Hot water freezing faster than cold water

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Discussion Overview

The discussion revolves around the phenomenon known as the Mpemba effect, where hot water is reported to freeze faster than cold water. Participants explore various explanations, anecdotal evidence, and the reliability of experimental results related to this effect.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation

Main Points Raised

  • Some participants reference multiple explanations for the Mpemba effect, including links to articles and papers that discuss potential mechanisms.
  • One participant suggests that the Mpemba effect may be a myth, attributing its occurrence to poorly controlled experiments and specific conditions.
  • Another participant notes that while the effect is observed, the exact reasons behind it remain unknown, emphasizing the lack of consensus on the phenomenon.
  • Concerns are raised about the generalization of the effect, with participants arguing that it does not always occur and that experimental repeatability has been inconsistent.
  • A historical anecdote is shared regarding the origin of the idea that hot water freezes faster, suggesting it stemmed from a misprint in a household tips column.

Areas of Agreement / Disagreement

Participants express disagreement regarding the validity and consistency of the Mpemba effect, with some viewing it as a myth while others acknowledge its occurrence under certain conditions. The discussion remains unresolved with multiple competing views present.

Contextual Notes

Participants note that the phenomenon may depend on specific experimental conditions and variables that have not been fully identified, leading to uncertainty in the results.

Yashbhatt
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This question has puzzled me for a long time and there have been many kinds of answer for it. The most sensible explanation I have heard is this one. http://physics.stackexchange.com/a/33026/40382

But then I found another explanation at http://shows.howstuffworks.com/brainstuff/hot-water-freeze-faster-video.htm and http://www.iflscience.com/chemistry/hot-water-freezes-faster-cold-and-now-we-know-why

Here's the original paper : http://arxiv.org/abs/1310.6514

Can anyone shed some light on what is the correct explanation of the Mpemba effect?
 
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The best "explanation", to me, is that it is mostly a myth; a product of poorly controlled experiments. It only happens under certain, generally highly contrived situations.

We have a few threads on this: you should do a search for them.
 
Last edited:
You make it sound like this always happens. Not the case.
 
I have read something like that it happens when water is heated to 35 degree Celsius.
 
Vanadium 50 said:
You make it sound like this always happens. Not the case.
Agreed, experimental repeatability has been elusive. This suggests we have not yet identified all the relevant variables.
 
I know the origin of the idea that hot water freezes faster than cold water. It was a misprint in a list of hints in a syndicated household hints column in newspapers.

The original tip was "For faster ice, use cold water. For clearer ice, use hot water."

When it was put on the wire service, someone accidentally left part of the text out: "For faster ice, use hot water."

I actually didn't read that column. I read the correction notice a few days later and thought it was funny. But don't ask me when it happened. That was decades ago.
 

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