Why should it explode

Scientists have repeatedly stated that a thermonuclear reaction that takes place inside a single star in our system could destroy not only the yellow dwarf, but all nearby planets. This can happen due to the "premature aging" of the Sun - processes that accelerate the "wear" of the star and shorten the life cycle. You need to understand that our Sun has already lived almost half of its life.

The maximum lifespan of a star is 10 billion years "\u003e

The maximum lifespan of a star is 10 billion years

Second copy of Earth

When a huge star is torn apart into atoms, it goes supernova. Trillions of tons of dust and gas are thrown out. New worlds are born from this building material, but the transition of a star to a supernova often becomes the last event for already formed planets.

The explosion of the Sun will definitely kill all the terrestrial planets, but there are pluses "\u003e

The explosion of the Sun will definitely kill all the planets of the terrestrial group, but there are pluses

We will die before the explosion

None of the scenarios for the destruction of the terrestrial planets, oddly enough, includes the explosion itself. When the sun begins to die, it, according to forecasts of scientists, will have to increase in size and, most likely, will become significantly colder.

Over time, it mutates from a yellow dwarf to a red giant "\u003e

Over time, it mutates from a yellow dwarf to a red giant.

Cold and hellish heat

The exact scenario of a solar explosion still does not exist, and everything that is connected with reasoning about the death of an entire planetary system is exclusively in the theoretical plane. For example, the scenario of "burning out all living things" is far from the only one. There is another direction - cooling after the explosion.

Photo: © KInopoisk / "\u003e"\u003e

Such an explosion will not violate the integrity of the Sun, but will stop the thermonuclear reaction "\u003e

Such an explosion will not violate the integrity of the Sun, but will stop the thermonuclear reaction.

Soccer ball

The sun not only warms the earth, but also keeps it in a comfortable (in all respects) orbit. If the central star explodes, then one fine morning earthlings will find that they are far from their usual habitat.

The destruction of the Sun will "erase" the usual orbit of the Earth "\u003e

The destruction of the Sun will "erase" the usual orbit of the Earth

Doomsday live

If the Sun explodes in the way that filmmakers and science fiction writers imagine it, then the planet will not turn into vapor. And although scientists refused from the original scenario, which assumed "burning out" the Earth's surface and soil down to the core in eight minutes, other options are not much better.

Space expert Mikhail Lapikov noted that with some variants of the explosion of the Sun, the daytime side of the planet at high speed will simply "sterilize" - animals and other living organisms will be burned at a temperature of several million degrees.

First, the atmosphere will be "evaporated", then the surface temperature will be such that several layers will simply melt

Mikhail Lapikov

With this development of events, even bacteria and other protozoa can disappear. Water and all volatile gases will evaporate irrevocably. Further, the globe will gradually crack from the cold, and the planet will be outside the habitable zone. Earthlings will be able to observe all this splendor with their own eyes melted and burnt.

Calculated and average time of destruction "\u003e

Calculated and average destruction time

The glow of the sun is caused by the intense burning of various substances, primarily hydrogen and helium. The combustion temperature is so high that the reaction proceeds like a thermonuclear, due to which the sun ...

The glow of the sun is caused by the intense burning of various substances, primarily hydrogen and helium. The combustion temperature is so high that the reaction proceeds like a thermonuclear, thanks to which the sun is able to heat the Earth at such a considerable distance.

Why does the sun have to go out?

The sun is a very small star, there are luminaries thousands and tens of thousands of times larger... Initially, all stars shine due to the thermonuclear reaction of hydrogen nuclei, which turns into heavier substances: helium, oxygen, iron and even gold.

Under the influence of high temperature and pressure, these substances also begin to participate in the emission of light by the sun. Due to their high atomic mass and large amount of energy, the sun begins to cool down, increasing in size. But at a certain stage, when there are too few light chemical elements, the temperature becomes insufficient for a thermonuclear reaction of heavier substances.

After that, the development of the star can follow two scenarios. The heaviest stars, due to the high density of matter, the absence of buoyancy forces from the extinct core, begin to shrink, in a short time turning into a black hole - an unusually dense area of \u200b\u200bspace.

Since the size of the sun is more than modest, its extinction will follow a different scenario. After 2 billion years, it will noticeably increase in size, absorbing Venus. Then, having reached the Earth's orbit, and possibly also engulfing our planet, the sun will begin to burn the remnants of matter. When even the iron burns out, the giant ball will explode, completely stripping its upper shell.

In place of the sun, only a dense and gradually cooling core will remaincomposed of very heavy metals - a white dwarf. Based on astronomical data and a large number of examples, this should happen in 4-5 billion years.

What happens if the sun explodes?

The extinction of the sun will not be gradual - our luminary will spend its last days very violently and actively... According to the pessimistic forecast, the Earth will not at all catch the extinction of the sun - being absorbed by the chromosphere of the luminary, our planet will turn into a high-energy plasma. If the surface of the sun does not reach the Earth, then up to 90% of the sky will be occupied by the star. By that time, the oceans will evaporate, even a thin solid layer of the earth's crust - the lithosphere - will become liquid.

