1 00:00:01,920 --> 00:00:07,080 Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, 2 00:00:07,120 --> 00:00:10,080 Speaker 1: Lauren bog Obam Here. If you're an American and you've 3 00:00:10,080 --> 00:00:12,480 Speaker 1: ever had a conversation with someone from another country about 4 00:00:12,480 --> 00:00:15,240 Speaker 1: the weather, you've probably been a little confused when he 5 00:00:15,400 --> 00:00:18,560 Speaker 1: or she said, the afternoon temperature is a nice twenty 6 00:00:18,560 --> 00:00:21,800 Speaker 1: one degrees. To you, that might sound like a chilly 7 00:00:21,800 --> 00:00:25,280 Speaker 1: winter day, but to them it's a pleasantly warm springtime temperature. 8 00:00:26,200 --> 00:00:29,360 Speaker 1: That's because virtually every other country throughout the world uses 9 00:00:29,400 --> 00:00:32,880 Speaker 1: the Celsius temperature scale, part of the metric system, which 10 00:00:32,920 --> 00:00:36,240 Speaker 1: denotes the temperature at which water freezes as zero degrees 11 00:00:36,479 --> 00:00:39,040 Speaker 1: and the temperature at which it boils as a hundred degrees, 12 00:00:39,640 --> 00:00:42,680 Speaker 1: but the US and a few other holdouts the Cayman Islands, 13 00:00:42,720 --> 00:00:46,600 Speaker 1: the Bahamas, Belize, and Palau, cling to the fahrenheit scale, 14 00:00:46,800 --> 00:00:49,280 Speaker 1: in which water freezes at thirty two degrees and boils 15 00:00:49,320 --> 00:00:52,440 Speaker 1: at two hundred and twelve. That means that the twenty 16 00:00:52,440 --> 00:00:55,400 Speaker 1: one degrees Celsie's temperature that we previously mentioned is the 17 00:00:55,440 --> 00:00:58,920 Speaker 1: equivalent of a balmy seventy degrees fahrenheit. In the United States, 18 00:01:00,160 --> 00:01:03,840 Speaker 1: the persistence of fahrenheit is one of those puzzling American idiosyncrasies, 19 00:01:03,960 --> 00:01:06,360 Speaker 1: like how the US uses the word soccer to describe 20 00:01:06,360 --> 00:01:09,399 Speaker 1: what the rest of the planet calls football. So why 21 00:01:09,480 --> 00:01:11,679 Speaker 1: is it that the US uses a different temperature scale 22 00:01:11,880 --> 00:01:13,800 Speaker 1: and why doesn't it switch to be consistent with the 23 00:01:13,800 --> 00:01:16,399 Speaker 1: rest of the world. There doesn't seem to be a 24 00:01:16,440 --> 00:01:21,360 Speaker 1: logical answer, except perhaps inertia. Americans generally seemed to distrust 25 00:01:21,400 --> 00:01:24,560 Speaker 1: the metric system. A fifteen pole found that just one 26 00:01:25,000 --> 00:01:27,960 Speaker 1: of the public favored converting to metric measures, while sixty 27 00:01:28,080 --> 00:01:31,600 Speaker 1: four percent were opposed. It might make more sense if 28 00:01:31,600 --> 00:01:34,959 Speaker 1: Fahrenheit was old school and Celsius was some modern upstart, 29 00:01:35,319 --> 00:01:38,200 Speaker 1: sort of the new Coke of temperature, but in reality 30 00:01:38,240 --> 00:01:42,160 Speaker 1: they were created only about two decades apart. Fahrenheit was 31 00:01:42,200 --> 00:01:46,240 Speaker 1: created by its namesake, a German scientist named Daniel Gabriel Fahrenheit, 32 00:01:46,440 --> 00:01:48,720 Speaker 1: who in the early seventeen hundreds was the first known 33 00:01:48,760 --> 00:01:51,920 Speaker 1: person to design alcohol and mercury thermometers that were both 34 00:01:52,000 --> 00:01:55,080 Speaker 1: precise and consistent, so that any two of his instruments 35 00:01:55,120 --> 00:01:57,559 Speaker 1: would register the same temperature reading in a given place 36 00:01:57,600 --> 00:02:00,080 Speaker 1: at a given