Interestingly, this kit you can buy has a slit cut into it for a window and it still seems to drop slowly in the video: http://www.grand-illusions.com/acatalog

Interestingly, this kit you can buy has a slit cut into it for a window and it still seems to drop slowly in the video: http://www.grand-illusions.com/acatalog/Lenz_s_Law_Demo.html http://www.grand-illusions.com/acatalog/Lenz_s_Law_Demo.html