At the moment of the explosion, the most powerful shock wave will throw the Earth and other planets remaining by that time from the solar system. Since there will be nothing to shine - only a small white point of the former sun will be located in the firmament - the temperature on the Earth will quickly approach absolute zero.

The usual change of day and night, surface lighting will also be completely absent. The shape of the Earth, which has undergone significant asymmetry after the explosion, will forever remain unchanged, since any tectonic activity in the mantle, core, due to old age and low temperature, will cease. There could be trillions of such lonely, wandering ice planets, devoid of stars due to a supernova explosion.

What will happen on Earth if the Sun stops shining?

Despite the fact that this option does not correspond to modern scientific data, such theories exist. Some scientists assume that our star will not become a red giant and will not explode. It is assumed that as it grows old, the sun will shine weaker and weaker, subsequently extinguishing altogether.

A momentary cessation of solar activity will not make the Earth a block of ice at once - our planet also has an internal source of heat - a red-hot core. After 12 hours, it will become noticeable that climatic changes are taking place. In areas with a sharply continental climate, 0 ° C will be reached. The oceans and coastal areas will cool the longest - water is an excellent heat accumulator - up to a week.

The lack of sunlight will force all the plants on the planet, right up to the moment of their freezing, to switch to the absorption of oxygen, which will cause its deficiency. Due to the uneven cooling of the planet, hurricane winds of the type that blow in the Antarctic will begin on the surface - up to 300 kilometers per hour.

A month later, the entire surface of the ocean will freeze, except for the deepest depressions. A completely uniform temperature will be reached after six months. By that time, all gases except hydrogen will turn into ice and life will be possible only in super-deep mines.

When exactly will the sun go out?

When will the sun go out? The answer to this question has been obtained with the help of modern technologies and a variety of express methods. Everything in the Universe has its beginning and end. Not only plants, animals and people die, but also stars and planets, although their lifespan differs from that of terrestrial flora and fauna.

Humanity at all times was afraid of the end of the world. Many scientists have tried to calculate when this will happen, linking Armageddon with the end of the Sun's existence, but when exactly this will happen is unknown. Today, as well as many years ago, scientists all over the world are wondering that when the Sun goes out and humanity finds itself in this passion, will it be able to live without a star on Earth.

How can the sun die?

So far, there are no particular reasons for concern, since this will not happen soon. Neither this nor the next generation will see the outcome and will not know why it happened. Perhaps the death of the Sun will become a new stage in the evolution of mankind, as it will force people to roam in space. Only sports and good physical training will help them in this.

However, it is unpleasant to realize that this Sun can explode, the world will scatter into small pieces, and the trace of humanity on the planet will evaporate. There are many variations on how this Sun will cease to exist. How this can happen, no one knows. Our Sun can simply go out, turn into a nebula, be reborn and become a red giant, after which it will face the fate of a supernova that is not capable of emitting sunlight. Or perhaps this Sun will simply explode and scatter throughout space.

Over time, the hydrogen contained in the solar core is completely converted into helium, as a result of which the core will heat up and condense, the star itself will increase in size, passing into the stage of a giant red star. There is a theory that hot gases will have to escape into space and move our planet away, which will prevent a catastrophe. According to scientists, this will happen in 5-6 billion years, it is for this period that the reserves of the yellow star will be enough. The red giant stage does not last so long, about a hundred million years. After that, the luminary can simply go out.

By this time, the Earth will become completely uninhabitable. Neither sport nor a person's high adaptability to changing environmental conditions will help here. The immense energy of the reborn star will burn the entire atmosphere and surface, which will become an absolute desert. After some time, people will have to move to live underground so as not to burn out at a temperature of 70 ° C. It will be necessary to find a planet in another galaxy and go there, because due to the increased temperature, the rate of decay of carbon dioxide will increase, which will make the plants disappear, without which the existence of people is impossible. The water will evaporate under the increased solar radiation, and the atmosphere will dissipate.

After some time, the star is likely to engulf nearby planets, including the Earth. If it does not touch it, then it will simply move away later, and, being left without attraction, will leave the Milky Way and wander. Unfortunately, the people of this generation never know what the outcome of this story will be.

After the red stage, this Sun will begin to pulsate intensely, its atmosphere will break out into the Universe, in place of a colossal bright star a small one will appear, similar in composition to a diamond, which will soon completely cool down, becoming a black dwarf.

If you believe the second theory, then this Sun will simply go out. Each star during its existence evolves from a nebula to a protostar, which turns into a yellow dwarf, which is also our star. After that, there are two possible events: the star goes out, turning into a blue dwarf, gradually becomes a nebula again. Or it is reborn into a red giant with even more energy. In both cases, such an outcome could be disastrous for the Earth.

How long will the Earth live?

According to scientists, the Sun is slowly but surely approaching the "noon" of its life. Its age, according to computer calculations, is approximately 5 billion years. In total, the lifetime of a star is about 10 billion years. If the star becomes a blue or white dwarf, a dead star, then it simply will not be able to give our planet enough heat and energy, life will cease to exist not immediately, but gradually.

