Big crunch
The big crunch is in cosmology - next to the big rip ("the great tear") and the big chill ("the great cooling", the eternal expansion ) - a hypothetical temporal end of the Universe . The universe collapses more and more under the effect of the force of gravity until it finally ends in a kind of reversed big bang , the "Big Crunch", and thus disappears completely.
state of research
Which of the three models occurs depends on the amount or density of dark matter that is in the universe. The current data suggests an eternal expansion of the universe, since measurements exclude a larger deviation from the critical density. However, even more precise measurements are required in order to completely rule out a collapse according to the big crunch theory.
If one assumes that the dark energy would remain the same , the universe would continue to expand, but this expansion would take place increasingly slowly. However, supernovae evaluations from 2008 show that the dark energy held responsible for the expansion of the universe could also have decreased in the last two billion years.
Hypothetical process
On the other hand, if one assumes that there is enough matter and that dark energy is reduced, then in a few billion years the effect of gravity would become stronger than that of dark energy. From this point onwards, the expansion of the universe would come to an end and turn into an accelerating contraction. This would also continue to increase its temperature. 100,000 years before a hypothetical Big Crunch (collapse) of the universe, the background radiation would be hotter than the surface of today's stars .
Minutes before the Big Crunch, radiation would blast the atomic nuclei before they end in huge black holes . A few seconds before the Big Crunch, supermassive black holes would merge. In the end, there is only one “black mega-hole” which contains all matter and swallows the universe, including itself, at the last moment of the Big Crunch.
It is conceivable that such a big crunch at once to a new Big Bang ( Big Bang would be), which would entail the creation of a new universe.
A fundamentally different model was derived from the oscillating universe and leads to the big bounce .
Web links
- What's the Big Crunch? from the alpha-Centauri television series(approx. 15 minutes). First broadcast on June 22, 2005.
supporting documents
- ↑ Rainer Kayser: Astronews: Is Dark Energy Waning? In: astronews.com. April 14, 2009. Retrieved April 15, 2009 .