Friends, we honestly admit that we did not have time to write anything interesting, so we will use someone else's work :) On the Web, we came across an excellent article that describes one of the key mysteries of theoretical physics in an accessible language. We decided to bring this material in full, because it is the original author's style that makes it especially fascinating. We hope it will appeal to those who are interested in the mysteries of our universe.

So what happens if you fall into a black hole?

Surely you believe that if you fall into a black hole, then instant death awaits you. But in reality, as physicists believe, your fate will be much stranger. This could happen to anyone in the future. Maybe you're trying to find a new habitable planet for the human race, or you just fell asleep on a long journey. What happens if you fall into a black hole? You might expect to be crushed or torn apart. But it's not like that.

The moment you enter the black hole, reality will be split in two. In one, you will be immediately destroyed, and in the other, you will plunge into a black hole completely unscathed.

A black hole is a place where the laws of physics known to us do not apply. Einstein taught us that gravity bends space itself, deforms it. So given a sufficiently dense object, space-time can become so curved that it wraps itself in on itself, punching a hole in the very fabric of reality.

A massive star that has run out of fuel could provide the extreme density needed to create this warped patch of space. Bending under its own weight and collapsing, a massive object pulls space-time along with it. The gravitational field becomes so powerful that not even light can escape it, which dooms the region in which this star is located to a grim fate: a black hole.

The outer boundary of a black hole is its event horizon, the point at which the force of gravity counteracts the attempts of light to escape it. Get too close and there will be no return.

The event horizon glows with energy. Quantum effects at this boundary create streams of hot particles flowing back into the Universe. This is the so-called Hawking radiation, named after the physicist Stephen Hawking, who predicted its existence. After enough time, the black hole will evaporate its mass completely and disappear.

As you dive into the black hole, you will find that space becomes more and more curved until the very center becomes infinitely curved. This is the singularity. Space and time no longer have any meaning, and the laws of physics we know that require space and time no longer apply.

What happens at the singularity? No one knows. Another universe? Oblivion? Matthew McConaughey floating on the other side of the bookshelves? Mystery.

What happens if you accidentally fall into one of these cosmic aberrations? First, ask your space partner - let's call her Anna - who watches in horror as you swim towards the black hole while she remains at a safe distance. She observes strange things.

As you accelerate towards the event horizon, Anna sees you stretch and distort as if she is looking at you through a giant magnifying glass. Also, the closer you get to the horizon, the more your movements slow down.

You can't shout since there's no air in space, but you can try signaling Anna a Morse message with your iPhone's light (there's even an app for that). However, your words will reach it slower and slower as the light waves are stretched to lower and lower and redder frequencies: “Okay, good, good…”.

When you reach the horizon, Anna will see that you are frozen, as if someone has pressed the pause button. You will be imprinted there, immobilized and stretched across the entire surface of the horizon, as the rising heat begins to consume you.

According to Anna, you are slowly being erased by the stretching of space, the stoppage of time, and the heat of Hawking's radiation. Before you plunge into the darkness of a black hole, you will turn into ashes.

But before we start planning the funeral, let's forget about Anna and see this macabre scene from your point of view. And you know what's going on here? Nothing.

You swim straight into nature's most sinister manifestation and don't get bumped or bruised - and certainly not stretched, slowed down, or fried on radiation. Because you're in free fall and don't experience gravity: Einstein called it "the happiest thought."

After all, the event horizon is not a brick wall floating in space. It's a perspective artifact. An observer who stays outside the black hole cannot see through it, but that's not your problem. There is no horizon for you.

If the black hole were smaller, you'd be in trouble. The force of gravity would be much stronger at your feet than at your head and stretch you like spaghetti. But luckily for you, it's a big black hole, millions of times more massive than the sun, so the forces that could spaghettify you are weak enough to be ignored.

What's more, you could live the rest of your life in a large enough black hole and then die in a singularity.

How normal this life will be is a big question, given that you were sucked against your will into a gap in the space-time continuum and there is no turning back.

But if you think about it, we all know this feeling, from the experience of communicating not with space, but with time. Time only goes forward, never backward, and sucks us in against our will, leaving no chance for retreat.

This is not just an analogy. Black holes warp space and time to such an extreme state that inside the black hole's event horizon, space and time actually reverse roles. In fact, it is time that sucks you into the singularity. You can't turn around and walk out of a black hole just like you can't turn around and walk back into the past.

At this point, you ask yourself: what is wrong with Anna? If you're chilling inside a black hole, surrounded by empty space, why does your partner see you burn up in radiation at the event horizon? Hallucinations?

