There's also the units command: http://www.gnu.org/software/units/units.html
This file is actually /usr/share/misc/units.dat from units.
Exhaustive, commented, list of units
31–36 of 36 posts
Re: Exhaustive, commented, list of units
#32Earlier quoted context omitted.
Also, it's really hard to resist the temptation to "rant back" on the kilogram question. Unfortunately / fortunately, HN comments are not the right place for that. (Basically, kg is the perfect unit of mass and if you disagree you are a heathen and should be burned)
His complaint is that if kg is the perfect unit of mass then make what we call the kg be the base unit and call that a gram instead. Makes perfect sense to me. Of course this is an imperfect world. In a perfect world I'd like a meter chosen so that gravity is, to a good approximation, 1 m/s at sea level, and I'd like all of the units to be in base 12. (Easy divisibility by 3 is often very useful.) Including time, so…
I want my number system to be in base 11 or some other prime number. You see: The vast majority of numbers are never going to evenly divide our base, no matter what base we choose. So we might as well go for a solution that minimizes the special cases.
Re: Exhaustive, commented, list of units
#33Earlier quoted context omitted.
There's also a comment in Kelvin regarding how the triple point of water is defined to be at 0.01 °C, not 0 °C, that reads a little confused. I wonder why it's defined like that, anyway. The bit is used for information because information is almost defined as the expected length of an optimally (context-free) coded word, using a base 2 code. Some physicists prefer base e , in which case it's measured in nat s.
the triple point of water is defined as 0.01 °C in order for a difference of 1 °C to be equal to a difference of 1 K. To put it another way, the triple point of water is known to be 273.16 K, and the boiling point 373.15 K. Now if this mapped on to 0 °C and 100 °C, then we'd be left with a situation where 100 kelvins would be equivalent to 100.01 Celsius degrees. Instead, by defining the triple point of water as 0.01…
By the way, they should re-rig the definition of the Kelvin, to make Boltzmann 1. (The Planck units already do this.)
We would probably need either very tiny or very large multiplies of this new Kelvin for anything practical, though. (Depending on your choice for the other units. The The Planck unit of temperature is way too big for practical uses for example.)
Re: Exhaustive, commented, list of units
#34Tangentially related, large named numbers in Japanese:
http://en.wikipedia.org/wiki/Japanese_numerals#Large_numbers
無量大数=muryōtaisū=10^88.
Re: Exhaustive, commented, list of units
#35Earlier quoted context omitted.
His complaint is that if kg is the perfect unit of mass then make what we call the kg be the base unit and call that a gram instead. Makes perfect sense to me. Of course this is an imperfect world. In a perfect world I'd like a meter chosen so that gravity is, to a good approximation, 1 m/s at sea level, and I'd like all of the units to be in base 12. (Easy divisibility by 3 is often very useful.) Including time, so…
I want my number system to be in base 11 or some other prime number. You see: The vast majority of numbers are never going to evenly divide our base, no matter what base we choose. So we might as well go for a solution that minimizes the special cases.
The vast majority of the time that people wish to divide something evenly, they want to divide it by a small number.
Re: Exhaustive, commented, list of units
#36Earlier quoted context omitted.
I want my number system to be in base 11 or some other prime number. You see: The vast majority of numbers are never going to evenly divide our base, no matter what base we choose. So we might as well go for a solution that minimizes the special cases.
The vast majority of the time that people wish to divide something evenly, they want to divide it by a small number.
Yes. I just wanted to give the standard mathematician's tongue-in-cheek reply to proposals like base 12.
To be earnest, octal is quite a nice base. Or -2 (minus two!). Or 10, but with digits from -5 to +5, though that representation should be redundant, I guess.
To speak of redundant representations: Fibonacci numbering is also interesting (http://en.wikipedia.org/wiki/Fibonacci_coding). Or skew binary numbers.