"Our magic interfers with magnatism and electro-magnetic waves so anything electronic either doesn't work or works poorly. However, there are wizards who have managed to create enchanted cars. And the Hogwarts Express is an enchanted train." Hermione explains.

"There is also a reason to the magic. You just need someone to explain it to you." And Hermione is a good candidate, since she has the right scientific mind.

"Of course. Arthimancy is my favorite subject. It is based on the magic of math." Hermione waves her wand over her beaded bag, and several Arthimancy runes float into the air. "By using extended calculations and equations... I can use these runes to predict the outcome of a certain situation."