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In geology as in cancer research, the silver bullet theory always gets the headlines and nearly always turns out to be wrong. For geologists who study mass extinctions, the silver bullet is a giant asteroid plunging to earth.
Word of the Day
- A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.
The word 'pawl' probably comes from a Latin word meaning 'stake'.