The Fate of the Universe | Astrophysicist Alex Filippenko

You know, how will the Universe end? Well, if the dark energy continues to be repulsive, then the Universe will expand faster and faster and faster with time. A runaway Universe. So if you want to see galaxies with your very own eyes through a telescope, you'd better go to your local observatory or planetarium soon, in the next few tens of billions of years, because beyond that time, those galaxies will have been whisked away To such great distances that you won't be able to see them. Alright? But there is one other possibility. Since we don't know what the dark energy is, it's conceivable that, although it's repulsive right now, someday the sign will change and it'll become attractive. In that case, it's still conceivable that the Universe will someday recollapse into a Big Crunch, and ending in fire, rather than eternal expansion and ending in ice. And Robert Frost might not know— well, he certainly did not know about anti-gravity, but he was at least sufficiently well-educated to know that the Universe could have one of these 2 possible fates: an implosion, an ending in fire, hot, or eternal expansion, an ending in ice, cold. Because he wrote this famous poem, right? Fire and Ice. Some say the world will end in fire. Some say in ice. From what I've tasted of desire, I hold with those who favor fire. But if it had to perish twice, I think I know enough of hate to say that for destruction, ice is also great and would suffice. So you see, Frost would prefer the recollapsing universe ending in fire. But if the universe and he had to perish twice, then eternal expansion and an ending in ice would be okay with him. And that's perhaps appropriate, Given his name, Robert Frost. So that summarizes the science. To summarize just things that you can take away with you, applying to your lives: focus on the big picture, clarify with analogies and examples, accept new challenges, build and nurture a first-rate team, innovate, take risks, give additional incentives, jump on leadership opportunities, Take advantage of any opportunities that fall in your lap. Embrace competition. Think outside the box. Consolidate resources. And recognize when to collaborate. So those are some of the things I've learned through my research over the years, and especially on this project. And I hope you found not only the astronomy interesting, but something to take away that will apply more broadly in your careers. Thank you very much. How about a question there? Yeah, OK. That was great. Thank you, Tim. Thank you. I'm wondering, have you also measured our existing solar system, which is closer to us, and is it also spreading further apart? Right. So our own solar system is not spreading apart because it's sufficiently tightly bound due to the mass of the Sun to overcome any tendency of space to expand. Even our own galaxy isn't expanding. Even our own local group of galaxies isn't. So, what's actually expanding? I didn't want to get into the technical details, but since you asked, this is good. The vast spaces between clusters of galaxies are what are expanding, okay? And local things are like these ping-pong balls that I had. They're not expanding. It's the space between the clusters of galaxies, which these ping-pong balls, in a sense, represent. That's what's expanding. Thank you.