A Breeze and a Paper Glider

I noticed a cool draft coming from the cracked window above the living room sill, so I decided to test its aerodynamics! I took a small strip of stiff cardstock from an empty envelope on the side table, folded a crisp center crease, and angled two neat dihedral wings. When I held it out into the incoming air stream, the lift caught under the paper instantly. By shifting my grip and testing different pitch angles, I managed to get it to glide in a clean, stable glide path right across the sill.