1. You’ll have seen this stuff being used.
When a free kick is awarded, the referee sprays a circle around the ball. He paces out 10 yards and sprays a line where the defensive wall stands. The spray then disappears within a minute.
The invention, first used at the 2011 Copa America tournament, serves two purposes. It stops the defensive wall creeping closer when the referee has his back turned, and it stops the player taking the free kick from gaining ground by rolling the ball forward.
2. But what’s in it?
Well, according to LiveScience, it contains “a mixture of butane, isobutane and propane gas; a foaming agent; water; and other chemicals. When it leaves the can, the gas depressurizes and expands, creating small, water-covered droplets on the field. The butane mixture later evaporates, leaving only water and surfactant residue behind.”
3. So now you know.
Yes it does.