Wendy Freedman

Calibrate them locally and then use the inverse square law to get the distance.

So there is a very clean method.

So we're using the James Webb Space Telescope to measure distances to galaxies using these three different methods, the carbon stars, the red giant stars, and Cepheids.

And that will allow us ultimately, and we're partway through this project,

to determine how well we've measured the distances, right?

Do all three methods agree really well?

Is there a large spread in the values?

Do two agree, one's an outlier?

This will give us a chance to say, what are the overall uncertainties?

And those nearby galaxies that we're observing with JWST,

those galaxies then tie into the distant universe where we can see Type Ia supernovae well out into what we call the Hubble flow.

That's right.

We can measure the relative distances of supernovae.

We can see which ones are farther away, but we don't know what the absolute distance is.

Yeah, I think...

You know, to quote the late Carl Sagan, extraordinary claims require extraordinary evidence.

And I'm not yet seeing extraordinary evidence.

So our result, we're getting a value of about 70.

And that agrees very well with what we got from Hubble using these red giant branch stars.

And I think the uncertainties still, they're not at the level that come out of the cosmic microwave background measurements yet.