康奈爾大學19世紀“溫水青蛙實驗”可能並不存在，實驗故事可能源自一則[b]德國傳言[/b]
——康奈爾大學21世紀2019年的“青蛙跳高實驗”倒是正式發表、有理有據的科學實驗 ——蛙類耐受酷寒的特殊生理機制受到重視，對人類器官保護與移植具有重要借鑒意義 所謂康奈爾大學19世紀的“溫水青蛙實驗”，中英文網頁隨處可見。然而，澳大利亞的科學節目類主持人、30多本科普著作的作者卡爾博士（KARL KRUSZELNICKI）指出：“所謂溫水青蛙實驗的故事或許源自E.W.Scripture之口，他在1897年撰寫了《新心理學》，在該著述裡了引用了所謂較早的德國研究成果（陳昌春注：或許未注明出處）：“如果水加熱得足夠慢，活青蛙實際上可以在溫水裡保持安定； 在一個實驗中，溫度以每秒0.002攝氏度的速度升高，過了2.5小時發現青蛙並沒有不安，而是死了。”（詳見附4） 從證偽的角度來看，19世紀離現在不算太遠，如果康奈爾大學19世紀的“溫水青蛙實驗”確實進行並得出結果，通常會以書面的形式記載及發表。然而，似乎並沒有這樣的書面記錄或線索存在。 21世紀的2019年，該校有研究團隊進行了包括“青蛙跳高實驗”在內的一些水生動物及兩棲動物跳高試驗（詳見附8）。據稱，青蛙可以跳出自己身長的5-10倍的高度，目的主要是捕捉食物（Mid-sized animals, such as frogs or archer fish, may jump five to close to 10 times their body length, mostly to catch prey. ）
關於蛙類，有文章分析了樹蛙為何具備耐受酷寒、笑傲冰霜的特殊生理機制（《Cryobiology: Frozen Wood Frogs and Adaptations for Survival》， owlcation.com/stem/Fro...r-Survival），並對人類與蛙的生理特性進行了對比，指出蛙的耐寒能力與機理對人類的器官移植等具有重要的借鑒意義（Understanding how the frog's body responds to temperatures below and then above freezing may help us improve the cryopreservation (preservation at low temperatures) of human cells, tissues, and organs. These need to be preserved in excellent condition so that they can be transplanted into the patients that need them. Improving the preservation of organs would be especially helpful. At the moment, these are cooled but not frozen, which limits their availability to patients who need them. The organs eventually die unless they are frozen. Freezing and thawing are much more successful for small items such as eggs, sperm, and embryos than for large items such as organs. Frozen organs are damaged by cracking during the thawing process.）。 溫水裡的青蛙真的會坐以待斃嗎？科學實驗告訴你寓言不可信 奇點先驅 發布時間：18-12-27 關於青蛙，還有一個耳熟能詳的故事，那就是溫水煮青蛙。一開始大家都認為這是中國的傳統故事，實際上這個故事是從美國傳過來的，而且它還是來源於一項科學實驗。在1894年，美國康奈爾大學的科學家用青蛙做了一個實驗，看看青蛙是如何應對環境變化的。他先是在一個器皿中裝滿了溫水，然後將青蛙放進去，青蛙一碰到溫水就立馬跳了出來。然後他把溫水換成冷水，將青蛙放進去，再逐漸加熱冷水。他驚訝地發現青蛙對溫度變化竟然毫無反應，一點掙扎都沒有，最後青蛙在水溫逐漸上升的過程中就被煮死了。我們姑且不探討這個實驗的真實性，這個實驗本身就很有寓意。中國人也經常引用這個故事來勸告別人，不要對自己所處的環境一點察覺都沒有，否則最後將大禍臨頭。雖然這是一個十分有寓意的實驗，但如果追究其科學性和真實性的話，青蛙是不會在逐漸升溫的水中坐以待斃的。因為我國有一所中學曾經就做過類似的實驗，實驗人員將青蛙先放在一鍋冷水裡面，鍋中放有一根溫度計。然後再慢慢給水加熱，一開始青蛙確實毫無反應，但是當溫度上升到了40攝氏度以上後，就有青蛙開始跳出鍋了。等到溫度上升到50攝氏度，鍋裡的青蛙全部都跳出去了。 溫水煮青蛙理論是真的假的？有人做過驗證麼？
作者：知乎用戶
奧克拉何馬大學的動物學教授霍奇森選定的加熱速率，是每分鍾2華氏度，也就是差不多1.1攝氏度。霍奇森發現，到了一定溫度以後，青蛙會開始躁動不安，試圖逃離這個環境，如果裝載的容器允許，青蛙還是會跳出來的。基於此，霍奇森宣布，溫水煮青蛙的故事是錯誤的。
1872，一個叫做亨滋曼的宣布，如果你加熱的速率足夠低，那麼，青蛙並沒有跳出來的打算。1875年，這個實驗還被另外一個人證實。
兩個實驗矛盾嗎？哥而茨與亨滋曼的實驗的區別是加熱的速度不同。
這些“煮”青蛙的實驗目的都是考察溫度和神經反射性的關系。在較快的加熱速率下，青蛙能跳出來，原因很好理解：熱刺激引起了青蛙的應激反應——跳走。而在較慢升溫過程中，由於類似“感覺適應”的原因，持續細微的溫 度變化使得青蛙適應了這種刺激，反射應激性降低，直到達到可耐受的臨界高溫，無法逃生。
結論： 在溫度變化明顯的情況下，青蛙可以迅速跳出。而當水溫變化很微小的時候，青蛙就難於察覺，而失去逃生的機會。“溫水煮青蛙”故事背後的依據是有一定道理的，只不過能煮死青蛙的這個升溫條件和我們一般理解的“煮”不太一樣。 @蘇莉安 所做的實驗和霍奇森教授所做的實驗是一樣的，但並不能因此判定這個理論是假的。如同離開劑量談毒性都是耍流氓一樣，忽略水溫的加熱速度而得出結論的都是耍流氓。
Do you know theres nothing wrong with boiled frog in warm water? Are frogs really that stupid?
