2329 utenti della rete avevano questa curiosità: Spiegami: the strongest magnet in the world boasts 900 times the earths magnetism, so why wouldn’t a compass point towards those superior magnets?
Also does anyone know how those ultra strong magnets are affecting our planet if at all?
Edit: sorry the link says 900,000 times the earths magnetism
Edit 2: Thank you wonderful people for clearing that up. Your minor support did more for my mental health than you realize not just for the knowledge but also the general support from the community. Y’all are amazing.
Ed ecco le risposte:
Magnets ability to do, well, magnet stuff decreases rapidly over distance. Very rapidly. That means to effect a long distance, magnets need to either be super big or bonkers, absolutely wildly powerful, or even both.
The earth’s magnetic field is both powerful and super big…. so it does its thing, its really really big
I’m not sure exactly what magnet you’re talking about, but im sure its fairly small in comparison. Even industrial facilities that do extreme magnetism, with powerful magnets, the magnetism doesn’t stretch out very far, think like in terms of like several meters, with most of the power right up near the magnet as it drops off tremendously with distance. The earth’s magnetic field though is just insanely massive, so it still has some strength even at a great distance
So if you put a compass right up to a small powerful magnet, yeah it’ll fuck up the compass, but even if its just a little bit away, the power of that small magnet won’t be much, so it won’t affect the compass, the earth will though
It doesn’t have 900 times more magnetism, it’s magnetic field strength at the surface of the magnet is 900 times stronger than that of the earth at the same point.
Field strength drops as the inverse cube of the distance. So the earth’s magnetic field is stronger once you get more than 10m away from the magnet.
And as for the effect on the earth – zero. The planet is really, really big, and ten metres is really no distance at all in comparison.
It’s because the claim is a lie. This magnet is not 900,000 times more powerful than Earth’s magnet is. Earth’s magnet is MUCH stronger. But Earth’s magnet is also MUCH further away from you – it’s the core.
What they can claim is not that this magnet is 900,000 times stronger than Earth’s magnet, but that if you keep this artificial magnet right next to you while you are located 6.371 million meters away from Earth’s magnet, that great distance from Earth’s magnet drops its effect enough to being only 1/900,000th as much as this artificial magnet is right next to you.
Magnetic force drops with distance, and it’s not the whole Earth that’s magnetic, it’s just the core. And way the heck out here on the surface of the crust, you are quite far from that core.
The link you’re referring to is talking about magnetic field strength, which is a measurement of the magnetism at that specific point. It doesn’t mean that the magnet is more powerful than the earth “in total”, just that the field it produces is much more powerful in that local area.
Think about it this way. If I took a big bucket of salt and dumped it in the ocean, then that local bit of water would (temporarily) be way, way saltier than the rest of the ocean. But that certainly doesn’t mean that there was more total salt in my bucket than there was in the whole ocean, right? A powerful magnet can create a field that is locally way stronger than the Earth’s field, but the Earth’s field is MASSIVE, it’s still far more powerful “in total” than the small magnet.
I watched a video today about ships compasses. And how they need to counteract the magnetism of a giant steel ship to be accurate.