I've heard of something similar, but the magnetic field was static.

The idea was that you could have a set of magnets that would hold fast, but you could unlock them by rotating one of the magnets.

: Imagine having a surface composed of nano-sized electric charged domains. On
: a large scale there will be equal numbers of +ve and -ve domains so that
: the surface as a whole appears to be neutral. The -ves balance out the
: +ves over large distances.

Question one: Wouldn't that surface have to be kept clean to work? About how much of a gap can exist between the surfaces before it starts losing its grip?
Question two: How well would it handle lateral forces? If the gun is recoiling and momentum is holding a scope in place, wouldn't it slide forward and lose gripping power?

Perhaps a hybrid system between this and a Picatinny Rail can be used.

: It can then up the number of pattern generating iterations to become super
: stuck.

: Power is only used when aligning patterns and changing stickiness.

: So we have about 5 parameters: x/y origin of pattern, x/y extent of pattern
: and the iteration number.

: The control code will be distributed across all domains with neighbours
: talking to neighbours. The active surface would be a massively parallel
: computing surface. maybe it can do other computing tasks when it's not
: flipping domains.

: Note that altering pattern origins can be used to move a scope backwards and
: forwards by nano-meter intervals. You could turn a knob to change the
: position or use a keypad to specify it as a number in nano-meters ;-)

Hmm... If you really had control that could be reliably measured in nanometers, could this be used in applications that demand a high degree of control? Would this offer any benefit to, say, telescope controls?