Science distinguishes four basic ways in which the universe can meet his destiny. This is a big freeze Big Crunch, more changes and a big gap. If you have these names do not say anything, now everyone will realize . You should not surprise the fact that our planet is doomed. In a short time, only 6 billion years old, and the earth is likely to evaporate when the sun will expand to a red giant and engulf the planet.

But the Earth - it's just a planet in the Solar System, the Sun - one of hundreds of billions of stars in the galaxy, and the observable universe are hidden hundreds of billions of galaxies. What ugotovleno for all of them? How would end up the universe?

Science can only guess how this happens. We are not even sure exactly how the universe will die in a certain way, or just slowly come to naught. Our best understanding of physics leads us to a number of options for global apocalypse. It also gives us some tips on how to, in principle, could have survived.

The first hint of a possible end of the universe comes to us from the law of thermodynamics, the science of heat. Thermodynamics - Physics is a preacher wild-eyed, who holds a cardboard banner with a simple warning: "Heat Death is coming."

Despite its name, the heat death of the universe is not a fiery hell. On the contrary, it is the death of all levels of heat. That does not sound very scary, but the heat death - it's worse than bake until brown. This is because almost everything in daily life requires a certain temperature difference, either directly or indirectly.

For example, your car is running, because they are inside the engine warmer than outside. The computer runs on electricity from the local power plant, which probably works by heating water and the heat dissipation to the turbine. You eat the food, which owes its existence to the huge difference in temperature between the Sun and the rest of the universe.

When the universe will reach heat death, all will be one temperature. This means that nothing interesting will never happen. All the stars will die, all matter will disintegrate, everything will turn out in the rare soup of particles and radiation. Even the energy of this stock will decrease over time as a result of expansion of the universe, leaving with a temperature barely above absolute zero.

In this process, the Big Universe Freezing will uniformly cold, dead and empty.

Following the development of the theory of thermodynamics in the early 1800s, thermal death looks like the only possible way to end the universe. But after 100 years of Einstein's general relativity he proclaimed that the universe may be much more interesting fate.

General relativity says that matter and energy distort space and time. This relationship between space-time and matter-energy - between the stage and the actors in it - applies to the entire universe. All that is in the universe, according to Einstein, determines the ultimate fate of the universe itself.

The theory predicts that the universe as a whole must either expand or contract. It can not remain in the same amount. Einstein understood this in 1917 and so did not want to admit it, he refused to own theory.

Then in 1929 the American astronomer Edwin Hubble discovered irrefutable evidence that the universe is expanding. Einstein changed his mind, calling their previous insistence relatively static universe "greatest mistake" of his career.

If the universe is expanding, once she had to be less than it is now. This realization led to the Big Bang theory: the idea that the universe started with an incredibly small point and expanded rapidly. We can see this on the "afterglow" of the Big Bang - as the cosmic microwave background - a constant stream of radio waves coming from all directions in the sky.

It turns out the fate of the universe depends on a very simple question: will the Universe expand further and how quickly?

For the universe, containing the usual "stuffing" - matter and light - the answer to the question depends on the amount of filling. More filling - means more gravity, which pulls it back and slow the expansion. While the number of filling does not exceed the critical threshold, the universe will expand forever and eventually die of heat death.

