Researchers have gone to their graves trying to figure out what old man Fahrenheit was up to, Leslie. Daniel Gabriel Fahrenheit was a German instrument maker who invented the first practical mercury thermometer. Casting about for a suitable scale for his device, he visited the Danish astronomer Ole Romer, who had devised a system of his own. As it turned out, it was a case of the blind leading the blind.
Romer had decided that the boiling point of water should be 60 degrees, which at least had the strength of numerological tradition behind it 60 minutes in an hour, right? But zero was arbitrary, the main consideration apparently being that it should be colder than it ever got in Denmark. Boiling point for the time being he ignored altogether.
It dawned on him that it was going to look a little strange having the zero on his scale just hanging off the end, so to speak. So he cooked up the explanation that zero was the temperature of a mix of ice, water, and ammonium chloride. Later Fahrenheit established that the boiling point of water came in at degrees.
Grigull wrote "His fellowship of the Royal Society resulted in his thermometer, and thereby his scale, receiving particular acceptance in England and consequently later also in North America and the British Empire. Related: The world's oceans are heating up at an accelerated rate. However, only a few countries today still use Fahrenheit to measure temperature. The United States and its territories, along with the Bahamas, Palau, Belize, the Cayman Islands, the Federated States of Micronesia and the Marshall Islands, have stuck with the temperature scale, despite the rest of the world moving to the Celsius scale, according to the online geography resource World Atlas.
After Fahrenheit's death in , the Fahrenheit scale was recalibrated to make it slightly more accurate. The exact freezing and boiling points of plain water, minus the salt, were marked at 32 and degrees Fahrenheit, respectively. Normal human body temperature was marked at Read more: Has the average human body temperature changed? Celsius was a Swedish astronomer and is credited with discovering the connection between the aurora borealis , also known as the Northern Lights, and the Earth's magnetic field , as well as a method for determining the brightness of stars , according to the U.
National High Magnetic Field Laboratory. In a proposal to the Royal Swedish Academy of Sciences in , Celsius proposed a scale based on two fixed points: 0 the boiling point of water and the freezing point of water. Following Celsius' death in , the famous Swedish taxonomist Carl Linnaeus proposed that the fixed points be switched, with 0 indicating the freezing point of water and its boiling point, according to The Legacy of Anders Celsius in JSTOR Daily, a digital library.
The scale has also been extended to include negative numbers. Celsius initially called his scale "Centigrade" from the Latin for one hundred "centi" degrees "grade" , because there were points between water freezing and boiling. In , an international conference on weights and measures Conference General des Poids et Measures changed the name to "Celsius" in honor of Anders Celsius, according to the U.
Related: As the Paris Agreement aims to cut emissions, we have already blown past warming targets. The second point, at 32 degrees, was a mixture of ice and water without the ammonium chloride at a ratio. The third point, 96 degrees, was approximately the human body temperature, then called "blood-heat". Fahrenheit multiplied each value by four in order to eliminate fractions and increase the granularity of the scale.
The story is this, as much as I remember. Fahrenheit chose the zero point on his scale as the temperature of a bath of ice melting in a solution of common table salt a routine 18th century way of getting a low temperature. After Fahrenheit died, his successors used the boiling point of water to calibrate the thermometers.
This answer has nothing to do with physics, but I was taught in grade school - and, yes, this was in an actual elementary school text - that the Fahrenheit thermometer was based on the coldest and hottest days in in Holland where he lived.
I have never been able to verify that, so I assume it was false, but the temperatures of zero and do represent about the extremes that one can expect to experience in Western Europe where I have lived for several years now. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
Create a free Team What is Teams? Learn more. What is the logic behind the Fahrenheit scale? There you have it. Fahrenheit, following Roemer, simply determined the distance between the marks for the freezing point of water and body heat on his glass thermometers 64 degrees, in the scale he would ultimately develop , measured off half this distance 32 degrees below the freezing point, and called that zero.
Recounting this story in a article, R. Soulen of the U. Fahrenheit chose to define a zero below the coldest temperature likely to be encountered by everyday use of his thermometers.
As I said. At least these benchmarks were practical.
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