A mirror is going to flip the word anyway, so somebody flipped it first and let the two reversals cancel out. The driver ahead reads it in the one second where it counts. Try writing your own name in mirror image with nothing to copy from: reading one is far easier than making one.

Nobody voted on this. The direction comes from a stick pushed into the ground, and the shadow it threw across the northern hemisphere for centuries before any gear existed. Set the same sundial up in the southern hemisphere and it runs the other way, which is the fully checkable part.

A square cover, turned and tipped on its diagonal, drops straight into its own hole, because that diagonal runs about forty percent longer than a side. A circle is the same width from every angle, so falling in isn't unlikely, it's impossible. And the circle is not the only shape that manages it.

Wartime Britain really did run the campaign: posters, a cartoon character, slogans. A night-fighter ace really was running up victories, thanks to airborne radar. The part almost everybody adds afterwards, that the whole thing was staged to fool the Germans, is the part resting on nothing solid.

Hours in the freezer and it is still liquid, well below freezing, waiting. Ice needs a starting point to organize itself around, and very pure, very still water is short of them. Set the bottle down a little hard and the whole thing goes solid in seconds. The jolt is what matters.

Touching it will not make the mother abandon her chick, because that isn't how she recognizes it. But the conclusion isn't the permission you were expecting, since there is a real risk here and it has nothing to do with contact. It has to do with coming back, over and over.

A centimeter cube of it would weigh on the order of a billion tons. The star it came from is about a dozen miles across and carries roughly the mass of the Sun. Run the same thought experiment on your own body, and what's left is smaller than one of your red blood cells.

Your taste buds never detect it. The receptor a chili opens is the one that reports dangerous heat, at around a hundred and ten degrees. The pepper brings no heat with it at all; it just presses the button. Which is also why reaching for a glass of water goes so badly.