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{{Short description|Tanzanian game warden and scientist (1950–2023)}}
'''Erasto Bartholomeo Mpemba''' (1950) is a [[Tanzania|Tanzanian]] game warden who as a schoolboy discovered the eponymous [[Mpemba effect]], a paradoxical phenomenon in which hot water freezes faster than cold water under certain conditions. He discovered the [[Mpemba effect|phenomenon]] at Magamba Secondary School in 1963 while preparing [[ice cream]] to earn pocket-money. The correctness of his observations was proven experimentally.<ref>{{Cite web|url=http://math.ucr.edu/home/baez/physics/General/hot_water.html|title=Can hot water freeze faster than cold water?|website=math.ucr.edu|access-date=2018-03-05}}</ref>
{{Infobox scientist
| name = Erasto B. Mpemba
| image = Erasto Mpemba (1963).jpg
| image_size =
| caption = Mpemba as a schoolboy (~1963)
| birth_date = {{birth year|1950}}
| birth_place = [[Tanganyika Territory]]
| death_date = May 14, 2023 (aged 73){{refn|group=note|name=first}}
| death_place = Tanzania
| nationality = Tanzanian
| field = [[Natural resource management]]
| work_institution = [[Ministry of Natural Resources and Tourism (Tanzania)|Ministry of Natural Resources and Tourism]]
| alma_mater = [[College of African Wildlife Management]]
[[University of Canberra]]
[[Sul Ross State University]]
| doctoral_advisor =
| doctoral_students =
| known_for = [[Mpemba effect]]
| prizes =
| footnotes =
}}


'''Erasto Bartholomeo Mpemba'''<ref name=":7" /> (1950–2023){{refn|group=note|name = first|Conflicting sources: According to TRT Afrika he died on May 14, 2023, aged 73;<ref>{{Cite web |last= |date=2023-05-31 |title=Mpemba: The man who froze hot water faster than cold water. – TRT Afrika |url=http://www.trtafrika.com/lifestyle/mpemba-the-man-who-froze-hot-water-faster-than-cold-water-13439436 |access-date=2023-06-30 |website=Mpemba: The man who froze hot water faster than cold water. |language=en}}</ref> according to his coauthor's widow, he died around 2020.<ref name=":1" />}} was a [[Tanzania|Tanzanian]] game warden who, as a schoolboy, discovered the eponymously named [[Mpemba effect]], a paradoxical phenomenon in which hot water freezes faster than cold water under certain conditions; this effect had been observed previously by [[Aristotle]], [[Francis Bacon]], and [[René Descartes]].
During his studies at the [[College of African Wildlife Management]] near [[Moshi, Tanzania|Moshi]], he published in 1969, together with [[Denis Osborne|Dr. Denis G. Osborne]], a paper on the phenomenon.<ref>{{Cite journal|last=Mpemba|first=E. B.|last2=Osborne|first2=D. G.|date=1969|title=Cool?|url=http://stacks.iop.org/0031-9120/4/i=3/a=312|journal=Physics Education|language=en|volume=4|issue=3|pages=172|doi=10.1088/0031-9120/4/3/312|issn=0031-9120|bibcode=1969PhyEd...4..172M}}</ref> Later he worked in the [[Department of Natural Resources and Tourism]] in the Wildlife Division. He has since retired.<ref>{{Cite web|url=https://web.archive.org/web/20141026030355/http://tedxdar.tumblr.com/post/13200426765/tedxdar-speaker-erasto-b-mpemba-in-1963|title=TEDxDar • #TEDxDar Speaker Erasto B. Mpemba In 1963,...|date=2014-10-26|access-date=2018-03-05}}</ref>

== Life ==
Mpemba was born in 1950.<ref>{{Cite web |title=Mpemba-Effekt |url=https://brockhaus.de/ecs/enzy/article/mpemba-effekt |access-date=2024-03-01 |website=[[Brockhaus Enzyklopädie]] |language=de}}</ref> He visited the Magamba Secondary School in [[Tanzania]], where he rediscovered the [[Mpemba effect]] when he was 13 years old.<ref name=":0" />

