# What's the point of Celsius? **URL:** \ **Category:** Factual Questions\ **Created:** [November 20, 2005, 10:11pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987 "2005-11-20T22:11:20Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [November 21, 2005, 12:52pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/61 "2005-11-21T12:52:57Z")
> [@DrDeth](#): > > F is more useful in weather and other such day-to-day usages, as rarely does one need to concern oneself with negative numbers. On the other hand -C comes in quite a bit in everyday weather. 0 and 100 are generally extremes of weather- something we use daily rather than a need to tell at what temp water boils or freezes. This is why Americans still use Fahrenheit. It’s a superior system for dealing with the weather. Negative numbers (in Fahrenheit) correspond to temperatures that are dangerously cold, even if you dress warmly. Anything over 100 degrees F is dangerously hot. Along these lines, the American units for volume are hands-down superior to metric units for everyday usage. A fluid ounce is a small, but useful amount of liquid. Trial-size bottles are usually 1 oz in size. A pint (16 oz) makes for a decent drink to accompany a meal. A gallon, being larger than a liter, is more convenient for liquids that are bought in bulk, like gasoline or water. Metric is superior for scientific purposes, and I use it myself in this way (I’m an engineer), but for practical matters it has no advantages. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [November 21, 2005, 12:58pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/62 "2005-11-21T12:58:33Z")
> [@Futile Gesture](#): > > I can’t think of any measurable temperature points that are more significant to life on Earth. Can you? > > Beyond that, any unit of measurement is arbitary. It’s simply a matter of what’s practical and familiar. The freezing point is important, but the boiling point is too hot to be useful. Most lifeforms are dead by then. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [November 21, 2005, 1:16pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/63 "2005-11-21T13:16:01Z")
> [@GorillaMan](#): > > …assuming that the Fahrenheit reading isn’t just a conversion from the Celsius one. Which is a big assumption to make, if you’re concerned about such fine accuracy. Based on my experience with IPRT readouts, the ADC resolution is such that it nicely accommodates the °F resolution, and rounds to the least significant digit. ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [November 21, 2005, 1:48pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/64 "2005-11-21T13:48:08Z")
> [@Malacandra](#): > > I’d hope that all meridians were much the same length. :dubious: I’d assume too, but it’s always mentionned that it’s the Paris meridian they measured. ---
**Author:** ![slaphead](https://avatars.discourse-cdn.com/v4/letter/s/e9bcb4/32.png) [@slaphead](https://boards.straightdope.com/u/slaphead)\ **Post date:** [November 21, 2005, 1:50pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/65 "2005-11-21T13:50:07Z")
> [@Diceman](#): > > Along these lines, the American units for volume are hands-down superior to metric units for everyday usage. A fluid ounce is a small, but useful amount of liquid. Trial-size bottles are usually 1 oz in size. A pint (16 oz) makes for a decent drink to accompany a meal. A gallon, being larger than a liter, is more convenient for liquids that are bought in bulk, like gasoline or water. This keeps coming up as advantage of the imperial system, but I’ve never been convinced by the inherent advantages of ‘whole units’. If you are fond of the ‘decent drink to accompany a meal’ size, what difference does it make to you whether it is a pint or a half-liter or 0.75 squadroonies? Why is 1oz so superior to 15ml? Provided the math works out OK it is, as has been pointed out before, totally arbitrary and dependent on what you are used to. Plenty of people know exactly how much butter makes 500g but would have no idea about 1 lb, and vice-versa. The only beef I ever had with non-metric ystems was that they were always a pig to remember and they never really worked out well with base-10 calculations. Which was a big deal for me, because I need to use my fingers and toes. Anyhow, I suspect this is one of those cultural things where almost anyone raised on one system will find the other dangerously illogical. The brits have been putting up a spirited defence of their pounds, pints and miles for several decades. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [November 21, 2005, 2:15pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/66 "2005-11-21T14:15:45Z")
Too damn right. When I order a pint of beer I want a _pint_, not some four-fifths-of-a-pint oddity reverse-engineered to make a pint and a pound cozy up to each other. (Or whyever.) 🙂 **clairobscur** , I wouldn’t be _astonished_ to learn that the Paris and London meridians differ by a small amount, at least once you get down to measuring them to the nearest metre. The Earth isn’t a perfect sphere, after all. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 21, 2005, 2:31pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/67 "2005-11-21T14:31:12Z")
