Running head: MPEMBA EFFECT - DECIPHERED
Mpemba Effect - Deciphered
Chris Gilbert Waltzek
Northcentral University
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MPEMBA EFFECT - DECIPHERED
Abstract
This brief paper proposes a startling and unique solution to the question asked by The Royal
Society of Chemistry: “Why does hot water freeze faster than cold water.” The Mpemba Effect
still baffles scientists several hundred years after Roger Bacon posed the question to colleagues.
During the course of this investigation, the empirical results indicate that hot water does not, in
fact freeze at a faster pace than does cold water. A simple control is imposed on both the hot and
cold bodies of water. Boiling water and cold water are each poured into two separate airtight
containers, without any remaining airspaces, the results are surprising. The test results are
conclusive, although hot water freezes more rapidly than does cold water, when the test water is
held in sealed containers, the results are reversed.
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MPEMBA EFFECT - DECIPHERED
Mpemba Effect - Deciphered
In 1968, a Tanzanian student Erasto Mpemba posed visiting professors an ancient problem
that has eluded great thinkers for centuries: “Why does hot water freeze faster than cold water.”
In fact Roger Bacon reportedly used the conundrum to argue for the scientific method (Bacon,
1733). The question which still stymies scientists to this day earned the moniker, The Mpemba
Effect. The Royal Society of Chemistry rehashed the investigation by offering the public a
generous prize for the solution. This brief paper proposes a startlingly simple solution to The
Mpemba Effect, riddle. Please click the play button in Figure 1.1 to play the accompanying
video of the test results
Figure 1.1. Mpemba Effect - Video
Figure 1.1. The bumper video is courtesy of Thomas Dolby and Joe Kerr from their album: The
Golden Age Of Wireless (1982), copyright 2012. All Rights Reserved.
Findings
During the course of this investigation, the empirical results indicate that hot water does not,
in fact freeze at a faster pace than does cold water. The Mpemba Effect appears to be the result
of dissolved hot water molecules changing states into water vapor, in the process releasing large
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MPEMBA EFFECT - DECIPHERED
amounts of heat, lowering dissolved gas levels while lowering the freezing point. Whereas cool
water evaporates more slowly, retains a higher relative proportion of dissolved gases, a lower
freezing point and thus freezes more slowly.
However, in order to adequately answer the question posed by President Professor David
Phillips at The Royal Society of Chemistry: “Why does hot water freeze faster than cold water,”
a simple control is imposed on both the hot and cold bodies of water. For instance, when boiling
water and cold water are each poured into separate airtight containers, without any remaining
airspaces, the results are reversed.
Discussion
By sealing both the hot and cold water in airtight containers, no gases escape. Since water
vapor is no longer released from the containers, the hot water cools at a far slower pace. In fact,
in every test conducted, regardless of the container type used, the results were identical: cold
water freezes more rapidly than does hot water. Thus it appears that the riddle has been solved.
The reason why cold water freezes more quickly than hot water is that hot water does not
develop an ice cap (insulation) as quickly as cold water, allowing water vapor to escape,
removing relatively more heat from the hot water. The test results are conclusive, although hot
water freezes more rapidly than does cold water, when the test water is held in sealed containers,
the results are reversed.
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MPEMBA EFFECT - DECIPHERED
References
Roger, B. (1733). Opus majus. London, England. Retrieved from
http://www.archive.org/details/opusmajusofroger002065mbp