It don’t get much weirder than this. The universe is about to lose its dimension of time says a group of theoretical astrobods at the University of Salamanca in Spain. And they got the evidence to prove it.
The idea comes from the study of braneworlds: the thinking that the universe we see around us is a 4-dimensional cosmos called a braneworld embedded in a multidimensional universe. The “signature” of our universe is the number of space and time-like dimensions it has: in our case we got 3 space-like dimensions and one time-like dimension. It’s what astrobods call a Lorentzian universe. So far so good: lots of astronutters think the same thing.
But our universe may not always have been like this. Some theorists think it may once have had a Euclidean signature meaning that all the dimensions were space-like. Now Marc “Bars” Mars and a few pals in Spain say that the Universe’s signature might be about to flip from Lorentzian to Euclidean. In other words, our dimension of time is about turn space-like. Gulp!
This ain’t entirely bonkers and here’s why. Bars Mars has calculated what it’s like to be an observer in a universe that is about to flip and get this: it would look as if it were expanding and accelerating away from us. Sound familiar?
Yep, it’s exactly what astrobods have been observin over the last few years, a phenomenon they attribute to dark energy. If Bars Mars is right, dark energy ain’t got nothing to do with it and we’re all starin’ down the barrel of a cosmic catastrophe.
Still, maybe four space-like dimensions will be better than three. Who needs time anyway?
Ref: arxiv.org/abs/0710.0820: Is the Accelerated Expansion Evidence of a Forthcoming change of Signature?