Science — older stories

Two ordinary facts about sunlight, not measurement error, explain why the equinox never delivers a true 12-hour split anywhere on Earth.

A new Nature study finds ordinary raindrops build up enough static electricity to punch through protective coatings on metal, a corrosion mechanism nobody had measured before.

Club soda and sparkling water start with identical carbonation, but one goes flat first because of what else is dissolved in it.

Two glasses of tap water from two different cities aren't the same water. Source rock, disinfectant choice, and plumbing all leave a taste behind.

Mars looks lopsided on the surface — mountains in the south, flat plains in the north. New research shows the asymmetry runs all the way to its molten heart.

Tonight's deep lunar eclipse won't repeat next month, or even next year. Here's the orbital mechanics behind why eclipses arrive in pairs, twice a year, and no more.

Dry ice skips the liquid phase entirely because of basic physics — and a widening CO2 supply gap is turning that same physics into a shipping headache.

Swapping the battery is supposed to end the chirping. When it doesn't, the real cause is almost always one of four things, and a dead battery usually isn't one of them.

A Berkeley vision scientist studied 214 land animals and found pupil shape isn't random. It's optics, tuned to whether an animal ambushes, grazes, or chases.

No one steers a train around a curve. A 19th-century trick of geometry, the conical wheel, does that job instead, and railroads are still refining it.

One insect, two very different stingers. The barb is why a worker honeybee dies after a single sting, and why the queen never does.

A burst of radiation from the sun can scramble the atmosphere GPS signals pass through — in 2024, it sent tractors and ships drifting off course.

Trains can't steer their wheels independently, so tight curves force a stick-slip vibration that turns steel into a very loud, unintentional bell.

Water's density peaks at 39.2°F, not at freezing. That single anomaly drives the seasonal mixing that keeps a lake's deep water breathing.

Red light protects a submarine crew's night vision before a periscope watch. A Coast Guard researcher's blunt 2002 verdict complicates the tidy version of that story.

Unpopped "old maids" aren't random. A Purdue food chemist found the difference between a good popper and a dud comes down to moisture and a kernel's cellulose hull.

Tuesday's magnitude 7.1 Kumamoto earthquake struck as one sudden jolt, while sequences in the Philippines and the Canary Islands unfolded as sprawling swarms. The difference comes down to fluid, not fault size.

Plants that fold their leaves at night aren't wilting or sleeping — they're running an evolved, energy-spending routine called nyctinasty.

The Schumann resonance is a real electromagnetic hum circling the planet, discovered in 1952 and confirmed in 1960. Here's the physics, and why the wellness claims built on it don't hold up.

NASA, ESA, MIT and University of Arizona scientists agree the space-debris cascade is plausible. They do not agree on whether it has already begun, or how bad it gets from here.