From the March 2008 issue

Does the Hubble constant change over time?

David E. West, Kenmore, Washington
By | Published: March 1, 2008 | Last updated on May 18, 2023
It does — which is why some prefer to call it a parameter. Measurements of the Hubble constant — the rate of the universe’s large-scale expansion — continue to improve and push to earlier and earlier times. As we look toward more and more distant galaxies, the name “constant” becomes increasingly inaccurate.