Xah's Math Blog Archive 2011-11 to 2011-11

Giant Parabolic-dish Photo Gallery
Spaceship Earth
Regular Polyhedron Domes (Geodesic Dome) Photo Gallery

Old Variant Form of the Letter “s” ſ and etymology of the integral sign ∫

Brain Hat

brain hat 4 medium2
“brain hat” by lani-rae. 〔source http://www.ravelry.com/projects/lani-rae/brain-hat

Klein Bottle Opener by Bathsheba

klein bottle opener klein bottle opener 2
klein bottle opener.

These are made by Bathsheba. You can buy it on her site, at: www.bathsheba.com.

Klein bottle is a exotic math surface that has only one side. That is, a ant crawling on the surface can get to the other side without crossing any edge. (the natural space of Klein bottle is 4th dimension. In 3-dimension, as in the picture, the ant would have to pass wall. For more about Klein bottle and a app for interactive rotation, see: Klein Bottle.)

Note: Bathsheba has also been creative in Second Life.

ammonite 75
Flying Ammonite in Second Life by Bathsheba.

She has also made a Seaslug Ride. To see more pics of her Second Life creation and location to buy, see: Seaslug RideFlying Ammonite.

Math: ID System, Number Base vs Number of Digits