But if the filling is too much expansion of the universe slowed down and stopped. Then the universe will begin to contract. Cutting the Universe will become smaller and smaller, denser and hotter until it's over in a colorful, compact hell opposite to the Big Bang and known as the Big Crunch.
For most of the 20th century, astrophysicists were not sure which of these scenarios take effect. Big Freeze or a Big Crunch? Ice or fire? They tried to hold cosmic census, counting the number of stuffing in our universe. It turned out that we are strangely close to the critical threshold, and our fate is still in question.
At the end of the 20th century, everything changed. In 1998, two rival groups of astrophysicists made an incredible statement: the expansion of the universe is accelerating.
Normal matter and energy could affect the universe in such a way. This was the first evidence of the existence of new fundamental type of energy, "dark energy" whose behavior is completely mysterious to us.
Dark energy pushes the universe apart. We do not understand what it is, but about 70% of the energy of the universe account for dark energy, and the number is increasing day by day. The existence of dark energy means that the amount of filling in the universe determines its ultimate fate. Space manages dark energy, it is accelerating the expansion of the universe. Therefore, the Big Crunch scenario is unlikely.
But this does not mean that the Big Freeze and inevitable. There are other possible outcomes.
One of them did not take place in the course of space exploration, and the world of subatomic particles. This is perhaps the most bizarre of the possible fate of the universe: something fantastic and at the same probability.
In the classic science fiction novel by Kurt Vonnegut's "Cat's Cradle," "ice-nine" is a new form of water ice with interesting properties: it is formed at a temperature of 46 degrees, not 0. If the crystal of ice-nine to drop into a glass of water water around the crystal takes its form as its energy is lower than that of liquid water. New ice crystals nine will do the same thing with the water around him, and in an instant the chain reaction will turn all the water in the glass - or in the oceans of the Earth - in solid ice-nine.
The same can happen in real life normal normal ice and water. If you type in a very clean glass of water is very clean and cool it below freezing, the water becomes supercooled: it will remain liquid below the natural freezing. In the water, there are no impurities in the glass and no irregularities that began to form ice. But if you drop the ice crystals in the water, the water quickly freezes as ice-nine.
Ice-nine and supercooled water may seem little to do with the fate of the universe. But something similar is happening with the space itself. The quantum physics states that even in absolute vacuum a small amount of energy. But then there must be a different type of vacuum that contains less energy. If so, then the whole universe is like a glass of supercooled water. And it will remain so until the show "bubble" of the vacuum with low energy.

Fortunately, we do not know of such bubbles. Unfortunately, quantum physics states that if low-energy vacuum is possible, the bubble with the vacuum will inevitably appear somewhere in the universe. When this happens, it is like the history of ice-nine new vacuum "convert" old vacuum around itself. The bubble will grow with the speed of light, and we'll never see it coming. Inside the bubble is all totally different, and obviously not very hospitable. The properties of fundamental particles such as electrons and quarks can be quite different, rewrite the rules of chemistry and may prevent the formation of atoms. People, Planet, and even the stars themselves may be destroyed in the process of great changes. In the 1980 Physics Sidney Coleman and Frank de Lucchi called it "a global environmental catastrophe."

Universe

After more changes and dark energy will behave differently. Instead of pushing the expansion of the universe, dark energy the universe can suddenly collapse into itself, causing it to collapse into more compressed.

There is also a fourth possibility, and again dark energy takes center stage. This idea is very controversial and incredible, but it is not necessary to dump it off. Dark energy may be much stronger than we think, in and of itself cause the universe to the end without any more changes, freezing and compression.

In the dark energy is a peculiar property. As the universe expands, its density remains constant. This means that over time it grows to keep pace with the increase in the volume of the universe. It is unusual, though, and does not violate the laws of physics.

However, everything can be much stranger. What if the dark energy density is increasing with the expansion of the universe? More specifically, if the amount of dark energy in the universe is growing faster than the expanding universe itself?

This idea was put forward by Robert Caldwell of Dartmouth College in Hanover, New Hampshire. He called it a "phantom dark energy." And it leads us to an incredibly strange fate of the universe.

If phantom dark energy exists, then we are waiting for the dark side of the force, the language of "Star Wars." Now the dark energy density is extremely low, much lower than the density of matter in the world or even the density of the Milky Way galaxy, which is much less dense than Earth. However, over time, phantom density of dark energy may grow to tear the universe apart. In the 2003 Caldwell and his colleagues presented a script called "cosmic doomsday". Once the phantom dark energy becomes more dense than a specific object, the object is torn to shreds.

