Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,
Speaker 1: Lauren bog Obam Here. If you're an American and you've
Speaker 1: ever had a conversation with someone from another country about
Speaker 1: the weather, you've probably been a little confused when he
Speaker 1: or she said, the afternoon temperature is a nice twenty
Speaker 1: one degrees. To you, that might sound like a chilly
Speaker 1: winter day, but to them it's a pleasantly warm springtime temperature.
Speaker 1: That's because virtually every other country throughout the world uses
Speaker 1: the Celsius temperature scale, part of the metric system, which
Speaker 1: denotes the temperature at which water freezes as zero degrees
Speaker 1: and the temperature at which it boils as a hundred degrees,
Speaker 1: but the US and a few other holdouts the Cayman Islands,
Speaker 1: the Bahamas, Belize, and Palau, cling to the fahrenheit scale,
Speaker 1: in which water freezes at thirty two degrees and boils
Speaker 1: at two hundred and twelve. That means that the twenty
Speaker 1: one degrees Celsie's temperature that we previously mentioned is the
Speaker 1: equivalent of a balmy seventy degrees fahrenheit. In the United States,
Speaker 1: the persistence of fahrenheit is one of those puzzling American idiosyncrasies,
Speaker 1: like how the US uses the word soccer to describe
Speaker 1: what the rest of the planet calls football. So why
Speaker 1: is it that the US uses a different temperature scale
Speaker 1: and why doesn't it switch to be consistent with the
Speaker 1: rest of the world. There doesn't seem to be a
Speaker 1: logical answer, except perhaps inertia. Americans generally seemed to distrust
Speaker 1: the metric system. A fifteen pole found that just one
Speaker 1: of the public favored converting to metric measures, while sixty
Speaker 1: four percent were opposed. It might make more sense if
Speaker 1: Fahrenheit was old school and Celsius was some modern upstart,
Speaker 1: sort of the new Coke of temperature, but in reality
Speaker 1: they were created only about two decades apart. Fahrenheit was
Speaker 1: created by its namesake, a German scientist named Daniel Gabriel Fahrenheit,
Speaker 1: who in the early seventeen hundreds was the first known
Speaker 1: person to design alcohol and mercury thermometers that were both
Speaker 1: precise and consistent, so that any two of his instruments
Speaker 1: would register the same temperature reading in a given place
Speaker 1: at a given moment, thanks to his working skill in
Speaker 1: managing glass. When Fahrenheit started out, the key thing he
Speaker 1: was interested in was coming up with the same temperature
Speaker 1: reading all the time, not comparing temperatures of different things
Speaker 1: or different times of day. But when he presented a
Speaker 1: paper on his system for measuring temperature to the Royal
Speaker 1: Society of London in seventeen twenty four, he apparently realized
Speaker 1: that he had to come up with a standard temperature
Speaker 1: scale as well. But we spoke with Don Hilger, a
Speaker 1: research meteorologist at Colorado State University's Cooperative Institute for Research
Speaker 1: in the Atmosphere and also president of the U S
Speaker 1: Metric Association, a group that advocates conversion to the metric system.
Speaker 1: He explained basically, the fahrenheit scale was devised was zero
Speaker 1: as the coldest temperature for a mix of ice and
Speaker 1: salt water, and the upper end was thought to be
Speaker 1: body temperature approximately nine degrees fahrenheit, making a scale that
Speaker 1: could be progressively divided by two. This resulted in the
Speaker 1: freezing melting temperature being thirty two degrees fahrenheit, not a
Speaker 1: very useful number. The boiling temperature for water was then
Speaker 1: set at two twelve, again not a very useful number.
Speaker 1: The two temperatures are a hundred and eighty degrees apart
Speaker 1: again a multiple of two. Nevertheless, the system apparently sounded
Speaker 1: pretty good to officials of the British Empire, who adopted
Speaker 1: fahrenheit as their standard temperature scale, which is how eventually
Speaker 1: became established in the American colonies as well. Meanwhile, though,
Speaker 1: in seventeen forty two, a Swedish astronomer named Anders Celsius
Speaker 1: came up with a less unwieldy system based on multiples
Speaker 1: of ten, in which there was precisely a one hundred
Speaker 1: degree difference between the freezing and boiling temperatures of water
Speaker 1: at sea level. The neat one hundred degrees symmetry of
Speaker 1: the Celsius scale made it a natural fit for the
Speaker 1: metric system, which was formally developed by the French in
Speaker 1: the late seventeen hundreds, but the English speaking world nevertheless
Speaker 1: clung stubbornly to its preference for awkward units such as
Speaker 1: the pound and the inch, and fahrenheit went along for
Speaker 1: the ride. But finally, in nineteen sixty one, the UK
Speaker 1: met Office then called the UK Meteorological Office, switched to
Speaker 1: using Celsius to describe temperatures in weather forecasts in order
Speaker 1: to be consistent with other European countries. Most of the
Speaker 1: rest of the world soon followed suit, with the notable
Speaker 1: exception of the US, where the National Weather Service still
Speaker 1: publishes temperature data in fahrenheit, even though its own staff
Speaker 1: long ago switched to celsius. Hilder explained the NWS as
Speaker 1: catering to the public by reporting in degrees fahrenheit, whereas
Speaker 1: much of their operations, such as forecast models, use degrees celsius,
Speaker 1: and for most automated weather observations the temperatures are recorded
Speaker 1: in celsius as well. Should we choose to go metric
Speaker 1: and weather reports, the fahrenheit layer that's now added for
Speaker 1: the u S public could be removed. We also spoke
Speaker 1: via email with j Hendrix, who heads the u S
Speaker 1: National Institute of Standards and Technologies Thermodynamic Meteorology Group. He
Speaker 1: points out that the fahrenheit scale does have one significant
Speaker 1: advantage a quote. It has more degrees over the range
Speaker 1: of ambient temperatures that are typical for most people. This
Speaker 1: means that there's a finer grain temperature difference between seventy
Speaker 1: degrees fahrenheit and seventy one degrees fahrenheit than there is
Speaker 1: between twenty one degree celsius and twenty two degree celsius.
Speaker 1: Since a human can tell the difference of one degree fahrenheit,
Speaker 1: this scale is more precise for the human experience. On
Speaker 1: the other hand, though, the advantage goes away if a
Speaker 1: fractional temperature in celsius is used. Hendricks explained. For example,
Speaker 1: the equivalent celsius temperature for seventy and seventy one fahrenheit
Speaker 1: are equivalent to twenty one point one and twenty one
Speaker 1: point seven degrees celsius. Today's episode was written by Patrick
Speaker 1: Jake Tiger and produced by Tyler Clang. Brain Stuff is
Speaker 1: a production of iHeart Radio's How Stuff Works. For more
Speaker 1: and this and lots of other topics that humans are
Speaker 1: sensitive to, visit our home planet how stuff Works dot com,
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