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 ...

Light released by a distant star does not simply wink out after crossing some threshold of space. In a vacuum, photons keep moving indefinitely, and astronomers routinely detect light that has ...

Do constants of nature—the numbers that determine how things behave, like the speed of light—change over time as the universe expands? Does light get a little tired traveling vast cosmic distances? It ...

Fresh dark energy findings suggest the universe’s expansion might reverse in about 11 billion years, leading to a collapse 20 billion years from now. This challenges the long‑held belief in endless ...

Scientists know very little about the mysterious force dubbed “Dark Energy” that seems to be quickening the expansion of the universe but, according to LSU Physics and Astronomy Associate Professor ...