fundamental theory describing our world: quantum theory and the theory of space-time and gravity of Einstein, she’s the General theory of relativity.
Black holes and gravity
These two theories seem incompatible. And it’s not even a problem. They exist in different worlds, quantum mechanics describes the very small, and General relativity describes the very large.
Only when you get to extremely small scale and extreme gravity, these two theories collide, and somehow one of them turns out to be wrong. In any case, it follows from the theory.
But there is in the Universe one place where we might actually witness the problem and maybe even solve: the border of a black hole. It is here that we meet the most extreme gravity. Except there’s one problem: no one has ever “seen” a black hole.
What is a black hole?
Imagine all the drama in the physical world unfolds in the theater of space-time but gravity is the only force that actually changes the theatre in which plays.
The force of gravity governs the Universe, however, may not even be a force in the traditional sense. Einstein described it as a consequence of the deformation of space-time. And maybe she just does not fit into the Standard model of particle physics.
When a very large star explodes at the end of his life, her most inner part collapses under its own gravity, as to maintain the pressure acting against the force of gravity is no longer enough fuel. In the end, gravity is still able to provide power like this.
Matter collapses and there is no power in nature can not leave this collapse.
Over infinite time, the star collapses into an infinitesimal point: a singularity, or let’s call it a black hole. But for the final time, of course, the stellar core collapses into something that has a finite size, and will still have a huge mass in an infinitely small area. And will also be called a black hole.
Black holes don’t suck all around
It is noteworthy that the idea that a black hole is inevitably sucked everything into itself, is wrong
In fact, no matter you rotate around a star or black hole formed from a star, it doesn’t matter if the mass remains the same. Good old centrifugal force and your angular momentum will keep you safe, and will not let you fall.
And only when you turn on your rocket brake to interrupt the rotation, you will start to fall inside.
However, once you begin to fall in a black hole, gradually you will accelerate to higher speeds until it finally reaches the speed of light.
Why quantum theory and General relativity incompatible?
At the moment everything turns to dust, because according to General relativity nothing can move faster than the speed of light.
Light is the substrate used in the quantum world for the exchange of forces and transportation information in the macrocosm. Light determines how quickly you can connect cause and effect. If you move faster than light, you will be able to see the events and change things before they happen. And this has two consequences:
- At the point where you reach the speed of light, falling inside, you also need to take off from this point on more speed that seems impossible. Consequently, common physical wisdom will tell you that nothing can escape a black hole, breaking this barrier, which we also called the “event horizon”.
- It also follows that they violated the basic principles of conservation of quantum information.
Is this true and how do we modify the theory of gravity (or quantum physics) is the questions that seek answers very many physicists. And none of us can tell what are the arguments we come to the end.
Are there black holes?
Obviously, all this excitement would be justified only in the case if black holes really existed in this Universe. So do they exist?
In the last century proved that some double stars with intense x-rays are actually stars, collapsibility in black holes.
Moreover, in the centers of galaxies, we often find evidence of a huge, dark mass concentrations. This can be a version of supermassive black holes probably formed in the process of merger of many stars and gas clouds that plunged into the center of the galaxy.
Evidence is convincing but indirect. Gravitational waves let us at least “hear” the merger of black holes, but the signature of the event horizon are still elusive and we have never “seen” black holes so far — they are simply too small, too distant and, in most cases, too black.
Looks like a black hole?
If you look directly into a black hole, you will see the darkest darkness you can imagine.
But the immediate environment of a black hole can be quite bright because the gases spiral inward slowing down due to the resistance of the magnetic fields they carry.
Due to the magnetic friction gas is heated to enormous temperatures in the tens of billions of degrees and emits ultraviolet and x-ray radiation.
Altragracia the electrons interacting with the magnetic field in the gas, start to produce an intense radio emission. Thus, black holes can glow and can be surrounded by a fiery ring, radiating at different wavelengths.
