How glad the waiters of the whole planet would be if their bosses were shown the experiment of the physicists of Princeton University. Even the most experienced and careful staff of cafés, bars and restaurants have repeatedly spilled coffee. Now American scientists have found a scientific excuse for this. This drink splashes out at any movement, even from a half-empty mug, because of small waves. Now, when hiring a waiter, an employer can be sure that he will certainly hear such a well-founded excuse.
The truth is in the foam
Have you noticed that waiters sometimes carry a really large number of glasses of beer for several tables with ease, without spilling a drop? What helps them to be so careful? As the basis of their experiment the physicists took a container with beer and, separately, one with coffee. The task was to prove a hypothesis that refers to the special influence of the foam in the glass. A special apparatus subjected them to motion and recorded it with a high-speed camera. It turned out that the foam restricts the movements of the liquid. Even a small layer of this natural “brake” damps the oscillations. This is explained by the dissipation of energy in a special viscous medium.
The physicists of Princeton University prepared a clear video demonstration of their interesting experiment and showed it at the meeting of the American Physical Society in November 2014, held in San Francisco. The relevance of this research lies in applying the knowledge gained to the transport of all kinds of liquids. Perhaps soon we shall witness some new revolution in the transportation of goods. The video contains not only the image of the effect of adding foam but also the readings of the instruments and the formulas of the calculations. One can become acquainted in more detail with the course of this experiment in scientific articles and in the scientists' future works. They will surely interest even those who do not know much about physics.
The truth is in the foam
Have you noticed that waiters sometimes carry a really large number of glasses of beer for several tables with ease, without spilling a drop? What helps them to be so careful? As the basis of their experiment the physicists took a container with beer and, separately, one with coffee. The task was to prove a hypothesis that refers to the special influence of the foam in the glass. A special apparatus subjected them to motion and recorded it with a high-speed camera. It turned out that the foam restricts the movements of the liquid. Even a small layer of this natural “brake” damps the oscillations. This is explained by the dissipation of energy in a special viscous medium.
The physicists of Princeton University prepared a clear video demonstration of their interesting experiment and showed it at the meeting of the American Physical Society in November 2014, held in San Francisco. The relevance of this research lies in applying the knowledge gained to the transport of all kinds of liquids. Perhaps soon we shall witness some new revolution in the transportation of goods. The video contains not only the image of the effect of adding foam but also the readings of the instruments and the formulas of the calculations. One can become acquainted in more detail with the course of this experiment in scientific articles and in the scientists' future works. They will surely interest even those who do not know much about physics.