This is the science podcast for April 30th, 2026. I'm Sarah Crespi. First this week, we have a roundup of online news stories with editor David Grimm and staff writer Adrian Cho. After that, we have bioethicist Jackie Leakes Scully. She talks about how we should think about the ethics of epigenetics.

This is marks on our DNA that change our gene regulation and can sometimes be passed down

to the next generation. In the last segment, we are launching the 2026 book series. This is on science biographies. We picked six.

We're going to hear from books and culture editor Valerie Thompson and books host Angela Saney about how we chose what we covered.

Okay, so we're going to talk about online news stories from the last week, maybe a little bit before that, with David Grimm, our online news editor.

He's going to do the bulk of that work.

But first, we have a special appearance from staff writer Adrian Cho.

He specializes in physics, and he's going to walk us through one of the more difficult stories that we're going to tackle this week. It's on whether or not there are singularities at the center of black holes. So, hi, Adrian. Hi, Sarah. How are you? Good. I'm excited to talk about this because I know some of these words. Like, I know what a singularity is. I know what a black hole is. But I didn't know

that it was a debate whether or not there would be one inside of the other. The situation is that

since the 1960s, physicists have known that if a star collapses to form a black hole, then according

to the prevailing theory of gravity, which is Einstein's general theory of relativity,

you have to form a singularity or something like it in space. And essentially what happens

is the star gets smaller and smaller and smaller and denser and denser and denser, and the gravitational

field it produces gets more and more intense. And that gravitational field is actually the warping of space time.

So time actually runs a little bit slower in a strong gravitational field.

And so what actually happens is that when the star collapses to a point, you get this point

of infinite stretching of space time. If you go back to high school

algebra, you remember the function 1 over X goes to infinity, right? That's kind of what's happening,

right? Space gets infinitely stretched out. For those of us who are visual slash graphic learners,

that's very helpful. In the 60s, Roger Penrose, who won the Nobel Prize,

he proved that in general relativity,

if a star collapses enough to form an eventorize,

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