Got it: Bunching! To review, you can sometimes cut a tough slice of meat (say) with a dull spoon rubbing it against the side of a glass bowl. Bizarrely, it feels almost like the bowl is cutting the meat. Cutting requires very high pressure = force/area. A sharp knife works because this area is very small. Replace the knife by a dull spoon, and you would seem to be wasting your time. But, as you saw back and forth, the normally inadequate pressure along the bottom of the cut is boosted by a bunching effect toward the leading edge of the spoon, which is *not* sliding like a knife blade in the bottom of the cut! The high cutting pressure is due to bunching (created by friction) over a very short interval. —Bill On Wed, Aug 16, 2017 at 10:29 AM Bill Gosper <billgosper@gmail.com> wrote:
(The horse is still twitching.) Easy proof this phenomenon has everything to do with the hardness of the bowl: Try cutting instead against the inside of a paper (technically cardboard) Chinese takeout box. It's practically impossible. --rwg
On Thu, Apr 27, 2017 at 2:26 AM, Bill Gosper <billgosper@gmail.com> wrote:
On Sun, Jan 15, 2017 at 4:57 PM, Bill Gosper <billgosper@gmail.com> wrote:
while sliding back an forth against the inside of a slippery bowl? --rwg
No one took this question seriously, but I claim the phenomenon needs explaining. It definitely requires some friction with the bowl: Just now I had it work improbably well on a piece of meat, yet fail on a tenderer but slipperier partially stewed tomato in the same bowl. --rwg
[Chop]