Daniel Okafor — older stories

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.

Inkjet printers periodically flush ink through their nozzles to stop them clogging — sending it straight into a hidden waste pad, whether or not you've printed a page.

A coffee stain or a peeling sticker shouldn't kill a QR code, and usually it doesn't. Here's the redundant-data trick, borrowed from deep-space communication, that keeps damaged codes readable.

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.

SSDs need free blocks to write fast. The real reason a drive suddenly feels slow is almost always capacity, not calendar age.

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.

Deep discharge, heat and a bad charger all break down a battery's electrolyte into trapped gas. Here's the actual chemistry, the real fire risk it creates, and how to stop it in a device sitting in a drawer.

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.

Waymo just told Uber it's building its own app for Austin and Atlanta. Behind the split is a messier question riders rarely think about: who pays when the car with no driver hits something.

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.

An FAA order to inspect 471 Boeing 737 MAX jets sounds alarming. The mechanism behind it, and why no cracks have actually turned up on the model, explains why airlines aren't changing their schedules.

Microwave ovens and Wi-Fi routers share almost the same frequency, and one of them is about 35,000 times more powerful than the other.

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.

Your black-and-white document didn't need cyan, but your printer used it anyway, and in some models an empty color cartridge stops every print job cold.