#Ignited PARADOX : The Mpemba Effect Sitting in front of you are two glasses of water that are identical except for one thing: The water on your left is hotter than the water on your right. Place both of these glasses in the freezer. Which will freeze faster? You’d think the colder glass on the right would, but that might not be the case. Hot water can freeze faster than cold water.This odd effect is named after a Tanzanian student who observed it in 1986 while freezing milk to make ice cream. But some of history’s greatest thinkers—Aristotle, Francis Bacon, and Rene Descartes—had previously noted this phenomenon without being able to explain it. Aristotle mistakenly attributed it to what he called “antiperistasis,” the idea that a quality intensifies in the environment of its opposite quality. Several factors contribute to the Mpemba Effect. The hot glass of water may lose a large amount of water from evaporation, leaving less water that needs to be cooled. Warmer water also holds less dissolved gas, which could cause the water to more easily develop convection currents, thereby making it easier for the water to freeze. Another theory lies in the chemical bonds holding the water molecule together. A molecule of water has two hydrogen atoms bonded to a single oxygen atom. When water heats up, the molecules move apart, and the bonds can relax and give up some of their energy. This lets them cool faster than water that had not been heated to begin with.
Posted on: Mon, 17 Mar 2014 13:59:54 +0000
Trending Topics
Recently Viewed Topics
© 2015