THE Earth’s magnetic field was three times its present strength when
dinosaurs roamed the planet, supporting theories that it is generated by an
internal dynamo rather than static magnetic material. Ancient magnetic fields
leave their imprints on volcanic rocks, but field strength is much harder to
measure than direction. John Tarduno of the University of Rochester in New York
state has now used a superconducting device to measure field strength in
crystals that formed 113 million years ago, during a 37-million-year interval
when the magnetic field was exceptionally stable and did not flip direction
(Science, vol 291, p 1779). The…
To continue reading, today with our introductory offers
Advertisement
More from 51¶¯Âþ
Explore the latest news, articles and features
Popular articles
Trending 51¶¯Âþ articles
1
Mathematicians stunned by AI's biggest breakthrough in mathematics yet
2
Photos reveal unexpected details from the world's first atomic test
3
The Selfish Gene at 50: Why Dawkins’s evolution classic still holds up
4
How I used psychology to come back from the worst year of my life
5
The distant world that is our best hope of finding alien life
6
The ‘doomsday’ glacier’s giant ice shelf is about to break away
7
We may finally know why dinosaurs like T. rex evolved tiny arms
8
The 3 things you need to know about protein, according to an expert
9
51¶¯Âþ recommends a devastating account of farming honeybees
10
Epic dreaming is leaving people exhausted and distressed
