This is a site that makes you think. Check out inventions that didn’t work, and then try to puzzle out why they went wrong. Definitely a site worth exploring. It’s also very educational and written at a level where almost anyone can understand.
The main gallery includes: It’ll Never Work!, Overbalanced Wheels, Stevin’s Problem, Friction and Idealizations, What about free energy? Buoyancy Motor, and
And that’s not all, there are more galleries. My favorite was “The Gallery of Artistic Impossibilities”, which explains the principles of artistic illusion.
Check this site out!