For some more time the Sun will “burn”, but this light will be a gradual cooling phenomenon. The planet will not be covered in an instant by an ice crust, a person will notice this phenomenon only after 8 minutes, and the energy that is stored at the bottom of the oceans will give off heat for some time, it will support life on Earth. The planet's temperature will drop by about 20 ° C. Having reached zero soon, it will decrease even more, so in a year the Earth will be -40 ... -50 ° С, permafrost will come, only the simplest microorganisms can survive in such conditions, but not people.

If the Sun goes out, the Earth will be in open space, day will cease to replace night, the Moon will disappear from the firmament, and with it the ebb and flow, a series of earthquakes will take place on the planet's surface. Photosynthesis will stop, plants will disappear, respectively, oxygen production will stop. The earthlings will still have enough air supply for some time, but this resource will already be limited. For heating people everywhere will use geothermal sources, as is now practiced in Iceland.

Sun explosion theory

There is a theory of the explosion of the sun. Many scientists dispute it, saying that the mass of the star is too small for such an outcome of events. Others, on the contrary, support the founders of the version, adding other details. If the Sun explodes, then in time it will be in about 6 thousand years. The theory arose from the fact that the temperature of the solar core has doubled over the past two decades. If this trend continues, the luminary will explode like glass before it goes out. It will be able to scatter throughout the universe. After the explosion, a neutron star or black hole is formed. Some experts fear a man-made explosion where outer bodies will cause the star to collapse at any moment. However, there is no adequate reason to worry about this.

What happens if the sun goes out? No one can give an exact answer to this question, but this will certainly mean the end of the blue planet. But not necessarily the end of humanity, since most people choose sports, so they can easily adapt to any conditions. It is impossible to accurately answer the question of how many people will die as a result of the death of the fireball, and how many will be helped by sport and the desire to live. It is difficult to predict the future exactly, but based on modern knowledge of physics, the death of a star will be exactly like this - it will simply cool down.

What will happen if the sun's rays go out? No one can give an exact answer to this question, there are only assumptions: perhaps the world will scatter into millions of small fragments, or maybe nothing will happen to the Earth, and the sports spirit and endurance of people will be able to overcome all obstacles. Or maybe sports on the planet and the desire of mankind to exist here will not be able to overcome and overcome world cataclysms.

What will happen to the Earth if the Sun goes out?

Scientists assume that in 5 billion years, the only star in the solar system will go out. What happens if the sun goes out?

Why the sun can go out or explode

For the Sun to explode, one condition is necessary - the hydrogen that is part of it must turn into helium. But this is not an explosion in the literal sense. Astronomers mean by this phenomenon a decrease in temperature and a simultaneous increase in size. Quasars and entire star clusters can literally explode.

It is known from the physics course that with decreasing temperature, the volume of most bodies decreases. But this is not the case for the Sun and other stars. Due to the forces of attraction, these objects should be compressed. In this case, their density increases so much that thermonuclear reactions begin to proceed. Helium is formed from hydrogen, and then most of the heavier elements listed in the periodic table.

On the surface of the Sun visible from the Earth, the temperature fluctuates around 6,000 ° C. Stars with such indicators belong to the yellow spectral class. The temperature in the inner layers of the star is about 17 million degrees. Due to this, the celestial body should increase in size.

Dynamic equilibrium occurs when gravitational contraction is compensated by thermal expansion. Nuclear reactions proceed spontaneously, therefore, the given temperature data are averaged. We perceive temperature changes in different parts of the surface as dark spots that determine solar activity, including magnetic.

Approximately half of the evolution of our star has passed. To date, solar hydrogen reserves have decreased by 40% from the original. The burning out of this gas leads to a decrease in the mass of the Sun. And this, in turn, leads to a decrease in the value of gravitational forces compressing it. The star begins to increase in size, the probability of thermonuclear reactions decreases, the temperature decreases. This is how red giants and supergiants appear. Our star is an ordinary star. The same fate awaits him, but it will not be able to completely extinguish.

What awaits us

It is wrong to say that if the Sun goes out, then it will cease to be a source of heat and light. But its physical characteristics will change. When the Sun explodes, it will not scatter to pieces like shell fragments, but will transfer to another class of stars and turn into a red giant.

When the sun goes out, its size will increase so much that the radius of the star will exceed the radius of the orbit of Venus. Mercury and Venus will "fall" on him and be swallowed up by him. It is not known exactly how many years this will happen. Could the sun swallow our planet? According to scientists, it will remain in its orbit, but how life on Earth will change is still a mystery.

Our luminary is a source of heat and light. If the Sun goes out, it can be compared to a stove that shines and heats weaker, but is located closer to us.

In 5 billion years the Sun will go out. But over a long period of time, life on our planet will evolve, adapting to changing conditions. But life in today's understanding requires the conditions in which it was born.

