Highest useful Fahrenheit temperature?

In summary: I don't know... Kelvins?In summary, the conversation discusses the usefulness of Fahrenheit equivalents for temperatures outside the range of -40°F to 1000°F. Some points are made about the standard use of Celsius internationally and the differences in temperature scales between countries. The conversation also touches on the use of Fahrenheit in domestic USA and the need for conversions in scientific papers. It is suggested that there is no point in including Fahrenheit conversions outside of the -40°F to 1000°F range, but others argue that it may still be useful for the general public. Finally, the conversation raises the question of when it is appropriate to switch from using degrees Celsius to Kelvins.
  • #1
Algr
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TL;DR Summary
At what temperature is there no longer any value in including Fahrenheit equivalents?
I was watching a video about energy storage, and the subject was stuff that was around 1500° celsius, and for the whole video the graphics kept including Fahrenheit equivalents. Now I use Fahrenheit when checking the weather outside. But that doesn't make 2732F° any more relatable a temperature than 1500C°. Who exactly would find those temperature conversions useful? I know that lots of cooks use Fahrenheit, but that is only going to take you to about 500F° max. Is there any sort of industry today where people work with four-digit temperatures in Fahrenheit? I suspect that the conversions don't really benefit anyone.
 
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  • #2
Celsius is the international standard, and is used everywhere.
Except in domestic USA, where the old Fahrenheit scale is still being used.

If you publish in the USA, independent of magnitude, you will need to translate all temperatures to Fahrenheit, or none. Except for -40°.
 
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  • #3
Algr said:
I was watching a video about energy storage, and the subject was stuff that was around 1500° celsius, and for the whole video the graphics kept including Fahrenheit equivalents. Now I use Fahrenheit when checking the weather outside. But that doesn't make 2732F° any more relatable a temperature than 1500C°. Who exactly would find those temperature conversions useful? I know that lots of cooks use Fahrenheit, but that is only going to take you to about 500F° max. Is there any sort of industry today where people work with four-digit temperatures in Fahrenheit? I suspect that the conversions don't really benefit anyone.
Ehh? It sounds like you are saying all big numbers are the same. No, they really aren't.
 
  • #4
From an emotional standpoint they are. It is just when math gets involved that they are different, and anyone doing math on temperatures is probably fine with celsius.
 
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  • #5
Algr said:
Who exactly would find those temperature conversions useful?
People who know absolutely nothing about Celsius and how it relates to Farenheit. Ten thousand degrees Celsius is meaningless if you've never used Celsius before.
 
  • #6
Algr said:
Summary: At what temperature is there no longer any value in including Fahrenheit equivalents?

I was watching a video about energy storage, and the subject was stuff that was around 1500° celsius, and for the whole video the graphics kept including Fahrenheit equivalents. Now I use Fahrenheit when checking the weather outside. But that doesn't make 2732F° any more relatable a temperature than 1500C°. Who exactly would find those temperature conversions useful? I know that lots of cooks use Fahrenheit, but that is only going to take you to about 500F° max. Is there any sort of industry today where people work with four-digit temperatures in Fahrenheit? I suspect that the conversions don't really benefit anyone.
One uses the scale which he needs or is accustomed or which let's him conform to some understandable communication. Only really needed for practical purposes is know that water freezes or melts at 0 C or 32 F; and water boils at 100 C or 212 F. The typical conversion formula comes from that. Most of the world uses C, or Celsius scale.
 
  • #7
Drakkith said:
Ten thousand degrees Celsius is meaningless if you've never used Celsius before.
Ten thousand degrees Fahrenheit is meaningless if the hottest oven you've ever seen goes to five hundred. What I am asking: Is there anyone out there today who mesures stuff that is thousands of degrees, and has their thermometer set to Fahrenheit?

Baluncore said:
If you publish in the USA, independent of magnitude, you will need to translate all temperatures to Fahrenheit, or none. Except for -40°.

I didn't know this. I thought that scientific papers and serious engineering was being done in metric everywhere these days. Didn't NASA stop using imperial units after one of those conversions crashed a lander into Mars?
 
  • #8
Algr said:
I thought that scientific papers and serious engineering was being done in metric everywhere these days.
I'm sorry, I was referring there to "domestic USA" not to real scientists.

I think we should prohibit the use of °F on this scientific website.
 
  • #9
Baluncore said:
I think we should prohibit the use of °F on this scientific website.
I'd say Fahrenheit is okay, but only between -40° and 1000°. There is just no point to it outside that range.
 
  • #10
Algr said:
I'd say Fahrenheit is okay, but only between -40° and 1000°. There is just no point to it outside that range.
We have K and C scales now, why does any scientist here on PF need to use °F inside that arbitrary range ?
 
