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If freezing is continued, initially-cold water always completely freezes before initially-hot water. Variations There are many possible explanations for the Mpemba effect which you could choose to explore. There are many reasons why you might not be seeing the Mpemba Effect, and to be perfectly honest, no one really knows the true reason behind the Mpemba Effect. Another scenario concerns the O: However, it should be perfectly fine to use normal thermometers as long as you try your best to be as quick and efficient as possible. Try one of our science activities for quick, anytime science explorations.

However, he accidentally placed the mixture in the refrigerator while it was still warm. Others say the phase change from water to ice is an important part of the effect and you must measure the time until it freezes solid. They think that the phenomenon people claim to observe is actually a red herring caused by slight inaccuracies in measurement. The Mpemba effect and its reverse a cooler sample may heat faster than a hotter sample have been shown, by theory and computation, to exist in the simple system of a uniform granular fluid [ ]. It seems that because of all the different variables at play, subtle variations in the experimental technique can lead to huge differences in the results that are observed. Thus, their supercooling before clathrate ice formation from hot water is far greater than that from cold water [ ].

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We are interested in conducting this experiment because the Mpemba Effect seems very contradictory to reality; therefore, we want to prove to the skeptical that what should be seen as the impossible can be proven possible.

It takes less than a minute and it’s completely free. Accessed 22 May Mpemba followed his curiosity and did more experiments with both water and milk, which confirmed his initial findings. He describes his discovery on YouTube. It seems that because of all the different variables at play, subtle variations in the experimental technique can lead to huge differences in the results that are observed.


The Mpemba effect: fact or fiction? | News | Chemistry World

Similar behavior has been observed in carbon nano-tubes resonators [ ]. By Emma Stoye 9 November Eventually, many other accounts proved his contradicting conclusion.

research paper mpemba effect

Effct is a measure of the average molecular motion of matter. Conduction is heat transfer by direct molecular interactions, without mass movement of matter.

For most objects you encounter every day, this would be infrared radiation: Will the conditions in your experiment lead to hot water or cold water freezing first? In some cases people have seen the Mpemba effect, in other cases the hotter water does not freeze faster.

The nucleation of ice crystals, supercooling and evaporation have all been put forward as things that can affect the behaviour of hot and cold water. Wffect used identical Pyrex beakers for his water samples, since they could go from the stove to the freezer without breaking.

The Mpemba Effect

You can find this page online at: They are also covering our cups with foil to be sure that the cups are insulated. When Mpemba later asked his teacher for an explanation of how his hotter ice cream mixture could freeze before a cooler one, the teacher teased him, “Well all I reseaech say is that is Mpemba physics and not the universal physics” quote in Jeng, The papef certainly exists for certain conditions, but no one really knows why it doesn’t exist for other conditions.

Recently, it has been discovered that the charge on the liquid interface affects the freezing point of supercooled water [ ]. Related to this explanation, part of the cause may be due to the variously sized and persistent convective currents created when hot water cools in different experimental set-ups.

It was fun, original, and I made it up myself! Faster Than Cold Water. He took four ounces of boiling water, four ounces of non-heated water, poured the water in identical containers, and placed them outside during the winter. The Mpemba Effect goes along with this field because it includes how water, a liquid, undergo changes within its properties.


research paper mpemba effect

Burridge has replied to my points, and I give his unedited reply below even though I believe it to be mistaken, misleading and highly contentious. If you put both hot and cold water in a freezer, the hot water allegedly takes less time to turn to ice. The effect is named after its discoverer — Erasto Mpemba, who as a teenager went to school in Tanzania in mpemb s. How am I supposed to keep the freezer shut as much as possible if I have to open it every 5 minutes to check on the temperature?

The best advice we have is to try to carefully control your experiments as much as possible. When printing this rresearch, you may NOT modify it in any way. Experiments on the low-density water around macromolecules have shown that such clustering processes may take some time [ 4 reseadch.

Background Research – Mpemba Effect

The most likely scenario described in [ ], disputed [ ], but later supported [ ] is that the degree of supercooling is greater, under some circumstances, in initially-cold water than initially-hot water. It may seem counterintuitive, but folk wisdom and a body of published evidence agree that, under some conditions, warmer water can freeze faster than colder water for an excellent review on the subject, see Jeng, The results for experiment c efffct equivocal—it’s difficult to say whether the time differences are significant or not.

Many meat thermometers are very sensitive to how far into the meat they are inserted, and typically you should insert it about half mpemmba.