Question

what is the Physics principles or laws of candle swing experiment?

Answer 1

The candle is acting like a seesaw. When melted wax drips off one end, that end becomes lighter, so it rises up. The end that’s lower now will drip wax off until it’s lighter, so it’ll rise up pushing the first end down. Once it starts rocking it will keep on going until you blow it out.

Answer 2

you can see the experiment here: http://www.youtube.com/watch?v=4u7OwGkWqrk