A lot of the areas of study in the field of physics relate to cause and effect. As we learned in previous lessons, for any form of movement or state change, such as heating, melting, evaporating, or changing shape, a transfer or conversion of energy must occur.

The law of conservation of energy states that energy cannot be destroyed or created, which means that if you knock on a hard surface or push something over, some of the chemical energy from your body is used up. When it comes to hauntings, it is harder to establish where the required energy comes from.

In the case of poltergeist activity, if something is pushed, thrown, or broken and the energy to perform this work isn't coming from somewhere else, then the energy has been created, which is a violation of the law of conservation of energy.

Another form of energy transfer we've discussed is when...