On Thursday, October 31, 2013 12:38:48 AM UTC-4, Ed Pawlowski wrote:
> On Wed, 30 Oct 2013 21:16:42 -0700 (PDT), Helpful person
> >On Wednesday, October 30, 2013 3:38:36 PM UTC-4, Brooklyn1 wrote:
>
> >> Flatness doesn't matter for even heating with a gas stove. Most
> >> quality cookware is designed with a slightly concave bottom that will
> >> become flat when metal expands as it's heated.
>
> >Why will it flatten when heated?
>
> Metal expands when heated. It will sort of push the sides out and
> flatten. Some pans are designed that way to allow for the expansion.
> A metallurgist can explain it better.

Rubbish.

http://www.richardfisher.com