There is a hypothesis according to which the Milky Way, which includes our planetary system, will be swallowed up by the nearest neighboring Andromeda Nebula. Today, both galaxies are converging at a speed of 120 km / s. Computer simulations have shown that due to the increasing gravitational interaction, a change in the structure of the Milky Way will begin in 2 billion years, i.e., 3 billion years earlier than the sun goes out. And after 5 billion years, both spiral galaxies form one new ellipse.

Astronomy is developing at a rapid pace. It is likely that in the near future there will be new hypotheses describing the prospects of our star and what will happen to the Earth if the Sun went out.

How long is the sun left to live? Science answers this question as follows: the age of our star is approximately 4.5 billion years. During this time, she managed to use up half of the hydrogen in its core. In other words, the Sun should have enough "fuel" for another 4-5 billion years. The term is quite long, and mankind seems to have nothing to worry about. But recently, the Dutch astrophysicist Pierce van der Meer, an expert of the European Space Agency (ESA), compared data on the temperature of the solar core over the past 11 years and came to completely sensational conclusions. According to van der Meer, what is happening now on the Sun is very similar to the changes that precede the explosion of a supernova. According to the Dutch scientist, the core temperature of the Sun, which is usually 27 million degrees Fahrenheit, has risen to 49 million degrees in a few years. If the sun's interior continues to heat up at the same rate, the process will become irreversible, and the sun will inevitably explode in about six years!

Now imagine what an observer sees on a planet in the immediate vicinity of an exploding supernova. The script of the apocalypse was prepared by specialists from the Institute of Solar-Terrestrial Physics, Siberian Branch of the Russian Academy of Sciences, at the request of Itogi. Approximately 8 minutes after the explosion, a monstrous flash will flood the whole sky, and this will be the last thing a person will see: along with the blinding light of the explosion, an invisible stream of X-ray, ultraviolet and gamma radiation of such power will come that it will overcome the protective layer of the atmosphere and kill in a matter of seconds all living things. The radiant energy of the explosion will heat the atmosphere and surface of the planet to temperatures of many thousands of degrees. Intense ocean evaporation will begin, and the hot planet will be enveloped in hot steam. A monstrously bright, growing ball will shine through through the dense searing fog. The night sky will turn red-violet, in terrible divorces: a glowing cloud of ionized gas expanding at a speed of several thousand kilometers per second will gradually obscure the entire sky. Very quickly, streams of incandescent plasma from the exploding star will reach the planet. The atmosphere will be destroyed, and the history of the Earth as an inhabited planet will end there. It will take a very long time before the melted radioactive "cinder" of the dead planet begins to slowly cool down.

Impressive? Dr. van der Meer's calculations and conclusions are truly shocking. There is only one consolation: the construction of the Dutchman is just a hypothesis, which many experts immediately questioned. For example, Sergei Yazev, a senior researcher at the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences, said in an interview with the Itogov correspondent: “The conclusions of Dr. van der Meer about the increase in the temperature of the Sun's core look very strange. continuously recording the flow of solar radiation over the past decades, show that the rate of energy release of the main source of energy in our planetary system, as before, remains stable - every second the Sun emits energy equal to approximately 3.84 x 1026 joules. This value does not change at least For decades. By indirect evidence, we can conclude that the Sun has been shining in this mode for a very long time. That is, the same amount of solar energy falls on the Earth all the time. " Referring to historical and geological data, scientists argue that the Sun has been radiating and radiating energy quite steadily for at least several million years. If it were not so, they say, the Earth would bear the traces of the past boiling oceans or global glaciers. Fortunately, the "firebox" of the Sun worked and is working stably.

There are other arguments against van der Meer's hypothesis. In general terms, the mechanism of the death of a star looks like this. As a result of thermonuclear reactions, the available hydrogen "burns out", instead of it nuclei of helium atoms and heavy elements - iron, cobalt and nickel - are formed. When the hydrogen fuel finally dries up, the outer shells of the star begin to rapidly "collapse" and fall inward, attracted by the massive iron core. As the density increases, electrons are captured by protons, resulting in the formation of neutrons and the release of a huge amount of neutrinos. Neutrinos rush out. The powerful neutrino flux rising from the center of the star carries with it the falling shell of the star, and it scatters in space with great speed - the star explodes. However, scientists say that all this does not threaten small stars of the Sun class at all. For a star to explode and go supernova, it must be at least three times the mass of the Sun.

“In addition, astrophysicists are well aware of the signs of a so-called pre-supernova star,” says Sergei Yazev. “The fact is that the spectrum of a star can be used to determine its chemical composition. the end, and soon - however, this "soon" may continue for many thousands of years! - the phase of instability of the star should begin. But 90 percent of the atoms on the Sun are hydrogen! And it will still have a very, very long time to transform into heavier elements. that nothing dangerous in this sense is observed on the Sun. "

Alternative scenarios of the end of the world, proposed, in particular, by American scientists, look much less dramatic. For example, professor at the University of Pennsylvania James Casting does not deny that the Sun, like any other star, does not last forever: “It is inexorably getting brighter and hotter. This leads to a gradual" dehydration "of the Earth. billions of years, as is commonly thought, and much earlier. Computer simulations show that these processes can begin in about 500 million years. " Fred Edems, a physicist at the University of Michigan, calls a more optimistic timeline: “About 3.5 billion years are left before the cataclysm, and hardly anyone will observe the explosion of the Sun. It will destroy all life much earlier. And the already dead Earth will then be burned in the result of an explosion that will absorb, in addition to her, Mercury, Venus and Mars. "

However, more exotic hypotheses are being put forward. Thus, computer calculations carried out by American specialists show that there is a possibility that Jupiter - the largest planet in the solar system - will be ripped off its orbit by a passing star. As a result of this cataclysm, the Earth will rush into the icy depths of the Universe, where it will freeze. However, this scenario is unlikely to be realized in the foreseeable future.

