"I hope everyone had a lovely time with their parents this weekend, and is fully recovered from the trauma and ready to get back to work," Jean-Paul said. "My sister has apparently moved to San Francisco, where one of her will no doubt be deeply traumatized, so she could not be here." He sounded thrilled about this.
"Today, we begin talking about mass. The
law of conservation of mass states that mass can be neither created or destroyed; it must come from somewhere. There is a set amount of mass in the universe, and it just gets...shifted around, if you will. When you gain weight, it does not happen for no good reason, and likewise you cannot gain
more than the weight of the food you have eaten." Jean-Paul paused, then said, "And as you might expect, there are superhumans who blow this law of physics right out of the water. Some shapeshifters have a static mass they merely shift around, it is true. But others do not.
Raven Darkholme, also known as Mystique, is a shapeshifter from my home universe." Jean-Paul had been careful to get a picture of her where she was wearing clothes. "She has a history of terrorism, and has used her ability to assume the identity of a number of public figures, including those who outweigh or underweigh her default form by several kilograms. She is, however, restricted to a human baseline form; she cannot become, say, the size of a housecat. Some can. A
former coworker of mine could assume an alternate form much larger than he is normally.
"So. When a person shrink or grows, where does the additional mass go or come from? Pocket dimensions? An exchange across realities? Something about
tiny strings? What are some reasons a person might have this ability? Discuss."