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Latest Timothy J. Bralower Stories

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2010-03-01 13:02:12

An asteroid strike may not only account for the demise of ocean and land life 65 million years ago, but the fireball's path and the resulting dust, darkness and toxic metal contamination may explain the geographic unevenness of extinctions and recovery.


Word of the Day
pawl
  • 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'.
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