Lagrange Point Episode 531 - Measuring the expansion of the universe

Understanding the future of the universe requires peering into the past. How quickly the universe is expanding has been an active area of science since the 1920s, with several prizes and breakthroughs. Each time we get new or more accurate measurements it forces scientists to re-evaluate the assumptions and formulas. These breakthroughs then need to be confirmed with follow up studies. The measurement of Hubble's constant using supernova won a Nobel Prize in 2011, and new gravitational lensing measurements have provided extra confirmation to those numbers. Dark matter can influence a lot in our universe, but measuring it is difficult but using lensing techniques a more accurate measurement can be derived.

1. Mauricio Cruz Reyes, Richard I. Anderson. A 0.9% calibration of the Galactic Cepheid luminosity scale based on Gaia DR3 data of open clusters and Cepheids. Astronomy & Astrophysics, 2023; 672: A85 DOI: 10.1051/0004-6361/202244775
2. Princeton University. (2023, April 7). How to see the invisible: Using the dark matter distribution to test our cosmological model. ScienceDaily. Retrieved April 14, 2023 from www.sciencedaily.com/releases/2023/04/230407215847.htm