online: 9 april 2010 modified: 9 april 2010 9 april 2010 units of measurement
in physics and biology
prefixes:
M = mega = 106
K = kilo = 103
d = deci = 10-1
c = centi = 10-2
m = milli = 10-3
μ = micro = 10-6
n = nano = 10-9
suffixes:
°C = degrees Celsius
(0°C = 273°K)
J = Joule
m = metre
s = second
h = hour
g = gram
mole = 6.023 x 1023 particles
(ions, atoms, molecules)
dm/3 = 1,000 cm/3 or 1 litre (l)
ha = 104m2
ppm = parts per million
yr = year
BP = before present
Ig = immunoglobulin
spp = species (plural)
atm = atmosphere
N = Newton
bar = 103Nm-2
as i slowly copy this out from The Penguin Dictionary of Biology* i am thinking how beautiful are these units for 'exact measurement' (itself an ugly or ridiculous process, in that it involves reduction of the unknowable whole of things to knowable or laughable or even tragic fragmentation... but useful!)... yes, the units themselves, and the careful thoughts that they embody, are indeed beautiful, as beautiful as a painting, a piece of music, a poem can seem (at least for a time)... and units of measurement may thmselves last 'forever'... though scientific enquiry (or perhaps only philosophical thinking?) can show that concepts like 'forever' or 'beautiful' or 'exact' are imaginary or even invalid... but the term 'imaginary' may itself be imaginary... as 'invalid' may be invalid!
...i am reminded of how beautiful are the new uses that Mario Merz** made of the Fibonacci series when he scaled and decorated his glass domes and other constructions according to these magical numbers 1, 1, 2, 3, 5, 8, 13, 21 (each being the sum of the two numbers before it) that can also be discerned in the proportions of sea shells, leaves, petals, bones and other phenomna of natural or logarithmic growth (and also in 'compound interest')... and they may seem to be evident too in the proportions of classical or neo-classical architecture... though perhaps the 'golden section' (as it is called) is a self-conscious addition to the facades of (but may not be evident in the backs of) such buildings...
bio logy :
the study or measurement of living things : the basis of our present way of living : but itself close to being an illusiion? : and these exact units, they are all approximations... but they suffice to inform and guide our actions... thinking for instance of the moon landing... accurate within a few metres though controlled from a moving control centre at a distance of up to 400,000,000 :
*The Penguin Dictionary of Biology, compliled by M Thain and M Hickman, with diagrams by Raymond Turvey, 11th edition of a work originally compiled by M Abercrombie, C J Hickman, and M L Johnson and published in 1951, Penguin Books, London 2004.
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