Mpemba aspired to become a doctor, but financial constraints hindered his ambitions. Recognizing that working with wildlife presented an opportunity for an overseas scholarship, he enrolled in [[College of African Wildlife Management|Mweka Wildlife College]] in [[Moshi, Tanzania|Moshi]].<ref name=":4">{{Cite web |last=Bliss |date=2021-07-31 |title=The Teenager Who Disproved Thermodynamics: The Mpemba Effect |url=https://theretrobliss.medium.com/the-teenager-who-disproved-thermodynamics-the-mpemba-effect-d8b2a432d8b2 |access-date=2024-03-01 |website=Medium |language=en}}</ref><ref name=":5">{{Cite web |last= |date=1997-05-01 |title=The Mpemba Effect |url=https://www.tzaffairs.org/1997/05/the-mpemba-effect/ |access-date=2024-03-01 |website=Tanzanian Affairs |language=en-GB}}</ref><ref name=":6">{{Cite web |date=2011-11-26 |title=Who killed Zinjanthropus? |url=https://www.ted.com/tedx/events/1083 |access-date=2024-03-01 |website=TEDXDar}}</ref> Upon earning his diploma, Mpemba rose to the position of Regional Natural Resources Officer in Mara Region in 1967. It took him eight years to fulfill his goal of studying abroad:<ref name=":4" /><ref name=":5" /> He studied [[Natural resource management|Natural Resource Management]] at the [[Canberra College of Advanced Education]] (now [[University of Canberra]]) in Australia, subsequently earning a master’s degree at [[Sul Ross State University]] in [[Alpine, Texas|Alpine]], [[United States|USA]].<ref name=":6" /> He later became Principal Game Officer for the [[Ministry of Natural Resources and Tourism (Tanzania)|Tanzanian Ministry of Natural Resources and Tourism]] and vice-chairmen of the [[Food and Agriculture Organization|African Forestry and Wildlife Commission]]'s working party on the management of wildlife in 2002.<ref name=":6" /><ref name=":7">{{Cite web |date=2002-03-22 |title=Report of the 14th session of the Working Party on the Management of Wildlife and Protected Areas |url=https://www.fao.org/3/ai572e/ai572e.pdf |website=African Forestry and Wildlife Commission}}</ref> He had retired from the Tanzanian Ministry as of 2011.<ref name=":6" />

Mpemba was married and had children, his wife was a doctor.<ref name=":5" /> Mpemba's death is not well-documented; according to Christine Osborne, the widow of the physicist who played a key role in documenting and publishing Mpemba's findings, he died around 2020.<ref name=":1" /><ref>{{Cite web |last=Mann |first=Adam |date=2022-07-09 |title=A Very Basic Experiment Is Stumping the World's Best Physicists |url=https://www.theatlantic.com/science/archive/2022/07/mpemba-effect-hot-water-freezes-fast/661525/ |access-date=2024-03-01 |website=The Atlantic |language=en}}</ref> However, TRT Africa reports that he died on May 14, 2023.<ref>{{Cite web |last= |title=Mpemba: The man who froze hot water faster than cold water |url=http://www.trtafrika.com/lifestyle/mpemba-the-man-who-froze-hot-water-faster-than-cold-water-13439436 |access-date=2024-03-01 |website=TRT Africa |language=en}}</ref>

== Discovery of Mpemba effect ==
Mpemba discovered the phenomenon at Magamba Secondary School in 1963 while preparing [[ice cream]] in a cooking course.<ref name=":3">{{Cite journal |last=Romanovsky |first=Andrej A |date=2015-03-31 |title=Which is the correct answer to the Mpemba puzzle? |url=https://www.tandfonline.com/doi/full/10.1080/23328940.2015.1009800 |journal=Temperature |language=en |volume=2 |issue=1 |pages=63–64 |doi=10.1080/23328940.2015.1009800 |issn=2332-8940 |pmc=4843877 |pmid=27227006}}</ref><ref name=":0" /> Due to lack of time, he skipped the cooling phase when preparing the ice cream and immediately put it into the freezer; unexpectedly, his milk mixture froze faster than that of his classmates.<ref name=":1">{{Cite web |last=Mann |first=Adam |date=2022-06-29 |title=Controversy Continues Over Whether Hot Water Freezes Faster Than Cold |url=https://www.quantamagazine.org/does-hot-water-freeze-faster-than-cold-physicists-keep-asking-20220629/ |access-date=2022-06-29 |website=Quanta Magazine |language=en}}</ref> His physics teacher at the time told him that his observation was clearly not possible.<ref name=":1" /> A few years later, the head of Mpemba's school invited British physicist [[Denis Osborne]] (1932–2014) from the [[University of Dar es Salaam]] to give a guest lecture on his work.<ref name=":2">{{Cite web |last=Bischoff |first=Manon |date=2020-08-12 |title=Physik: Inverser Mpemba-Effekt |url=https://www.spektrum.de/magazin/inverser-mpemba-effekt/1752466 |access-date=2023-05-15 |website=Spektrum |language=de}}</ref> At the end of the presentation, Mpemba asked the question that had been bothering him for so long: “If you take two beakers with equal volumes of water, one at 35°C and the other at 100°C, and put them into a refrigerator, the one that started at 100°C freezes first. Why?”<ref name=":1" /> Teachers and classmates present thought the claim absurd and mocked Mpemba for the question.