In fact, Anna is in perfect health. From her point of view, you really burned out on the horizon. This is not an illusion. She could even collect your ashes and send them home.

In fact, the laws of nature require that you stay outside the black hole, as seen from Anna's point of view. This is because quantum physics requires that information not be lost, not lost. Every bit of information that speaks of your existence must remain outside the horizon so that Anna's laws of physics are not violated.

On the other hand, the laws of physics also require that you sail across the horizon without hitting hot particles or anything out of the ordinary. Otherwise, you will be violating Einstein's "happiest thought" and his general theory of relativity.

So, the laws of physics require that you be both outside the black hole as a pile of ash and inside the black hole, alive and well. And there is also a third law of physics which says that information cannot be cloned. You must be in two places, but there can only be one copy of you.

Somehow, the laws of physics lead us to a conclusion that seems rather nonsensical. Physicists call this puzzle the black hole information paradox. Fortunately, in the 1990s they found a way to solve it.

Leonard Susskind concluded that there is no paradox, since no one sees your copy. Anna sees only one copy of you. You see only one copy of yourself. You and Anna will never be able to compare them (and your observations too). And there is no third observer who can simultaneously observe a black hole from inside and outside. So no laws of physics are violated.

But you probably would like to know whose story is true. Are you dead or alive? If black holes have taught us anything, then there is simply no answer to this question. The reality depends on who you ask. There is Anna's reality and your reality. That's all.

At least that's what they thought for a long time. In the summer of 2012, physicists Ahmed Almeiri, Donald Marolph, Joe Polchinski, and James Sully, collectively known as AMPS, conceived a thought experiment that threatened to upend everything we had gathered about black holes.

They suggested that Susskind's decision was based on the fact that any discrepancy between you and Anna is mediated by the event horizon. It doesn't matter if Anna saw an unfortunate version of you torn apart by Hawking radiation, because the horizon prevents her from seeing another version of you floating in a black hole.

But what if she had a way to find out what was on the other side of the horizon without crossing it?

Ordinary relativity will say no, no, but quantum mechanics blurs the rules a bit. Anna could see beyond the horizon using a little trick that Einstein called "creepy action at a distance."

This happens when two sets of particles separated in space are mysteriously "entangled". They are part of a single invisible whole, so the information that describes them is mysteriously linked between them.

The idea of ​​AMPS is based on this phenomenon. Let's say Anna scoops up some information from the horizon - let's call her A.

If her story is correct, and you've already gone to a better world, then A, scooped up in the Hawking radiation outside the black hole, must be entangled with another bit of information B, which is also part of the hot cloud of radiation.

On the other hand, if your story is correct and you are alive and well on the other side of the event horizon, then A must be entangled with another piece of information C, which is somewhere inside the black hole. But here's the point: each bit of information can only be confused once. It follows that A can be entangled with either B or C, but not both at the same time.

So Anna takes her particle A and puts it in a manual entanglement decoding machine, which gives her the answer: B or C.

If the answer is C, your story wins, but the laws of quantum mechanics are violated. If A is entangled with C, which is deep inside the black hole, then that piece of information is lost to Anna forever. This violates the quantum law of the impossibility of information loss.

That leaves B. If Anna's decoding machine detects that A is entangled with B, Anna wins and general relativity loses. If A is entangled with B, Anna's story will be the only true story, which means that you are in fact burned to the ground. Instead of sailing straight across the horizon as relativity would suggest, you will encounter a blazing wall of fire.

So we're back to where we started: what happens when you fall into a black hole? Do you slide through it and live a normal life thanks to a reality that is strangely dependent on the observer? Or do you approach the horizon of a black hole only to encounter a deadly wall of fire?

Nobody knows the answer, which is why this question has become one of the most controversial in the field of fundamental physics.

For more than a hundred years, physicists have been trying to reconcile general relativity with quantum mechanics, believing that one of them will eventually have to give in. Solving the paradox of the aforementioned wall of fire should point to the winner, as well as lead us to an even deeper theory of the universe.

One of the clues may lie in Anna's decoding machine. Figuring out which of the other bits of information is entangled with A is an extremely difficult task. So physicists Daniel Harlow of Princeton University in New Jersey and Patrick Hayden of Stanford University in California set out to figure out how long it would take to decode.

In 2013, they calculated that even with the fastest computer available, it would take Anna an incredibly long time to decipher the entanglement. By the time she finds the answer, the black hole will have long since evaporated, vanished from the universe, and taken with it the riddle of the deadly wall of fire.

