Light released by a distant star does not simply wink out after crossing some threshold of space. In a vacuum, photons keep ...
Cosmological redshift depends upon a galaxy's distance. Credit: NASA/JPL-Caltech/R. Hurt (Caltech-IPAC) In 1929 Edwin Hubble published the first solid evidence that the universe is expanding. Drawing ...
The long-standing problem of the cosmological constant, described both as “the worst prediction in the history of physics” and by Einstein as his “biggest blunder”, is being tackled with renewed ...