124 | Solo: How Time Travel Could and Should Work

<p>Time! It doesn't stop, psychological effects of being under lockdown notwithstanding. How we experience time depends on our situation, but time itself just marches forward. Unless, of course, it's possible to travel to the past, as countless science-fiction scenarios have depicted. But does that really make sense? Couldn't we then change the past, even so dramatically that our own existence would never have happened? In this solo podcast I talk about both the physics and fiction of time travel. I point out that it <em>might</em> be allowed by the laws of physics, and explain how that would work, but that we really don't know. And I try to make sense of some of the less-sensible depictions of cinematic time travel. Coming up with a logical theory that could account for <em>Back to the Future</em> isn't easy, but podcasting isn't for the squeamish.</p> <p><em>Support Mindscape on </em><a href="https://www.patreon.com/seanmcarroll" rel="noopener noreferrer" target="_blank"><em>Patreon</em></a><em>.</em></p> <p>But wait, there's more! I was contacted by Janna Levin, who we fondly remember from <a href="https://www.preposterousuniverse.com/podcast/2018/12/17/episode-27-janna-levin-on-black-holes-chaos-and-the-narrative-of-science/" rel="noopener noreferrer" target="_blank">Episode 27</a>. Janna moonlights as Chair and Director of Sciences at <a href="https://pioneerworks.org/" rel="noopener noreferrer" target="_blank">Pioneer Works</a>, an institution dedicated to bringing together creative people in art and science. Like the rest of us, they've been looking for ways to offer more online content in these pandemic times, so we thought about ways to collaborate. Here's what they came up with: artist <a href="https://azikiwephoto.com/" rel="noopener noreferrer" target="_blank">Azikiwe Mohammed</a> has created an animated video backdrop to this podcast episode. The visuals are trippy, colorful, and inspired by (without trying to directly illustrate) what I talk about in the episode. You can check out <a href="https://pioneerworks.org/broadcast/sean-carroll-time-travel/" rel="noopener noreferrer" target="_blank">a brief write-up at the Pioneer Works site</a>, or view the video directly below.</p> <p><a href="https://www.youtube.com/watch?v=kHy1j4LiyGQ" rel="noopener noreferrer" target="_blank">https://www.youtube.com/watch?v=kHy1j4LiyGQ</a></p>