THE internal compasses of some animals might work by detecting minute changes
in the pace of biochemical reactions in different magnetic fields, researchers
in the US suggested this week. They say their theoretical studies could
contribute to the debate on whether the electromagnetic fields of powerlines
cause diseases such as cancer.
Many creatures, including some birds, amphibians and reptiles, navigate by
sensing tiny changes in the Earth’s magnetic field. Sea turtles, for instance,
can sense changes as small as a tenth of a microtesla—less than 0.2 per
cent of the typical geomagnetic field.
But nobody knows exactly how these…
