Berkeley CSUA MOTD:Entry 44091
Berkeley CSUA MOTD
 
WIKI | FAQ | Tech FAQ
http://csua.com/feed/
2025/07/09 [General] UID:1000 Activity:popular
7/9     

2006/8/22-24 [Uncategorized] UID:44091 Activity:nil
8/21    What exactly does "degree" mean in measurement?  For example,
        temperature can be expressed in "degree Celcius" or "degree
        Fahrenheit", but "kelvin" instead of "degree kelvin".  Angles can be
        expressed in "degrees" or in unit-less radian.  Is it arbitrary for
        the inventor of the unit whether or not the unit will carry the word
        "degree"?
        \_ as for why it's used for temperature:
           http://en.wikipedia.org/wiki/Farenheit
        \_ yes... to a certain degree
           \_ :-)
        \_ Because temperatures are relative to something except for Kelvin
           which uses an absolute scale.
Cache (3384 bytes)
en.wikipedia.org/wiki/Farenheit
fever when he conducted his experiments or that his thermometer was inaccurate), and divided his original scale into twelve divisions; later dividing each of these into 8 equal subdivisions produced a scale of 96 degrees. salt melts (some say he took that fixed mixture of ice and salt that produced the lowest temperature); and ninety-six degrees as the temperature of blood (he initially used horse blood to calibrate his scale). Initially, his scale only contained 12 equal subdivisions, but later he subdivided each division into 8 equal degrees ending up with 96. Rmer's scale, at which water freezes at 75 degrees, and multiplied each value by 4 in order to eliminate the fractions and increase the granularity of the scale (giving 30 and 240 degrees). He then re-calibrated his scale between the freezing point of water and normal human body temperature (which he took to be 96 degrees); the freezing point of water was adjusted to 32 degrees so that 64 intervals would separate the two, allowing him to mark degree lines on his instruments by simply bisecting the interval six times (since 64 is 2 to the sixth power). by his original scale, the actual freezing and boiling points would have been noticeably different from 32 F and 212 F Some time after his death, it was decided to recalibrate the scale with 32 F and 212 F as the exact freezing and boiling points of plain water. That change was made to easily convert from Celsius to Fahrenheit and vice versa, with a simple formula. degree' as well is said to have been derived from the degrees of masonry. This may well be coincidence, but there is no conclusive evidence to the contrary, so the thought persists. A fifth version maintains that Fahrenheit based 0 degrees on an estimate of the temperature someone would freeze to death, and 100 degrees on the temperature someone would die of heat exhaustion from, therefore making 0 to 100 the livable range for human beings. A sixth version maintains that Fahrenheit marked the freezing point of water, normal human body temperature, and the boiling point of water. He then divided the span from freezing to boiling into 180 degrees. Setting the normal human body temperature as 100 resulted in the FP and BP being 32 and 212, respectively. edit Usage The Fahrenheit scale was the primary temperature standard for climatic, industrial and medical purposes in most English-speaking countries until the 1960s. Fahrenheit supporters claim its previous popularity was due to Fahrenheit's user-friendliness. The unit of measure, being only 5/9 the size of the Celsius degree, permits more precise communication of measurements without resorting to fractional degrees. Also, the ambient air temperature in most inhabited regions of the world tends not to go far beyond the range of 0 F to 100 F: therefore, the Fahrenheit scale would reflect the perceived ambient temperatures, following 10-degree bands that emerge in the Fahrenheit system: * 10s Deep Frost. However, such a correlation is largely the result of habit: in the same way, Celsius supporters might indicate that 0-10 C indicates cold, 10-20 C mild, 20-30 C warm and 30-40 C hot. Fahrenheit is sometimes used by older generations however for measurement of higher temperatures while lower temperatures are always measured in degrees Celsius. Most other countries have adopted Celsius as the primary scale in use.