Metric much easier to remember prime points,

Like what prime points in Celsius?

 

Hot = Can't hold yer finger on it!
Warm = Don't need a jacket.
Cold = Like a tall glass of iced sweet tea.
Freezing = Ice Cream ain't melted yet.

 

As an engineer/scientist who works in °C but lives in °F, those numbers feel so random.

It's a matter of context. Becoming extremely familiar with one system of units in a particular context does not mean that that system is ever going to feel familiar in another context.

To me, Celsius is the natural way to work in the engineering contexts that I'm most familiar with, because that has always been how the associated calculations have been done. But, to a very large degree, those are numbers on a page and so they do very little to help me get a sense of how warm or cold it is in some location when I'm told the temperature in Celsius.

Perhaps an even better example, in my case, is which is more natural to me, six feet or two meters? Depends on context. If I hear that someone is two meters tall, I have to mentally convert that to "a little bit over six feet" for it to have meaning to me. But if someone tells me that a radio wave has a two foot wavelength, I have to convert that to "a little less than six meters" for it to have meaning to me.

 

Yes it is.
But in all my technical work I used the Celsius scale as all the tech requirements were in Celsius (expect for the thermostats in my office building, which were in Fahrenheit ).
My use of Fahrenheit was/is for ambient room/outdoor temperature readings in a non-technical environment.
I suppose it could be considered a disadvantage to use both Fahrenheit and Celsius temperature scales, but I'm used to it.

I’d concur with that, you can measure the same parameter in two different situations in two different units, and if the two don’t interact then there’s no problem.

When did you last need to multiply the temperature on your thermostat by Boltzmann’s constant?

 

If I hear that someone is two meters tall...

...I think of Darth Vader.

Strange.

 

But if someone tells me that a radio wave has a two foot wavelength, I have to convert that to "a little less than six meters" for it to have meaning to me.

two foot is just over 0.6m, six meters is 20ft (ish).

 

Policeman: “Do you know how fast you were driving?”

Me: “My groundspeed was 78.2 knots with a heading of 2,3,oh, but as a had a tailwind my indicated airspeed was 65.17 knots which at this temperature and barometric pressure equals 0.0977 Mach. Or 1.118x10^-7 C. I wasn’t speeding.”

Policeman: “Step out of the vehicle, please.”

 

Policeman: “Step out of the vehicle, please.”

"But I'm not as thunk as you drink I am."

 

I have a curiosity about using the Celsius temperature scale versus Fahrenheit.
I know the USA is likely considered somewhat backwards for still using the Fahrenheit temperature scale for non-technical uses, (most science/technical functions use Celsius) but I find the scale more relatable to human comfort for ambient temperature readings.
0°F is really cold and 100°F is uncomfortably hot with 70°F being in the comfortable indoor range.
And 1°F is a good adjustment increment for an indoor thermostat.

I would suppose you get used to the Celsius temperature values for those arbitrary comfort levels, but it seems less intuitive.
Also I believe Celsius home thermostats use 0.5°C setting increments as a 1°C jump is likely too coarse.

I'm interested in thoughts on this from those in the rest of the world who use Celsius for ambient temperature readings.

On a side note, I also find the gallon a handy unit for liquid measure such as gasoline and milk.
I could live with kilometers instead of miles though, even though the word has too many syllables.

I'm from the UK. All my life I used C but was well aware of F and the respective definitions, all thermometers were dual scale. When I came here (as an adult) I had trouble mapping an F temp to a "feeling" and had to map F to C where it was easy. But after time that slowly changed. Now any weather temperature in C bewilders me just as F once did.

You are right though, I think a degree C is rather coarse, a temp in C in Britain often has a fractional part, so 30.5 means something tangible compared to 30.0, whereas here one never see weather reports that have fractions of degrees F, one degree change in C is the same span as 1.8 degrees in F.

But you want to talk old fashioned look at the old sterling currency: Pounds, Shillings, Pence, which was replaced - overnight - in 1971:

 

two foot is just over 0.6m, six meters is 20ft (ish).

10m is 1 atmosphere. That one is easy to remember, as well as 3e+8 m/s = 1 ft./ns, and 330 m/s + ~0.5m/s/C (good enough for napkin calculations).

 

I'm pretty sure I see his point and it's not unreasonable.

Just like Americans like the term 'soccer' while the rest of the world likes 'football', it is a matter primarily not of which term is better, but which term you grew up with, are exposed to more often, and use most often. We (Americans) like the Fehrenheit scale not because it has any particular advantage over Celsius, but because it is what we grew up with and what we think in terms of. When we point to its "conveniences" we are essentially cherry picking data points that we have grown accustomed to and emphasize those as being advantages. But the people that grew up with Celsius can (and do) the exact same thing.

Hi W,
I also grew up with Fahrenheit, but changed to Celsius for physics reasons, now I'm stuck with it. I also grew up with £.S.D.
I used to use lathes which had thousandths of an inch dials, and had to read drawings in MMs.

On the back of school exercise books were chains and furlong tables.

I'm glad it's more simple now!
C.

 

I'm pretty sure I see his point and it's not unreasonable.

Just like Americans like the term 'soccer' while the rest of the world likes 'football', it is a matter primarily not of which term is better, but which term you grew up with, are exposed to more often, and use most often. We (Americans) like the Fehrenheit scale not because it has any particular advantage over Celsius, but because it is what we grew up with and what we think in terms of. When we point to its "conveniences" we are essentially cherry picking data points that we have grown accustomed to and emphasize those as being advantages. But the people that grew up with Celsius can (and do) the exact same thing.

