Question: Why do I get static shocks when I touch the door knob?
Answer: Static charges build up on shoes when you walk.
Most modern shoes have highly insulating rubber or plastic soles. As you walk, static charges can build up on the soles of the shoes. This is especially true if the floor is also insulating. Some older nylon carpets are particularly good at generating static electricity. The charge on the shoes soles induces static electrical charge on your body, and when you touch something conductive, such as metal, the static will discharge and cause a the shock. If you are indoors, the point can be proved by walking around for a while with no shoes on – you will probably not experience shock.
Every Thursday, Transforming Technologies will answer questions concerning all things ESD: static causes, threats,  ESD prevention, best practices and all things static in a feature we call ESD Q&A.  If you have ESD questions that you would like to be answered, email info@transforming-technologies.com  with Q&A in the subject line.