1. The Best Way to Solve cookie puzzles
Chenhui Shao
Assistant Professor
Department of Mechanical Science and Engineering
University of Illinois at Urbana-Champaign
November 16, 2017

2. Cookie Puzzle
You have a cookie, but you cannot enjoy it unless you solve a puzzle.
The cookie is placed inside a bowl.
The bowl is covered by a piece of grid paper.
Each time, you are allowed to “observe” one grid using the stick.
Something or nothing
Repeat this process until you are confident about what cookie is in the bowl.

3. Cookie Puzzle Materials: 1 bowl, 1 cookie, 1 stick
Outcome: a correct guess about the cookie shape
Winner: a correct guess AND the minimum number of trials

4. An Example
How to find the cookie shape correctly and quickly?

5. It Matters More Than Just Cookies…
1.4 mm
Knurl
Optical progression
Geometry evolution
Tool surface degradation of ultrasonic metal welding