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I acquired a cube puzzle called Force Field a few weeks

ago which I don't recall having seen discussed on this

list. It's called Force Field (by Mattel), and it consists

of 8 cubies, each measuring about 1" on a side, and each

solid black. The idea is to arrange these 8 cubies into

a 2x2x2 cube. This sounds and looks trivial, until you

learn that there are magnets attached to some (but not all)

of the inner surfaces of the cubies. This means that

the sides of two cubies may:

a) repel each other

b) attract each other but jog off-center (since

the magnets are not necessarily at the center of the side)

c) neither attract nor repel each other (if magnets

don't exist on both of the sides involved)

d) attract each other and stay perfectly aligned

The final 2x2x2 cube has to hold together perfectly, without one

or more of the cubies popping out. Furthermore, it is not enough

to juxtapose the sides with no magnets, since the final cube has

to be placed in a special stand which balances it on one of

its corners. This is the acid test-- the cube might look ok when

resting on the table, but in order to survive in the stand, all

internal sides must actively attract each other with perfect

alignment.

I finally had to resort to temporary labels on the cubies in order

to systematically search for a solution. One of the first things

you learn is that each cubie has 3 magnets, precisely the number

required. This cuts down the search space tremendously: since the

3 sides with magnets must be internal, this constrains a particular

corner of each cubie be at the center of the large cube. But it

still involves over 33 million possible positions (3^8)*(7!).

I'd be interested to hear if any of you folks have played with this,

and if anybody has developed a procedure for putting the cube together

which does not involve labeling, which is what I'm working on now.

Happy cubing,

Clive -------