From asteroid strikes to alien invasions, doomsday theories about Earth’s end have long captured our imagination. But scientists now suggest one chilling scenario rooted in real physics and they've even estimated when it could happen.
According to this theory, the universe, which burst into existence with the Big Bang, could eventually reverse its course. Instead of expanding outward, everything including Earth and the farthest galaxies may collapse inward in a cosmic implosion known as the "Big Crunch."
In this dramatic finale, all matter could be crushed back into the ultra-dense singularity from which it emerged, erasing the universe as we know it.
What is Big Crunch?
The Big Crunch is considered the reverse of the Big Bang, which marked the universe’s beginning 13.8 billion years ago. Following the Big Bang, the universe expanded rapidly, cooling into the particles that form the cosmos today.
In a Big Crunch scenario, this process would reverse collapsing space back into an extremely hot, dense state.
This expansion has long been attributed to dark energy, a mysterious force thought to be constant. But recent observations by astronomers from the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI) suggest otherwise.
Their findings point to dark energy possibly evolving over time a revelation that challenges a key principle of modern physics and raises the possibility that the universe’s collapse could happen sooner than previously thought.
Some scientists now believe that dark energy may be weakening, potentially allowing an inward force known as the cosmological constant to draw the universe back in on itself.
Dr. Ethan Yu–Cheng from Shanghai Jiao Tong University explained to MailOnline: “It’s just like throwing a basketball straight up.”
“The negative cosmological constant acts like Earth’s gravity, pulling the basketball down. It slows down, reaches its peak, and then begins to fall.”
Will there be signs of Big Crunch?
To picture life during the Big Crunch, imagine the universe as a balloon covered in tiny dots. As the balloon deflates, those dots move closer together just like galaxies would.
The first sign of this reversal would be a rise in cosmic temperature.
“It is the reverse history of our expanding universe,” explained Professor Avi Loeb, a theoretical physicist from Cornell University, to MailOnline.
As the universe has expanded, it’s been cooling much like gas escaping a pressurized container. But during the Big Crunch, that cooling process would flip, causing space to heat up once again.
When it will happen?
Scientists believe the Big Crunch remains a distant event in the cosmic timeline but it's not infinite.
According to Professor Henry Tye, a cosmologist at Cornell University, “We calculate that this will lead to a Big Crunch about 19.5 billion years from now.” With the universe currently aged at 13.8 billion years, that would give it a total lifespan of roughly 33.3 billion years.
In a recent pre-print study, Professor Tye and his colleagues, Dr. Luu and Dr. Yu-Cheng, estimate that the collapse could begin in about 11 billion years. Once it starts, the universe would take approximately 8.5 billion years to contract fully into a singularity.
That means the "beginning of the end" might be just 10 billion years away closer than one might expect and the universe is already past its halfway point.
Still, with modern humans only existing for around 300,000 years, we’ve got a long cosmic buffer before any crunch begins.
Discover the latest Business News, Sensex, and Nifty updates. Obtain Personal Finance insights, tax queries, and expert opinions on Moneycontrol or download the Moneycontrol App to stay updated!
