First of all, would it even be possible for a human to sense a magnet under any circumstances in the way you can sense, say, a 500 watt radio transmission from within a few feet of the antenna (very unpleasant sensation, by the way)?
If so, what would it feel like, how strong would the magnet have to be and how near would it need to be?
And yes, I’m well aware that a typical human could easily feel the effects of a bar magnet hurled at his head from 4 feet away–that’s not what I’m asking.
Chemists who take their own NMR spectra have regularly been exposed to magnetic fields as high as 10 Tesla (about 200,000x the magnetic field of Earth) at a distance of 0.5-1 meter and from personal experience I can say that I feel absolutely nothing out of the ordinary.
However, you’ll feel a weird sensation in your pocket if you forget to remove your keys as you walk up to the machine, and you’ll feel a weird sensation at the store if you forget to remove your credit cards and they get wiped out …
MRI (or more correctly, NMR, Nuclear Magnetic resonance; it got bowdlerized to MRI to assuage nervousness about anything nuke) is the one with the magnets – powerful enough that there have been incidents of unsecured metal objects in the room being propelled into the chamber with force to inflict grievious or fatal injury. When inside one I was too distracted by the thunking and whirring and vibrating and the uncomfortable contrast-medium IV injection site and the bad muzak, to really feel any magnetic vibe.
The machinery emits a lot of audible mechanical noise, in a repetitive pattern. The best way I can describe it is to imagine the sound a flatbed scanner makes when quickly scanning a document, then imagine you are inside a machine that makes a similar noise, periodically interrupted by loud clicking.
I’ve felt MRI’s – by touching them with my hands. I suspect you are really asking if humans can detect magnetism like we can detect light, heat, or air pressure.
I’d say the answer is no, despite some research into directional-awareness and the earth’s magnetic field.
OK, it’s RRSQT (Really, Really Stupid Question Time). If the magnet were powerful enough, wouldn’t all the iron in your bloodstream be attracted to it, thereby causing a massive disruption in the functioning of your circulatory system, which in turn would result in your untimely and certainly somewhat unpleasant demise? This is just a simple question, mind you—there’s no need for everybody to hit me with the retard baton all at once.
I don’t think it’s a stupid question but a firm answer is surprisingly elusive. I’ve found several sites debunking magnetic therapies (i.e. stick these magnets on your wrists to rebalance your aura and crap like that) delving into the possible effects on hemoglobin and they tend to claim that even extremely powerful magnets will have trivial or no effect.
I worked in an MRI unit for a few months to make some extra money. A few people said they felt something in their fillings.
I volunteered to have my neck scanned to test some new software. I have more fillings than whole teeth and didn’t feel a thing, in fact, I fell asleep.