A visual approach — Imagine a rectangle with aspect ratio of √2. Dissect it into a grid of tiny squares: u squares long by v squares wide (Figure 1).

2 Thought Experiments To Mess With Your Head — For our first demonstration you will need your cat, a laser pointer and the Moon. Place your cat on the Moon. (Take necessary precautions to ensure the well-being of your cat.) Fire up the laser pointer and point it towards the Moon. (You will need a strong battery or a…

Integral calculus makes it easy — Watch on YouTube! To find the volume of a unit sphere, approximate the sphere with numerous discs, each of thickness dR (Figure 1). We’ll do this with the northern hemisphere only. Then we can double our result.

Why is it the same as the curved strip which surrounds it? — Watch this on YouTube! Grab a perfect sphere. Enclose it in a tube of paper (Figure 1). I claim that the rectangular sheet required to make the tube has the same area as the surface of the sphere. How can this be?

And where’s my £10K? — I have a math channel on YouTube. Videos take effort. And research. People watch my videos. They leave nice comments. Thank you, People. Yet, somehow a 30-second video that took me about a long to create is on its way to being the most-viewed effort on my whole channel. Folks…

Satire. Seriously, this is satire. Do I have to say it again? — (From the Horton Hears a WHO Department) The World Health Organization now recommends cold showers to combat Covid-19. “I read this awesome book by this guy who calls himself the Iceman,” confided a top WHO epidemiologist, who spoke on condition of anonymity. …

PART XI — Unaccompanied Minor Previous parts (if you’ve missed them): I A Face In The Window II The Ferryman III Bent Fork IV The Librarian V Sharon’s Side Quest VI What Happened With The Whiffle VII Within The Whiffle VIII What David Found At The End Of The Hallway IX What Sharon Found At The End Of The Hallway X Return To…

Messing with middle-school math. — "The simplest solution is the one most likely to be true." -- William of Ockham "Phhhhhht! Where's the fun in that?" -- Rube Goldberg Your kid comes home with a math worksheet. It’s full of number sequences. Find the pattern. That sort of nonsense. Here’s a sequence of numbers. …