# Is the world going to end in next 3.7 bn years?

Washington: The universe and everything in
it could end in less than 3.7 billion years from now, a new
study has claimed.

The universe, began in a Big Bang about 13.7 billion
years ago, has been expanding at an ever accelerating rate
ever since and according to standard cosmology models it is
most likely to expand forever.

But, a team of physicists led by Raphael Bousso from the
University of California, Berkeley, claimed that their
calculations showed the universe would end most probably in
the next 3.7 billion years, the Discovery News reported.

According to the team, there's a "measure problem" in the
cosmological theory of eternal inflation -- the quantum
cosmological model where inflationary bubbles can appear out
of nothing.

Some of these bubbles, each being a universe, expand and
go on forever while others collapse and disappear again. They
pop in and out of existence like bubbles in boiling water,
said the scientists.

In an eternally inflating universe, they said, every
event that is possible will eventually occur -- not just once,
but an infinite number of times. This makes predicting when
each event will occur impossible, such as the probability that
a universe like ours exists.

"If infinitely many observers throughout the universe win
the lottery, on what grounds can one still claim that winning
the lottery is unlikely?" they wrote in blog arXiv.org.

Bousso's and his team have been trying to determine the
number of bubbles that exist at any given time and the number
of 'observers' in each bubble to come up with the relative
frequency of observers that can live in one universe compared
to the relative frequency of observers who can live in another
universe.

But the "measure problem" makes calculating this value
impossible. The only way to avoid this conundrum is to
introduce a cut-off point, which then helps make sense again,
they said.

By introducing this cut-off, they reached a conclusion
that there is "a 50-50 chance of the universe ending in the
next 3.7 billion years."

However, Charles Lineweaver from the Australian National
University's Mount Stromlo Observatory criticised Bousso's
theory, saying the team is simply imposing a catastrophe for
statistical reasons.

The need for a better statistical solution has led the
researchers to a false conclusion about the end of the
universe, Lineweaver said.

He said: "Because the problem won't go away in their
calculations, they conclude the universe must really end.

"Bousso's average life of a universe is a set time, only
because that's what happens when you introduce a cut off point
to get a reasonable probability. It's a statistical technique
being taken probably too seriously."

PTI