First phantom dark energy will break the Milky Way, sending him flying stars. Then it explodes the solar system, because the attraction of dark energy will be more powerful than the pull of the Sun relative to the Earth. Finally, a few minutes the Earth just explode. Atoms themselves begin to disintegrate, and a second later the universe will be torn. Caldwell calls it a big gap. Big Break, as recognized by the Caldwell "very bizarre" scenario.

Phantom dark energy defies the fundamental ideas of the universe, such as the assumption that matter and energy can not move faster than the speed of light. These are good arguments against the Big Break. Observations of the expansion of the universe, as well as experiments with the particle physics show that as the end of the world is more likely Big Freeze, followed by a greater change, and then the Big Crunch.

But it's a pretty grim picture of the future - a century of cold emptiness that await vacuum decay and the final explosion, rolling into oblivion. Is there any other option? Or are we doomed?

Clearly, specifically we have no reason to worry about the end of the universe. All these events will take place through trillions of years in the future, except maybe the biggest change so far everything is going according to plan. Also, there is no reason to worry for humanity. If you do not happen to other genetic gap change our descendants unrecognizable long before that. However, whether the sentient beings of any kind, people or not survive at all?

Physicist Freeman Dyson of the Institute for Advanced Study in Princeton, NJ, has considered this issue in the classical work of 1979. At the time he came to the conclusion that life can change themselves in order to survive Big Freeze, which is considered a physicist to be less problematic than hell Big Crunch. But these days, he is less optimistic, thanks to the discovery of dark energy.

"If the universe is accelerating, this is bad news, - says Dyson. Accelerated expansion means that we will eventually lose touch with all but a handful of galaxies that drastically limit the amount of energy available to us. - In the long term, this situation will be very sad. "

However, things could change. "We do not really know whether the expansion continues and why it is accelerating, - says Dyson. - The optimistic view of things is that the acceleration will slow down as the universe expands. If that happens, the future will be more favorable. "

But what if the extension will not slow down or becomes aware that a big change is coming? Some physicists offer a solution, mad at all. To avoid the end of the universe, we have to build your own universe in the laboratory and run away with her.

One of the physicists working on this idea, it is well-known Alan Guth of the Massachusetts Institute of Technology in Cambridge; he is known for his work on the theme of the young universe.

"I can not say that the laws of physics allow for the possibility of such - says Gut. - If possible, require technology beyond anything we can imagine. This will require a gigantic amount of energy that will still need to obtain and maintain. "

The first step, according to Guth, is to create an incredible dense form of matter - so dense that it is on the verge of collapse into a black hole. If you do it right, then quickly remove the matter outside of this bunch, you can get a region of space, which will expand rapidly.

In fact, you provoke jump in the creation of an entirely new universe. With the expansion of the field of space, the border will be reduced, creating a bubble of curved space inside of something bigger. Fans of "Doctor Who" this may sound familiar, and according to Guth, TARDIS is fairly accurate analogy of what is at stake. In the end, the "outside" will shrink to zero, and the newborn universe begins its own existence independent of the fate of the previous universe. Obviously, this scheme will work in reality, it is unclear. We do not know, maybe it or not.

However, the gut has another source of hope for a better fate for our world - a glimmer of hope. Guth first proposed that in his youth the universe expanded extremely rapidly in a split second, this idea is known as "inflation." Many cosmologists believe that inflation is the most accurate description of the expansion of the young universe, Guth proposes to create a new universe, it is relying on this process of rapid expansion.

Inflation has intriguing implications for the ultimate fate of the universe. According to this theory, our universe - is a small part of the multiverse, a plurality of pocket universes that float around.

"In this case, even if we are convinced that our private universe will die in the process of freezing, the multiverse will live forever, and a new life will be born in each pocket universe - says Gut. - Multiverse indeed infinite, and the infinite future separate universes can live and die as they please. "