- #1
Incredible_bulk
- 6
- 0
Hi all,
I read the FAQ so please take into account that this is NOT a perpetual motion (free energy or whatever) question but a theorical case that puzzles me.
I read that magnetic fields have an infinite (but decreasing) range. What bothers me is this :
let's put a magnet and a iron far way from each other (in space far from any influence, for the sake of the reasoning let's say no gravity nor other magnetic fields). Then the iron should be attracted by the magnet no matter how far they are (even if it takes a very long time to attract each other).
If I demagnitize the magnet after the iron has been accelerated towards the magnet, then we get an object with cinetic energy ? If we let the iron ball pass the magnet and magnetize the magnet again, then the ball and the magnet will attract each otehr again.
My problem here is : the energy necessary to (de/re)magnetize the magnet is not proportional to the distance between the iron and the magnet. Meaning, if we wait a very long time in order to have the iron very far from the magnet, then we'll get a bigger cinetic energy once we magnetize the magnet again.
Of course, this process would take a very long time since magnetism's strength decrease very quickly with distance but since range is infinite, it would be only a question of time before the iron would come back.
Far from me to say it's a free energy concept, I just would like to know what is wrong in the reasoning above in order to better understand magnetic principles. Thanks in advance
I read the FAQ so please take into account that this is NOT a perpetual motion (free energy or whatever) question but a theorical case that puzzles me.
I read that magnetic fields have an infinite (but decreasing) range. What bothers me is this :
let's put a magnet and a iron far way from each other (in space far from any influence, for the sake of the reasoning let's say no gravity nor other magnetic fields). Then the iron should be attracted by the magnet no matter how far they are (even if it takes a very long time to attract each other).
If I demagnitize the magnet after the iron has been accelerated towards the magnet, then we get an object with cinetic energy ? If we let the iron ball pass the magnet and magnetize the magnet again, then the ball and the magnet will attract each otehr again.
My problem here is : the energy necessary to (de/re)magnetize the magnet is not proportional to the distance between the iron and the magnet. Meaning, if we wait a very long time in order to have the iron very far from the magnet, then we'll get a bigger cinetic energy once we magnetize the magnet again.
Of course, this process would take a very long time since magnetism's strength decrease very quickly with distance but since range is infinite, it would be only a question of time before the iron would come back.
Far from me to say it's a free energy concept, I just would like to know what is wrong in the reasoning above in order to better understand magnetic principles. Thanks in advance