Dr Paul Thomas once bubbled...
Thanks Rick,
No one ever explained that to me. It certainly makes for easier calculations. The nearest I got to being an artilleryman was my Sergeant Major's offer of letting me take a mortar base plate on a battalion jump. I reluctantly declined the offer of 45 lbs (or was it 45 kgs?) of additional weight!!!
Pi x 2000 = 6,284 mils in a full circle. 90 degrees = 1,571 mils. ( I much prefer degrees and minutes of arc for navigation!)
I am not sure decimals are due to us having ten fingers, I think it is more to do with moving decimal points and the mathematical powers of the magical number "10".
Is this thread about The Metric system or a metric system? I concur with mdonaldson. The Metric system is based on the Metre as the unit oflength and all other measures of length follow from it; in divisions of ten, 100 or 1,000 with appropriate prefixes. Because the area of an object is determined by the squared power of its linear dimensions, and volume by the cube power of its linear dimensions the prefixes are not interchangeable from length to area to volume.
In the scientific world units are normally restricted to the power of 10^+-3 (that is one thousand units or a thousandth of a unit.) It is far easier to understand and to work with 2.5 millimetres than 0.0025, 2.5 x10^-3 or 2.5/1000 of a metre, which are all the same length!
As for microscopy, I do not know if there is a term for a millionth of a Metre (1x10^-6) but if I remember correctly one Micron is 1x10^-9, while an Angstrom is a tenth of a Micron; 1 x 10 ^-10 Metres.
For the same reason (simplicity in the use of those particular units alone) we tend to use the same prefixes for volume, at least. A decilitre is 1/10 of a litre and a millilitre is 1/1000 of a litre. Blood cell volumes are measuerd in fentilitres.
A decimeter (pronounced "desimeter") is a tenth of a metre and a decameter (dekametre) would be 10 metres. A centimetre is 1/100 of a metre (and 100 meters would I suspect be a centametre but this a term that I have never used.) A millimetre is 1/1000 of a metre and 1000 meters is a mil . . .
a kilometre!!!!
A kilogram is 1,000 grams. A litre is 1,000 mls so if one ml. weighs 1 gram a litre weighs a kilogram.
What about bytes, kilobytes, megabites and gigabites? There are 1,028 bytes in a kilobyte becuse this is a binary, not a decimal system.
All of which proves you should only use the system with which you are familiar or you WILL make mistakes
You have a mistake so here is a table for you
otta [Y] 1 000 000 000 000 000 000 000 000 = 10^24
zetta [Z] 1 000 000 000 000 000 000 000 = 10^21
exa [E] 1 000 000 000 000 000 000 = 10^18
peta [P] 1 000 000 000 000 000 = 10^15
tera [T] 1 000 000 000 000 = 10^12
giga [G] 1 000 000 000 (a thousand millions = a billion)
mega [M] 1 000 000 (a million)
kilo [k] 1 000 (a thousand)
hecto [h] 100 (a hundred)
deca [da]10 (ten)
1
deci [d] 0.1 (a tenth)
centi [c] 0.01 (a hundredth)
milli [m] 0.001 (a thousandth)
micro [µ] 0.000 001 (a millionth)
nano [n] 0.000 000 001 (a thousand millionth)
pico [p] 0.000 000 000 001 = 10^-12
femto [f] 0.000 000 000 000 001 = 10^-15
atto [a] 0.000 000 000 000 000 001 = 10^-18
zepto [z] 0.000 000 000 000 000 000 001 = 10^-21
yocto [y] 0.000 000 000 000 000 000 000 001 = 10^-24