How to measure nearby galaxies
Terren Tao explains how astronomers use Cepheid variable stars to measure cosmic distances, determining the brightness and distance of nearby galaxies.
MAIN POINTS FROM TRANSCRIPT
- Cepheid supergiant stars are thousands of times brighter than the sun.
- These stars are variable, with brightness oscillating over specific periods.
- The brightness and period of Cepheids help determine their distance.
- This method allows measurement of distances to thousands of galaxies.
TAKEAWAYS
- Cepheid stars serve as crucial tools for measuring cosmic distances.
- The relationship between a Cepheid's brightness and period aids in calculating its distance.
- This technique is a foundational step in understanding the universe's scale.
- Despite its utility, this method only covers a small portion of the universe.