Sherlock Holmes and Dr Watson are going camping. They pitch their tent under the stars and go to sleep. In the middle of the night Holmes wakes Watson up: "Watson, look up at the stars, and tell me what you deduce."
Watson: "I see millions of stars and even if a few of those have planets, it's quite likely there are some planets like Earth, and if there are a few planets like Earth out there, there might also be life."
Holmes: "Watson, you idiot, somebody's stolen our tent!"
How can I check if there is electricity in a power socket without a tester or other specialized tools?
Note: The method should not involve the destruction the socket or my whole power supply!