If so, then the sheer complexity of this problem may prevent Anna from finding out whose story is true. Both stories will remain equally true, the laws of physics intact, reality dependent on the observer, and no one in danger of being swallowed up by the wall of fire.

It also gives physicists new food for thought: the tantalizing links between complex calculations (like the ones Anna can't do) and spacetime. Perhaps there is more hidden here somewhere.

These are black holes. They are not only annoying obstacles for space travelers. They are also theoretical laboratories that bring the laws of physics to white heat, and bring the subtle nuances of our universe to such a level that they can no longer be ignored.

If the true nature of reality is lurking somewhere, the best place to look for it is in a black hole. True, it is better to look from the inside. Let's send Anna, now it's her turn.

P.S. If you have interesting materials, references, tips, life hacks on absolutely any topic, then send them to This e-mail address is being protected from spambots, you need JavaScript enabled to view it

MOSCOW, November 10 - RIA Novosti, Olga Kolentsova. The trajectory of a falling person, the length of the flight and the place of landing depend on many conditions. Forensic experts by the nature of the injury can determine the circumstances of the fall. Information about how the human body behaves in flight can help not only solve a crime, but also reduce the severity of injuries.

Falls can be "active" or "passive". In the first case, a person is accelerated by some extraneous force (for example, he was pushed) or by himself (having made a jump or pushed off the window sill). "Passive fall" occurs without additional acceleration - for example, when falling off the roof.

In both cases, during the flight, the body can change position, as well as deviate from the perpendicular connecting the point from which the fall began and the landing site. This occurs due to the mutual movement of body parts having different masses and volumes, as well as due to the rotation of the torso around the center of gravity or the point of impact with obstacles. This factor depends on the physique - height, weight, individual characteristics, as well as on the starting position, fall height, trajectory, the presence of an accelerating force and the point of its application.

The initial push does not always increase the departure distance. The closer to the center of gravity (it is located in the navel area) the accelerating force is applied, the farther the body flies away from the perpendicular. Conversely, an impact much above or below the center of gravity is usually accompanied by a downward motion in a straight line, and the body lands at or even in front of the point of impact perpendicular to the plane of impact (if the starting point was a protruding part of the building).

If the body falls from a vertical position without additional acceleration, then it flies along a parabola, and the place of impact with the surface is always further than the fall perpendicular. The amount of deviation in such cases depends on the height.

© RIA Novosti illustration. Alina Polyanina

The researchers found that when falling, the dummy rotates around the center of gravity in the frontal plane. The number of turns depends on the height. Falling from seven or eight meters (third floor), he turns 180 ° and hits the ground with his head; flying from a height of ten to eleven meters (fourth floor) results in a 270° turn, after which the person lands on their back.

© RIA Novosti illustration. Alina Polyanina

The impact force during landing depends on the mass of the body and the speed of its movement. Moreover, the mass itself does not affect the speed in any way. The different speed of falling bodies with different masses is associated with air resistance, which, of course, will be greater for a feather than for a weight. If the human body is at rest before the flight, then the speed of its movement will depend on the height and acceleration of free fall. The latter value depends on the level at which the object is initially located, but it is so insignificant that this change is usually neglected. In practice, the speed of a body's flight is determined by its height.

© RIA Novosti illustration. Alina Polyanina

© RIA Novosti illustration. Alina Polyanina

The severity of the injuries received is directly related to the speed of the fall, and not to the height. In flight, a person instinctively tries to cling to branches or balconies in order to slow himself down. Of course, this can lead to additional injuries, but it will mitigate the damage on the last hit to the ground.

Greater speed is obtained when falling from a fast moving object. When we fall off a bike or jump out of a car, our body gets the speed of that vehicle and tends to move forward. This is how inertia works - the property of a body to remain at rest or uniform rectilinear motion in the absence of external influences (air resistance or friction force). Due to inertia, we are flying forward when the vehicle stops abruptly.

In the case of a forced jump, you can choose the direction in which to jump. Physics says that it is more correct to jump backwards in order to reduce the speed acquired from a moving object. But in any case, there is a threat to fall, since the upper body will still move when the legs have already stopped, touching the ground. Therefore, it is safer to fall in the direction of the train than backwards - in this case, the person puts his feet forward (or runs a few steps), preventing a fall. When jumping back, this saving movement will not be, and the likelihood of injury becomes higher. In addition, jumping forward, a person puts his hands in front of him and weakens the force of the blow. However, if you want to throw luggage from the train, it is better to do it against the movement of the train.

