Please note that
212 - 32 = 180
The number of degrees from freezing point to boiling point on the fahrenheit scale is exactly 180 degrees, a fairly reasonable round number.
This shows that Fahrenheit did in fact take the boiling point into account, and that his scale is not as weird as all that.
:dubious:
In the linked article, it says that Fahrenheit multiplied the numbers by 4 to give him 30 and 90, then multiplied it by 16/15 to get 32 and 96 for some unknown reason. Is it possible that that reason was to make the boiling point of water, along with those other two values all whole numbers? If he hadn’t multiplied by that, boiling point would be 198.75.
As for 180 degrees being the difference, being that he had intended to base the system on freezing point and human body tempurature, the fact that it happens to be a multiple of 10 (which is what I assume you mean by “reasonable”) isn’t necessarily evidence that it was taken into account. Similarly, the “fact” that his zero point coincides with ice water and ammonium chloride, doesn’t necessarily mean he actually took that into account either.
[QUOTE=Blaster Master]
As for 180 degrees being the difference, being that he had intended to base the system on freezing point and human body tempurature, the fact that it happens to be a multiple of 10 (which is what I assume you mean by “reasonable”) isn’t necessarily evidence that it was taken into account. Similarly, the “fact” that his zero point coincides with ice water and ammonium chloride, doesn’t necessarily mean he actually took that into account either.
[/QUOTE]
I thought that the significance of the number 180 was so immediately obvious that it didn’t need any further comment. Obviously, I was wrong. Ever use a protractor? Ever hear the expression “180-degree turn” ?
The numbers 60, 180, 360 have been used for divisions of time and space for thousands of years.
You noticed that 180 is divisible by 10. If you wok it out, you’ll find that it’s actually divisible by 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 90. That’s why it’s useful, especially if you don’t have a calculator.
My point is that the article is wrong.
Fahrenheit based his scale on the freezing point of water and the boiling point of water, nothing else. He set the difference as 180 - an obvious number to anyone familiar with geometry or astonomy. He then made the starting point 32 degrees further down in order to avoid negative numbers, which were still quite esoteric to ordinary people at that time.
[QUOTE=GreenWyvern]
I thought that the significance of the number 180 was so immediately obvious that it didn’t need any further comment. Obviously, I was wrong. Ever use a protractor? Ever hear the expression “180-degree turn” ?
The numbers 60, 180, 360 have been used for divisions of time and space for thousands of years.
You noticed that 180 is divisible by 10. If you wok it out, you’ll find that it’s actually divisible by 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 90. That’s why it’s useful, especially if you don’t have a calculator.
My point is that the article is wrong.
Fahrenheit based his scale on the freezing point of water and the boiling point of water, nothing else. He set the difference as 180 - an obvious number to anyone familiar with geometry or astonomy. He then made the starting point 32 degrees further down in order to avoid negative numbers, which were still quite esoteric to ordinary people at that time.
[/QUOTE]
All of which would be quite nice, if it wasn’t for the fact that we have the actual writings of Daniel Farenheit himself saying you are wrong. Farenheit wrote in 1724 that he created a scale in which body temperature was 96° and mercury boiled at 600°. It wasn’t until someone came along later and adjusted the scale to create an easy conversion that the boiling point of water got fixed at 212° (which resulted in mercury’s boiling point being actually 674° F).
So Farenheit himself never actually mentioned the difference between the boiling and freezing points of water as relevant to his scaling, and this would be unsurprising given that his original scale didn’t establish a neat interval between the two. It was the later editors that helped us out, there.
If you are going to call Uncle Cecil “wrong,” you probably ought to have, like, you know, evidence to support you. 
Citation: D. G. Fahrenheit.
Experimenta et Observationes de Congelatione aquae in vacuo factae a D. G. Fahrenheit, R. S. S..
Philosophical Transactions (London), volume 33, page 78 (1724).
the relevant text of which can be found here.
[QUOTE=DSYoungEsq]
So Farenheit himself never actually mentioned the difference between the boiling and freezing points of water as relevant to his scaling, and this would be unsurprising given that his original scale didn’t establish a neat interval between the two. It was the later editors that helped us out, there.
[/QUOTE]
I concede that the scale wasn’t originally conceived that way by Fahrenheit himself, and that it was later changed by people with more common sense.
However, the original question said,
*“On the Fahrenheit scale, however, freezing is 32 degrees and boiling 212. How on earth were these numbers arrived at?”
*
This is a question about the scale as it is now, not about how Fahrenheit originally conceived it. I think that I’ve answered this question, whereas the original reply didn’t.
[QUOTE=GreenWyvern]
If you wok it out…
[/QUOTE]
What temperature should the wok be?
[QUOTE=GreenWyvern]
This is a question about the scale as it is now, not about how Fahrenheit originally conceived it. I think that I’ve answered this question, whereas the original reply didn’t.
[/QUOTE]
No, you haven’t, and yes, it did.