2019-03-28 Production | Netease Science and Technology Know or not column group (public number: tech_163) Many people have heard the story of boiled frogs in warm water, but is it true that it has been told for hundreds of years? Are frogs really that dumb? The phrase boiled frog in warm water comes from a boiled frog experiment conducted by scientists at Cornell University in the late 19th century. When scientists plunged frogs into 40 degrees Celsius water (not boiling water), they could not stand the sudden high temperature and jumped out of the boiling water to escape. When scientists put frogs in containers filled with cold water and then heated them slowly (up 0.2 degrees Celsius per minute), the results were different. Frogs, on the contrary, are comfortable in the water because of the comfortable water temperature at the beginning. When the frog found that he could not stand the high temperature, he had enough energy and was boiled to death in hot water unconsciously. This story is implied by people that changes in the general environment can determine your success or failure. Too comfortable environment often contains danger and perceives small changes in trends. You must stop and think from different angles. Learning is the best way to discover changes. For example, people are often used in the workplace, many people can easily complete their work in their own work, the work is not challenging, and lack of motivation for progress, slowly being worn off the spirit, motivation for progress and innovation, once the company changes, it may be abandoned. But is this story, which has been told for hundreds of years, true? Are frogs really that dumb? It was reported on the Internet that a female biology teacher organized the whole class to do the experiment of boiling frogs in warm water. When the water temperature was heated to 60 degrees Celsius, some frogs began to jump out of the water. When the water temperature continued to rise to 65 degrees Celsius, all the frogs in the container jumped out. This proves that Cornell University scientists are wrong. In fact, Hodgson, a professor of zoology at the University of Oklahoma, did a similar experiment. Hodgson studied the response of different types of amphibians to temperature. Frogs belong to amphibians. Amphibians are cold-blooded and thermophilic animals, and their body temperature will be adjusted with the temperature of the environment. Hodgsons research is about the maximum temperature that amphibians can tolerate. Hodgsons chosen heating rate is 2 degrees Fahrenheit per minute (about 1.1 degrees Celsius). At a certain temperature, the frog starts to get restless and tries to escape from the environment. If the container is loaded, the frog will jump out. Based on this, Hodgson declared that the story of boiling frogs in warm water was wrong. When the story of boiled frog in warm water was considered false, there was another experiment called Huntsmans experiment. 1872, a publication called Huntsman, if you heat at a low enough rate, the frog has no intention of jumping out. Huntsman used 90 minutes to heat water from 21 degrees Celsius to 37.5 degrees Celsius, with an average heating rate of less than 0.2 degrees Celsius per minute. No abnormal behavior was observed in frogs. The critical high temperature (CTM) that frogs can tolerate is about 36 - 37 degrees Celsius. If heated to 37.5 degrees Celsius, the frog has lost its ability to jump up even if it does not die immediately, and death is not far from it. Therefore, frogs can jump out quickly when the temperature changes obviously. When the water temperature changes very slightly, frogs are hard to detect and lose the chance to escape. So the story of boiled frogs in warm water has some truth. Whatever the authenticity of the experiment, the implication of boiling frogs in warm water still needs our vigilance. The worst case is not that we are in a bad environment, but that we gradually degenerate without knowing it. When we finally wake up, it is too late. Netease Science and Technology Know or not column, curious about the world, with you to explore the unknown. Pay attention to Netease Technological Micro-Signal (ID: tech_163), send Know or Not, you can see all the knowledgeable manuscripts. Source: Editor in charge of knowledge: Qiao Junjing_NBJ11279 |