Nevertheless, in the coming years, the Sun can present surprises to humanity. Vladimir Obridko, an authoritative specialist in the field of solar studies, head of the heliophysical laboratory at the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences, draws attention to the coincidence of several cycles of solar activity at the beginning of the millennium - 11-year, 22-year, 100-, 400- and 900 -year old. "Some kind of solar mess is coming, which cannot yet be predicted. We simply do not have sufficient knowledge of how a star behaves before an explosion," says Vladimir Obridko. An accurate calculation of the behavior of a star is hampered by the lack of rigorous data, because according to all the rules, the Sun has been studied for a little more than a hundred years. Science still has very scanty information about both the structure and behavior of the Sun. Only now, heliophysicists around the world are finally completing a large-scale work on creating a standard model of the internal structure of our star. Nevertheless, it is hardly about the imminent death of the solar system. Sergei Yazev, for example, is so sure of this that he is even ready to risk a large sum of money: “Taking this opportunity, I can offer Dr. van der Meer a bet for 10 thousand dollars. If, after three years, astrophysicists still find clear signs that he is right , I give him the money. But if it turns out that the scientist's assumption is not true, then I expect him to transfer to my account. "

The age of the Sun is estimated by most astrophysicists at about 4.59 billion years. It is classified as a medium or even small star - such stars exist longer than their larger and rapidly fading sisters. The sun has so far managed to use up less than half of the hydrogen it contains: out of a 70.6 percent share of the original mass of solar matter, 36.3 remain. In the course of thermonuclear reactions, hydrogen inside the Sun turns into helium.

In order for the fusion reaction to proceed, high temperature and high pressure are required. Hydrogen nuclei are protons - elementary particles with a positive charge, an electrostatic repulsion force acts between them, preventing them from approaching. But inside there are also significant forces of universal attraction, which prevent the protons from scattering. On the contrary, they push the protons so close together that nuclear fusion begins. Part of the protons turns into neutrons, and the forces of electrostatic repulsion are weakened; as a result, the luminosity of the sun rises. Scientists estimate that at the initial stage of the Sun's existence, its luminosity was only 70 percent of what it emits today, and in the next 6.5 billion years, the star's luminosity will only increase.

However, they continue to argue with this point of view, which is the most widespread and included in textbooks. And the main topic for speculation is precisely the chemical composition of the solar core, which can be judged only by very indirect data. One of the competing theories suggests that the main element in the solar core is not hydrogen at all, but iron, nickel, oxygen, silicon and sulfur. The light elements - hydrogen and helium - are present only on the surface of the sun, and the fusion reaction is facilitated by the large number of neutrons emitted from the core.

Oliver Manuel developed this theory in 1975 and has been trying to convince the scientific community of its validity ever since. He has a number of supporters, but most astrophysicists consider it complete nonsense.

Photo: NASA and The Hubble Heritage Team (AURA / STScI)

The variable star V838 Monocerotis (V838 Monocerotis) is located at the edge of our galaxy. This image shows part of the star's dusty envelope. This shell is six light years across. That light echo, which is visible now, lags behind in relation to the flash itself by only two years. Astronomers expect the light echo to continue flashing the dusty surroundings of V838 Mon as it expands for at least the rest of this decade.

Whichever theory is correct, the "solar fuel" sooner or later will run out. Due to the lack of hydrogen, thermonuclear reactions will begin to stop, and the balance between them and the forces of gravity will be violated, causing the outer layers to press against the core. From the contraction, the concentration of the remaining hydrogen will increase, nuclear reactions will intensify, and the core will begin to expand. The generally accepted theory predicts that at the age of 7.5-8 billion years (that is, after 4-5 billion years), the Sun will turn into a red giant: its diameter will increase more than a hundred times, so that the orbits of the first three planets of the solar system will be inside the star ... The core is very hot, and the temperature of the giants' shell is low (about 3000 degrees) - and therefore red in color.

A characteristic feature of the red giant is that hydrogen can no longer serve as "fuel" for nuclear reactions inside it. Now helium, accumulated there in large quantities, begins to "burn". In this case, unstable isotopes of beryllium are formed, which, when bombarded with alpha particles (that is, the same helium nuclei), turn into carbon.

It is on this that life on Earth, and the Earth itself, is most likely already guaranteed to cease to exist. Even the low temperature that the solar periphery will have at that time will be enough for our planet to completely evaporate.

