Is it possible to build a sand castle the size of a real castle? We imagine how it could be done, using a pneumatic drill and a huge, solid gold steamroller!

We find out what would happen if you shrank the earth. You could jump higher and move faster, but you would end up with altitude sickness even at sea level.

If you had a tree that could grow money, would that make you rich? Even if you wait 20 years for your tree to grow, you will probably end up no richer than you started.