What will be the ultimate end of the universe

Future of the Universe: Outlook for the Ultimate End of Everything

There have always been people who claim they knew what the future of everything would look like. If astronomers do that today, however, their predictions will have a more solid foundation than those of other visionaries. Because astronomers have data, a lot of data, and they sometimes go back millions of years in the past. In this respect, it is not a lot of hocus-pocus, but just a cool calculation to extrapolate the future of the universe from it. Of course, there is also all sorts of speculation involved, but our knowledge of our cosmic future has never been more profound than it is today.

Let us first stick with our world and its impending doom. What is certain is that the earth will not exist forever. How the earthly life ends, there are of course several possibilities. A runaway greenhouse effect, an asteroid impact or star explosions could bring down life on earth in no time, but not the planet itself.

Downfall in "red-white-cold"

The fate of the earth depends largely on the sun, and unlike us humans, the earth may enjoy another seven billion years of life. Then the nuclear fusions of hydrogen to helium in the sun will have reached such an extent that it will swallow the earth as a red giant. Initially, physicists assumed that the earth could escape, but according to current calculations, unfortunately, nothing seems to come of it.

At some point the core of the sun is so dense and hot that helium fuses to form heavier elements. Eruptions cause the sun to shed its outer shell and only an incandescent core, about as small as our earth is today, remains - a white dwarf. A few billion years later, the sun with our remains is dark and cold.

How a priest invented the big bang

So much for the end of our solar system, but there is still the rest of the universe. The physicist Albert Einstein, to whom we owe the foundations of our understanding of the cosmos, originally thought the universe was static. But he was wrong. In 1927, the Belgian astrophysicist and priest Georges Lemaître published a work according to which the universe is expanding - a thesis that prevailed thanks to numerous measurements. It could be observed that galaxies are moving further and further away from us.

The expansion of the universe also allows conclusions to be drawn about its formation: Lemaître deduced from this that the universe was created through the explosion of a primordial atom in which all energy was compressed. The critics of this thesis called it the Big Bang Theory. In particular, physicists like Einstein or Arthur Eddington initially rejected the idea, as the idea that everything should have started with a creation-like bang seemed too religious to them. After all, Lemaître was able to convince not only the Catholic Church but also scientists of his theory.

The big showdown

We have known since the late 1990s that the universe is not only expanding, but that this process is even accelerating. As far as the future development of the cosmos is concerned, this will be determined by two forces: the expansion that is driving the universe apart, on the one hand, and the gravitation, which is drawing it together, on the other. Depending on which force gains, we either counteract extreme cold or heat.

Several physical theories compete in predicting the downfall of everything. Superlatives must not be spared, each of these theories consequently claims the attribute "big": Big Crunch or Big Chill are just two of these theses. With Big Chill, also known as Big Freeze, Big Whimper or the big freezing, the universe continues to expand. Most of the data support this model. In the process, the universe continues to cool and finally steers towards absolute temperature zero. In the Big Crunch, on the other hand, gravity wins: Everything gets hotter and denser until the universe comes to an end in a kind of inverted Big Bang.

There is no such thing as nothing

The only question that remains to be answered is what actually is when there is nothing left. Modern physics has a hopeful message in this regard. This has to do with a fundamental principle of quantum mechanics - Heisenberg's uncertainty principle.

As the physicist Werner Heisenberg recognized in 1927, energy and time as well as place and momentum cannot be precisely determined at the same time. Even in empty space, energy fluctuations could arise for very short periods of time - so-called vacuum fluctuations. Their meaning is controversially discussed in the professional world, but in many cases they are understood as the fundamental something that still remains should the universe one day give way to the void. Whatever the ultimate showdown looks like: There is no such thing as nothing! (Tanja Traxler, February 12, 2019)