Discover
/
Article

Measuring the Hubble Constant

JAN 01, 1986

Hubble’s celebrated constant, which relates the recessional velocities of galaxies to their distances, is perhaps the most important number in extragalactic astronomy. Using it, along with their favorite models, astronomers and cosmologists derive the age of the universe, estimate its size, calculate the luminosity of quasars and much more. Unfortunately, astronomers are far from agreeing on a value for Hubble’s constant. Some believe that H0 is about 50 km/sec Mpc; others think it is closer to 100 km/sec Mpc. Depending on the details of the cosmological model chosen, this can lead to a discrepancy of a factor of 2—ten billion years or so—in the age of the universe.

This article is only available in PDF format

Related content
/
Article
In the closest thing yet obtained to a movie of a breaking chemical bond, there’s a surprise ending.
This Content Appeared In
pt-cover_1986_01.jpeg

Volume 39, Number 1

Get PT in your inbox

pt_newsletter_card_blue.png
PT The Week in Physics

A collection of PT's content from the previous week delivered every Monday.

pt_newsletter_card_darkblue.png
PT New Issue Alert

Be notified about the new issue with links to highlights and the full TOC.

pt_newsletter_card_pink.png
PT Webinars & White Papers

The latest webinars, white papers and other informational resources.

By signing up you agree to allow AIP to send you email newsletters. You further agree to our privacy policy and terms of service.