ELI5, why aren’t all the paper clips flying towards magnetic north but my compass is pulled anywhere in the world?


Conversely, the moons gravity affects the largest bodies of water on earth but yet nothing else.

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You would have to magnetize the paperclip in order for it to point north and south. Since there is not a lot of ferrous material in paper clips you would need to put it on water or suspend it so it is barely balancing on something so it can turn more easily. That is what a compass does, the needle is not just laid on the surface but suspended so it is easily able to spin with little force. Take a paper clip, rub a magnet on it in the same direction a few times, and set it on something that floats, like a cork or piece of plastic. If you have a very steady hand you can just set a dry paper clip on water and it will float (different long story) and it WILL act like a compass.

The moon DOES effect everything on Earth. That is why there are high tides on both sides of the Earth at the same time. Because the entire far side of the Earth (the side further from the moon) is being pulled too but it is being pulled less than the close side. That makes a bulge on both sides.

Just to clarify, and im not saying you do not know this, but magnetism and gravity are different forces but that act similarly.

In addition to magnetizing one end of the paper clip, it would need to be able to turn on its own, like a compass needle. A paper clip sitting on a table is held down by gravity. Compass needles sit on a pin or float in space juice.

As someone else mentioned, gravity ≠ magnetism. But as far as the nothing that moon’s gravity affecting nothing other than the oceans . . . I’m not so sure I agree with that premise. I mean, we do have seasons after all.

Pieces of metal do, very slightly, try to align themselves north-south along the axis of the Earth’s magnetic field. But the effect is quite small. Compass needles are stronger magnets than the weak responsive magnetism of a paper clip, and they’re mounted in such a way that they can spin freely. The weak force on a paper clip isn’t enough to overcome friction and cause the paper clip to move. (In fact, it’s probably not strong enough to overcome small vibrations breaking up any particular magnetism in the paper clip, but a sufficiently cold paper clip would still align.)

As for the tides: the Moon’s gravity *does* affect everything else on Earth. It just only affects it very, very slightly. The oceans, which are many miles deep and flow freely, only move up and down by a few feet. Solid objects flow much less freely than this, and are much smaller than this in most cases, so they distort by much less. But in fact, the Earth’s rock and atmosphere do bend slightly in response to the tides, you just don’t notice this because the effect is very very small.

Or why aren’t there tidal changes on ponds, puddles, lakes only giant oceans?