The Cosmic Distance Ladder – How We Measure the Universe

Podcast: Talking Science · Stavros kinnas

Opublikowano: 2026-10-18

How do astronomers know a galaxy is two million light years away, or thirteen billion? This episode climbs the cosmic distance ladder rung by rung, from bouncing radar off Venus, to parallax and the Gaia satellite, to pulsating Cepheid stars and exploding white dwarfs, to the redshift of the expanding universe itself — and arrives at a genuine, unresolved disagreement between two ways of measuring the universe's expansion rate. You'll come away understanding how radar and parallax give us rock-solid distances close to home, how Henrietta Leavitt's discovery about Cepheid variable stars unlocked distances across galaxies, why Type Ia...