One Size Fits All

Problem: The universe is "smooth" in that as a whole, pretty much every part of it looks like every other part. Yes, one part may be empty and another part have a star, but once you expand the scale, on average they're all alike. Kind of "regular irregularity." Solution: The universe started out smooth and always has been.

Problem: A universe that was completely smooth at its beginning would not, as it developed, have any irregularities. Stars and planets condense from gigantic clouds of interstellar gas, clumping together by gravity. But complete uniformity would not allow for any gravitational variations to produce clouds, stars, planets or us. Solution: The universe started out lumpy enough to produce its regular irregularities.

And the real problem for these conditions is that neither one of them allows for a universe that looks like we believe it to have looked when it formed to become a universe that looks like the one we're in today. There's a couple of different possibilities considered for ways to tweak one theory or another to get from where we were to where we are. One is inflation, which argues that the original lumpiness of the universe was minute. But right after the Big Bang, a period of rapid expansion caused it to balloon enough so that it had enough time to come to look like it does. Inflation solves some problems but leaves others and whips up a couple of its own.

Another is the "ekpyrotic picture." This idea is more complicated, but it basically suggests that the smoothing out of the universe happened during a period of contraction rather than inflation. Like inflation, it doesn't solve all of the mysteries about how we got the universe we did and adds a couple of wrinkles of its own.

Cosmologists Anna Ijjas and Paul Stenhardt decided that neither of these theories was weird enough and so came up with their "anamorphic" cosmology, in which the inflation and contraction happen at the same time. In essence, they have taken the things about inflation that work, discarded the ones that don't, done the same with the ekpyrotic picture and combined the remains. The blog post at Nova gives a brief explanation of how this works and offers links to the team's more detailed papers.

It may seem at first like just a silly, dreamt-up solution that really couldn't fix anything, but there's some observational evidence that doesn't yet, at least, allow anamorphic cosmology to get tossed out the window. And in a world where an photon can be a wave and a particle at the same time until you measure it, and the way you measure it determines which one, the idea that things expanded and contracted at the very same time isn't as out there as you might first want to believe.