Why do onion fumes make us cry? The answer involves volatile sulfur compounds, an enzyme, your eyes’ natural defense system, and a chemical called syn-propanethial-S-oxide — and it is more interesting than you’d expect.

Phantom kangaroos — sightings of kangaroos and wallabies far outside their native range in Australia — have been reported across the United States, Europe, and beyond for over a century. Nobody has a satisfying explanation.

The physics of rainbows — refraction, reflection, and the dispersion of light — is one of the most beautiful demonstrations of optical science in the natural world, hiding in plain sight above every rainy sky.

The problem of evil is the most challenging argument against the existence of a benevolent God — and engaging seriously with it reveals something profound about the nature of suffering, free will, and moral responsibility.

The idea that humans are the only animals that use tools is one of the most thoroughly debunked myths in biology — and what the evidence reveals instead is more humbling, more fascinating, and more philosophically provocative.

The Plague of Justinian was the first pandemic in recorded history — and its impact on the Byzantine Empire, the Mediterranean world, and the trajectory of Western civilization was devastating and lasting.