Digital BW, The Print

Perhaps in the interest of brevity, I sacrificed clarity.  Of course the
basic physics or chemistry doesn’t change, but the *relevant* physics or
chemistry may.  Your example of the marble is a good illustration.  In its
intact state, the marble sinks through the fluid, governed by gravity and
viscous forces, with some surface-force contributions, to its behavior.
Once ground into particles, the same principles apply, but at sufficiently
small size, surface forces may dominate even to the point of relegating
direct gravity to second or third order.

More fun: suppose the “marble” is an aluminum sphere cleaned (say, by
bombardment in a near perfect vacuum system) so that the surface is
uncontaminated Al only (actually, not realizable.)  Now grind the particles
down to a couple of nanometers in diameter.  Still have Al.  But if this Al
dust is expose to air, the Al particles will immediately adsorb oxygen and,
by diffusion, the Al particles will convert to Al2O3 in a very short time.
Different chemistry this time.

Sorry for drifting so far OT.

Harry




On 8/21/07 10:52 AM, "Editor, P.O.V. Image Service" <editor@...>
wrote:

>  
>  
>  
> 
> It would make a particular particle apparently more reactive. It doesn't
> change the basic physic or chemistry.
> 
> On a physical level, if you have a bunch of marbles and throw them onto
> a lake surface, they sink. Grind them up fine enough and they float.
> Have the rules of physics, in this case the relationship between
> floating and displacement, changed? No. But the size has made them sit
> on the surface as the result of surface tension. Stir the lake and
> they'll sink.
> 
> What worries me overall is that the digital printing lists are becoming
> more and more like fora for marketing battles. They're also becoming
> realms where photographers/printers seem all too obsessed/preoccupied
> with developing terminology that obfuscates basic truths.
> 
> Any good photographer knows that there are really no "secret"
> techniques. If you see something, it can be replicated. The same applies
> to chemistry and physics here.  This language of  secret
> techniques/chemistry is the kind of hype that  once surrounded the term
> "giclee."  It's great for short-term marketing, but doesn't hold water
> in the end.
> 
> Harry Lockwood wrote:
>> > Well, I don¹t have the credentials to contribute much here, but I do have a
>> > question.
>> >
>> > Given that carbon is not non-reactive, grinding it to a superfine level
>> > enormously increases the surface to volume ratio and may, therefore make it
>> > much more physically (not chemically) reactive, no?
>> >
>> >   
> 
> Keith Krebs
> _._,___


-- 

Harry F. Lockwood




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