Contrary to the author's belief, grocery store doors do not open when you step on a mat. They open due to change in incident light on a photoelectric effect sen

Contrary to the author's belief, grocery store doors do not open when you step on a mat. They open due to change in incident light on a photoelectric effect sensor above the door. It makes me so happy to think the Nobel committee, which was dominated by experimentalists, when considering Einstein's contributions to science, could only bring themselves to award him the prize for grocery store door openers.