Hmmm, I don’t think I’ve seen a guest so cocky that they’d use a smilie to compliment themselves on taking on Cecil.
FWIW, I heard a very reasonable explanation for the choice of 32 & 96 degrees: it makes it easy to build an accurate thermometer because 32 and 64 are both powers of two. This is important because the original thermometers would have been made by hand, not in a factory. So each thermometer would be a little different, and would have to be calibrated by hand.
You take your brand new (unmarked) thermometer and measure human body temperature, and the temperature where water freezes. Make little marks on the thermometer for each. It’s easy to then find the midpoint between the two marks - that’s 64 degrees. You can then measure out exactly where 0 degrees should be. You then divide the regions in half, over and over. Since 32 and 64 are both powers of two, it’s easy and accurate.
At least, that’s what I heard long ago.
[QUOTE=GreenWyvern]
You noticed that 180 is divisible by 10. If you wok it out, you’ll find that it’s actually divisible by 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 90. That’s why it’s useful, especially if you don’t have a calculator.
My point is that the article is wrong.
[/QUOTE]
And what good does this do you? Exactly what type of problem requires you to divide the temperature? Half as warm? Twice as cold?
[QUOTE=russl5445]
FWIW, I heard a very reasonable explanation for the choice of 32 & 96 degrees: it makes it easy to build an accurate thermometer because 32 and 64 are both powers of two. This is important because the original thermometers would have been made by hand, not in a factory. So each thermometer would be a little different, and would have to be calibrated by hand.
You take your brand new (unmarked) thermometer and measure human body temperature, and the temperature where water freezes. Make little marks on the thermometer for each. It’s easy to then find the midpoint between the two marks - that’s 64 degrees. You can then measure out exactly where 0 degrees should be. You then divide the regions in half, over and over. Since 32 and 64 are both powers of two, it’s easy and accurate.
At least, that’s what I heard long ago.
[/QUOTE]
That’s is what I remember my history of science prof saying years ago as well. Makes sense from a manufacturing standpoint.
[QUOTE=GreenWyvern]
I concede that the scale wasn’t originally conceived that way by Fahrenheit himself, and that it was later changed by people with more common sense.
However, the original question said,
*“On the Fahrenheit scale, however, freezing is 32 degrees and boiling 212. How on earth were these numbers arrived at?”
*
This is a question about the scale as it is now, not about how Fahrenheit originally conceived it. I think that I’ve answered this question, whereas the original reply didn’t.
[/QUOTE]
Well, they weren’t arrived at by worrying one jot about the number 180. First of all, just because it’s a cool number is meaningless. Unlike some things (hours of a day, e.g.), it isn’t important to be able to divide a temperature difference up into parts like that. What purpose would it serve? Second of all, we have no evidence that 180 was in their thinking. We DO have evidence that the adjustment was made simply to allow for an “easy” conversion factor, given that 32° F was going to stay as the freezing point of water. In short, they looked at the scale as calibrated by Farenheit, which had no easy conversion factor, and they said, “Hey, you know what? If we set the boiling point at 212°, we can use 9:5 as a conversion factor!” The only part 180 played in this was the fortuitous happenstance of being 9/5ths of 100.
I’m glad you dropped by; we always enjoy new vict…, er, that is, new guests. 
However, if you decide to stay, you will quickly find that what you did here, which is simply speculate on an answer, based on what seemed to be a good idea to you, simply isn’t an acceptable method of proof here. We like to rely on things like evidence (when we aren’t relying on our own big egos :smack: ).
I’d like to underline something DSYoungEsq only implied: Modern “Faherenheit” has been modified to give simple conversions to Celsius. Fahrenheit purists can weep to realize they’re using a partially Celsius-derived system!
Incidentally, you know how we’re all told that human body temperature is 98.6 degrees? Poppycock. Human body temperature is no way consistent enough to require a measurement to a 10th of a degree Fahrenheit. In Celsius, one speaks of human body temperature as 37.
37 / 5 * 9 + 32 = 98.6
Some fool translated a reasonable approximation to an average degree Celsius into a pseudo-precise measurement of no real scientific value. :rolleyes:
Fahrenheit in general is kind of a joke anyway, no one needs degrees that finely graded.
[QUOTE=foolsguinea]
I’d like to underline something DSYoungEsq only implied: Modern “Faherenheit” has been modified to give simple conversions to Celsius. Fahrenheit purists can weep to realize they’re using a partially Celsius-derived system!
Incidentally, you know how we’re all told that human body temperature is 98.6 degrees? Poppycock. Human body temperature is no way consistent enough to require a measurement to a 10th of a degree Fahrenheit. In Celsius, one speaks of human body temperature as 37.
37 / 5 * 9 + 32 = 98.6
Some fool translated a reasonable approximation to an average degree Celsius into a pseudo-precise measurement of no real scientific value. :rolleyes:
Fahrenheit in general is kind of a joke anyway, no one needs degrees that finely graded.
