Featuring a Mad Science Show, explosive science activities, test tube concoctions, lab treats, Purim delights, dinner, and more. Costumes encouraged—Einstein lab coats welcome. $10–$15. 4:30 p.m. Chabad Jewish Center of Petaluma. 205 Keller St., Ste. 101, Petaluma. tinyurl.com/5atf9tdu.