You may have heard about the discovery of gravitational waves - or at least evidence thereof - last month by the BICEP2 collaboration. The discovery is absolutely groundbreaking: the imprint of gravitational waves, produced when a massive object accelerates, was observed in the Cosmic Microwave Background - a radiation field left behind from the early life of the Universe, about 380 000 years after the Big Bang. These waves are the orange and blue undulations in the picture below. Einstein first predicted the existence of these waves in 1916, with his General Theory of Relativity, but BICEP2's discovery provides the first experimental evidence of them.
As if that weren't exciting enough, the discovery confirms a cosmological theory known as inflation: basically, that the Universe expanded to about ~10^20 its original size a few seconds after the Big Bang - that's a pretty enormous acceleration rate! And this, in turn, brings us one step closer towards proving (or disproving) a related theory: eternal inflation. Personally, I am quite fond of the theory of eternal inflation, which postulates that our Universe is one among many that are constantly being born out of their own 'Big Bangs'! I'll tell you why. According to the laws of thermodynamics, our days here are numbered. I don't just mean human lives - I mean everything that is beautiful about the Universe: life - of course, stars, light, planets, and even atoms themselves will eventually decay and cease to exist, a phenomenon known as 'Heat Death.' If eternal inflation is confirmed, we can have hope! It means that new Universes - with their own beautiful stars, planets, atoms, and even life - will continue to exist in an endless cycle.
Pinning down inflation may shed some light on the end of the universe, too. Guth and his colleagues favour a theory called eternal inflation, which says that the universe is constantly giving birth to smaller "pocket" universes within an ever-expanding multiverse. We live in one of these pockets, and our cosmos will continue expanding forever until everything is diffuse, dark and cold. But other pockets will continue to be born, inflate and grow to produce stars, planets and maybe life at a rapid and ever-increasing rate. "Life as a whole has a very great prognosis," says Guth.