[mlyle]

Magnetic field falls off with inverse cube of distance once you're past the approximate size of the magnet. Not to mention that the drive itself is in a ferrous enclosure that provides a lot of shielding... the magnetic field you applied at 6 inches is approximately nothing.

[EvanAnderson]

I will definitely concede that I may have the 6" measurement wrong. Heck-- I may have actually put my hand right on the PC.

I stack running hard disk drives, all of which have large neodymium magnets inside them, in close proximity all the time with no ill effects. It makes no sense.

[FabHK]

Isn't it inverse square?

[mlyle]

No. Magnetic fields fall off as 1/d when d is small compared to the size of the magnet, progressing to 1/d^3 when d is large compared to the magnet. (E.g. weird edge case-- it's inversely proportional to distance from an infinitely long wire).

Electromagnetic radiation from point sources falls off as 1/d^2.

[FabHK]

Thanks a lot, both of you, learned something!

[egdod]

No, it’s a dipole moment instead of a monopole like electric charge. It goes as 1/r^3 in the far field.