2D Universe...

Image Credit (and text credit below): Atra Materia

"Recently, physicists Jonas Mureika from Loyola Marymount University in Los Angeles, California, and Dejan Stojkovic from SUNY at Buffalo in Buffalo, New York, have proposed an interesting way to investigate lower dimensions of the Universe. They’ve published their study in a recent issue of Physical Review Letters.

"According to them, our four-dimensional spacetime may not have been the same in the past: it may have existed in a lower dimensional state. In the beginning, spacetime would have only two dimensions, one dimension of space and one dimension of time. In other words, shortly after the Big Bang, the Universe was a straight line. With the expansion, this straight line “wrapped up” so that it appears as the four-dimensional spacetime we see today, after going through a three-dimensional state, with two dimensions of space."

[Focus] Physics Review Letters: Testing for Vanishing Dimensions