4 ms·

Interesting that he didn't feel gradual increase of pull force while he was approaching the MRI machine. I guess cubic growth (?) changes from mild to dangerou

Interesting that he didn't feel gradual increase of pull force while he was approaching the MRI machine. I guess cubic growth (?) changes from mild to dangerous so quickly when walking towards a MRI machine that once you realize what happening it's already too late.

wtcactus 1y ago
Magnetic force works quite like gravity (depends on r^2). When you drop something it immediately starts going.
KineticLensman 1y ago
> Interesting that he didn't feel gradual increase of pull force while he was approaching the MRI machine. There isn't a gradual increase in pull when magnets are involved. My wife used to work for a company whose product involved powerful magnets. For a while they produced a demo kit in which a magnet would hold a large ball-bearing levitated against gravity. That thing was lethal. If the ball-bearing approached the magnet too closely it instantly became a dangerously fast finger-crushing hammer.
voidUpdate 1y ago
I think it's inverse-square, and as you get closer, the acceleration increases quadratically, so your speed increases faster (possibly cubic?)
- phkahler 1y ago
  >> I think it's inverse-square No, for "a magnet" it's an inverse cube law. I've often wondered if the force holding a nucleus together is really magnetism. No, physicists you don't need to correct me, I know how off the wall that sounds ;-)
  - r2_pilot 1y ago
    For nuclear forces it's actually the strong force binding the nucleus (electromagnetic force is far, far, far too weak to do this) but you can theoretically unify the weak force and the electromagnetic force into the electroweak force : https://en.m.wikipedia.org/wiki/Electroweak_interaction https://en.m.wikipedia.org/wiki/Electroweak_interaction
  - voidUpdate 1y ago
    Ah, yes, I was assuming it was essentially like any other electromagnetic force, but apparently it being a dipole messes with things and it's inverse cube. TIL

wtcactus 1y ago

Magnetic force works quite like gravity (depends on r^2). When you drop something it immediately starts going.

KineticLensman 1y ago

> Interesting that he didn't feel gradual increase of pull force while he was approaching the MRI machine. There isn't a gradual increase in pull when magnets are involved. My wife used to work for a company whose product involved powerful magnets. For a while they produced a demo kit in which a magnet would hold a large ball-bearing levitated against gravity. That thing was lethal. If the ball-bearing approached the magnet too closely it instantly became a dangerously fast finger-crushing hammer.

voidUpdate 1y ago

I think it's inverse-square, and as you get closer, the acceleration increases quadratically, so your speed increases faster (possibly cubic?)

phkahler 1y ago
>> I think it's inverse-square No, for "a magnet" it's an inverse cube law. I've often wondered if the force holding a nucleus together is really magnetism. No, physicists you don't need to correct me, I know how off the wall that sounds ;-)
- r2_pilot 1y ago
  For nuclear forces it's actually the strong force binding the nucleus (electromagnetic force is far, far, far too weak to do this) but you can theoretically unify the weak force and the electromagnetic force into the electroweak force : https://en.m.wikipedia.org/wiki/Electroweak_interaction https://en.m.wikipedia.org/wiki/Electroweak_interaction
- voidUpdate 1y ago
  Ah, yes, I was assuming it was essentially like any other electromagnetic force, but apparently it being a dipole messes with things and it's inverse cube. TIL