Throughout the history of space exploration, many theories have been put forward about its state and development. Sean M. Carroll, one of the leading cosmologists of our time, explained in an exclusive interview with Naked Science the essence of the most generally accepted model of the development of the universe today.
In 1998, two independent projects - the Supernova Cosmology Project and the High-Z Supernova Search Team - discovered that the universe was not only expanding, as Edwin Hubble had shown in the late 1920s, but also accelerating.
It is not easy to register this phenomenon, since it requires observing the same object for a long time. By observing distant galaxies, astronomers and astrophysicists can see that they are receding. The speed at which these galaxies are moving can be recorded. Then, if after a while you return to observing the same objects, it turns out that they began to move away faster. And the further the galaxy is from us, the faster it moves away from us.
“We are talking about the cosmological constant, about vacuum energy - an idea expressed by Einstein. According to her, energy lurks in the empty space. It pushes space apart, accelerates galaxies receding from us,”explains Dr. Carroll, professor of physics at the California Institute of Technology (Caltech). - Vacuum energy is curious in that it does not change. Does not dilute during the expansion of the Universe."
According to Professor Carroll, unlike all known types of matter and radiation, the amount of which decreases in any area of space as it increases, vacuum energy remains the same for every cubic centimeter, regardless of the degree of expansion of space. In other words, the more space we get, the more vacuum energy we get.
Dr. Carroll argues that if this trend does not change in the future, then the universe will be forever stretching and expanding. According to current models, built from the latest cosmological data, space does not collapse back into a singularity - the Great Compression - precisely because of the cosmological constant. As a result, after many billions of billions of years, the Universe is waiting for a future in which the stars will exhaust all their fuel reserves and finally stop burning, plunging it into eternal darkness. According to the professor, all objects in space move away from each other so much that the universe, in fact, becomes empty space.
“This is the simplest interpretation of what we know about the universe and its fate. Different things can happen. Dark energy can phase out and disappear, and then zero or negative energy can appear in empty space - and everything can collapse, says Carroll. - It's curious that we think of the universe as something old, because it is 14 billion years old. But we are greatly mistaken. The universe is very young compared to how old it will eventually become."
Vladimir Guillen
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