Brace for the ‘Big Crunch’: Scientists predict when universe will end,
Scientists have predicted exactly when the universe will end – and it’s trillions of years earlier than originally thought.
Until now, it’s been widely assumed that the universe will suffer a gradual ‘heat death’ in trillions of years.
But scientists from Donostia International Physics Center now predict that the universe will come to a dramatic end far sooner.
According to their simulations, the entire cosmos will reach the end of its life precisely 33.3 billion years after the Big Bang.
Given that the universe is currently 13.8 billion years old, that leaves us with a little less than 20 billion years left before doomsday.
During the so–called ‘Big Crunch’, the universe’s current expansion will reverse, and galaxies, stars, and planets will all collapse towards a single point.
As this happens, the Earth and everything else in existence will be violently crushed and swallowed by black holes.
The authors write in their new pre–print paper: ‘Eventually, it is plausible that the universe ends in giant black holes.’
The latest observations of the universe show that the universe’s expansion might reverse into a ‘Big Crunch’. Now, calculations show this could come trillions of years earlier than expected
Scientists generally believe that there are two ways the universe might end – either it keeps expanding until it becomes a frozen void or it collapses in a fiery crunch.
Which of these becomes reality depends largely on the strength of ‘dark energy’ – the mysterious force driving the universe apart.
Until very recently, astronomers thought that the value of dark energy was a universal constant that would ensure the universe’s expansion kept accelerating.
However, new measurements from the Dark Energy Survey Instrument (DESI) suggest that this is not the case.
This massive map of 47 million galaxies made the shocking discovery that dark energy is not a constant but actually changes over time.
If true, this means that the universe’s relentless expansion might slow and even reverse, pulling matter back together like a rewind of the Big Bang.
To see when this might happen, the researchers considered a model for dark matter which can explain how it might change over time.
On this view, dark energy is made by combining a very light form of dark matter called an axion field and a fixed background expansion baked into the structure of spacetime called the cosmological constant.
New modelling suggests that the universe could collapse 33.3 billion years after it started with the Big Bang, or around 20 billion years from now
The researchers applied this model, known as the axion dark energy (aDE) model, to the data from the DESI survey and found that it could explain everything scientists have observed about the universe.
However, they also found that this form of dark energy inevitably leads to the Big Crunch.
Once the universe expands beyond a certain size, the interaction between the axion field and the cosmological constant pulls the universe back together.
This reverse expansion will continue until the entire universe is crushed back into a single point of matter known as a singularity, just like it was before the Big Bang.
As acceleration reverses, the researchers say that matter will be ‘squeezed together’.
Lead author Dr Hoang Nhan Luu and his co–authors say that this will ‘enhance the formation of black holes, in particular the merging of black holes.’
They added: ‘As the universe is collapsing, one can imagine that matters are push together to form a giant black hole, which in turn shields/hides the crunch singularity.’
On the positive side, the researchers point out that this might not matter tremendously to any future citizens of Earth.
As the universe collapses, black holes will grow and merge. Eventually, the entire cosmos will be crushed into a single giant black hole
Dr Luu writes: ‘On the local level, the possible collision of our Milky Way with its largest neighbour, the Andromeda galaxy, is predicted to occur in about four to 10 billion years.
‘It is interesting to re–estimate the time of their collision (or no collision) before the big crunch.’
However, as Dr Luu and his co–authors admit, the future of our universe is far from certain.
The observations from DESI’s latest survey of the universe have only just been collected, and scientists will need time to check through the data.
Read More
The universe is expanding ‘too fast’ – and scientists have no idea why
The first papers on the DESI’s observations aren’t expected until sometime next year, which should help confirm whether dark energy really is changing or not.
Likewise, scientists will need to gather a lot more data about the universe before we can confirm whether the aDE model is correct.
Dr Luu writes: ‘More and better data are expected in the near future and the aDE model will be rigorously tested.
‘If confirmed, the aDE model parameters – and the universe’s lifespan – will be more precisely determined.’
WHAT IS DARK ENERGY?
Dark energy is a phrase used by physicists to describe a mysterious ‘something’ that is causing unusual things to happen in the universe.
The universe is full of matter and the attractive force of gravity pulls all matter together.
Then came 1998 and the Hubble Space Telescope observations of very distant supernovae that showed that, a long time ago, the universe was actually expanding more slowly than it is today.
The universe is not only expanding, but it is expanding faster and faster as time goes by,’ Dr Kathy Romer, scientist at the Dark Energy Survey told MailOnline, as illustrated in this Nasa graphic
So the expansion of the universe has not been slowing due to gravity, as everyone thought, it has been accelerating.
No one expected this, no one knew how to explain it. But something was causing it.
‘The universe is not only expanding, but it is expanding faster and faster as time goes by,’ Dr Kathy Romer, scientist at the Dark Energy Survey told MailOnline.
‘What we’d expect is that the expansion would get slower and slower as time goes by, because it has been nearly 14 billion years since the Big Bang.’
