PHOTOS: GETTY X2“billions
of other
universes
may exist
like our
own”
EXPERT COMMENTWhat is
a bubble universe?
According to the theory of cosmic inflation –
an idea that is accepted by most, but not all,
leading cosmologists – the Universe expanded
incredibly rapidly in all directions in a tiny fraction
of a second following the Big Bang, much like
a balloon does as it is blown up. After this initial quick
burst, it continued to expand, but much more slowly.
In contrast, the theory of eternal inflation states
that following the Big Bang, inflation did cease
in some pockets of space, but also continued in others.
This means that we could live in a so-called ‘bubble
universe’ – an area of slowly expanding space
embedded in a much larger, rapidly expanding
space that is still undergoing inflation.
What’s more, there might also be countless other
bubble universes embedded in this larger space
that are being propelled away from us at breakneck
speed. In some of these bubbles, the laws of physics
could be completely different from those that apply
in our own Universe – making these other universes
very strange worlds indeed.An artist’s
impression of
multiple ‘bubble
universes’Discoveries
science
The leading theory was that the Cold Spot
is not cold at all, but is instead caused by
a vast area of relatively empty space dubbed
a ‘supervoid’. Radiation passing through
this void would have its energy reduced,
thus making the area appear cooler.
However, new measurements suggest
that there is no such supervoid in the direction
of the Cold Spot. Assuming this is correct,
then simulations of the standard model of
the Universe give odds of just 1 in 50 that
the Cold Spot arose by random fluctuations.
“This means we can’t entirely rule out that the
Cold Spot is caused by an unlikely fluctuation
explained by the standard model,” said lead
researcher Tom Shanks. “But, if that isn’t the
answer, there are more exotic explanations.
Perhaps the most exciting of these is that the
Cold Spot was caused by a collision between
our Universe and another bubble universe.
If further analysis of CMB data proves this
to be the case, the Cold Spot might be taken as
the first evidence for the multiverse – and billions
of other universes may exist like our own.”
The team now plans to further test their theory
through more detailed observations of the CMB.
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