Re: mass extinctions and DDT

[Graydon <graydon@dsl.ca>]

On Sun, Dec 30, 2001 at 11:34:25AM -0800, Rob Gay scripsit:
> >it's regarded as most parsimonious to consider the variations in glass
> >thickness as a function of the available manufacturing techniques, which
> >could not produce glass of consistent thickness, rather than in-situ changes
> >due to behaviour under gravitational stress over time.
> Blerg! My geology texts have lied to me then! Why was this information in
> there, then, if its known that counterexamples exist?

It's one of those ideas that got a good running start before anyone
checked it; the folks who did the original measurements found
statistically significant variation, all right, but they didn't check
enough windows and they didn't question what shape the glass had when it
started.  (Probably through not knowing what the manufacturing technique
was; a lot of that has been found out by quite recent experimental
archeology.)

So, basically, very successful scientific urban legend.

-- 
graydon@dsl.ca   |  Hige sceal þe heardra, heorte þe cenre,
                 |  mod sceal þe mare þe ure maegen lytlað.
                 |   -- Beorhtwold, "The Battle of Maldon"