How Stuff Works

Thermal polish is sometimes sold as mood polish. (Lelê Breveglieri) — Thermal nail polish is a type of polish that changes colors according to temperature. It’s like wearing a mood ring on your nails, except most thermochromic polish only switches between two colors rather than displaying the whole rainbow. The cool (or hot!) effect involves a bit of chemistry. Here’s how […]

How Does Thermal Nail Polish Work? Recently updated !

This entry was posted on December 12, 2018 by Anne Helmenstine (updated on December 12, 2018)

Science can explain the phenomenon of spontaneous human combustion. (Elti Meshau) — Every now and then, there’s a news story about a mysterious death where the victim has burned, seemingly without being set on fire or in proximity to a heat source. In other cases, a fresh corpse began to burn, without external assistance. If forensics rules out obvious causes, like passing […]

Is Spontaneous Human Combustion Possible?

This entry was posted on December 5, 2018 by Anne Helmenstine (updated on December 5, 2018)

Water forms a teardrop shape just before it falls from an object. (Ed Leszczynskl) — If asked to draw a raindrop, just about everyone draws a teardrop shape. When water drips from a surface, like the tip of a leaf, this is the shape it makes just before the drop falls. But, once the drop is released, it forms a sphere. Raindrops form spheres, too, […]

The Real Raindrop Shape Is Not a Teardrop

This entry was posted on November 10, 2018 by Anne Helmenstine (updated on November 24, 2018)

For many people, hair grows faster on one side than on the other. (Christopher Campbell). — Have you ever noticed your hair grows faster on one side than the other? Your stylist may have pointed it out when you went in for a cut or you may have observed it when shaving your face or legs. Your fingernails and toenails may grow faster on one side […]

Why Hair Grows Faster on One Side

This entry was posted on September 27, 2018 by Anne Helmenstine (updated on December 2, 2018)

Nail Polish — Every nail polish stash contains a few bottles of gloopy, dried-out polish. Unless you hate the color, don’t throw it out! You can fix dry nail polish, returning it to its fluid consistency. Just be aware, there’s a right way and a wrong way to save the polish. The Wrong […]

How to Fix Dry Nail Polish

This entry was posted on June 4, 2018 by Anne Helmenstine (updated on June 28, 2018)

When it's really cold, you can see your breath. — If you’re outside on a cold winter day or even if you breathe into the freezer, sometimes you can see your breath. Yet, sometimes it’s not all that chilly and see you puffs of vapor, while other times it’s downright frigid and you don’t see anything at all. What’s going […]

Why Do You See Your Breath When It’s Cold?

This entry was posted on May 28, 2018 by Anne Helmenstine (updated on November 12, 2018)