Osborne was also caught off guard, but later invited Mpemba to the university in Dar es Salaam to test his observations. In these tests, the pair were able to find ''some'' evidence for Mpemba's claim; however, Osborne admitted that these tests were crude and required more sophisticated reproduction to confirm. Subsequent studies have proven inconclusive, with researchers noting the difficulty of accurately determining when water has completely frozen, as well as the large variations in measurements when measured even slightly imprecisely.<ref name=":1" /><ref name=":2" /> In 1969, during Mpemba's studies at the [[College of African Wildlife Management]] near [[Moshi, Tanzania|Moshi]], a paper that he and Osborne had written on the phenomenon was published.<ref name=":0">{{Cite journal|last1=Mpemba|first1=E. B.|last2=Osborne|first2=D. G.|date=1969|title=Cool?|url=http://stacks.iop.org/0031-9120/4/i=3/a=312|journal=Physics Education|language=en|volume=4|issue=3|pages=172|doi=10.1088/0031-9120/4/3/312|issn=0031-9120|bibcode=1969PhyEd...4..172M|s2cid=250771765 |doi-access=free}} republished as {{Cite journal| title = The Mpemba effect | journal = Physics Education | publisher = Institute of Physics | year = 1979 | volume = 14 | pages =410–412 | doi = 10.1088/0031-9120/14/7/312 | author = Mpemba, E B | last2 = Osborne | first2 = D G|bibcode = 1979PhyEd..14..410M | s2cid = 250736457 }}</ref>

== Notes ==
{{Reflist|group=note}}


== References ==
== References ==
{{reflist}}
{{Reflist}}


{{DEFAULTSORT:Mpemba, Erasto B.}}
{{DEFAULTSORT:Mpemba, Erasto B.}}
[[Category:1950 births]]
[[Category:1950 births]]
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[[Category:2020s deaths]]
[[Category:Year of death uncertain]]
[[Category:Magamba Secondary School alumni]]
[[Category:Tanzanian scientists]]
[[Category:Tanzanian scientists]]
{{Authority control}}
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[[Category:Living people]]


{{Tanzania-bio-stub}}

Latest revision as of 15:06, 4 January 2025

Erasto B. Mpemba
Mpemba as a schoolboy (~1963)
Born1950 (1950)
Tanganyika Territory
DiedMay 14, 2023 (aged 73)[note 1]
Tanzania
NationalityTanzanian
Alma materCollege of African Wildlife Management

University of Canberra

Sul Ross State University
Known forMpemba effect
Scientific career
FieldsNatural resource management
InstitutionsMinistry of Natural Resources and Tourism

Erasto Bartholomeo Mpemba[1] (1950–2023)[note 1] was a Tanzanian game warden who, as a schoolboy, discovered the eponymously named Mpemba effect, a paradoxical phenomenon in which hot water freezes faster than cold water under certain conditions; this effect had been observed previously by Aristotle, Francis Bacon, and René Descartes.

Life

[edit]

Mpemba was born in 1950.[4] He visited the Magamba Secondary School in Tanzania, where he rediscovered the Mpemba effect when he was 13 years old.[5]

Mpemba aspired to become a doctor, but financial constraints hindered his ambitions. Recognizing that working with wildlife presented an opportunity for an overseas scholarship, he enrolled in Mweka Wildlife College in Moshi.[6][7][8] Upon earning his diploma, Mpemba rose to the position of Regional Natural Resources Officer in Mara Region in 1967. It took him eight years to fulfill his goal of studying abroad:[6][7] He studied Natural Resource Management at the Canberra College of Advanced Education (now University of Canberra) in Australia, subsequently earning a master’s degree at Sul Ross State University in Alpine, USA.[8] He later became Principal Game Officer for the Tanzanian Ministry of Natural Resources and Tourism and vice-chairmen of the African Forestry and Wildlife Commission's working party on the management of wildlife in 2002.[8][1] He had retired from the Tanzanian Ministry as of 2011.[8]

