Why touching and feeling the hotness of a body is not sufficient to measure temperature?
The problem is magnified by the fact that the feelings of hot and cold are perceived by different nerve endings. Physicists will tell you there is no such thing as cold; cold is merely the absence of heat. Well, don’t try to tell that to your nervous system, which has developed cold sensors that are different from hot sensors. It is even possible, by putting your hand on a carefully engineered surface with narrow stripes of hot and cold temperature, to stimulate both sensors at once, creating a feeling that is very definitely hot and cold at the same time, and is therefore quite difficult to describe, although I apparently have just done so.
Another common demonstration on your inability to detect absolute temperature is to immerse your two hands in two bowls of water, one as hot as you can comfortably tolerate, and the other as cold as you can. After a minute or two, remove both hands and plunge both of them into a single basin of room-temperature water. The hand that was in cold water will feel hot, and the hand that was in hot water will feel cold—yet it is clearly only one basin with water of one temperature.
The only reliable way to discern temperature is with a thermometer.
Hope this helps :)
The problem is magnified by the fact that the feelings of hot and cold are perceived by different nerve endings. Physicists will tell you there is no such thing as cold; cold is merely the absence of heat. Well, don’t try to tell that to your nervous system, which has developed cold sensors that are different from hot sensors. It is even possible, by putting your hand on a carefully engineered surface with narrow stripes of hot and cold temperature, to stimulate both sensors at once, creating a feeling that is very definitely hot and cold at the same time, and is therefore quite difficult to describe, although I apparently have just done so.
Another common demonstration on your inability to detect absolute temperature is to immerse your two hands in two bowls of water, one as hot as you can comfortably tolerate, and the other as cold as you can. After a minute or two, remove both hands and plunge both of them into a single basin of room-temperature water. The hand that was in cold water will feel hot, and the hand that was in hot water will feel cold—yet it is clearly only one basin with water of one temperature.
The only reliable way to discern temperature is with a thermometer.
Hope this helps :)