> [@DrDeth](#): > > The French picked Celsius for one & only one reason- the despised English used Fahrenheit. That’s also the reason why a meter doesn’t equal a yard, or a liter doesn’t equal a quart, and so forth. > > It would have been easy to pick a standard “English” measure and design a “Metric” system around it. For example- they could have started with "1 meter= 1 yard’ and gone on from there. But they didn’t. Nor, in general are the Metric measures “human -freindly”. Note the need for such terms as a "hectare’ and a “metric tonne”. I don’t think this would be as easy or convenient as you suggest; lacking is the easy punctuated linear correlation between units of weight and volume, for example; one Kilolitre of water is contained in a 1m cube and weighs 1000 kilograms; how many KiloInches cubed is KiloPint of water and how many KiloOunces does it weigh? You’d have to redefine the actual size of some of the measures to make it work and you’d just be reinventing the process of the metric system at the same time as losing the connection with the legacy of imperial/English measures. > [@](#): > > F is every bit as "metric’ as C. I (sort of) agree; both are devised as a scale of 100 divisions of a range of temperatures, except that the upper and lower limits in Celsius relate to measurements of the same medium (water), whereas in Fahrenheit, the limits are two different, arbitrarily chosen ones (a really cold day somewhere in the world and a human person apparently running a slight fever). > [@](#): > > F is more useful in weather and other such day-to-day usages, as rarely does one need to concern oneself with negative numbers. On the other hand -C comes in quite a bit in everyday weather. 0 and 100 are generally extremes of weather- something we use daily rather than a need to tell at what temp water boils or freezes. Again, ‘more useful’ is a subjective term; it could just as easily be argued that the negative numbers, far from being an inconvenient matter of fuss, actually mark a significant meteorological event; that of water freezing; quite a lot of weather is about water, so it isn’t at all unnatural that zero is the point where weatherwise things start behaving very differently. ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [November 21, 2005, 2:32pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/68 "2005-11-21T14:32:37Z")
> [@Diceman](#): > > Along these lines, the American units for volume are hands-down superior to metric units for everyday usage. A fluid ounce is a small, but useful amount of liquid. Trial-size bottles are usually 1 oz in size. A pint (16 oz) makes for a decent drink to accompany a meal. A gallon, being larger than a liter, is more convenient for liquids that are bought in bulk, like gasoline or water. > . That’s completely arbitrary. An ounce of perfume is obviously too much to be handed out for free. You want deciliters. You obviously want to drink much more than a pint of water every day. You want liters. A gallon is too small for liquid bought in bulk (heating oil) but is obviously too large for beverages and doesn’t have a fine enough resolution for gasoline. This unit just does’t makes sense. Now, of course, a meter is “just the right size” to measure appartment floors. A kilometer is ideal for distance. A kilo is the quantity of fruits you want to buy, and so on… Proof is that I measure my appartment floor in meters, distances in kilometers, essentially always buy fruits by the kilo, etc… Basically, you’re stating that the units you’re accustomed to happen to be the best one, hence that all people who didn’t live in the UK/ USA and used different units for most of history were just clueless people while for some reason, medieval english people, after thinking hard about the amount of gasoline one would want to buy and the size of samples handed out at the mall, came up with perfectly convenient units. Everybody later realized the error in their ways and abandonned their customary units, but somehow were fooled into using other equally unconvenient ones by adopting the metric system instead of picking the vastly superior imperial units. Besides, they don’t even seem to even realize how poor these units are, for some reason. The huge advantage of the metric system is that it’s easy to make calculations using it while the imperial system is ludicrously complicated to use (this doesn’t apply to temperatures) . The units themselves are arbitrary, and how convenient they are depends entirely on you being acccustomed to them or not. ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [November 21, 2005, 2:38pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/69 "2005-11-21T14:38:04Z")
> [@Malacandra](#): > > **clairobscur** , I wouldn’t be _astonished_ to learn that the Paris and London meridians differ by a small amount, at least once you get down to measuring them to the nearest metre. The Earth isn’t a perfect sphere, after all. That’s why I assume they picked the Paris meridian out of convenience, and not because, driven by nationalism, they thought it would be better than the Moscow meridian. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [November 21, 2005, 2:46pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/70 "2005-11-21T14:46:00Z")
