Really can't feel the temperature?

"Boil a frog in warm water" is a meaningful proverb, which tells us to be prepared for danger in times of peace, stop and observe our environment at any time, then think about it and make corresponding countermeasures to avoid being eliminated.

Of course, this proverb is not groundless, but the conclusion of an experiment conducted by scientists in the 1960s from 65438 to 2009, but this experiment is not that simple. Let us know the truth.

Experiment of boiling frog in warm water

In fact, the experiment of boiling frogs in warm water has a lot to do with the experiment of soul, because the soul is still controversial. As early as the early 20th century, Duncan MacDougall, a doctor in Black friel, Massachusetts, USA, did experiments on the soul. He got the consent of six dying people, put them on an accurate weighing platform, and recorded the weight difference between the living and the dead.

Results Their weight did not change after death. Two people lose one ounce (28 grams) per hour within four hours before death, and one person loses 0.375 ounce (10.6 grams) at the moment of death. However, after his death, he gained weight again, and the last one lost 0.75 ounces (2 1 g) at the moment of his death.

So the doctor came to the conclusion that the human soul weighs 2 1 g. Of course, this experiment is obviously unreasonable, not to mention that he took one of the six subjects, but that when people die, gas leakage in the body and metabolism before death will take away some weight.

In fact, the exploration of the soul began in the19th century. At that time, German scientist Gilds was an avid soul seeker. He did a lot of experiments. 1869, Geerds has an idea, that is, put the frog in cold water and heat it slowly to see its reaction.

But instead of putting a healthy frog in it, this experiment cut off the frog's brain, immediately put it in 17.5℃ water, and then heated it to 56℃, with an average temperature increase of 3.8℃ per minute. As a result, the frog was boiled to death

This is a well-known experiment. In fact, after the frog was boiled, he immediately made a control experiment with a healthy frog. As a result, when the water was heated to a certain temperature, the frog jumped out quickly. It's just that this control experiment didn't spread, and it's just that the first experiment was taken out of context, so there is the saying that frogs are boiled in warm water (in fact, I don't know why a soul experiment can be against frogs).

Warm water boiled frog experiment upgraded version

Originally, this was a simple experiment, but with the experimental results of the control group, many scientists also became interested: how much heat does the frog need before jumping away? Will the speed of warming affect the time when frogs jump away? So the upgraded version of boiling frogs in warm water began.

1872 Three years after Geerds' experiment, biologist Huntsman also did the same experiment, but in his experiment, he changed the heating rate to increase by 0.2℃ per minute. At this heating speed, Huntsman heated the water from 2 1℃ to 37.5℃ in 90 minutes. As a result, the frog did not show any abnormality in this process, but.

Later, Professor Hodgson, a zoologist at the University of Oklahoma, made a similar experiment. But he chose to increase the heating rate of 1. 1℃ per minute. When the water temperature exceeds the ambient temperature, the frog obviously becomes restless and tries to leave the container.

Through these experiments, scientists have drawn several conclusions: first, it is wrong to cook frogs in warm water; Second, the higher the heating rate, the shorter the time for frogs to jump out of the water; Thirdly, the critical temperature that frogs can tolerate is around 37℃. It is worth mentioning that if the critical temperature is exceeded, frogs will struggle, but they will not have the strength to jump out of the container and will eventually be boiled to death.

The frog's perception ability

In fact, the experiment of boiling frogs in warm water (exactly cold water) is not completely meaningless, because the purpose of this experiment is to explore the relationship between amphibians' emergency reflex ability and temperature. Experiments show that if the temperature rises slowly enough, the frog's reflex stress will gradually decrease, which is a process in which frogs gradually adapt to the stress response system through few temperature changes. Of course, even if it is gradually increased, frogs have the limit of heat tolerance and will still react.

In fact, the frog's perception system is relatively developed. They have five main perception systems: smell, hearing, vision, taste and touch, among which touch is related to our temperature perception, because frog's skin is moist, it can't prevent most chemicals from passing through like our skin, but it will reach the subcutaneous layer smoothly. It is precisely because of this that they can obtain information better and more accurately through touch.

In fact, animals' perception of temperature is also through the skin. The temperature sensor on the skin can capture the change of temperature, form information and transmit it to the brain through the nervous system, and then make analysis and judgment. In the first experiment, the frog's brain was removed, so the transmission of information was interrupted, and no system issued an order, and the frog was boiled alive.

abstract

Although the first result of the experiment of boiling frogs in warm water is that frogs are boiled to death, frogs without brains can obviously only live for a few minutes even if they are not boiled to death, so the question is not whether they are boiled or not. As for the normal frog, as long as it reaches the critical temperature, it will run away, but if the temperature rises at a very low rate, it may eventually be difficult to jump out because the body temperature is too high for a long time.