Dear Santa: Please Send Owl Puke; December 2010; Scientific American Magazine; by Anna Kuchment; 1 Page(s)

1. Geomag magnetic building set From $11 at reevesintl.com; ages 3 and up. William Shih of Harvard University’s Wyss Institute for Biologically Inspired Engineering suggests discussing with kids what makes some structures (such as a cube) less stable than others (a tetrahedron).

2. Galileoscope $30 at galileoscope.org; all ages. Cameron Hummels, a Ph.D. candidate in astronomy at Columbia University and head of outreach for the department, says that these are by far the best-quality telescopes for the price. “Because they’re so inexpensive, they don’t come with a tripod, so I’d recommend getting a cheap camera tripod—the taller the better. Also, download some free sky-visualization software for identifying astronomical targets” (www.stellarium.org).