> [@Crafter\_Man](#): > > So for a fixed number of significant digits, a Fahrenheit thermometer will always have better resolution than a Celsius thermometer when measuring changes in temperature. Let’s say a medical thermometer has 3 significant digits. If it’s Celsius, you’re measuring somewhere between 36 and 42 degrees, so a 3-digit thermometer has a resolution of 0.1 degree C. If it’s in Fahrenheit, you’re measuring 96-105 (?), so a 3-digit thermometer has a resolution of 1 degree F, which is significantly worse. ---
**Author:** ![max\_power](https://avatars.discourse-cdn.com/v4/letter/m/db5fbb/32.png) [@max\_power](https://boards.straightdope.com/u/max_power)\ **Post date:** [November 21, 2005, 2:51pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/71 "2005-11-21T14:51:29Z")
I knew this thread was going to turn into a metric v. imperial pile-on. I don’t understand why people get so worked up. What i find particularly entertaining is the imperial proponents trying to make out that imperial units are inherently more usable. It seems plain to me that imperial and metric weights and measures are both arbitrary and the units which are most convenient are the ones you are familiar with. For everyday use, where conversions don’t have to be made, any unit will work. Getting back to the C v F debate, I grew up with C, and have a feel for the system. Temperatures here range from about 0 to 25 C, so this silly thing about Farenheit reperesenting the standard range of temperatures, not for everyone it doesn’t, certainly not in our temperate climate. I’m sure if i lived in the US, I would quote temps in F and not worry about C, but I don’t, so I use Celsius. Big. Feckin. Deal. ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [November 21, 2005, 3:14pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/72 "2005-11-21T15:14:36Z")
I figure, temperature is used for a number of different tasks: Scientific - Here Kelvin is king. The fact that Celsius is based on the physical properties of water is nice, but only valuable if you are working with pure water. Everything else is some random number with as many decimal places as your equipment can define, who cares what 100 is? Kelvin has the right zero point, so there you go. Weather - Celsius has more limited resolution when you use whole numbers, but that isn’t really too critical for this purpose. If you were going to create a temperature system specifically for the weather, you would probably have 0-100 be more like Fahrenheit than Celsius. Maybe 0 would be at the freezing point of water and 100 at or near 100F. I’d give the slight edge to Fahrenheit here, since its 0-100 range is at least within existing weather temperatures. Medical - Celsius’ limited resolution could be an issue here. Are 4 values, 38-41, a wide enough range to make accurate fever diagnosis? I don’t think so, you need to add a decimal or half degree to diagnose. Fahrenheit has 7 values in the typical fever range 100 - 106, it gets the edge. Having 100 be the trip point for when you have a fever is another bonus. Cooking - Both have way more resolution than cooking needs. The 0-100 for Celsius is probably an advantage here, since so much cookery is based on water liquids, and the reaction of water in food. 200 is also a good hot oven, and a bit hotter than you need for candymaking or deepfrying. Even though I’m used to Fahrenheit, I have to give Celsius the edge here. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [November 21, 2005, 3:18pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/73 "2005-11-21T15:18:55Z")
Having been brought up in Fahrenheit, I naturally prefer it. Celsius has almost one degree for every two in Fahrenheit, so Fahrenheit does have more resolution, which is important to your average individual, and easier than adding decimal points. But I could easily get along in a Celsius country. Easy rule for conversion – to take a Celsius temperature to Fahrenheit, double and add thirty. It’s not exact, but, across your average temperature run, it’ll get you within two degrees, which is the Celsius resolution, anyway. (The real formula is 9/5 times degrees Celsius plus 32, but it’s a slower calculation). To go the other way, subtract thirty from Fahrenheir, _then_ take half to get Celsius. At what temperature do the two scales agree? -40 degrees (forty below zero) ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [November 21, 2005, 3:35pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/74 "2005-11-21T15:35:52Z")
> [@scr4](#): > > Let’s say a medical thermometer has 3 significant digits. If it’s Celsius, you’re measuring somewhere between 36 and 42 degrees, so a 3-digit thermometer has a resolution of 0.1 degree C. If it’s in Fahrenheit, you’re measuring 96-105 (?), so a 3-digit thermometer has a resolution of 1 degree F, which is significantly worse. O.K. – you’re right. But perhaps I shouldn’t have used the term “significant digits.” What I _meant_ to say was that, for a given 10[sup]n[/sup] readability (X, X.X, X.XX, etc.), Fahrenheit has more resolution than Celsius. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [November 21, 2005, 4:01pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/75 "2005-11-21T16:01:02Z")
