Elon Musk cites first principle thinking in physics as a key to identifying neglected market opportunities. Can someone give me an example of how it may work in that application?

Recently moridinamael wrote about diswashers: As a pampered modern person, the worst part of my life is washing dishes. (Or, rinsing dishes and loading the dish washer.) How long before I can buy a robot to automate this for me?

If you reason from first principles then there's nothing stopping a device in which you input a pile of disher and that afterwards sorts them into the cupboard from existing. Especially with the recent advances in machine vision and google opensourcing Tensor flow.

Another nonautomated kitchen task is cutting vegetables. There no good reason why a robot shouldn't cut vegetables as well as humans.