Charles Liu

And so there's something called an extinction curve, okay?

And every kind of dust has a different extinction curve.

So you look in a direction, say I look at a galaxy that's in that direction, far away.

I first have to ask, okay, what does the galaxy's light look like from my telescope?

And the second thing is I have to ask somebody who did measurements of extinction.

Say, hey, what is the dust capacity?

What is the dust density and the dust variety in this line of sight?

And then that person will say, oh, that...

line of sight was measured to have this much extinction and these kinds of gases and dusts.

And then you go, okay, and then you make a correction to make your galaxy light what it would have looked like had the dust not been there.

It's a complicated story.

Although it sounds awful in one way, yes, it makes our ability to understand those distant galaxies that much tougher.

It's also a blessing in disguise because it allows us to understand dust in the universe.

If we want to know what we humans were created out of, literally, stardust.

Stuff that came off of stars, cooked in the hearts of stars, and then spewed out into the universe in the Milky Way galaxy.

So if we want to know where we came from as human beings or as life forms or even as planets, we need to understand that dust.

So the combination of being forced to be able to compensate for that dust and to be able to know what's behind that dust has given us the opportunity to study the dust itself, which I think is pretty awesome.

People spent entire careers doing these kinds of maps.

I'm sure, Neil, you'll remember Schlegel did a lot of this.

Bruce Drain did a lot of this.