The Solar System: Old or Young?

Strong channels in Earth’s core drive its magnetic field, but the energy loss–as in an electrical circuit–tend to drain off in the passage of time. Our planet has no exemption to this, and as such should have parted with its magnetism a very, very long time ago. Cal Tech geophysicist David Stevenson remarked: “We do not understand how the Earth’s magnetic field” has not dissipated. Read more: