Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!adm!husc6!m2c!umvlsi!pswanson
From: pswanson@umvlsi.ECS.UMASS.EDU (Paul Swanson)
Newsgroups: comp.sys.amiga
Subject: Re: Seagate (let's not get out of hand)
Summary: Chemistry (or is it physics?) police
Message-ID: <350@umvlsi.ECS.UMASS.EDU>
Date: 28 Jul 89 03:21:55 GMT
References: <417@mindlink.UUCP>
Reply-To: pswanson@umvlsi.ecs.umass.edu.ECS.UMASS.EDU (Paul Swanson)
Organization: University of Massachusetts, Amherst
Lines: 44

The "common sense" of several people involved in this thread (including
one who claimed to be a chemist) is making me cringe.  I am posting
this response to hopefully enlighten, or at least give plausible
explanations for "this molecular stuff".

In article <417@mindlink.UUCP> a309@mindlink.UUCP (George Lin) writes:
>> thad writes:
>> 
>> (Stuff from Thad deleted)

>You are joking right?  I didn't think anyone could think about spreading
>anything 5 molecules thick with a linin cloth.

You are right but you are wrong.  A linen cloth by itself cannot spread
things on a molecular scale but it doesn't need to.  All that is
necessary is for the cloth to put down the required amount of material.
Surface tension forces should take care of spreading it out on a
molecular scale.

>IF (a big IF) Caig Labs suggests application of a lubricant with a linin cloth
>(and not to mention 1 swipe of this linin cloth) don't try measuring thickness
>with molecules unless you're using DNA chains.

Actually I am willing to bet that the lubricant molecules are quite
large although not as large as DNA molecules.  However, the calculation
of the layers of molucules was probably done macroscopically.  Take the
total number of molecules put down on the surface.  Determine the "size"
of a single molecule (i.e. call it a sphere and guess its radius).
Determine how many molucules it will take to make a single layer.
Divide the total number of molucules by the number of molecules per
layer and call it the molecular thickness.

Of course this calculation is garbage since the disk platter is nowhere
near smooth on a molecular level.  The surface is no doubt very much
like a mountain range and the lubricant will tend to fill in the valleys
but this is beyond the scope of this news group.

>(more stuff deleted)

In a previous article someone said they didn't see how 6 layers of
molecules could stick two surfaces together.  Well if 6 layers can't do
it then what can?  The Bonding at the interface of two materials is the
only thing that determines how well they will stick together not the
thickness of them.