Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years. Yacold also

partners with nature portfolio to advance gut microbiome science through the global grants for

gut health, an investigator-led research program. To learn more about Yachtold, visit yawcult.co.

com.j.p. That's Y-A-K-U-L-T.C-O.J-P. When it comes to a guide for your gut, count on Yacolt.

Hi, I'm Clara Moskowitz, a space editor here at Scientific American. We're taking a break this week to look back at some of our favorite podcast episodes. I chose this one about the physics of time travel because I'm a big sci-fi geek, so I'm fascinated by the topic. But also, it was such a fun debate to have with my colleague and friend Lee Billings, another space

editor here. We each picked aside. I was pro time travel, he was con, and dug our heels in. Check it out.

We're here today to talk about time travel, a perennial, dare I say timeless, topic of science fiction, but is it possible?

Is there any chance at all that it could actually happen?

No, no, no, no, no, no, no.

Well, okay, kind of, but not really.

I'm Lee Billings.

I'm Clara Moskowitz, and this is Cosmos Quickly, the bi-weekly space podcast from Scientific American.

We're going to have a little friendly debate.

Really, Clara?

I came for a throwdown.

Well, a wrangle. A parley. A confab.

Lee, what do you have against time travel?

So I love the idea of time travel, and in fact, I do it all the time.

Like most everyone else, I'm traveling into the future at one second per second.

I'm less of a fan, though, of more speculative time travel, which is good fodder

for goofy sci-fi stories, but in the real world, it's an implausible distraction. But really,

...