Could we develop the ability to sense other fields like magnetic fields?

It is a very, very good point, very exciting. I have students at the moment, three students. We have ethical approval, they actually have magnets implanted in their fingers and they can feel - literally if they go into a bank they can feel EM [electromagnetic] signals. They have the magnet in their finger, a little coil of wire around the magnet and then that is attached to different sensory input. So, these are students doing the course, they can feel ultrasonic signals, feel distance, or feel infra-red which can be a heat signal. So it's converting different signals to magnetic signals. We haven't actually tested whether they can follow their finger and know which way to go as a compass would. That's an interesting one. We'll have to try that.