Mental Floss

BIG QUESTIONS

Stainless steel is rust-resistant, but not quite rust-proof.

Stainless steel has a secret ingredient that makes it highly resistant to rust.

These days, we use ‘GOP’ to refer to Republicans—but that wasn’t always the case.

What ‘GOP’ means isn’t complicated—but its history is.

Like all great things, this classic snack doesn't last forever.

Discover whether or not popcorn expires, plus how long you can keep that bag you took home from the movie theater before it’s time to toss it out.

He wants you to learn about the symbol’s history.

Uncle Sam is an easily recognizable piece of wartime propaganda. And legend says he was based off a real person—though that may not actually be the case.

Legionella in a Petri dish under UV light.

The unusual respiratory illness was named for a 1976 outbreak among attendees of an American Legion conference.

Happy or terrified?

Laughter is a surprisingly common reaction to being scared out of your mind.

It’s kind of weird that ‘ghost’ is spelled with a ‘gh.’

Only a handful of English words start with ‘gh’—what gives?

You better knock, knock, knock ... on wood.

Discover the origins of the classic phrase 'knock on wood,' which could be tied to a Victorian-era children's game or have more direct ties to old pagan traditions.

We hope this vehicle is stationary.

Dogs love a good sensory experience. But letting them stick their head out of a moving car’s window is not a good idea. Here’s why.

There’s a reason they’re not rectangular.

Believe it or not, the shape of airplane window is a matter of life and death.

Shiitake mushrooms (left) are edible, while fly agaric (right) is extremely toxic, causing serious symptoms like dizziness, confusion, and hallucinations.

The definitions of toadstools and mushrooms are a bit intertwined.

Showers are great for getting a fresh start to your day or winding down for the night.

The answer isn‘t as straightforward as you’d think.

The Phillips head in all its glory.

Believe it or not, nobody named Phillips actually invented it.

The teddy bear has a very specific origin story.

The origins of the teddy bear involve President Theodore Roosevelt, a bear hunt, a political cartoon, and the owner of a candy shop in New York.

Blowing gray bubbles just wouldn’t feel as fun.

We uncover why bubblegum is traditionally pink—and also explore what flavor bubblegum even is.

Bonobo on the left, chimp on the right.

They basically share a genome, but chimps and bonobos have some not-so-subtle differences.

Caffeine is just one of the things that may be to blame for the irritating spasms.

Apple pie is a classic fall treat for Americans.

The phrase “American as apple pie“ leaves out the dish’s complicated history as an English dessert made of fruit that originated in Asia.

If you drive the same route long enough, sign fonts become fascinating.

Attentive drivers will notice more than one kind of typeface during their travels.

It’s easy to recognize these political symbols.

Andrew Jackson’s 1828 political campaign kicked it off, and cartoonist Thomas Nast made the political symbols really gain traction.

Here‘s the hole story.

Yes, they‘re often bullet holes. No, that‘s not the only explanation.

The official beverage of fall (sorry, PSL.)

They’re both fruit beverages, but apple juice and apple cider are not quite the same thing.

“God” and “Jesus” are the only Simpson characters that have five fingers.

It‘s normal for cartoon characters to be missing a digit, but how did the style originate?

Keep a look out for the origins of this weird phrase.

Popular theories involve pirates—and police.