How 1 Tbsp of Olive Oil Calms Half an Acre of Waves

A video posted online shows a Harvard lec­turer demon­strat­ing how a mere table­spoon of olive oil can calm half an acre of waves. The sci­en­tist, Greg Kestin, explains the sci­ence behind the mind-blow­ing phe­nom­e­non.

Kestin can be seen at the begin­ning of the footage nav­i­gat­ing on a lake in a canoe. He then pours a table­spoon of olive oil into the water as a count­down starts.

The footage is accel­er­ated so it resem­bles a time-lapse and the oil has already spread quite far dur­ing the first minute of the exper­i­ment. Two min­utes in, the oil has already cov­ered a large sur­face around the canoe and waves that were present on the sur­face have essen­tially dis­ap­peared.

Eight min­utes later, the olive oil is cov­er­ing a sur­face around the canoe that is equiv­a­lent to half an acre, and waves have com­pletely calmed down in that area.

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Kestin, who posts on his YouTube chan­nel What The Physics? goes on to explain how such a tiny quan­tity of olive oil has basi­cally man­aged to calm the waves on such a large perime­ter. His expla­na­tion is rather sim­ple and is has to do with the way oil and water mol­e­cules inter­act with each other.

Oil mol­e­cules are dou­ble sided with pos­i­tively and neg­a­tively charged ends. The oil mol­e­cules depro­to­nate — they lose a pos­i­tively charged pro­ton — when they come in con­tact with the water mol­e­cules.

The oil mol­e­cules flip onto their neg­a­tively charged ends when they touch the water mol­e­cules, which are pos­i­tively charged (Positively charged par­ti­cles attract neg­a­tively charged ones, and vice versa.) The neg­a­tively charged ends of the oil mol­e­cules flip towards the sur­face of the water while the pos­i­tively charged ends flip towards the sky.

The result is that each and every oil mol­e­cule that was con­tained in the table­spoon of olive oil has no choice but to spread out across the sur­face of the water once it touches it.

The oil mol­e­cules even­tu­ally form a layer that is just one mol­e­cule thick; that scrimpy layer of olive oil is what pre­vents the wind from mak­ing waves at the sur­face of the water.

“Usually, the wind builds up waves by get­ting trac­tion on the sur­face of the water but here, the oil acts like a tan­gled shaggy car­pet on top of the water, which does­n’t bend or stretch eas­ily, so instead of mak­ing waves, the wind just drags the car­pet across the water,” explained Kestin.

That’s how a mere table­spoon of oil was able to cover such a large area and calm the waves.

Just imag­ine what it can do for your bruschetta.

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• What The Physics?! YouTube chan­nel


• Yahoo! News