1. Some humans would do anything to see if it was possible to do it.
If you put a large switch in some cave somewhere, with a sign on it saying 'End-of-the-World Switch. PLEASE DO NOT TOUCH', the paint wouldn't even have time to dry.
2. The best way to handle a know it all is to take a curious subordinate role.
interact by asking “how” or “What” questions.
tap into their knowledge. it feeds the ego of the know it all, And potentially it allows them to change their position or point of view as they are explaining something to you.
avoid the “why“ questions as they may be perceived as a challenge.
remember to thank a know it all for their contribution.