Evidence that our universe may have collided with another universeS

This image reveals something bizarre about our early universe. On a large scale, there are greater temperature fluctuations to the right of the gray line than to the left. Could we be seeing the bruise from an early smashup with another universe? Some physicists think so.

This is one of several images of the cosmic microwave background taken by space-based telescopes of the farthest reaches of our universe. It shows what our universe looked like shortly after it came into being.

Over at Simons Foundation, Natalie Wolchover writes:

If our universe slammed into a neighboring one during a growth spurt in its first second, the collision would have left a mark.

And Matthew Kleban thinks he sees it in the most detailed snapshot yet taken of the dawn of the universe. The satellite image, released by astronomers in March, confirmed what an earlier imagesuggested: Half of the young cosmos was slightly coarser than the other.

With few other leads about what went on in the early moments of the universe, Kleban is among dozens of theoretical cosmologists trying to piece together a cosmic origin story from the grainy shadow of a new clue.

“When they smack into each other, there’s kind of a shock wave that propagates into our universe,” said Kleban, an associate professor of physics at New York University. Such a shock wave — if that’s what the image shows — would be evidence in support of the multiverse hypothesis, a well-known but unproven idea that ours is one of infinite universes that bubbled into existence inside a larger vacuum.

Most of the cosmologists are quick to admit they could be following a false trail.

“This is a high-stakes game,” said Marc Kamionkowski, a professor of physics and astronomy at Johns Hopkins University who has proposed several new Big Bang models to explain the asymmetry between the two halves of the cosmos. “We’d really like to learn more about where our universe came from, but nature has not left us with too many hints.”

The asymmetry “might be a statistical fluke,” Kamionkowski said, or “it could really be the tip of the iceberg.”

Read the rest of the article on the Simons Foundation website.