  • #11
They don't. It's for people like me who think that you should wear a jacket because it is 50° outside.

More precisely I am saying that there is no point in including the Fahrenheit conversion if the temperature is outside that range, even if the video is intended for the general public.
 
  • #12
Algr said:
They don't. It's for people like me who think that you should wear a jacket because it is 50° outside.

More precisely I am saying that there is no point in including the Fahrenheit conversion if the temperature is outside that range, even if the video is intended for the general public.
Decide if you are or are not in favor of effective communication.
 
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  • #13
Algr said:
Summary: At what temperature is there no longer any value in including Fahrenheit equivalents?
-459.67°F
 
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  • #14
Algr said:
It's for people like me who think that you should wear a jacket because it is 50° outside.
Here Down Under, @Algr, we'd be the exact opposite.

"Fifty degrees outside? Strewth, it's enough to turn you troppo. But stone the crows, is that some galah wearing a jacket? Fair dinkum, must be a few stubbies short of a six-pack, what a larrikan."
 
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  • #16
How about a simpler question - at what point does it make snese to stop talking about "degrees Celsius" and start using "Kelvins"?
 
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  • #17
Boilers and exhaust gases ducts in power plants in USA use thermopar based instruments and pyrometers that provide data above 4,000 Fahrenheit degrees.
I believe the technicians and engineers who work in those plants do not care about the Celcius scale in their daily tasks.

Please, see:
https://www.infra-view.com/infrared-pyrometers/portable-infrared-boiler-furnace-thermometer/

hvacbackground.jpg
 
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  • #18
I remember an article from the bicentenial, 1976. It said that each and every year since around 1800, Congress passed a resolution saying, "This is the year America switches to metric." But it never happened.

Scientists are free to use any units they want. The public doesn't care. The association of numbers with feelings depends of memories of past days; usually from childhood. It will be 90 today. Ay, hot! It will be -40 today. Ay ay, very cold.

Workers who need to buy new tools do care. TV weathermen care about ratings.

So where is the incentive for the public to change? They have no need to follow the whims of science. They had no seat at the table when the SI system was adopted.

p.s. The most irrational units of all are those for time. Even the SI system did nothing to fix those.
 
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  • #19
anorlunda said:
p.s. The most irrational units of all are those for time.
How so?
 
  • #20
Bystander said:
How so?
It's π o'clock, time for lunch.
 
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  • #21
Bystander said:
How so?
No decimal gradations. More rational would be 100 second minutes, 100 minute hours, 10 hours per day, 10 days per week, 10 months per year. Other scales based on powers of 10 would serve just as well. That implies that the second would be defined as 10-5 days. A more precise unit would be better for science.

Are the day and year also rational? At least they tie to something physical, although not exactly constant.
 
  • #22
anorlunda said:
No decimal gradations.

anorlunda said:
Are the day and year also rational? At least they tie to something physical, although not exactly constant.

..., annddd you need the "larger, non-constant" time units for what purposes? Social (re-)/engineering just for the "halibut?"
 
  • #23
Bystander said:
..., annddd you need the "larger, non-constant" time units for what purposes? Social (re-)/engineering just for the "halibut?"
Yes, for humans. It would be impractical for humans to use the currently defined second as their only unit of time. For example, "I'll call back in 86400 seconds." or "I signed a giga second mortgage."

But science can define any time unit it wants, but not try to tie it to days and years. One Plank might be a good candidate, because no human would be tempted to say, "I'll call you back in 5x1044 Planks." So scientists can have a precisely defined unit, and lay people could have units practical to their everyday uses, but there would be little temptation to convert one to the other.
 
  • #24
Vanadium 50 said:
How about a simpler question - at what point does it make sense to stop talking about "degrees Celsius" and start using "Kelvins"?
Randall Munroe touches on this briefly at one point. It's when the rounding error gets beyond three digits, like this:
"A supernova can have temperatures of 100 billion degrees kelvin (100 billion degrees celsius)."
Is there really anyone who needs to know the fahrenheit equivalent to this to understand what is going on?

The advantage of imperial units is that it tends to put measurements that ordinary people use into convenient two-digit precision. Fahrenheit is the best example of this. If the temperature isn't two positive digits, you've got dangerous weather going on. Feet/inches similarly tends to give you two digits when asking how tall someone is or how big is their yard. (Although imperfect obviously.)
anorlunda said:
10 hours per day
This is absolutely awful, and I think is the main reason that metric time did so badly it was forgotten about. A metric hour is 2.4 regular hours - a length of time that corresponds to absolutely nothing in natural human behavior. This forces the use of three irregular digits for absolutely everything people do. How long is lunch? .38 of an hour? How long should you sleep at night? 3.33 hours. The base 24/ subbase 60 system seems strange, but it arose from things people really need to do with time.

