The science behind an illusion

Fran Scott from the Royal Institution in England looks at the science behind an illusory Jeff Koons “sculpture”. In it, three basketballs sit motionless in a tank of water half way down with no visible means of suspension. This is what it looks like:

Jeff Koon - Three Ball Total Equilibrium Tank

Jeff Koon - Three Ball Total Equilibrium Tank

Now an inflated basketball would be full of air (um… by definition) so the fact that they’re underwater at all is unusual. And they couldn’t be filled with rocks because they would sink to the bottom. It’s also not a case of having some strategically positioned supports hiding behind the basketballs; you could walk all the way around the tank.

If you would prefer not to know, don’t watch this:

No wizardry or sleights of hand are involved in creating this illusion of a perfectly balanced basketball floating in pure water. Subscribe for regular science videos: http://bit.ly/RiSubscRibe Fran's has been a science presenter for the BBC and Channel 4, as well as a pyrotechnician and now the Science Content Producer at the Royal Institution.