Fall damage depends on both the laws of physics and the structure of the human body. Since the tissues of the body are elastic, have different elasticity and resistance, and some parts of the body can move, this significantly reduces the impact force. But, of course, it can be weakened by elastic flexion of the limbs and simultaneous landing on several points.

Incredible Facts

It is probably impossible to find a person among us who would not read (or listen to!) the following lines of the unforgettable Russian Soviet children's writer Agnia Barto in childhood: "A bull is walking, swaying, sighing on the go: - Oh, the board is ending, now I will fall!". It is difficult to say whether the quintessence of childhood nightmares, cruelty, or just normal childhood curiosity was a completely logical question: So what, after all, will happen to the bull when it falls? What awaits him in that obscurity that the "heartless" Agniya Lvovna painted for us? However, the years go by, and we understand that the bull-calf, in fact, was not in danger of anything! Well, I would have hit my forehead on the ground, I would have got up, and I would have gone for a walk on my own. Next time he will be more careful and think a hundred times before climbing where he shouldn't!

However, Americans, who are clearly not familiar with the work of the famous children's writer, continue to ask quite childish questions, already at a very respectable age! Judge for yourself: quite recently, on the pages of a well-known English-language Internet resource dedicated to various aspects related to travel and mysterious stories, slipped information about the study of American scientists, who were tasked with finding out what would happen to a person if he fell into ... a volcano? The question sounds at least strange, but there is one thing that cannot but be "reassuring" in this whole story - far-sighted scientists knew that a person who got too close to the edge of the vent and fell down would undoubtedly die. But how exactly will he die?

As it turns out, the question concerned mainly an active volcano. It is not known what research methods the Americans used when investigating this issue (whether they threw a couple of volunteers into the flaming abyss, or did without victims), but the question caused a much greater resonance than any sane person could at first glance seem! As a result, having made remarkable efforts, scientists were able to answer the question, without leaving a drop of hope to the most complete optimists: a person who falls into the mouth of a volcano will die!

However, his death will not be as colorful as, say, the death of Gollum, one of the heroes of the novels of the English writer Tolkien, whose works were filmed in the film trilogy "The Lord of the Rings". If anyone does not remember, the end of Gollum was terrible - he fell into the lava, which immediately swallowed him. However, Gollum is not alone - a similar end awaited all Hollywood (and not only) characters falling into lava or the crater of a volcano.

In fact, lava is a substance of extremely high density (of course, because it consists of molten solid rocks), which means that any living creature that falls from a height into the lava will not be absorbed by it, but rather simply stick to fire surface. However, this does not mean at all that the unfortunate inattentive wretch who got into such trouble will have at least some chance of salvation!

His fate is quite predictable - a person will immediately be engulfed in flames, and he will burn to the ground literally within minutes. Well, one cannot help but be filled with gratitude to the researchers, since now it becomes clear that one should stay away from the mouth of the volcano. However, a quite reasonable question arises: if a person who has fallen into lava fails to “drown” in it due to his small weight and high density of the fiery flow, then what will happen to a living object of greater mass? Say, with a cow? Or with an elephant! There is still something to think about for American scientists, there is something to experiment with ...

The most common cause of injuries in winter is playing catch-up with public transport. At the same time, we all understand that running after a minibus or bus is harmful: firstly, you still won’t catch up, and secondly, you will create many problems for yourself. The obvious ones are stress and stress on the cardiovascular system, as well as trauma. In a state where you can’t control the safety of movement, you step on an icy pavement, you slip… When young people fall, fractures of the ankles in the ankle joint most often occur, and they require quite serious and long-term treatment. Or a broken arm, if a person, falling, manages to put his hand forward, protecting his face from “meeting” with the sidewalk. In older people, the proximal femur most often breaks. Well, and of course, almost half of the active population of St. Petersburg receives bruises, dislocations and sprains during the winter.

What to do if you hurt your leg

If you fell and, overcoming pain, went on with oohs and aahs, watch your condition. A bruise that seems harmless can cause big problems: a chest bruise in a woman is fraught with tumor formation, and a concussion is fraught with headaches, decreased vision and hearing, and other neurological pathologies.

A fracture or severe dislocation is usually diagnosed without problems: sharp pain, increasing swelling, and the inability to move the injured arm or leg normally. If you are in the city, you should immediately call an ambulance. In the suburbs with an ambulance it is more difficult, so the victim must be given first aid correctly, otherwise the patient's condition can be aggravated.

In no case should you pull your arm or leg, twist, align. These uncontrolled actions can only do harm, unless, of course, they are performed by a doctor who is able to assess the situation in the "field" conditions. Everyone remembers that in case of a fracture, it is necessary to put a splint, or rather, to create rest for the damaged organ. This does not mean at all that you need to look for a stick for fixation, it is enough to wrap a sore leg to a healthy one, for example, with a scarf, and a hand to the chest. But all this must be done very carefully so that the person does not writhe in pain.