moment, thanks to his working skill in 37 00:02:00,160 --> 00:02:04,000 Speaker 1: managing glass. When Fahrenheit started out, the key thing he 38 00:02:04,080 --> 00:02:06,520 Speaker 1: was interested in was coming up with the same temperature 39 00:02:06,520 --> 00:02:10,040 Speaker 1: reading all the time, not comparing temperatures of different things 40 00:02:10,360 --> 00:02:13,400 Speaker 1: or different times of day. But when he presented a 41 00:02:13,440 --> 00:02:16,000 Speaker 1: paper on his system for measuring temperature to the Royal 42 00:02:16,040 --> 00:02:19,360 Speaker 1: Society of London in seventeen twenty four, he apparently realized 43 00:02:19,360 --> 00:02:21,079 Speaker 1: that he had to come up with a standard temperature 44 00:02:21,080 --> 00:02:24,880 Speaker 1: scale as well. But we spoke with Don Hilger, a 45 00:02:24,960 --> 00:02:29,000 Speaker 1: research meteorologist at Colorado State University's Cooperative Institute for Research 46 00:02:29,040 --> 00:02:31,520 Speaker 1: in the Atmosphere and also president of the U S 47 00:02:31,520 --> 00:02:35,800 Speaker 1: Metric Association, a group that advocates conversion to the metric system. 48 00:02:35,919 --> 00:02:39,520 Speaker 1: He explained basically, the fahrenheit scale was devised was zero 49 00:02:39,639 --> 00:02:42,120 Speaker 1: as the coldest temperature for a mix of ice and 50 00:02:42,160 --> 00:02:44,320 Speaker 1: salt water, and the upper end was thought to be 51 00:02:44,360 --> 00:02:48,120 Speaker 1: body temperature approximately nine degrees fahrenheit, making a scale that 52 00:02:48,120 --> 00:02:52,160 Speaker 1: could be progressively divided by two. This resulted in the 53 00:02:52,200 --> 00:02:55,400 Speaker 1: freezing melting temperature being thirty two degrees fahrenheit, not a 54 00:02:55,480 --> 00:02:58,320 Speaker 1: very useful number. The boiling temperature for water was then 55 00:02:58,320 --> 00:03:01,360 Speaker 1: set at two twelve, again not a very useful number. 56 00:03:01,760 --> 00:03:04,160 Speaker 1: The two temperatures are a hundred and eighty degrees apart 57 00:03:04,320 --> 00:03:09,359 Speaker 1: again a multiple of two. Nevertheless, the system apparently sounded 58 00:03:09,360 --> 00:03:12,160 Speaker 1: pretty good to officials of the British Empire, who adopted 59 00:03:12,200 --> 00:03:15,400 Speaker 1: fahrenheit as their standard temperature scale, which is how eventually 60 00:03:15,440 --> 00:03:19,320 Speaker 1: became established in the American colonies as well. Meanwhile, though, 61 00:03:19,360 --> 00:03:23,080 Speaker 1: in seventeen forty two, a Swedish astronomer named Anders Celsius 62 00:03:23,120 --> 00:03:25,800 Speaker 1: came up with a less unwieldy system based on multiples 63 00:03:25,840 --> 00:03:28,400 Speaker 1: of ten, in which there was precisely a one hundred 64 00:03:28,440 --> 00:03:31,320 Speaker 1: degree difference between the freezing and boiling temperatures of water 65 00:03:31,440 --> 00:03:34,560 Speaker 1: at sea level. The neat one hundred degrees symmetry of 66 00:03:34,639 --> 00:03:36,760 Speaker 1: the Celsius scale made it a natural fit for the 67 00:03:36,760 --> 00:03:39,520 Speaker 1: metric system, which was formally developed by the French in 68 00:03:39,560 --> 00:03:43,480 Speaker 1: the late seventeen hundreds, but the English speaking world nevertheless 69 00:03:43,520 --> 00:03:46,400 Speaker 1: clung stubbornly to its preference for awkward units such as 70 00:03:46,400 --> 00:03:48,960 Speaker 1: the pound and the inch, and fahrenheit went along for 71 00:03:49,000 --> 00:03:53,200 Speaker 1: the ride. But finally, in