David Kipping

That's what I love.

That's what scientists love.

Every time we've built a telescope that is 10 times more precise than the last thing,

Every time we've done that, we have been surprised.

And so these early galaxies are a good example.

The cosmological experiments that are going on now, one of the big surprises is this thing called the Hubble tension.

Have you heard of that?

Hubble tension?

So Hubble tension is measuring the expansion rate of the universe.

How fast are things flying apart?

And you can do it two ways.

You can use the cosmic microwave backgrounds.

That's the earliest radiation that we can detect.

This is that stuff that's about 3 Kelvin warm.

You can detect in the microwave.

And this is the light which has traveled basically when the universe was 380,000 years old.

It's that light, and we see it in all directions.

That's how we know the Big Bang kind of didn't happen in one place.

It happened everywhere because you just see this light coming in from all directions.

And from studying that radiation, you can kind of get a model of the universe and then you can calculate using this model how fast should the universe be expanding today if I run the clock forward.