Mathematical objects

Henry Segerman is a mathematician who likes to make clever, remarkable mathematical shapes and 3D print them out into real things. He then makes a youtube explaining their origins. Each beautiful object becomes a mathematical lesson. He favors odd gears, weird knots, unusual shapes. You can watch Segerman videos for very nerdy satisfaction, but to fully close the loop, you can also purchase one of his exquisite objects shown in the videos. I have a few on my shelf. They are both conversation pieces and mathematical proofs, and great gifts for the nerds in your life. — KK.