re: Tents work, too
I once thought I had developed a method of antigravity when I tried buttering a cat's back. The opposition of two irresistable forces--the "butter side down" rule and the "cats land on their feet" rule resulted in a cat slowly spinning in midair. Eureka! Unfortunately, I discovered that the cats soon lick all the butter off, and fall. This is not a good thing to find out when they have been harnessed to a vehicle.
Back to the drawing board... ;)