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Programmable Magnets
Martin Hellman writes "A few weeks ago Popular Mechanics awarded one of its Breakthrough Awards for the invention of 'programmable magnets.' Instead of having a single North or South pole, these clever devices have an array of North and South poles. If a matching device with exactly the same array is aligned with the first one, they will experience strong repulsion, just like two single North poles do when brought near one another. If the matching device has the complementary array (North and South interchanged), with correct alignment the two devices will attract. But a slight misalignment will cancel most of the force. Other configurations are possible as well, allowing frictionless magnetic gears and exploding toys. The inventor, Larry Fullerton, used techniques similar to those from CDMA modulation. (Watch the intro video for a brief explanation. While I don't understand magnetism that well, I do understand CDMA and carrying over those ideas to magnetic arrays does make sense to me.)"
Effing magnets - how do they work?
I don't think so. I think huge magnets will increase the mass of the spacecraft needlessly - and you'll still be using around the same amount of energy which you could use if you use fuel or whatever. Unless of course we put a ton of magnets around the solar system and we launch spacecraft in a manner similar to railguns.
Wake me up when they invent magnets with east and west poles.
The "frictionless" magnetic gear shown will still have friction in the bearing. The magnetic "teeth" will introduce a huge amount of backlash into the gear system. And you would run into problems if you tried to stack gears beside each other in a gearbox. The high pull-off force/low twist-and-pull force application is neat though. One limitation is that rare earth magnets tend to be brittle, and make a mess when they break.
To be clear though, magnets have been made with multiple poles for a long time, for example those flexible fridge magnets will often have alternating poles across their surface. Also, the pull off application is in many ways similar to the "switchable magnetic bases" . In these devices, the orientation of the magnetic is changed to force the field lines to go through the surface underneath, or to be contained within the base. The innovation in the present work is the use of coding theory to design the patterns.