What are the haps my friends

October 19th, 2007: A bunch of people sent me examples of situations in which addition is non-commutative: nonabelian groups, rotating objects in 3D space (try it! Pick up a book and rotate it 90 degrees left and then 90 degrees away from you, and then try the rotations in the opposite order: the book ends up in different positions, so the order in which you "add" the rotations together matters), non-commutative geometry and so on. That last one is interesting because it has a real-world application too: walking on a curved surface (like on a hill, or on our planet). If you start at the equator and go 1000k north and then 100k east, you'll end up in a different position than if you go east first and then north. So there's some math that doesn't commute and has the added benefit of having real-world applications! So that's something, huh?

Thanks to everyone who emailed me explanations! I haven't written you all back but I've read them all. I'm getting to the point where I can't respond to all the email I receive, and I'm already about a month behind, but I'm hoping to catch up.

To make sure the best gifts ever in time get to you when you want them, here are the HOLIDAY SHIPPING DEADLINES. Orders placed before or on these dates will get to you in time for Christmas!

December 3rd: Last day for international (non-US!) orders!
December 9th: Last day that ALL US shipping methods are safe.
December 16th: Last day that to use USPS Priority or UPS Ground!
December 20th: Only super express options work!

You and yours may DEFINITELY enjoy these items!!

One year ago today: can i - can i be a fictional character please

– Ryan

big ups and shouts out