Dark energy is a mysterious form of matter that manifests itself only through the expansion of the Universe. And it is decreasing, as some observations show. According to some scientists, this could lead to a “big crunch” of the Universe.
Dark energy
A study authored by a number of scientists from around the world has appeared on the arXiv preprint website. It states that the expansion of our Universe, which began with the Big Bang, may subsequently be replaced by a great contraction, the end result of which will cause all space to gather again at a single point.
The reason for this is dark energy — a mysterious form of matter that accounts for 70% of the mass of the Universe. Unlike dark matter, it does not manifest itself even in gravitational effects, but it is precisely this that causes galaxies to scatter.
Previously, the amount or influence of dark matter was considered to be constant. However, some recent measurements can be interpreted as indicating that it is decreasing. At some point, the expansion rate of the Universe may become negative and it will begin to contract.
Only 20 billion years left
Scientists have previously considered the theory that our Universe is pulsating, meaning that at some point, expansion is replaced by “great compression.” However, this idea was subsequently abandoned based on estimates of the curvature of space.
And now it’s back again. Researchers’ calculations show that approximately 33 billion years after the Big Bang, the Universe will once again collapse into a single point. Therefore, considering the 13.7 billion years that have already passed, we have approximately 20 billion years remaining.
First, the Universe will continue to expand and, in 7 billion years, will reach its maximum size, which will be 69% larger than its current size. And then the contraction will begin. However, this is still only a theory, and it is still possible that it will expand forever.
In any case, there is no need to worry that 20 billion years is not enough time. Because civilization on Earth has existed for about 10,000 years. Life appeared about 600 million years ago, and the Sun will turn into a red giant in 5–7 billion years.
According to phys.org
