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Hot water freezing faster than cold water

  1. Jul 14, 2014 #1
    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?
     
  2. jcsd
  3. Jul 14, 2014 #2

    russ_watters

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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: Jul 14, 2014
  4. Jul 14, 2014 #3

    Chronos

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  5. Jul 14, 2014 #4

    Vanadium 50

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    You make it sound like this always happens. Not the case.
     
  6. Jul 15, 2014 #5
    I have read something like that it happens when water is heated to 35 degree Celsius.
     
  7. Jul 15, 2014 #6

    Chronos

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    Agreed, experimental repeatability has been elusive. This suggests we have not yet identified all the relevant variables.
     
  8. Nov 2, 2015 #7
    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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