Of course, humanity as a whole, like each person individually, hopes for eternal life. The moment the Sun turns into a red giant imposes certain restrictions on this dream: if mankind manages to survive such a catastrophe, then only outside of its cradle. But it is pertinent to recall here that one of the greatest physicists of our time, Stephen Hawking, has long argued that the moment when the only way for humanity to survive will be colonization of other planets has almost come. Intraterrestrial reasons will make this cradle impossible to inhabit much earlier than something bad happens to the Sun.

Let's take a closer look at the timing here:

Weight \u003d 1.99 * 1030 kg.

Diameter \u003d 1.392.000 km.

Absolute magnitude \u003d +4.8

Spectral class \u003d G2

Surface temperature \u003d 5800 ° K

Orbital period \u003d 25 h (pole) -35 h (equator)

The period of revolution around the center of the galaxy \u003d 200,000,000 years

Distance to the center of the galaxy \u003d 25000 light. years old

The speed of movement around the center of the galaxy \u003d 230 km / sec.

The sun. The star that gave rise to all living things in our system is approximately 750 times the mass of all other bodies in the solar system, so everything in our system can be considered revolving around the sun, as a common center of mass.

The sun is a spherically symmetric incandescent plasma ball in equilibrium. It probably arose together with other bodies of the solar system from the gas and dust nebula about 5 billion years ago. At the beginning of its life, the sun was about 3/4 hydrogen. Then, due to gravitational compression, the temperature and pressure in the bowels increased so much that a thermonuclear reaction began spontaneously, during which hydrogen was converted into helium. As a result, the temperature in the center of the Sun rose very strongly (about 15,000,000о K), and the pressure in its depths increased so much (1.5x105 kg / m3) that it was able to balance the force of gravity and stop gravitational compression. This is how the modern structure of the Sun arose.

Note: The star contains a giant reservoir of gravitational energy. But you cannot draw energy from it with impunity. It is necessary for the Sun to shrink, and it should decrease by 2 times every 30 million years. The total supply of thermal energy in a star is approximately equal to its gravitational energy with the opposite sign, i.e., on the order of GM2 / R. For the Sun, the thermal energy is equal to 4 * 1041 J. Every second the Sun loses 4 * 1026 J. The reserve of its thermal energy would only last for 30 million years. Saves by thermonuclear fusion - the combination of light elements, accompanied by a giant energy release. For the first time, this mechanism, back in the 1920s, was pointed out by the English astrophysicist A. Edington, who noticed that four nuclei of a hydrogen atom (proton) have a mass of 6.69 * 10-27 kg, and a helium nucleus - 6 , 65 * 10-27 kg. The mass defect is explained by the theory of relativity. According to Einstein's formula, the total energy of the body is related to the mass by the ratio E \u003d Ms2. The binding energy in helium is one nucleon more, which means that its potential well is deeper and its total energy is less. If helium is somehow synthesized from 1 kg of hydrogen, an energy equal to 6 * 1014 J will be released. This is approximately 1% of the total energy of the spent fuel. So much for your reservoir of energy.

Contemporaries, however, were skeptical of Edington's hypothesis. According to the laws of classical mechanics, in order to bring protons closer to a distance of the order of the radius of action of nuclear forces, it is necessary to overcome the forces of Coulomb repulsion. For this, their energy must exceed the value of the Coulomb barrier. The calculation showed that to start the process of thermonuclear fusion, a temperature of about 5 billion degrees is required, but the temperature at the center of the Sun is about 300 times less. Thus, the Sun did not seem hot enough for helium synthesis to be possible.

Edington's hypothesis was saved by quantum mechanics. In 1928, the young Soviet physicist G.A. Gamow discovered that, according to her laws, particles can, with some probability, leak through the potential barrier even when their energy is below its height. This phenomenon is called sub-barrier or tunnel junction. (The latter figuratively indicates the possibility of finding oneself on the other side of the mountain without climbing to its top.) Using tunnel transitions, Gamow explained the laws of radioactive a-decay and thereby for the first time proved the applicability of quantum mechanics to nuclear processes (almost at the same time, tunnel transitions were discovered by R. Henry and E. Condon). Gamow also drew attention to the fact that, owing to tunnel transitions, colliding nuclei can come close to each other and enter into a nuclear reaction at energies lower than the Coulomb barrier. This prompted the Austrian physicist F. Houtermans (to whom Gamow told about his works even before their publication) and the astronomer R. Atkinson to return to Edington's idea of \u200b\u200bthe nuclear origin of solar energy. And although the simultaneous collision of four protons and two electrons to form a helium nucleus is an extremely unlikely process. In 1939, G. Bethe managed to find a chain (cycle) of nuclear reactions leading to the synthesis of helium. The catalyst for the synthesis of helium in the Bethe cycle is the carbon nuclei C12, the number of which remains unchanged

So - in reality, only their central part with a mass of 10% of the total mass can serve as fuel for stars. Let's calculate how long the sun will have enough nuclear fuel.