We must not forget that while the victim was being helped, all this time he was lying on the snow. Therefore, if there is damage allowing, he needs to be helped to move to a warm room, or move him to some kind of blanket to isolate him from the cold ground. To relieve pain, you can take any pain reliever (Nurofen, Ketanov).

At shoulder and shoulder injury there is an outpouring of blood into the joint cavity (hemarthrosis). Contusion and hemarthrosis are accompanied by severe pain, especially when moving the joint and feeling it. Swelling forms in the area of ​​the joints, their contours become smooth, sometimes a bruise is visible under the skin.

The fall may result in rupture of the large deltoid muscle(she moves her hand away). This injury can be determined by soft tissue edema, hemorrhage of the lateral surface of the shoulder. And also for severe pain when feeling the joint or when trying to move the shoulder, take it to the side. First aid for such injuries is immobilization (hang a hand around the neck on a scarf), taking an anesthetic, ice to the muscle. In no case should anything else be done - this injury is difficult to distinguish from a fracture, so you need to urgently consult a doctor.

At stretching of ligaments and muscles shoulder joint pain occurs mainly when moving in a certain direction. When the tendons are torn, the shoulder area hurts from tension, for example, when lifting even minor weights. Pain in these cases can be relieved by the use of painkillers and cold (ice) compresses.

Elderly trauma

The most characteristic and very dangerous injury for the elderly is a fracture of the proximal femoral neck. So if you saw that an elderly woman slipped, fell and could not get up, do not pass by. If she complains of ankle pain, that's one story, osteoporosis in the elderly leads to brittle bones that break easily. The victim must at least be dragged to the wall, if it is not possible to bring it into the room, and call an ambulance. When the pain is concentrated in the thigh area, it is not even worth moving it (if this did not happen on the roadway) - call an ambulance urgently.

Fall on the fifth point

Fractures or injuries of the coccyx are accompanied by damage to the so-called ischial tubercles. If a man or woman of non-childbearing age has suffered from a fall, then specific treatment is not required. The doctor will prescribe bed rest and medication. If a woman is to give birth, and the coccyx was deformed during the fall, then big problems are possible, it must be set, seriously treated.

It is very dangerous if, after a fall, the pain does not appear in the coccyx, but higher - in the lower back or cervical spine (it also manifests itself as headaches, and not just pain in the neck). This suggests that the person received not a direct, but an indirect injury. The consequences can be very different - from the acute development of a hernia to a vertebral fracture. In case of pain in the spine after a fall, you should immediately seek help from a traumatologist. Based on the results of the examination, he will either prescribe the necessary treatment, or refer you to another specialist. Diagnostics is appointed after examination: x-ray, CT scan, MRI.

Fall and hit head on ice

If, after an unsuccessful fall, loss of consciousness, nausea, vomiting, headache are observed, bed rest and a mandatory visit to the doctor are required. But even if there are no such symptoms, and a person after a fall does not remember how he fell, or who raised him, this is the first sign of a concussion, you should also consult a doctor. The principles of first aid for concussion were formed by Hippocrates. This is cold, hunger and rest plus symptomatic treatment.

With any injury, the main thing is not to panic and remember that the worst thing that could happen is behind you. ahead- recovery process. Even if you didn't plan it for the near future...

How not to become a victim of ice

1. Practice falling. If you feel that you have slipped and cannot keep your balance, pull your head into your shoulders, press your elbows to your sides, straighten your back, bend your legs slightly. Since you are falling, try to fall on your side without putting your straight arms forward.

Are you falling on your back? Press your chin to your chest, and spread your arms wider so that they serve as a shock absorber when you fall.

If you slip on the stairs and fly down, take care of your face and head, group up if possible.

Of course, remembering these tips when you are already falling is difficult. Maybe worth some practice? Our utilities are unlikely to work better in the coming years, so no one is immune from a fall.

2. Drunk people fall more often. Do not believe those who say that someone is laying straw at the place of the fall when they are drunk. It is not true. Most injuries happen to people who are drunk. Therefore, taking on the chest, stay at home.

3. Resist physical laws. You can reduce slip and fight gravity by following simple rules. Choose shoes with non-slip, better grooved soles. Women should give up high heels for this period, and even more so stilettos. Look under your feet. And if there is a slippery road ahead, step on the ground with your whole foot.

Irina Baglikova

Dr. Peter