Posting here rather than the 'What are you working on' thread.

3 weeks ago I got two magnets implanted in my fingers. For those who haven't heard of this before, what happens is that moving electro-magnetic fields (read: everything AC) cause the magnets in your fingertips to vibrate. Over time, as nerves in the area heal, your brain learns to interpret these vibrations as varying field strengths. Essentially, you gain a sixth sense of being able to detect magnetic fields, and as an extension, electricity. It's a $350 superpower.

The guy who put them in my finger told me it will take about six months before I get full sensitivity. So, what I'm doing at the moment is research into this and quantifying my sensitivity as it develops over time. The methodology I'm using is wrapping a loop of copper wire around my fingers and hooking it up to a headphone jack, which I will then plug into my computer and send randomized voltage levels through. By writing a program so I can do this blind, I should be able to get a fairly accurate picture of where my sensitivity cutoff level is.

One thing I'm stuck on is how to calculate the field strength acting on my magnets. Getting the B field for a solenoid is trivial, but with a magnetic core I'm sure it throws everything out of whack. If anyone has any links to the physics of how to approach that, I'd be much obliged.

And if you're curious about what it's like so far to have magnets in your fingers, feel free to ask.