Mpemba was married and had children, his wife was a doctor.[7] Mpemba's death is not well-documented; according to Christine Osborne, the widow of the physicist who played a key role in documenting and publishing Mpemba's findings, he died around 2020.[3][9] However, TRT Africa reports that he died on May 14, 2023.[10]

Discovery of Mpemba effect

[edit]

Mpemba discovered the phenomenon at Magamba Secondary School in 1963 while preparing ice cream in a cooking course.[11][5] Due to lack of time, he skipped the cooling phase when preparing the ice cream and immediately put it into the freezer; unexpectedly, his milk mixture froze faster than that of his classmates.[3] His physics teacher at the time told him that his observation was clearly not possible.[3] A few years later, the head of Mpemba's school invited British physicist Denis Osborne (1932–2014) from the University of Dar es Salaam to give a guest lecture on his work.[12] At the end of the presentation, Mpemba asked the question that had been bothering him for so long: “If you take two beakers with equal volumes of water, one at 35°C and the other at 100°C, and put them into a refrigerator, the one that started at 100°C freezes first. Why?”[3] Teachers and classmates present thought the claim absurd and mocked Mpemba for the question.

Osborne was also caught off guard, but later invited Mpemba to the university in Dar es Salaam to test his observations. In these tests, the pair were able to find some evidence for Mpemba's claim; however, Osborne admitted that these tests were crude and required more sophisticated reproduction to confirm. Subsequent studies have proven inconclusive, with researchers noting the difficulty of accurately determining when water has completely frozen, as well as the large variations in measurements when measured even slightly imprecisely.[3][12] In 1969, during Mpemba's studies at the College of African Wildlife Management near Moshi, a paper that he and Osborne had written on the phenomenon was published.[5]

Notes

[edit]
  1. ^ a b Conflicting sources: According to TRT Afrika he died on May 14, 2023, aged 73;[2] according to his coauthor's widow, he died around 2020.[3]

References

[edit]
  1. ^ a b "Report of the 14th session of the Working Party on the Management of Wildlife and Protected Areas" (PDF). African Forestry and Wildlife Commission. 2002-03-22.
  2. ^ "Mpemba: The man who froze hot water faster than cold water. – TRT Afrika". Mpemba: The man who froze hot water faster than cold water. 2023-05-31. Retrieved 2023-06-30.
  3. ^ a b c d e f Mann, Adam (2022-06-29). "Controversy Continues Over Whether Hot Water Freezes Faster Than Cold". Quanta Magazine. Retrieved 2022-06-29.
  4. ^ "Mpemba-Effekt". Brockhaus Enzyklopädie (in German). Retrieved 2024-03-01.
  5. ^ a b c Mpemba, E. B.; Osborne, D. G. (1969). "Cool?". Physics Education. 4 (3): 172. Bibcode:1969PhyEd...4..172M. doi:10.1088/0031-9120/4/3/312. ISSN 0031-9120. S2CID 250771765. republished as Mpemba, E B; Osborne, D G (1979). "The Mpemba effect". Physics Education. 14. Institute of Physics: 410–412. Bibcode:1979PhyEd..14..410M. doi:10.1088/0031-9120/14/7/312. S2CID 250736457.
  6. ^ a b Bliss (2021-07-31). "The Teenager Who Disproved Thermodynamics: The Mpemba Effect". Medium. Retrieved 2024-03-01.
  7. ^ a b c "The Mpemba Effect". Tanzanian Affairs. 1997-05-01. Retrieved 2024-03-01.
  8. ^ a b c d "Who killed Zinjanthropus?". TEDXDar. 2011-11-26. Retrieved 2024-03-01.
  9. ^ Mann, Adam (2022-07-09). "A Very Basic Experiment Is Stumping the World's Best Physicists". The Atlantic. Retrieved 2024-03-01.
  10. ^ "Mpemba: The man who froze hot water faster than cold water". TRT Africa. Retrieved 2024-03-01.
  11. ^ Romanovsky, Andrej A (2015-03-31). "Which is the correct answer to the Mpemba puzzle?". Temperature. 2 (1): 63–64. doi:10.1080/23328940.2015.1009800. ISSN 2332-8940. PMC 4843877. PMID 27227006.
  12. ^ a b Bischoff, Manon (2020-08-12). "Physik: Inverser Mpemba-Effekt". Spektrum (in German). Retrieved 2023-05-15.
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