97
votes
19answers
12k views

Which way should be “on” for a switch?

Most of us use switches every day in various forms. And although there are sometimes general norms in countries as to which direction is "on", there is variation between countries. So when ...
13
votes
3answers
929 views

What is the reason for Concave round buttons in Elevators

What is the reason many elevators have concave shaped buttons. Like this: Any special reason behind this?
20
votes
6answers
5k views

Why does the Redbox machine have barriers around the credit card swipe reader?

Perhaps you've seen one of these before. A couple of inches above and below the magnetic stripe reader are protrusions that allow just enough room to swipe a credit card. The barriers are a ...