The total energy of the Sun is M * c2 \u003d 1047 J, nuclear energy (Ead) is approximately 1%, i.e. 1045 J, and taking into account the fact that not all matter can burn up, we get 1044 J. Dividing this value by the luminosity of the Sun 4 * 1026 J / s, we get that its nuclear energy will last for 10 billion years.

In general, the mass of a star unambiguously determines its further fate, since the nuclear energy of the star is Ead ~ Mc2, and the luminosity behaves approximately like L ~ M3. The burn-up time is called nuclear time; it is defined as tad \u003d ~ Ead / L \u003d lO10 (M / M of the Sun) -2 years.

The larger the star, the faster it burns itself! The ratio of three characteristic times - dynamic, thermal, and nuclear - determines the character of the star's evolution. The fact that the dynamic time is much shorter than the thermal and nuclear time means that the star always has time to come to hydrostatic equilibrium. And the fact that the thermal time is less than the nuclear time means that the star has time to come to thermal equilibrium, that is, to equilibrium between the amount of energy released in the center per unit time and the amount of energy emitted by the surface of the star (the luminosity of the star). In the Sun every 30 million years, the supply of thermal energy is renewed. But energy in the Sun is carried by radiation. That means photons. A photon, born in a thermonuclear reaction at the center, appears on the surface after a thermal time, ~ 30 million years). The photon moves at the speed of light, but the thing is that, being constantly absorbed and re-emitted, it strongly entangles its trajectory, so that its length becomes equal to 30 million light years. For such a long time, the radiation has time to come into thermal equilibrium with the substance through which it moves. Therefore, the spectrum of stars and is close to the spectrum of a black body. If the sources of thermonuclear energy were "turned off" (like a light bulb) today, the sun would continue to shine for millions of years.

But even if the prophecy of Hawking and his many predecessors and like-minded people around the world is destined to come true and humanity goes to build an "extraterrestrial civilization", the fate of the Earth will still worry people. Therefore, many astronomers are particularly interested in stars similar to the Sun in their parameters - especially when these stars turn into red giants.

Thus, a group of astronomers led by Sam Ragland, using an infrared-optical complex of three combined telescopes Arizona's Infrared-Optical Telescope Array, studied stars with masses from 0.75 to 3 times the mass of the Sun, approaching the end of their evolution. The approaching end is quite easily identified by the low intensity of the hydrogen lines in their spectra, and, on the contrary, by the high intensity of the helium and carbon lines.

The balance of gravitational and electrostatic forces in such stars is unstable, and hydrogen and helium inside them alternate as a type of nuclear fuel, which causes changes in the brightness of the star with a period of about 100 thousand years. Many such stars spend the final 200 thousand years of their lives as World-type variables. (Variable Worlds are stars whose luminosity regularly changes with a period from 80 to 1 thousand days. They are named after the "progenitor" of the class, the stars of the World in the constellation Cetus).

Illustration: Wayne Peterson / LCSE / University of Minnesota

A rendered model of a red pulsating giant created at the Computational Science and Technology Lab at the University of Minnesota. Internal view of the star's core: yellow and red - areas of high temperatures, blue and aqua - areas of low temperatures.

It was in this class that a rather unexpected discovery took place: near the star V 391 in the constellation Pegasus, an exoplanet was discovered, previously immersed in the swollen shell of the star. More precisely, the star V 391 pulsates, due to which its radius increases and decreases. The planet, the discovery of which a group of astronomers from different countries reported in the September issue of the journal Nature, has a mass more than three times the mass of Jupiter, and the radius of its orbit is one and a half times the distance separating the Earth from the Sun.

When V 391 passed the red giant stage, its radius reached at least three-quarters of its orbital radius. However, by the beginning of the expansion of the star, the radius of the orbit in which the planet was located was smaller. The results of this discovery leave the Earth a chance to survive after the explosion of the Sun, although the parameters of the orbit, and the radius of the planet itself, are likely to change.

The analogy is somewhat spoiled by the fact that this planet, as well as its parent star, are not very similar to the Earth and the Sun. And most importantly, when V 391 turned into a red giant, it "dropped" a significant part of its mass, which "saved" the planet; but that only happens to two percent of giants. Although the "dumping" of the outer shells with the transformation of the red giant into a gradually cooling white dwarf surrounded by an expanding gas nebula is not so rare.

A too close meeting with its star is the most obvious, but not the only trouble awaiting the Earth from other large cosmic bodies. It is likely that the Sun will turn into a red giant, having already left our galaxy. The fact is that our galaxy, the Milky Way, and the neighboring giant galaxy, the Andromeda Nebula, have been in gravitational interaction for millions of years, which will eventually lead to Andromeda pulling the Milky Way toward itself, and it will become part of this large galaxy. Under the new conditions, the Earth will become a completely different planet, moreover, as a result of gravitational interaction, the Solar System, like hundreds of other systems, can literally be torn apart. Since the gravitational pull of the Andromeda Nebula is much stronger than the gravity of the Milky Way, the latter approaches it at a speed of about 120 km / s. Using computer models made with an accuracy of 2.6 million objects, astronomers have determined that in about 2 billion years the galaxies will converge, and the force of gravity will begin to deform their structures, forming long, attractive tails of dust and gas, stars and planets. After another 3 billion years, the galaxies will come into direct contact, as a result of which the new united galaxy will take an elliptical shape (both galaxies are considered spiral today).

