SUPPOSE the Earth’s magnetic field gave up and died on us. It would be quite a show: compasses going haywire, migratory birds getting lost, the surface of the planet bombarded with cancer-causing cosmic rays. If you want a taster, try watching Jon Amiel’s recent movie The Core, in which scientists discover that the Earth’s inner core has stopped rotating – though this is Hollywood, so best to take it with a pinch of salt.
Should we be worried? Will the future of the Earth follow the plot of a Hollywood disaster movie? It’s unlikely, but we can’t be absolutely sure. It’s…