> [@csharpmajor](#): > > I’d like to comment that “metric tonne” is only used in America. The rest of the world says “tonnes”. And, if the Metric system worked like they claimed- you’d say “megagram”. But it doesn’t- that’s akward and clumsy and thus “tonne”. Same for “hectare”. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [November 21, 2005, 4:17pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/76 "2005-11-21T16:17:02Z")
> [@Mangetout](#): > > I don’t think this would be as easy or convenient as you suggest; lacking is the easy punctuated linear correlation between units of weight and volume, for example; one Kilolitre of water is contained in a 1m cube and weighs 1000 kilograms; how many KiloInches cubed is KiloPint of water and how many KiloOunces does it weigh? > You’d have to redefine the actual size of some of the measures to make it work and you’d just be reinventing the process of the metric system at the same time as losing the connection with the legacy of imperial/English measures. > > . No, no, no. You’d just start with one measurement- say a "yard’- rename the yard the “meter” and go on from there. A “foot” would simply be a easy way of saying “1/3 of a yard”, and there’d be no inches, just 1/10th & 1/100ths etc. See, a meter is almost a yard anyway, and a liter is almost a quart, thus starting with either would have not changed the system hardly at all. However, defining a “meter” as “1/1,000,000 of a meridian” is about as useless as possible- we can hardly whip out a tapemeasure everytime we want to double check out meter-stcik. :rolleyes: ---
**Author:** ![mhendo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mhendo/32/3159_2.png) [@mhendo](https://boards.straightdope.com/u/mhendo)\ **Post date:** [November 21, 2005, 4:22pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/77 "2005-11-21T16:22:45Z")
> [@Diceman](#): > > Along these lines, the American units for volume are hands-down superior to metric units for everyday usage. A fluid ounce is a small, but useful amount of liquid. Trial-size bottles are usually 1 oz in size. A pint (16 oz) makes for a decent drink to accompany a meal. A gallon, being larger than a liter, is more convenient for liquids that are bought in bulk, like gasoline or water. I’m having trouble not laughing here. As i’ve said before, i have no trouble with people preferring the Fahrenheit system, or the non-metric system as a whole. But the number of times that subjective preference is being presented in the guise of objective superiority in this thread is pretty silly. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [November 21, 2005, 4:57pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/78 "2005-11-21T16:57:45Z")
This thread reminds me of a quote from Woody Allen’s “Radio Days:” =========================================== The Narrator (woody): Then there were my father and my mother. Two people who could find an argument in any subject. Father: Wait a minute. Are you telling me you think the Atlantic is a greater ocean than the Pacific?! Mother: No, have it your way. The Pacific is greater! # The Narrator: I mean, how many people fight about oceans? Living in a region of the world (Ottawa) where extreme cold equals -40 C. and extreme heat equals +40 C. the metric system works perfectly for me. Having been originally raised on Fahrenheit I am naturally temperature-scale bilingual. But Fahrenheit is arbitrary and Celsius is at least based on known properties. Did anyone mention that the mass of one litre of water is one kilogram? ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [November 21, 2005, 5:12pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/79 "2005-11-21T17:12:16Z")
> [@Cheesesteak](#): > > Scientific - Here Kelvin is king. The fact that Celsius is based on the physical properties of water is nice, but only valuable if you are working with pure water. Everything else is some random number with as many decimal places as your equipment can define, who cares what 100 is? Kelvin has the right zero point, so there you go. When you are trying to attain high precision and accuracy, you’ll find that the properties of “pure water” are unpredictable. There are two stable isotopes of hydrogen and three stable isotopes of oxygen. This means that the isotopic concentrations, and physical properties, depend on where the water is collected. Any temperature scale based on the properties of water has a flawed foundation. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [November 21, 2005, 5:15pm UTC](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987/80 "2005-11-21T17:15:41Z")
> [@Diceman](#): > > This is why Americans still use Fahrenheit. It’s a superior system for dealing with the weather. Negative numbers (in Fahrenheit) correspond to temperatures that are dangerously cold, even if you dress warmly. Hahahahahah!!! [Previous page](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987.md?page=3) [Next page](https://boards.straightdope.com/t/whats-the-point-of-celsius/331987.md?page=5)