May 11, 2020 0 Comments

dewiki Mpemba-Effekt; elwiki Φαινόμενο Mpemba; enwiki Mpemba effect; eowiki Mpemba-efiko; eswiki Efecto Mpemba; etwiki Mpemba efekt; fawiki اثر امپمبا. Erasto Mpemba, a los 13 descubrió el efecto como consecuencia de una tarea, en Iringa, Tanzania, más adelante comprobó su teoría en El efecto Mpemba segun Nikola Bregovic – Download as PDF File .pdf), Text File .txt) or read online.

Author: Merr Samubei
Country: Turkmenistan
Language: English (Spanish)
Genre: History
Published (Last): 22 August 2006
Pages: 303
PDF File Size: 13.75 Mb
ePub File Size: 18.45 Mb
ISBN: 263-4-58878-218-3
Downloads: 64185
Price: Free* [*Free Regsitration Required]
Uploader: Kagakora

Put some water in a clean glossy smooth cup in a microwave oven and it will go way over c before it starts to boil. But they both froze at around the same time. NO, you cannot dismiss this effect with the simple statement that “the warm water has to first get to where the cool water started”. The Mpemba effect is a process in which hot water can freeze faster than cold water.

A team of researchers from Universidad Carlos III de Madrid, the Universidad de Extremadura and the Universidad de Sevilla have defined a theoretical framework that could explain the Mpemba effect, a counterintuitive physical phenomenon revealed when hot water freezes faster than cold water. The idea in the article is suggesting instead that water has some sort of “memory” so that it remembers being previously hot even as its temperature is falling.

James Brownridge, a radiation safety officer at the State University of New Yorkhas said that he believes that supercooling is involved.

But we can’t survive without clean water. Stop pushing pseudoscience on a science site. But there is a difference.

Why can hot water freeze faster than cold water? | UC3M

A smaller amount of water mpemb a higher surface to volume ratio i. Generally, heating raises the energy of a substance by lengthening and softening all bonds involved. They ruled out loss of liquid volume by evaporation as a significant factor and the effect of dissolved air.

This contributes to the faster rate of cooling ie energy release of warm water vs cool water, and this is correct, as described in the article.

Researchers claim to have discovered why warm water freezes faster than cooler water

The Scottish scientist Joseph Black investigated a special case of this phenomenon comparing previously-boiled with unboiled water; [8] the previously-boiled water froze more quickly. Early modern scientists such as Francis Bacon noted that, “slightly tepid water freezes more easily than that which is utterly cold. There isn’t even an agreement on what “freezing” means in this context – whether you see frost on the surface or whether the whole volume goes solid, or whether it simply reaches 0 degrees C.


Can you explain that water at the bottom of a lake in winter is almost always at 4 degrees C? A reviewer for Physics World writes, “Even if the Mpemba effect is real — if hot water can sometimes freeze more quickly than cold — it is not clear whether the explanation would be trivial or illuminating.

Although we like to think that freezing and boiling water always occur at the 0c and c, this is not really true.

This explanation makes sense. You might start with Zephir’s very good explanation of why warm water freezes faster than cooler water. The velocity of a shrinking crystal is miniscule.

Water found to be an ideal lubricant for nanomachines. If you start with a stretched rubber band in pmemba fingers, releasing that energy by ‘flicking’ it off one your fingers, not only returns it to the loose state but it goes further and the sides close together.

At this point, the claims by the research team are still theory—they or others will still need to find a way to prove what they’ve suggested is true before the scientific community will deem the mystery of warm water freezing, solved once and for all. Perhaps scientists working in very specific fields enjoy reading about advances in other fields they wouldn’t normally have the time to read. Warm water has more hydrogen bond stretching going on than cool water, thus it stores more energyand has more to release when exposed to freezing temperatures.

Retrieved from ” https: Enthalpy of fusion Enthalpy of sublimation Enthalpy of vaporization Latent heat Latent internal energy Trouton’s ratio Volatility. You want to talk about that crap, go to a homeopathy website.

To me, the great thing about this website, is it provides a gateway for laymen like myself to learn about leading edge scientific research without having to subscribe to however many scientific journals.


There’s no room for crackpots and trolls here. After initial consternation, Osborne experimented on the issue back at his workplace and confirmed Mpemba’s finding. Registration is free, and takes less than a minute. The plain saying, that something doesn’t provide an explanation is not enough. Plus since I thought what you wrote was really stupid I thought I should say something to go along with my one karma point. Mpemba Effect in Granular Fluids.

What’s also known is that with water molecules, hydrogen atoms are also attracted to the oxygen atoms in other nearby water molecules—a force called a hydrogen bond. I know you are wrong, because I have researched the current state of the science involved with this principle from multiple reputable sources, and your explanations fit no where in there.

The researchers, who have recently published the findings in Physical Review Letters, have confirmed how this phenomenon occurs in granular fluids, that is, those composed of particles that are very small and interact among those that lose part of their kinetic energy. College of Engineering, has published his paper, “Testing the Paradigm Researchers of the Max-Born-Institute at Berlin, Germany, have observed how biomolecules transfer energy into extremely small water droplets in their environment.

We only “know” it because people keep insisting it does. The difference is that the formerly warm water has convection currents setup during the cooling process that persist as it’s temperature drops to and below that of the cool water. They published the results together inwhile Mpemba was studying at the College of African Wildlife Management. One half of the sample would then be heated say to 50c and both then refrigerated. Somehow because you make comments that makes you less of a sissy boy troll.

By continuing navigation, we understand that it accepts our cookie policy. However, its causes and effects have hardly been studied until now.