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 New 女生小视频
Explore the latest news, articles and features
Popular articles
Trending New 女生小视频 articles
1
The Selfish Gene at 50: Why Dawkins鈥檚 evolution classic still holds up
2
We may finally know why dinosaurs like T. rex evolved tiny arms
3
Mystery of the ancient giant stone jars of Laos may have been solved
4
The 鈥榙oomsday鈥 glacier鈥檚 giant ice shelf is about to break away
5
After news about Oliver Sacks's "lies", we revisit his best-loved book
6
The distant world that is our best hope of finding alien life
7
Odd 鈥渂utterfly鈥 molecule could lead to new parts of the quantum realm
8
The 3 things you need to know about protein, according to an expert
9
Solar farm on the ocean outperforms land-based solar in Taiwan
10
First test of CO2 removal with green sand finds no harm to marine life
