Looking at our Universe today, is very easy to get excited about what they saw. The stars in our night sky is only a small part, a few thousand of the hundreds of billions of what is present in our milky Way. He milky Way is just one own galaxy made up of trillions present in the observable Universe that extends in all directions approximately 46 billion light years. And it all started about 13.8 billion years ago from a hot, dense, fast growing state known as the Big Bang.
It is since the Big Bang we can describe our Universe as full of matter and radiation, and to connect the known laws of physics to explain the modern form of the space. But the universe continues to expand. New stars appear, the space evolyutsioniruet. What will be its end? Let’s ask science.
What an end to the Universe
For a long time, scientists studying the structure and evolution of the Universe, considered three options, based on simple physics-the General theory of relativity and the context of the expansion of the Universe. On the one hand, gravity is actively gathers all together; it’s drawing power, controlled matter and energy in all their forms present in the Universe. On the other hand, there is the initial rate of expansion that separates everything apart.
The big Bang was a shot, followed by the greatest race of all time and gravitation the expansion of the universe. Who will win in the end? The answer to this question will determine the fate of our world.
We thought that the Universe has these options:
- The universe collapses in the Big crunch process. The expansion will begin quickly and a large amount of matter and radiation will break apart. If matter and energy is more than enough, the universe will expand to a certain maximum size, the extension will draw the compression and the universe collapses again.
- The universe will expand forever and will lead to a Big Freeze. Everything starts the same as above, but this time the amount of matter and energy will be insufficient to resist expansion. The universe will expand forever, because the rate of expansion will continue to fall, but never reaches zero.
- The expansion of the Universe asymptotically tends to zero. Imagine a border situation between the above two examples. One proton more, and we collapse; one less — expanded infinitely. In this critical case, the universe expands forever, but with the lowest possible speed.
To find out which option is correct, we just had to measure how fast the universe is expanding and how the expansion rate has changed over time. The rest is a matter of physics.
It was one of the greatest challenges of modern astrophysics. Measure the speed with which the expanding universe, and learn how to change the fabric of space today. Measure changes in the expansion rate over time, and how the fabric of space has varied in the past.
Combine these two pieces of information, and the changes in the rate of expansion and what it was, will allow you to determine what is in the universe and in what proportions.
As far as we know, based on these measurements, we determined that the universe is composed of 0.01% of the radiation of a 0.1% neutrinos, and 4.9% ordinary matter, 27% is dark matter, 68% is dark energy. This quest, which for some began in the 1920-ies he received an unexpected response in the late 1990s.
So, if the dark energy dominates the expansion of the Universe, what does this mean for our lives? It all depends on how — or if — the dark energy will evolve with time. Here are five options.
Dark energy is a cosmological constant dominates the expansion. This is the default option that takes into account our best data. As matter becomes less dense as it expanded, the Universe is diluted by the expansion of volume, dark energy is a nonzero amount of energy inherent in the fabric of space itself. With the expansion of the Universe the density of dark energy remains constant, which leads to the fact that the extension always retains a positive value.
This leads to an exponentially expanding Universe, and ultimately’m gonna push them all that is not part of our local group. Already 97% of the visible Universe becomes unavailable in such circumstances.
Dark energy is dynamic and becomes more powerful over time. Dark energy, apparently, is a new form of energy, which is inherent to the space, which means that it has a constant energy density. But it can also change over time. One possible change is that it gradually increases, which will lead to acceleration in the rate of expansion of the Universe.
Deleted objects are not only removed from us, but do it faster and faster. Worse, objects that are currently associated gravitational — like clusters of galaxies, individual galaxies, solar systems and even atoms — once you unleash as a result of the strengthening of dark energy. In the last moments of the Universe and subatomic particles, the very fabric of space-time will break apart. This fate is a Big Gap — our second option.
Dark energy is dynamic and weakens over time. How can change the dark energy? Instead of stronger, it could weaken. Of course, the rate of expansion is consistent with a constant amount of energy belonging to the space, but this energy density may also be reduced.
If it weakens to zero, everything will come to one of the above-described possibilities: the Big Freeze. The universe will expand, but without a sufficient amount of matter and other forms of energy, which will help it to re-collapse.
If the decay becomes negative, it can lead to other opportunities: the Great Compression. The universe is filled with energy inherent to space that suddenly change the signs and give space to the compression. This option is also available.
Dark energy goes into another form of energy, rejuvenating the Universe. If dark energy does not decay and remains constant or even increases, another opportunity arises. This energy is inherent in the fabric of space may not always remain in this form. Instead, it can turn into matter and radiation, similar to what was, when I finished the cosmic inflation and the Big Bang started.
If the dark energy remains constant to this point, it will create very, very cold and scattered version of hot Big Bang, which themselves can only create neutrinos and photons. But if the force of dark energy will increase, this can lead to a condition similar to inflation, followed by a new, really hot Big Bang. This is the easiest way to rejuvenate a Universe with specified parameters.
Dark energy is related to the zero energy of the quantum vacuum and will disintegrate, destroying our Universe. This is the most devastating ability of all. What if dark energy is not the true value of a blank space in the configuration with the lowest energy and is the result of symmetries in the early stages of the Universe when they were in the configuration with the false minimum?
If so, there must be a way to create a quantum tunnel into a state with lower energy, changing the laws of physics and destroying all the bound States (i.e. particles) of quantum fields today. If the quantum vacuum is unstable in this sense, then, wherever this collapse may have occurred, the result will be the destruction of everything in the Universe through the bubble propagating at the speed of light. If the signal reaches us, we too will come to an end.
Although we do not know which of these possibilities will be true for our Universe, the data just frantically vote in favor of the first option: dark energy really is constant. Right now, our observations of how the universe evolved — especially with the cosmic microwave background radiation and large scale structure of the Universe imposes strong restrictions on how much wiggle room remains dark energy to change.
And until we have a new truth about the Universe, we will stick to this.