From Wechsler@world.std.com  Mon Dec 19 09:59:54 1994
Return-Path: <Wechsler@world.std.com>
Received: from europe.std.com by life.ai.mit.edu (4.1/AI-4.10) for /com/archive/cube-lovers id AA17311; Mon, 19 Dec 94 09:59:54 EST
Received: from world.std.com by europe.std.com (8.6.8.1/Spike-8-1.0)
	id JAA02475; Mon, 19 Dec 1994 09:59:52 -0500
Received: by world.std.com (5.65c/Spike-2.0)
	id AA05068; Mon, 19 Dec 1994 10:00:04 -0500
Date: Mon, 19 Dec 1994 10:00:04 -0500
From: Wechsler@world.std.com (Allan C Wechsler)
Message-Id: <199412191500.AA05068@world.std.com>
To: mouse@collatz.mcrcim.mcgill.edu
Cc: cube-lovers@ai.mit.edu
In-Reply-To: der Mouse's message of Sun, 18 Dec 1994 15:56:10 -0500 <199412182056.PAA13839@Collatz.McRCIM.McGill.EDU>
Subject:  How Big is Big?

   Date: Sun, 18 Dec 1994 15:56:10 -0500
   From: der Mouse <mouse@collatz.mcrcim.mcgill.edu>

   > [Physicists] are planning soon to start sending petabytes (10^15)
   > over the Internet.  10^15 is getting interesting close to the size of
   > Rubik's cube (never mind that I thought that the proper term for
   > 10^15 bytes was terabytes.)

   I thought it was

	   kilo	10^3
	   mega	10^6
	   giga	10^9
	   tera	10^12
	   peta	10^15
	   exa	10^18

[...]

   Also note that the Cube database storage size requires the highest
   prefix we have.  Time to get SI to think up some more, I guess :-)

(Warning to Cube-Lovers: this is off the topic, but it's a digression
I can never resist.  Alan is going to come over to my house and soap
my windows for this, I just know it.)

They _have_ thought up some more -- this was in Science News about 18
months ago.  But the ones they thought up are absolutely awful, and I
want to take this opportunity to advertise my own suggestions.

First note the following relationships, which I believe are entirely
the result of coincidence:

te(t)ra     1000^4	
pe(n)ta     1000^5
(h)exa      1000^6

In each case, the prefix for 1000^n looks like the neo-greek prefix
for n, with the second-to-last consonant deleted.  I merely propose
that we continue this scheme:

he(p)ta     1000^7
o(c)to      1000^8
(en)nea     1000^9

I admit to a fudge with n=9, but I like neabytes better than
eneabytes, and the prefix E was already taken by n=6.  I wanted to
keep up the unique sequence of prefixes: K, M, G, T, P, E, H, O, N.

For those who care, megameters are good for measuring small planets,
gigameters for big planets and stars, and terameters for solar
systems.  A petameter is about a tenth of a light year, and so it's
good for measuring near interstellar distances; exameters are good for
the 100-ly range, galaxies should be measured with hetameters, and
intergalactic distances with otometers.  Current theory says the
universe is considerably smaller than one neameter.