Ring of fire black-black center
And yet, in the center of the event horizon picks up like a bird of prey, each photon that gets too close.
Because the space is curved by the enormous mass of the black hole, paths of light are also bent and even form almost concentric circles around the black hole, like serpentines around a deep valley. This effect of the ring light was designed in 1916 by renowned mathematician David Hilbert in just a few months after albert Einstein finished his General theory of relativity.
After repeated bypass the black hole, some of the rays of light can escape, and the other will be in the event horizon. This intricate path of light you can literally look at a black hole. And “nothing”, which will appear to your view, will the event horizon.
If you made the black hole, you would see a black shadow surrounded by a luminous fog light. We call this feature the shadow the black hole.
Remarkably, this shadow seems larger than one would expect, if we take as starting point the diameter of the event horizon. The reason is that a black hole acts like a giant lens, amplifying itself.
Environment shadows will be submitted to the tiny “photon ring” due to the light that whirls around the black hole forever. In addition, you will see more rings of light that occur near the event horizon, however, concentrated around the shadow of a black hole due to the lensing effect.
Fantasy or reality?
Can a black hole be sheer fiction, which is that a computer can simulate? Or you can see it in practice? The answer is: maybe.
In the Universe there are two relatively nearby supermassive black holes that are so large and close that their shadows can be captured using modern technology.
In the center of our milky Way have black holes at a distance of 26,000 light years with a mass 4 million times the mass of the Sun and the black hole in the giant elliptical galaxy M87 (Messier 87) with a mass of 3-6 billion solar.
M87 is a thousand times more, but a thousand times heavier and a thousand times more, so both objects will have approximately the same diameter of the shadow projected on the sky.
To see a grain of mustard in new York from Europe
By coincidence, a simple theory of radiation predicted that for both objects the radiation generated near the event horizon will emit at radio frequencies of 230 Hz and above.
Most of us are facing these frequencies only when we have to go through the scanner in a modern airport. Black hole constantly rolling in it.
This radiation is very short wavelength of the order of millimeters — which is easily absorbed by water. In order that the telescope could observe the cosmic millimeter waves, it needs to be placed high on the dry mountain to avoid absorption of radiation in the Earth’s troposphere.
In fact, we need millimeter telescope that will be able to see an object the size of a mustard seed in new York, being somewhere in the Netherlands. This telescope will be a thousand times vigilantly the space telescope “Hubble”, and for millimeter wave range, the size of such a telescope will be from the Atlantic ocean or more.
A virtual telescope the size of the Earth
Fortunately, we don’t need to cover the Earth with a single radiomarelli because we can build a virtual telescope with the same resolution, by combining data from telescopes in different mountains all over the Earth.
This technique is called aperture synthesis and very long baseline interferometry (VLBI). The idea is quite old and proven several decades, but only now it became possible to use at high radio frequencies.
The first successful experiments have shown that the structure of the event horizon can be sampled at such frequencies. Now there are all necessary for this experiment on a large scale.
Work is already underway
BlackHoleCam project — a European project the final image, the measurement and understanding of astrophysical black holes. The European project is part of a global collaboration — consortium Event Horizon Telescope, which includes more than 200 scientists from Europe, the Americas, Asia and Africa. Together they want to make the first picture of a black hole.
In April 2017, they observed the galactic center and M87 with eight telescopes on six different mountains in Spain, Arizona, Hawaii, Mexico, Chile and the South pole.
All telescopes were equipped with accurate atomic clock for precise synchronization of their data. Scientists have recorded several petabytes of raw data due to surprisingly good weather conditions around the world at the time.
Photo of a black hole
If scientists will be able to see the event horizon, they will know what problems that occur at the interface of quantum theory and General relativity is not abstract, but very real. Perhaps then they can be resolved.
It can be done, if to get a clearer image of the shadows of black holes, or track stars, and pulsars in their way around black holes using all available methods to study these objects.
Perhaps black holes will be our exotic laboratories in the future.