Scientists propose new theory: the universe could start contracting in about 20 billion years
Researchers have outlined a scenario in which the universe's expansion could eventually slow, stop and reverse into a contraction ending in a so-called Big Crunch. The idea remains one of several theoretical possibilities, not a proven fact.
A team of scientists has presented calculations describing a possible long-term fate for the universe. The theory rests on the assumption that the properties of dark energy could change over time, which would in turn affect the pace of cosmic expansion.
The universe is currently expanding continuously. However, if the assumption about shifting dark energy properties proves correct, this expansion could eventually begin to slow and ultimately stop. After that, the opposite process would take hold — a contraction in which all matter would collapse back into an extremely dense point.
Scientists refer to this hypothetical event as the "Big Crunch," the theoretical opposite of the Big Bang, which is believed to have marked the universe's beginning.
Timing of the scenario
According to the calculations, the universe would first reach a maximum size — roughly 69% larger than it is today. Only after that point would expansion start slowing down and eventually turn into contraction.
The universe's current age is estimated at about 13.8 billion years. If this theory holds true, the possible Big Crunch would still be roughly 20 billion years away — placing the event in the very distant future.
Just one of several theories
Scientists stress that this scenario is neither a proven fact nor a precise prediction, but rather one of several theoretical possibilities for how the universe might evolve in the distant future. Research into the nature of dark energy continues and could significantly change current understanding of the universe's ultimate fate.
