All posts tagged: The big bang

The rise, the fall and the rebound of cyclic cosmology

The rise, the fall and the rebound of cyclic cosmology

Published by skeptic

The largest 3D map of our universe to date, with Earth at the center and every dot showing a galaxy DESI collaboration and KPNO/NOIRLab/NSF/AURA/R. Proctor The universe is dead; long live the universe. Not right at this moment, not yet. But one day everything we know will be gone. The cities we build, the lakes we swim in, the planet we live on, the solar system we inhabit, the star we orbit and every star we don’t – they’re all headed towards an inescapable finale. At the end of it all, what happens? Some say our ever-expanding universe will slow down and then one day do a cosmic U-turn, undoing all the growth that has happened since the big bang. Eventually, everything will crunch together into the tiniest possible space and then explode out again in a riot of rebirth – that’s the idea we call cyclic cosmology, or the big bounce. It’s been around for a long time, and the idea itself has faced a trajectory that mirrors its contents. It was briefly popular …

We’ve glimpsed before the big bang and it’s not what we expected

We’ve glimpsed before the big bang and it’s not what we expected

Published by skeptic

Imagine we had somehow filmed the whole history of the universe and you could play the movie in reverse. It would start off much as things stand today: a vast and elegant web of galaxies and nebulae. But as the tape rewinds, everything begins to shrink until it reaches an evanescent pinprick of energy – a point everyone knows as the big bang. And that is where the screen goes blank. To ask what came before this is to invite the scorn of scientists and philosophers alike. It is like asking what’s north of the North Pole – a meaningless, impossible question. Or is it? Over the past few years, a few physicists have honed a way to lift this curtain and peek at what lies beyond. It involves the realisation that, although we can’t solve the equations that describe this epoch exactly, we can sometimes do so roughly – and in many cases, that might still be informative. Eugene Lim at King’s College London, one of the foremost proponents of these ideas, says this …

The first quantum fluctuations set into motion a huge cosmic mystery

The first quantum fluctuations set into motion a huge cosmic mystery

Published by skeptic

Tiny oscillations in the early universe left a big mark on the universe Jozef Klopacka / Alamy The following is an extract from our Lost in Space-Time newsletter. Each month, we dive into fascinating ideas from around the universe. You can sign up for Lost in Space-Time here. “In the beginning”. These three words have cast quite a spell, ever since the 5th century AD when the Israelite priest known to biblical scholars as “P” put ink to parchment and wrote the opening lines of the Book of Genesis. Our modern telling of the creation story is no less poetic for being consistent with things we can observe in the universe today. Based on what we think we know, this is broadly how it goes. We have no words to describe the very beginning, because this is simply beyond physics and human experience. But we can extrapolate backwards from the present to say that the universe was formed in a hot big bang about 13.8 billion years ago. As it expanded, the very early universe suffered …