Who would’ve thought that a spring would make for a decent pastime? A naval engineer named Richard James, that’s who. After devising and manufacturing a small supply of Slinkys in the 1940s, James then went on to sell all 400 of his stock within an hour and a half of putting them up for sale.

The Slinky is probably most famously known for it’s ability to ‘walk’ down stairs autonomously once given an initial nudge. There’s something mesmerising about the effects you can make simply by moving and stretching a Slinky between your hands.

Despite being a simple spring that was devised around 70 years ago, you can still buy Slinkys (and similar alternatives) to this day.