Welcome to Quantum Magazine's podcast. Each episode we bring you stories about developments in science and mathematics.

I'm Susan Vallett. Our sun is getting brighter. If you could travel back in time to the dawn of the solar system

four and a half billion years ago, you'd find a star that was about 30% dimmer than it is now.

Over the subsequent eons, it has shown more and more brilliantly, a function of the nuclear

fusion process that takes place in the cores of stars

like our own. It will continue to do so until the end of its life, roughly 5 billion years

from now. But we might have that faint early sun to owe for life's existence. That's next.

Imagine you're in a lab where you've synthesized ancient DNA sequences and spliced them into modern bacteria just to see how they'd react. They needed each other, but they didn't

want each other. So, you know, it was like a very complicated relationship unfolding in front of me.

This isn't Jurassic Park or some sci-fi movie.

I'm Steve Strogetz, and this is the Joy of Why.

A new podcast from Quantum Magazine that takes you into some of the biggest unanswered mysteries

in science and math today, where the knots

with three crossings, the type you know from your shoelaces, are just the beginning of a much

bigger story.

There's one four crossing knot. There are two five crossing knots. We've tabulated all the possible

knots up to 19 crossings, and there's over 300 million of those knots up to 19 crossings.

And unraveling the mysteries of sleep

means studying fish, living in caves?

We can look at the differences in sleep

between each population of cave fish

and understand how genetic variation leads to sleep differences.

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