 

It would be an interesting experiment -- and one that I'm sure has been done more than once -- to see how much of a temperature difference most people can really sense. When I hear that the temperature tomorrow is going to be 86°F instead of the 84°F that it was originally forecast, that means nothing to me as both temperatures give me the same impression, namely "in the 80s" or, "in the mid-80s" at best. But could I actually sense the difference between two rooms, one at each temperature, as I went back and forth between them? Or if I went between them via an intermediary room that was five or ten degrees cooler or warmer than either? Possibly, but I'm skeptical. I think that there's very possibly a false sense of sensitivity based on resolution.

A classic example is the 98.6°F value that we are always told (in places that use Fahrenheit) is the normal human body temperature. This implies that the body regulates temperature to a small fraction of a degree Fahrenheit. The result is that many people think something is wrong if they get a reading of 98°F or 99°F. But that's not the case and never was. 98.6°F just happens to be the value you get when you convert 37°C to Fahrenheit. If we were told that normal body temperature was 98°F, we would tend to assume that changes of half a degree Fahrenheit are in the noise. Well, being told that normal body temp is 37°C implies that half a degree Celsius either way are in the noise, which translates to almost a full degree Fahrenheit). In fact, the 37°C itself is a rounded number (how astonishing would it be had the actual number worked out extraordinarily close to an integer value on any temperature scale?).

The history of where the 37°C number comes from is rather interesting. It came from one study performed by Carl Wunderlich using an 1851 data set of over a million readings, which he published in 1868. These measurements were taken by a variety of people in clinical settings during normal patient care spanning decades of time -- so lots of observer variability. The measurement were made using similar, but not identical, mercury thermometers, all of which were hand blown and scaled to a resolution of 0.1°C. It's been determined that they tended to read 0.2°C - 0.3°C high, that the scales were not quite linear, that they had larger errors at higher temperatures (common in this type of thermometer) and had instrument-to-instrument variations of ±0.2°C to ±0.4°C. He also used armpit measurements and not oral measurements (armpit measurements tend to be 0.3°C to 0.6°C lower than oral readings (which significantly offsets, by coincidence, the systematic bias of his thermometers). His reported results were that, while his calculated average was 37.0°C (modern reconstructions estimate that his true average was between 36.8°C and 36.9°C), he could only specify a range for normal temperature of between 36.2°C and 37.5°C.

So our sense of nature is distorted by about an order of magnitude because we use an exact conversion of a rounded number. Thank god the conversion didn't involve 'e' or 'π'!

 

Policeman: “Do you know how fast you were driving?”

Me: “My groundspeed was 78.2 knots with a heading of 2,3,oh, but as a had a tailwind my indicated airspeed was 65.17 knots which at this temperature and barometric pressure equals 0.0977 Mach. Or 1.118x10^-7 C. I wasn’t speeding.”

Policeman: “Step out of the vehicle, please.”

 

It would be an interesting experiment -- and one that I'm sure has been done more than once -- to see how much of a temperature difference most people can really sense.

Seriously: my wife and I fight over 1 degree F on the thermostat every single night.

I set 70F before I go to bed. She changes it to 71. I have to get up 30 minutes later to drop it back down to 70. Then she complains that she is cold.

I swear on my life this is a daily occurrence.

 

Majority of my science and engineering classes were metric with an engineering nod to imperial here and there. But even working in a chemical refinery I dealt with a lot of PSI, tons and gallons. Then there was Structural Steel and its supporting foundations, all imperial. Ft/lbs, tons, cubic yards, feet, and inches all the way. Never saw an electrical motor in anything but Horsepower rated and of course AWG wiring but then Metric Watts & Amps for electrical power distribution. Confusing ain't it...

 

Seriously: my wife and I fight over 1 degree F on the thermostat every single night.

I set 70F before I go to bed. She changes it to 71. I have to get up 30 minutes later to drop it back down to 70. Then she complains that she is cold.

I swear on my life this is a daily occurrence.

I admit that I do find that a bit surprising, particularly if either or both of you sleep under any kind of blanket.

Perhaps my insensitivity comes from spending most of my life with no control over the temperature beyond opening windows and running a fan, and sometimes not even that. Even today, I almost never adjust the thermostat and just live with whatever the temperature happens to be. I think I've changed the thermostat in our house three times in the six years that we've lived here. My wife is pretty much the same. At least this does prevent us fighting over the thermostat. Of course, the first decade of our marriage was in a home that we primarily heated by a wood-burning stove, so we couldn't be very picky at all about wanting a particular temperature in the house. As long as it wasn't too much before 60°F in the winter, we just wore our nice, thick bathrobes.

 

I admit that I do find that a bit surprising, particularly if either or both of you sleep under any kind of blanket.

Thank you. That's exactly what I tell her: if she's cold, put on an extra blanket.

When I'm hot, there is nothing I can do to make myself unhot but to lower the thermostat.

She says extra blankets are "too heavy". Princess and the Pea kinda stuff.

 

i solved that years ago by a little bit of cheating... bought identical thermostat, hacked it, then hacked the original as well. both were showing few degrees higher. i wanted second unit in case she claims that original is broken (and she did) so i casually pulled out brand new unit, unpacked and replaced it in front of her.

 

Thank you. That's exactly what I tell her: if she's cold, put on an extra blanket.

When I'm hot, there is nothing I can do to make myself unhot but to lower the thermostat.

She says extra blankets are "too heavy". Princess and the Pea kinda stuff.

You've just described the first 365 days of my married life ...