Billions

[Guy Steele <cbmvax!uunet!THINK.COM!cuvmb.cc.columbia.edu!gls>]

   Date:         Tue, 11 Feb 1992 09:17:37 GMT
   From: CJ FINE <C.J.Fine%BRADFORD.AC.UK@cuvmb.cc.columbia.edu>
   X-To:         lojbab@GREBYN.com
                                                                ... (I
   happen to think that anything outside Mego- to micro- is a worthless
   accretion to the metric system, but that is another matter).


I assure you that those who are buying memory chips and disk drives
for their computers are very interested in nanoseconds and gigabytes.
Terabytes and teraflops have become common terms of discussion over
the last few years as it becomes apparent that their implementation
will soon be a reality (indeed, terabyte tape backup was available
well over ten years ago).  Laser impulses for fiber optics are best
measured in picoseconds, if not femtoseconds, and we are already
beginning to think about petabyte computer memories.  Maybe the man
on the street doesn't use the more extreme prefixes every day, but
there are thousands of people who do.

The mass of the known universe is approximately 10^80 times the mass
of an electron.  It seems relatively safe to say, then, that 26
prefixes ought to suffice for nearly any conceivable purpose relating
to physical measurement (81/3 = 27, and the one in the middle needs
no prefix)!  We already have

atto  femto  pico  nano  micro  milli / kilo  mega  giga  tera  peta  exa

and these twelve constitute about half of what we might potentially ever
need in the future, which is not bad coverage--for now.

--Guy Steele