Discrepancy in the Hubble Constant Measurements: "And as you know, there's this possibility that there's a discrepancy between the nearby values of the Hubble constant that we measure locally and what you get infer from measurements of fluctuations in the cosmic microwave background."

Astronomical Observation Challenges: "The advantage of the tip of the red giant branch is that you don't have to work in the disk because in the disk, you have lots of dust, You have high surface density of stars, so you have potential crowding and blending of the objects, and that means you can't measure the velocities very accurately. And when we get out in the halo, you don't have those problems."

Discovery of Cepheid Variables: "What Henrietta Leavitt discovered was that there were stars in the Magellanic Clouds that were changing their brightness over time. And so she had access to harder plates, photographic plates, which was the detector at that time...She found was that the Brian of these stars, they would get greater and greater and then at full more slowly. So rapidly rise in brightness and then fall off more more slowly....She made the further observation that the brightness of these stars was related to how fast they were changing in their brightness, the period of variation of the stars."

"Challenges in Space Observation: And that's something that is, you know, it's we're starting to see hints of in the data, and and we need to follow-up and make sure that that these aren't problems."

"Revolutionizing Astronomy with Standard Sirens": "So the idea with standard sirens is these are objects that now have been detected, with LIGO and other gravitational wave detectors. So there are 2 neutron stars that start spiraling and coalesce, and, you can use the measurement of the gravitational wave interaction... It's independent completely of all the kinds of systematics that we're talking about for the local distance scale, and, conceivably, it could be measured at larger distances where you don't have to worry about peculiar velocities, etcetera, etcetera. But they turned out to be unbelievably rare. So there was this beautiful object that was discovered in 2017, almost as soon as they turned on the detectors found this object, and hundreds of people chased it in the optical and knew it was just an amazing"

"Accuracy in Astronomy": "It's my strong belief that we won't have a Hubble constant to 1% until we have several methods that are precise at the 1 to 2% level."

The Importance of Multiple Methods in Astronomy: "I don't think the local distance scale is gonna be providing the type of, you know, extraordinary claims required extraordinary evidence. Yeah. You need extraordinary evidence, and I don't think it comes from one method."

The Significance of Hubble's Projects: "So he put together a panel of gray beards as it was called at the time and asked them to consider, what were big projects that only Hubble could do."

"Advances in Supernova Observation": "It really wasn't until, it became possible to find large numbers of supernovae, and CCDs became available. And then the accuracy that with which, again, you could measure luminosities of supernovae and actually discover that there was this decline rate dependence and that you could standardize them."

The Quest for Precision in Astronomical Measurement: "Calibration is really important. It's not exciting, but nature isn't giving us a lot of geometric anchors."