Ever wonder why the moment cream hits coffee it appears to float? A group of MIT scientists have figured it out, which opens the door for more research of its kind in the future. The researchers have concluded that once cold cream is poured into a hot cup of coffee, the change in temperature makes the cream levitate.
Researchers recorded drops of cream at 2,000 frames per second and discovered that the base of the cream heats up once it hits the hot coffee, causing it to delay the mixing process. The area of coffee that the cream hits starts to cool while the cream heats, which results molecules in both the cream and coffee moving in a circular motion. That motion makes it appear as if the cream is floating for a split second because the air flow around the bottom of the drop is being pushed upwards.
Dr. John Bush, Professor of Mathematics, MIT, explained, “If you could maintain the temperature difference, it could be levitated indefinitely. Probably easier would be to put a hot drop on a cold bath, but if you basically add some heating element inside the drop, then that would work.”
The researchers’ revelation about cream and coffee carries over to improve other areas of technology, like DNA testing.