Today, I volunteered at Girls' Science Day, a fun and engaging day-long program of hands-on science experiments for middle school girls from New York public schools. Here's what my group of girls learned today: How volcanoes erupt. How Wi-Fi works. Which elements of the periodic table are exciting when you light them on fire. How to make a paperclip float using surface tension. How to reduce anthropogenic pollution in big cities. And how to make ice cream with liquid nitrogen. (We also ate said ice cream. It was delicious.)