I recently saw an unanswered "user question" in an old copy of the New Scientist which was supposed to be answered in the next edition. Unfortunately I don't have access to the next edition of the NS so I hope someone on this forum could answer it.
A fridge magnet needs to overcome the force of gravity to stay where it is. It does this with magnetism (obviously). Here is the question: the fridge magnet needs to use energy to overcome the force of gravity. Does this therefore mean that the magnet will eventually run out of magnetic energy because it's used it all up? If the fridge magnet can stay on the fridge indefinitely, then it seems to have an indefinite supply of energy it can use just to maintain its position. Right?