nineteen sixty one, the UK 72 00:03:53,360 --> 00:03:57,000 Speaker 1: met Office then called the UK Meteorological Office, switched to 73 00:03:57,080 --> 00:04:00,680 Speaker 1: using Celsius to describe temperatures in weather forecasts in order 74 00:04:00,720 --> 00:04:03,760 Speaker 1: to be consistent with other European countries. Most of the 75 00:04:03,760 --> 00:04:06,240 Speaker 1: rest of the world soon followed suit, with the notable 76 00:04:06,280 --> 00:04:09,119 Speaker 1: exception of the US, where the National Weather Service still 77 00:04:09,160 --> 00:04:12,480 Speaker 1: publishes temperature data in fahrenheit, even though its own staff 78 00:04:12,520 --> 00:04:17,240 Speaker 1: long ago switched to celsius. Hilder explained the NWS as 79 00:04:17,279 --> 00:04:20,400 Speaker 1: catering to the public by reporting in degrees fahrenheit, whereas 80 00:04:20,480 --> 00:04:24,080 Speaker 1: much of their operations, such as forecast models, use degrees celsius, 81 00:04:24,520 --> 00:04:27,560 Speaker 1: and for most automated weather observations the temperatures are recorded 82 00:04:27,600 --> 00:04:30,200 Speaker 1: in celsius as well. Should we choose to go metric 83 00:04:30,240 --> 00:04:32,960 Speaker 1: and weather reports, the fahrenheit layer that's now added for 84 00:04:33,000 --> 00:04:36,359 Speaker 1: the u S public could be removed. We also spoke 85 00:04:36,440 --> 00:04:39,160 Speaker 1: via email with j Hendrix, who heads the u S 86 00:04:39,279 --> 00:04:44,039 Speaker 1: National Institute of Standards and Technologies Thermodynamic Meteorology Group. He 87 00:04:44,160 --> 00:04:47,000 Speaker 1: points out that the fahrenheit scale does have one significant 88 00:04:47,000 --> 00:04:50,360 Speaker 1: advantage a quote. It has more degrees over the range 89 00:04:50,360 --> 00:04:53,600 Speaker 1: of ambient temperatures that are typical for most people. This 90 00:04:53,680 --> 00:04:56,960 Speaker 1: means that there's a finer grain temperature difference between seventy 91 00:04:57,000 --> 00:05:00,320 Speaker 1: degrees fahrenheit and seventy one degrees fahrenheit than there is 92 00:05:00,360 --> 00:05:03,359 Speaker 1: between twenty one degree celsius and twenty two degree celsius. 93 00:05:03,960 --> 00:05:06,760 Speaker 1: Since a human can tell the difference of one degree fahrenheit, 94 00:05:07,040 --> 00:05:10,760 Speaker 1: this scale is more precise for the human experience. On 95 00:05:10,800 --> 00:05:13,080 Speaker 1: the other hand, though, the advantage goes away if a 96 00:05:13,160 --> 00:05:17,560 Speaker 1: fractional temperature in celsius is used. Hendricks explained. For example, 97 00:05:17,720 --> 00:05:20,960 Speaker 1: the equivalent celsius temperature for seventy and seventy one fahrenheit 98 00:05:21,120 --> 00:05:23,560 Speaker 1: are equivalent to twenty one point one and twenty one 99 00:05:23,600 --> 00:05:32,480 Speaker 1: point seven degrees celsius. Today's episode was written by Patrick 100 00:05:32,560 --> 00:05:35,240 Speaker 1: Jake Tiger and produced by Tyler Clang. Brain Stuff is 101 00:05:35,240 --> 00:05:37,600 Speaker 1: a production of iHeart Radio's How Stuff Works. For more 102 00:05:37,640 --> 00:05:39,360 Speaker 1: and this and lots of other topics that humans are 103 00:05:39,360 --> 00:05:42,520 Speaker 1: sensitive to, visit our home planet how stuff Works dot com, 104 00:05:42,560 --> 00:05:44,720 Speaker 1: and for our podcast from my heart Radio, visit the 105 00:05:44,760 --> 00:05:47,359 Speaker 1: iHeart Radio app, Apple Podcasts, or wherever you listen to 106 00:05:47,400 --> 00:05:48,159 Speaker 1: your favorite shows.