Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
Hubble constant
Introduction References & Edit History Related Topics
Images & Videos
Dr. Edwin P. Hubble stands beside the large 48-inch Schmidt Photographic Telescope at Palomar Observatory, preparing it for a sky survey.
Britannica editor Erik Gregersen, a white man wearing glasses, holds a microphone in front of a galaxy background. Displayed above him are the phrases: Ask an Editor, and How old is the universe?
Quizzes
Nicolaus Copernicus. Nicolas Copernicus (1473-1543) Polish astronomer. In 1543 he published, forward proof of a Heliocentric (sun centered) universe. Coloured stipple engraving published London 1802. De revolutionibus orbium coelestium libri vi.
All About Astronomy
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
Dr. Edwin P. Hubble stands beside the large 48-inch Schmidt Photographic Telescope at Palomar Observatory, preparing it for a sky survey.
Dr. Edwin P. Hubble Edwin Hubble, namesake of the Hubble constant, prepares for the National Geographic Society-Palomar Observatory sky survey. 

Hubble constant

astronomy
Written and fact-checked by
Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
Britannica Editors
Last updated
•History

Hubble constant, in cosmology, constant of proportionality in the relation between the velocities of remote galaxies and their distances. It expresses the rate at which the universe is expanding. It is denoted by the symbol H0, where the subscript denotes that the value is measured at the present time, and named in honour of Edwin Hubble, the American astronomer who attempted in 1929 to measure its value. With redshifts of distant galaxies measured by Vesto...

Discover the world with Britannica

Subscribe to Continue Reading

Free Trial | No Ads | Exclusive Content
Explore Subscriptions
DNA
Right
Mobile