Sleepy Facts About the Universe

Tonight, if you look up and find that steady orange light in the northern sky, you are receiving photons that left their source when your grandparents were young. The object sending them, however, has already burned through three and a half billion y... more

We do not feel it, but our entire galaxy is in motion, falling toward the constellation Virgo at roughly four hundred kilometers per second. The destination is the Virgo Cluster, the nearest large gathering of galaxies to our own, situated fifty-thre... more

For most of the twentieth century, the central assumption about the cosmos was that gravity was steadily applying the brakes to its expansion. Astronomers expected to measure exactly how much this expansion was slowing down. Instead, observations of ... more

The universe is 2.7 degrees above absolute zero in every direction we look, a remarkably uniform glow that presents a deep cosmological puzzle. In the standard picture of the Big Bang, distant regions of space have never been close enough to exchange... more

The clay tablets of ancient Babylon and the digital catalogs of modern astronomy are separated by nearly three thousand years, yet they point to precisely the same stars. This episode traces the remarkable continuity of how humanity has encoded the s... more

A black hole is widely understood as a cosmic trap, a region of gravity so intense that nothing, not even light, can escape. Yet some of the largest and most energetic phenomena in the universe emerge directly from these objects. Across vast distance... more

For over a thousand years, the cosmos was imagined as a two-story structure with a corruptible Earth below and perfect, unchanging heavens above. This Aristotelian framework made sense of everyday experience: stones fell because it was their natural ... more

When we look up at the night sky, the scattered points of light appear randomly distributed across the darkness. For centuries, astronomers assumed that this randomness extended to the cosmic scale, with galaxies sitting more or less evenly throughou... more