We see a monkey holding a mirror and looking in it, looking at itself.

Mirror, mirror, what’s up with the mirror writing?

Ever wondered why sentences, words, and letters always exclusively seem to have their left and right reversed in the mirror, while they are almost never projected upside down? Probably, because mirrors do something else than you would expect. For starters, mirrors don’t reverse left and right. Continue reading Mirror, mirror, what’s up with the mirror writing?

A photoshopped image of an out-of-focus dude with a beard holding a little sphere between his thumb and index finger in front of his face. The little sphere has a plus-sign on it. There are multiple spheres floating around with a minus-sign on them. Have a lovely day today!

Just a minute: Minus minus and negative times negative

Minus minus is plus. And negative times negative is positive. Two negatives make a positive. You may have heard or uttered these expressions many times. Even though you will know this already, here you will find an algebraic proof, just for your reference. Requirements: simple algebra from the second year in secondary, high or grammar school. Continue reading Just a minute: Minus minus and negative times negative