Gravitational lens

Yeah, fuzzy dark matter.

And we're gonna look at how scientists are mapping it using what is basically the ultimate cosmic optical illusion, which is gravitational lensing.

It's such a wild concept.

So to start, I want you to imagine looking through a fun house mirror, but instead of glass, the mirror is made of pure invisible gravity that's warping the very fabric of space.

Yes.

We can map that gas perfectly with the Chandra X-ray Observatory.

But when we map the gravitational mass of that region using gravitational lensing, the vast majority of the mass is not in the middle with the gas.

Right.

This week we're talking maps because the UN is encouraging the world to adopt the Equal Earth Map that better represents the size of the planet's landmasses without the distortions of relative area that we see in the more familiar world map.

And next up, we're going to be looking at distortion on a much grander scale and how it's shining a literal light on the dark secrets of the universe via something called gravitational lensing.

Joining us to unpack all of that is Miguel Zumala-Kerigi of the Institute for Theoretical Physics in Madrid.

Welcome, Miguel.

Thanks for having me.

No, thank you, because you've got the hard questions.

Can you explain what gravitational lensing is in a simple way?

Right.

Um, but you do.

And, uh, I thought it was wonderful how you explained, you know, g- general relativity and, and this really cool thing called gravitational lensing.

Mm.

So tell us just a little bit about that, 'cause that's, that's really neat.

Let's go to some of the work that you've been focused on in recent years, George.

Let's start with gravitational lensing, which is a product of Einstein's, obviously, theory of relativity and the bending of light.

But Give some background on gravitational lensing over the last century, and then describe the kinds of research that you can do today where this is also part of a precision cosmology, instead of just looking at some blurred images that might be in the sky, but you can actually be very precise on what it means.

So it's very interesting.

I got interested in gravitational lensing more recently.

And part of it was I got interested in seeing whether it's phenomena that affect gravity waves, the gravitational radiation that LIGO and Virgo were seeing.

I was wondering if some of those could be gravitational lens.

Could we find a way to see that? I tried being so interested.