Photo: NASA, ESA, and The Hubble Heritage Team (STScI)

In this image, two spiral galaxies (the large one is NGC 2207, the small one - IC 2163) pass each other in the region of the Great Dog constellation, like majestic ships. The tidal forces of the galaxy NGC 2207 have distorted the shape of IC 2163, throwing stars and gas into streams stretching for hundreds of thousands of light years (in the right corner of the image).

The Harvard Smithsonian Center for Astrophysics Prof. Avi Loeb and his student TJ Cox suggested that if we could observe the sky of our planet through the notorious 5 billion , then instead of the usual Milky Way - a pale streak of dim twinkling dots - we would see billions of new bright stars. In this case, our solar system would be located "on the outskirts" of a new galaxy - about one hundred thousand light years from its center instead of the present 25 thousand light years. However, there are other calculations: after the complete merger of galaxies, the solar system may move closer to the center of the galaxy (67,000 light years), or it may happen that it will fall into the "tail" - a connecting link between galaxies. And in the latter case, due to the gravitational effect, the planets located there will be destroyed.

Considering the future of the Earth, the Sun, the solar system as a whole, and the Milky Way is as exciting as it is conventionally scientific. The huge time frames of forecasts, the lack of facts and the relative weakness of technology, as well as to a large extent the habit of modern people to think in terms of cinema and thrillers, influence the fact that assumptions about the future are more like science fiction, only with a special emphasis on the first word.

I heard that time erases everything ...

BG "Adelaide"

In fact - in my opinion, the main question of philosophy for thinking people should be as follows: "What will happen if the sun explodes?" or, more precisely, even “When the Sun will explode?” And not at all in well-known questions: “What is the meaning of life” or there, for example, “What is primary - matter or consciousness”. This question, of course, is deeper and more serious from a philosophical point of view, although the answer to it is short and obvious - "Our whole world will evaporate without a trace, and that's all", without any trace at all, nothing will remain at all, everything here will simply evaporate in the throat of plasma thermonuclear reactions and again everything will become the simplest atoms - the structure will disintegrate into individual smallest elements, and any information will simply disappear - forever and irrevocably. It is certainly an impressive sight when everything disappears, absolutely everything - without any hope of recovery. Whole and the world - everything that can be touched and remembered - everything will disappear - as And there will come again absolute silence and tranquility, on all waves. How - there was a drawing, they brushed it off and nothing is there - and you can't put back the main thing. And we will not notice this suddenness - when the drawing is suddenly swept away.

But on the other hand, suddenly and during our lifetime, this event will certainly not happen, well, unless some unexpected catastrophic solar reaction happens, something goes wrong on the Sun - like the sea and the river, too, are also stable substances, or mountains , and sometimes it will spill or a tsunami that will arise, or an earthquake or a landslide where no one expected - and everything is calm for a hundred thousand years. And it will destroy the half of the coast, or, for example, the country houses that were at the mouth of the river.

But also here is the feeling - if the Sun suddenly explodes - we will not even notice this at all - we will evaporate in a split second and that's it. (Of course, the heat wave will travel for about eight eight minutes - not faster than the speed of light. But if such a volumetric explosion in different directions with instantaneous expansion - we will not notice it all the same. There were immediately - no, here you are writing, for example, on a computer, coffee you drink, and someone reads. Since there is nothing at all - this is the depth of the meaning.)

I remembered an old anecdote on this topic:

The lecture is on astronomy on the topic "The life cycles of the Sun", which means the professor explains: "And after about five billion years, thermonuclear reactions will gradually stop and the Sun will go out." And from the back rows the question: "How much, how much?" The professor repeats: "In five billion years." And there: "Well, huh, otherwise you heard that after three billion" ...

Approximately such and the reasoning about what will happen when the Sun goes out are very exciting in their scale, but still purely empirical events for us. And anyway, too

But the Sun is not, of course, the largest star - so among the many, many stars of ours, not just the Universe, but the Galaxy, which is also just one of - as scientists suspect from 200 billion other galaxies.

And judging by how these stars are born, develop and then die, astronomers can judge the periods of life and our Sun.

In fact, everything will develop as follows: after about 1.1 billion years, the Sun will already be about 11% brighter (according to Wikipedia) - and at this time, approximately, the disappearance of life on planet Earth is possible. In another 3.5 billion years, the brightness of the Sun will increase by another 40% and all life will disappear on Earth. (You can get acquainted with the entire life cycle of the Sun, respectively.)

And the Sun, in fact, is not yellowish in color as we used to imagine - but it looks like this.

And of course everything in this world will end and disappear for each individual person. And not only will the Sun disappear for everyone, but the entire personal Universe will suddenly cease to exist, and everyone will ultimately gain absolute Freedom - in general from everything material. Forever and ever.

And finally, a wonderful informative video about the sizes of various objects in the Universe.