Group: sci.physics.particle
From: Helmut Wabnig
Date: Thursday, November 29, 2007 7:52 AM
Subject: Re: Why do crystals always have straight edges?

On Thu, 29 Nov 2007 13:35:40 GMT, "Androcles"
wrote:

>
>"Y.Porat" wrote in message
>news:91b89c64-863b-4a8e-b347-b0eab8c4f49d@e25g2000prg.googlegroups.com...
>: On Nov 28, 6:48 pm, "Androcles" wrote:
>: > "hanson" wrote in message
>: >
>: > news:AIg3j.31237$dh.31139@trnddc05...: "Androcles"
> wrote in message
>: >
>: > :news:vm23j.4020$EU1.2501@fe1.news.blueyonder.co.uk...
>: > : >
>: > : > : "Sam Wormley" wrote in message
>: > : > :news:ym%2j.200989$Xa3.64733@attbi_s22...
>: > : > : >
>: > : > : [Albert wrote]:
>: > : > : Why do crystals always have straight edges? I'm only in Year 8
>: > : > : Australia studying particles.
>: > : > : >
>: > : > : [Uncle rect-Al Schwartz]
>: > : > : All periodic crystals reduce to a tiny single unit cell that is
>: > : > : gaplessly stacked in 3-D to make the bulk. There are 230 periodic
>: > : > : crystallographic space groups. Each and every one has a
>: > : > : parallelepiped unit cell with sides a,b,c and angles
>alpha,beta,gamma.
>: > : > : When you gaplessly self-simlarly stack parallelepipeds you
>invariably
>: > : > : get straight edges.
>: > : > : >
>: > : > : [Sam]
>: > : > : I've seen single crystal turbine blades... all edges curved.
>: > : > :http://images.google.com/images?q=single+crystal+turbine+blade
>: > : > : >
>: > : > : [hanson]
>: > : > : ... ahahahaha... AHAHAHAHA.... well, so much for theory again
>: > : > : and rect-Al-ly buzz-wording about it with absolute certainty and
>: > : > : "gapless parallelepipeds" ... especially when "empirical"
>: > : > : observation shows the opposite.
>: > : > :
>: > : [Andro]
>: > : > Unfortunately it comes down to picking nits. A worn
>: > : > tyre is round but a new tyre isn't, it is covered with sprews.
>: > : > Likewise the single crystal turbine blade has planar facets,
>: > : > however small they may be, right down to the atomic level.
>: > : > Any two points define a straight line, any three points define
>: > : > a plane. The intersection of two planes is an edge.
>: > : > I doubt it is worth debating whether an atom is a point,
>: > : > sphere, cube or polyhedron.
>: > : > What is important to the young teenager is that crystals are
>: > : > indeed faceted.
>: > : > As much as I detest the idiotic bastard, I have to be fair.
>: > : > ---------------------------------
>: > : > Schwartzshit 1 - Worms 0
>: > : > ---------------------------------
>: > : > Even a blind squirrel finds a nut sometimes.
>: > : >
>: > : [hanson]
>: > : ahahaha... That is too much!... ahahaha... you must admit
>: > : that a tyre, even if it's a US tire, is a rather larger nit you have
>: > : picked for coming to uncle rect-Al's rescue because, a case
>: > : can be made that Sam produced illustrated precedences for
>: > : his claim. OTOH there are no references for single-crystal
>: > : tires or tyres... However, Schartzshit will adore you in undying
>: > : fartitude for you fair and valiant rescue attempt and he may
>: > : refrain from calling you clitter/cluttering names of unintended
>: > : glory from now on ... Thanks for the laughs, guys!... ahahanson
>: > :
>: > Schwartzshit or Wormsy... neither one is logical, I can afford
>: > to be impartial on that one. Wormsy is right that a turbine blade
>: > is a single crystal of unalloyed titanium, but that means a lattice!
>: > Your greatest admirer and "Totally queer arse humper"
>: > trave...@noasskissers.net knows all about lattices when he stated
>: > his heartfelt desire and declared his homosexuality
>innews:3r4ki3539l40nrg6f1b0v2kec49jpng7tl@4ax.com...
>: > : ahahaha... Bend over, Wabi. I'll show you some coordinates. ahahaha...
>: > : AHAHAHA... ahahaha..."
>:
>: ------------------
>: Mr Andricless
>: one you dont know - say i dont know:
>:
>: crystals do not have 'faces'!!
>
>I said "facets." Your English needs a major overhaul.
>
Which Porat will read as "faucets"
ahhahahahha, have fun,
w.