Disorienteering

[bnewman]

Something I read recently reminded me of this idea I once had.

Orienteering is the sport of navigating with a map and compass. I've done some orienteering activities at camps, it's fun — of course, competitive orienteering requires that you be a good navigator and a fast runner/biker/etc., and I'm only the former.

The basic idea of navigating with a map and compass is that you can use the compass to orient the map to the terrain. This works because the Earth's magnetic field is approximately uniform over a small area. However, the Earth's isn't the only magnetic field! "Disorienteering" is the (so far imaginary) sport of navigating with a map and compass through an obstacle course of strong, local magnetic anomalies. Puzzles involved in a disorienteering course might include instructions to turn electromagnets on or off to alter the course, instructions to travel in the straight line indicated by a bearing or to follow a (curved) magnetic field line, unmarked reference points located at the intersection of two path segments, etc.

One thing I'm curious about is how much hardware you'd need to set up a disorienteering course. The Earth's magnetic field isn't all that strong, but to create a magnetic obstacle course big enough for a person to get lost in (if you can't get physically lost in it, might as well just call it a board game...) might call for a lot of electromagnets...

Comments

[sildra.livejournal.com]

But the field from a current line goes in a circle, while the field from a solenoid goes straight. We aren't compensating over a whole room, but we are compensating over several cm. We do it with three pairs of Helmholtz coils--one pair for each axis. You probably wouldn't care about up-down, so you'd only need two pairs of Helmholtz coils.

P=I²R, so adding more wire doesn't require as much energy as raising the current. Also, in my experience, it's harder to find high current power supplies. Doing the calculations, though... it might still be prohibitively expensive.