Index

The Origin of the Universe

A survey of the evidence

Introduction
Measurement Overview
    Parallax Distances
    Star Sizes and Absolute Magnitudes
    Cepheid Distances
    Type 1a Supernovae Distances
    Redshift Velocities and Distances
    Age of the Stars in Globular Clusters
    The Oldest White Dwarfs
    The Cosmic Microwave Background
Conclusion

Parallax Distances

The positions of nearby stars change as the Earth orbits the Sun. The movement is called parallax. If a star's parallax is known, the distance to it can be calculated. Astronomers have used the technique to measure the distance to more than a million stars out to about 3,000 light years, beyond which parallax shifts become too small to yield accurate measurements.

Parallax