#mpemba effect

In physics, chilling out isn’t as simple as it seems.

A hot object can cool more quickly than a warm one, a new study finds. When chilled, a warmer system cooled off in less time than it took a cooler system to reach the same low temperature. And in some cases, the speedup was even exponential, physicists report in the Aug. 6 Nature.

The experiment was inspired by reports of the Mpemba effect, the counterintuitive observation that hot water sometimes freezes faster than cold. But experiments studying this phenomenon have been muddled by the complexities of water and the freezing process, making results difficult to reproduce and leaving scientists disagreeing over what causes the effect, how to define it and if it is even real (SN: 1/6/17).

تأثير مبيمبا – كيف يتجمد الماء الساخن قبل البارد؟ لغز حير علماء الأرض: كيف يتجمد الماء الساخن قبل البارد؟ السر العظيم وراء تأثير مبيمبا Mpemba effect   المقدمة الصادمة: كيف حطّم وعاء حليب يقين الديناميكا الحرارية؟ كان الهواء ثقيلاً ومشبعاً برطوبة استوائية خانقة في ظهيرة ذلك اليوم من عام 1963، داخل مختبر التدبير المنزلي بمدرسة ‘ماجامبا’ الثانوية في تنزانيا. رائحة الحليب المغلي الممزوج بالسكر…

Is the Mpemba Effect Real?

For more than 2,000 years, scientists  have observed the unique phenomenon that, in some conditions, hot water  freezes faster than cold water. In the fourth century B.C.E., Greek scientist Aristotle noted, “The fact that the water has  previously been warmed contributes to its freezing quickly: for so it cools sooner.” Seventeenth-century  English scientist  Francis Bacon noted, “slightly tepid…

And today I learned about the Mpemba Effect which states that hot water can in fact freeze faster than cold water.