[/QUOTE]
First of all, your statements start from an incorrect premise. No one is told that “the human body temperature is 98.6 degrees.” People’s temperatures vary a lot. What we ARE told is that the average temperature (measured orally) is 98.6°F. this IS an accurate statement, because it is a direct conversion from the 37° C figure that was arrived at as an average temperature for a normal, healthy human. And certainly one could determine an “average” (meaning median or mode, depending) temperature for a given sample of humans to the level of a single digit past the decimal; thermometers are certainly accurate to that extent in measuring human body temperature either orally or rectally (or any other way).
As for whether or not it is a “joke”, frankly, I am quite happy with the difference between the two scales. I can tell in my own house when the temperature has risen or fallen a single degree Farenheit, which means that it’s obviously of some use to know the difference between 71 and 72 degrees.
[QUOTE=DSYoungEsq]
No one is told that “the human body temperature is 98.6 degrees.”
[/QUOTE]
To quote Willmore the Rover, “Why, where hast thou lived? / Amongst the gods?”
Regardless of the historical evidence, I have always believed that 0 and 100 degrees on the Fahrenheit scale were markers for the human body’s tolerance of temperature extremes. Simply, 0 F. feels bitterly cold, and 100 F. feels horribly hot.
Could Fahrenheit have felt compelled to place a scientific justification on his scale while really creating something accessible to the general public?
[QUOTE=dennisjmillerdds@gmail.com]
Regardless of the historical evidence, I have always believed that 0 and 100 degrees on the Fahrenheit scale were markers for the human body’s tolerance of temperature extremes. Simply, 0 F. feels bitterly cold, and 100 F. feels horribly hot.
[/QUOTE]
This is so subjective as to be completely useless. If you are raised in the tropics, 100° isn’t so horribly hot, and anything below 40° is going to be bitterly cold. It all depends on your frame of reference.
Ah, yes, another warm, welcoming hand of friendship offered to a new poster here. :rolleyes:
dennisjmillerdds@gmail.com, the problem with your supposition is that, while 0° F certainly is cold, it’s not by any means the coldest temperatures that would be recorded in northeastern Europe, where Farenheit was from (Gdansk, actually), nor is 100° F any more or less “hot” than 101, or 99. Further, they aren’t measured very precisely. Finally, there was no reason to make it a scale of 100, given that the possible temperatures go above 100 (and, for that matter, below 0).
Further, Farenheit wasn’t working in a vacuum. Rømer’s scale had come out in 1701, and that was the first scale established using a brine solution for 0° Rø, where 7.5° Rø was the freezing point of water. Farenheit was apparently simply improving on this scale, attempting to remove some of the potential for negative numbers that the Rømer scale had when measuring temperatures of things you would want to measure the temperature of.
So, really, we must assume that the story he gave us is at least close to what he was attempting at the time, and the fact that we attach meaning to 0 and 100 is more to do with our view of these numbers as interesting than it is to do with anything intended by Herr Farenheit.
[QUOTE=DSYoungEsq]
First of all, your statements start from an incorrect premise. No one is told that “the human body temperature is 98.6 degrees.” People’s temperatures vary a lot. What we ARE told is that the average temperature (measured orally) is 98.6°F. this IS an accurate statement, because it is a direct conversion from the 37° C figure that was arrived at as an average temperature for a normal, healthy human. And certainly one could determine an “average” (meaning median or mode, depending) temperature for a given sample of humans to the level of a single digit past the decimal; thermometers are certainly accurate to that extent in measuring human body temperature either orally or rectally (or any other way).
[/quote]
:dubious: Really.
Which is more credible?[ul][li]That the true & perfect statistical average is within a 20th of a degree Fahrenheit, or[*]that given a typical variation of over 3 degrees Celsius (over 5 degrees Fahrenheit), Mr Celsius used a whole number in the middle of the range & considered further significant digits meaningless?[/ul]Good grief! What would Ockham say?[/li][quote]
As for whether or not it is a “joke”, frankly, I am quite happy with the difference between the two scales. I can tell in my own house when the temperature has risen or fallen a single degree Farenheit, which means that it’s obviously of some use to know the difference between 71 and 72 degrees.
[/QUOTE]
OK, so you have finely tuned temperature sense. You could then sense a shift of half a degree Celsius. That doesn’t change the fact that human body temperature varies more than a degree within a single body, & ambient temperature varies even more widely than that within a room, & even more from one side of a street to another. Your thermometer is showing a precise temperature where it is, which has a deviation of a couple of degrees from where you are. It’s interesting detail, but it’s sort of excessive.
And I like Fahrenheit, with its arbitrariness & non-decimal significant points, & sort of feel the “100° = body temperature” has a weird animal elegance that basing a scale on the boiling temperature of water lacks. But I know this is mere cultural prejudice, & I think people protest too much on its behalf.