Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACE There is no greater hero in our search for life on mars than a little robot named Opportunity. You can further support us on Patreon at https://www.patreon.com/pbsspacetime Get your own Space Time t­-shirt at http://bit.ly/1QlzoBi Tweet at us! @pbsspacetime Facebook: facebook.com/pbsspacetime Email us! pbsspacetime [at] gmail [dot] com Comment on Reddit: http://www.reddit.com/r/pbsspacetime Guest AuthorAll Guest Author Posts are submitted or additional content Wave Chronicle has added to the website. To be a Guest Author please visit our "Post Your Article" page.More Posts - Website

Thanks to Wix for supporting PBS Digital Studios. You can go to  https://bit.ly/2o1DSHZ to get started on Wix Code! In 100 trillion years the era of stars will be over. We live in an unusual age – the age when the stars still shine. We should count ourselves lucky – nearly all of future history will be dark. But events will still unfold in that long, cooling darkness, and civilizations may endure. So how will the universe and its far-future denizens spend eternity? You can further support us on Patreon at https://www.patreon.com/pbsspacetime Get your own Space Time t­-shirt at http://bit.ly/1QlzoBi Tweet at us! @pbsspacetime Facebook: facebook.com/pbsspacetime Email us! pbsspacetime [at]…

In simple terms, a gauge theory is one that has mathematical parameters, or “degrees of freedom” that can be changed without affecting the predictions of the theory. You can further support us on Patreon at https://www.patreon.com/pbsspacetime Get your own Space Time t­-shirt at http://bit.ly/1QlzoBi Tweet at us! @pbsspacetime Facebook: facebook.com/pbsspacetime Email us! pbsspacetime [at] gmail [dot] com Comment on Reddit: http://www.reddit.com/r/pbsspacetime Help translate our videos! https://www.youtube.com/timedtext_cs_… Guest AuthorAll Guest Author Posts are submitted or additional content Wave Chronicle has added to the website. To be a Guest Author please visit our "Post Your Article" page.More Posts - Website

We’ve established by now that black holes are weird. The result of an absolute gravitational collapse of a massive body: a point of hypothetical infinite density surrounded by an event horizon. At that horizon time is frozen and the fabric of space itself cascades inwards at the speed of light. Nothing can travel faster than light, and so nothing can escape from below the event horizon- not matter, not light, not even information. These ideas are pretty mind-blowing but as crazy as black holes are, they’re also kind of … simple.  Don’t get me wrong; the math is complicated. But the objects themselves are simple. In fact, every black hole…

The laws of physics are equations of motion. They are mathematical rules that dictate how systems evolve in time. Newton’s equations for classical mechanics, Maxwell’s equations for electromagnetism, and the Schrodinger equation for quantum mechanics. These laws can be used to predict how the universe will evolve into the future. They are deterministic; perfect knowledge of a system in the present perfectly predicts how the system will change in the next instant, and the instant after that, ad infinitum. But determinism in the forward-time direction does NOT guarantee that the same laws can perfectly predict the past. And yet this sort of deterministic symmetry – time-reversal symmetry – is essential…

For the sake of argument, let’s say that humanity survives the several ends of the world that await us.  We somehow persist the gradual heating of our Sun and the evaporation of our oceans. Our descendants cling to existence through countless generations we watch the Andromeda galaxy merge with the Milky Way, forming a vast elliptical galaxy. We seek refuge in the outer solar system as the Sun finally expands into a red giant – twice! And finally our heirs or successors find new homes among the stars after the Sun’s final death and transformation into a dim white dwarf. Hosted by Matt O’Dowd Written by Drew Rosen and Matt…