Our
huge universe might possibly be a just single one of several others, just like
a bubble in a foamy stream of cosmos-spawning mess? Sure, its sounds like
something from a 1970s British sci-fi novel, but its turn out to be a
widespread justification for the origin of our massive universe. But the main
question is; how can we possibly test this theory, when we're trapped in just
one universe? Physicists who were formerly wary of the multiverse theory have
started to consider this essential new way of thinking. This is fairly because
it helps in explaining why our universe just occurs to have the correct
physical constituents to make life possible. Natalie Wolchover and Peter Byrne,
in an interesting split article about the multiverse theory over at Quanta,
write:

“Many physicists loathe the multiverse
hypothesis, deeming it a cop-out of infinite proportions. But as attempts to
paint our universe as an inevitable, self-contained structure falter, the
multiverse camp is growing.

Image Credit: Olena Shmahalo / Quanta Magazine |

*The problem remains how to test the hypothesis. Proponents of the multiverse idea must show that, among the rare universes that support life, ours is statistically typical. The exact dose of vacuum energy, the precise mass of our underweight Higgs boson, and other anomalies must have high odds within the subset of habitable universes. If the properties of this universe still seem atypical even in the habitable subset, then the multiverse explanation fails. But infinity sabotages statistical analysis. In an eternally inflating multiverse, where any bubble that can form does so infinitely many times, how do you measure "typical"? Guth, a professor of physics at the Massachusetts Institute of Technology, resorts to freaks of nature to pose this "measure problem." "In a single universe, cows born with two heads are rarer than cows born with one head," he said. But in an infinitely branching multiverse, "there are an infinite number of one-headed cows and an infinite number of two-headed cows. What happens to the ratio?" For years, the inability to calculate ratios of infinite quantities has prevented the multiverse hypothesis from making testable predictions about the properties of this universe. For the hypothesis to mature into a full-fledged theory of physics, the two-headed-cow question demands an answer.*

You
can read the complete article at
Quanta.

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