A Cartesian diver is an object with a compressible air bladder to change its density. When the diver is placed in a sealed water bottle and the bottle is squeezed, the diver sinks. When the bottle is ...

Your guides to the weird side of the web show how to make a Cartesian diver in a bottle. Iran has reopened the Strait of Hormuz—but experts say it now holds a card that works almost like a nuclear ...