This winter was really, really cold. Outside of drought-stricken California, most of the U.S. suffered a severe and snowy winter. Temperatures in some states were briefly colder than the surface of Mars.
What's Up With ThatEach week, we'll explain the science behind a strange phenomenon that you may be wondering about, or may be hearing about for the first time right here. If you've seen or heard of something you'd like us to explain, let us know in the comments.
Beer in a Hot Pan Slides Around Like an Air Hockey PuckPart of the fascination with this experiment is that the air is so cold that even extremely hot water immediately turns to snow. This is presumably more impressive than cold water freezing as quickly. Turns out the exact opposite is true.
Certainly some of the effect, regardless of the temperature of the water, is due to the fact that throwing it into the air spreads the water out and exposes more of its surface to the cold, allowing it to quickly freeze.
But there’s another extremely bizarre effect going on that deserves a closer look: Something about hot water makes it freeze faster than cold water.
This counterintuitive phenomenon is part of a 2,000-year-old mystery, having been observed throughout history by scientists such as Aristotle, Francis Bacon, and Rene Descartes. It has the modern name of the Mpemba Effect, named for Erasto Mpemba, a Tanzanian high school student with an interesting story. In 1963, Mpemba’s class was dissolving sugar in boiling milk to make ice cream. Before churning, cooks are generally supposed to cool the milk but Mpemba was impatient and put his concoction in the churner while still hot. To his surprise, he found his ice cream formed faster than any of his classmates. His teacher didn’t believe him and told him he must have been confused.
When a professor of physics later came to visit the class, Mpemba asked him if it was possible for hot things to freeze faster than cold ones. The professor didn’t believe him either but, together, they performed an experiment. They put two glasses of water, one at 95 degrees Fahrenheit and the other at boiling, in a freezer and noted that the hotter one turned faster to ice. They published a paper on the experiment in 1969. The result has since been replicated many times, though it doesn't always work and depends on the relative temperatures of the two liquids.
I'm an enthusiast with a deep understanding of the Mpemba Effect, a fascinating phenomenon that has puzzled scientists for over 2,000 years. My knowledge extends to historical observations by prominent figures such as Aristotle, Francis Bacon, and Rene Descartes, and culminates in the modern-day experiments and studies surrounding this counterintuitive concept. One remarkable example is the experiment conducted by Erasto Mpemba, a Tanzanian high school student, in 1963.
In Mpemba's case, he noticed an unusual occurrence while making ice cream in class. Despite conventional wisdom dictating that cooling the milk before churning is necessary, Mpemba impatiently placed his hot concoction directly into the churner. To his astonishment, his ice cream formed faster than that of his classmates. The Mpemba Effect, named after this curious student, became a subject of scientific inquiry.
The Mpemba Effect revolves around the observation that hot water can freeze faster than cold water, challenging common expectations. The phenomenon involves multiple factors, including the increased surface area exposure of water when thrown into the air at low temperatures. This exposure enhances the freezing process.
The mystery of the Mpemba Effect persisted through the ages until Mpemba and a physics professor performed an experiment to test the phenomenon's validity. They placed two glasses of water, one at 95 degrees Fahrenheit and the other boiling, in a freezer. Contrary to intuition, the hotter water turned into ice faster. This groundbreaking result was published in 1969, and the Mpemba Effect has since been replicated in various experiments, although its occurrence depends on the specific temperatures of the two liquids.
In the context of the cold winter described in the article, the mention of temperatures colder than the surface of Mars emphasizes the extreme cold conditions. While the article primarily focuses on the intriguing Mpemba Effect, it also briefly touches on the experimental setup involving hot water turning to snow in frigid air. This aligns with the broader theme of unexpected phenomena in cold weather, offering readers a glimpse into the strange and counterintuitive nature of physical processes.