Ten day weeks were killed off by selfish employers who insulted their workers by pretending that they did not recognize the consequences of eight workdays in a row.

BTW, 100 units per day would have been much better for metric time. That is roughly a quarter of an hour, and we do lots of stuff by the quarter hour now.
 
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  • #25
Algr said:
Randall Munroe touches on this briefly at one point. It's when the rounding error gets beyond three digits, like this:
"A supernova can have temperatures of 100 billion degrees kelvin (100 billion degrees celsius)."
Is there really anyone who needs to know the fahrenheit equivalent to this to understand what is going on?
I do. It drives me crazy when I'm trying to make a point (as a layperson) and my sources use all manner of units. I spend more time than necessary converting and checking and verifying. As one of your hypothetical readers/viewers, I would very much appreciate you providing me with information that's as useful as possible - as well as giving me some credit for being an intelligent reader who is interested in reading your content.

In @Strato Incendus thread's we often discuss speeds and distances, but it's not outside the realm of possibility to discuss temperatures too. We could easily talk about the temps his ship might experience flying near a nova to harvest resources.

Or imagine if I said "Well, at 0.1c over a year, your ship will have traveled about 5.7 billion miles (or about 5.7 billion kilometres)". Argh!
And this is not technical physics paper stuff - this is hobby stuff. The very kind of the people who are interested in reading watching your content are the very kind of people who are numerate enough to know (and care) about the diff between 1 million C and 1 million F.
 
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  • #26
I fear that I hijacked this thread with side topic on the units of time. I regret the hijack.
 
  • #27
anorlunda said:
I fear that I hijacked this thread with side topic on the units of time. I regret the hijack.
:: Sends fighter jets to escort anorlunda to the airport. Has professional negotiators on standby. ::
 
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  • #28
Hoockle!
Use the scale you need! Convert if necessary, depending on who you want to communicate with! Use conventionally understood knowledge to help.
 
  • #29
symbolipoint said:
Use conventionally understood knowledge...
Says the guy who just said ... er ... Hookle? :oldbiggrin:
 
  • #30
DaveC426913 said:
In @Strato Incendus thread's we often discuss speeds and distances, but it's not outside the realm of possibility to discuss temperatures too. We could easily talk about the temps his ship might experience flying near a nova to harvest resources.
Indeed, in the prequel I show how the people heiring from different countries need to adapt to a common culture on board the ship, and that includes unified systems of measurement. For example, the Exodus uses the metric system - but of course also has English as its main language, and it's English-speaking countries where the metric system is least popular. So everyone has to adapt to some extent. Degrees Celsius seemed to be the way to go initially, as it's more widely used; however, in space it does indeed make more sense to go with Kelvin, which will be equally novel for most people on board.

It may sound a little weird to measure e.g. body temperature in Kelvin initially, but for the generations who grew up on the ship and never knew anything else, it won't feel strange at all anymore. This constant need for having to convert and recalculate of course still occurs whenever people from the ship converse with people from Earth (with a time-delay of up to two decades). But that's also true for the language of communication itself. 😁
 
  • #31
anorlunda said:
I regret the hijack.
Apologies for aiding and abetting.
 
  • #32
anorlunda said:
The association of numbers with feelings depends of memories of past days; usually from childhood. It will be 90 today.
I will add my usual plea for the preservation of the Fahrenheit scale . It is actually defined on humanist values. We are creatures made of saline solution. We will freeze solid at 0F We will be unpleasantly hot at 100F because we optimize at 98.6F. A good temperature is 70F...it is a passing score...
There is nothing to recommend the Celcius scale except ubiquity.
We represent a last bastion of Temperature Sanity on the planet.
Fahrenheit Forever.
 
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  • #33
Strato Incendus said:
Degrees Celsius seemed to be the way to go initially, as it's more widely used; however, in space it does indeed make more sense to go with Kelvin, which will be equally novel for most people on board.
I'd really question this. Even on a spaceship, the majority of measurements of temperature made would be of things related to human survival, not how cold it is outside.
 
  • #34
hutchphd said:
We are creatures made of saline solution. We will freeze solid at 0F We will be unpleasantly hot at 100F because we optimize at 98.6F. A good temperature is 70F...it is a passing score...
Of all things, man is the measure. - Protagoras
 
  • #35
DaveC426913 said:
Says the guy who just said ... er ... Hookle? :oldbiggrin:
You'll need to understand what this really means. Not directly telling, but I would cut the character size to 4, and the characters number 3 and number 4 are identical consonants. Your expected human intelligence, and enough familiarity with English will help you see what "Hoockle" was meant to be. Not absolutely clear how was the seriousness of your comment.
 

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