Earth's core spins faster than its surface

[Celebration]

http://seattlepi.nwsource.com/national/238080_spin26.html

Scientists who used decades' worth of earthquake data to study the planet's center say their information proves decisively that Earth's core spins faster than the outer crust.

The researchers first claimed nine years ago that the solid inner core was spinning faster than the outer part of the planet, but they were met with challenges by other seismologists who contended that their measurements were incorrect.

"Extraordinary claims require extraordinary proof," said Xiadong Song, a professor of geology at the University of Illinois-Urbana-Champaign and a co-author of a study published today in the journal Science. "We believe we have that proof."

[htuttle]

1. Silly me, I thought this was already the accepted theory

I would have sworn that this was the mainstream theory already. I thought that this is what produced Earth's magnetic field.

Huh.

:shrug:

[trotsky]

2. I believe it is convection currents

of molten iron in the core and mantle that cause the field.

[WindRavenX]

4. Yes

Also, plate tectonics seem to also play a critical- if not wholly necessary- role in producing a molten core.
In addition to providing a magnetic field, the speed of our rotation helps keep the atmosphere from dissipating into space.
Mars, which may have had one or both of the two factors discussed here- molten core + plate tectonics- may have been too small to hold an atmosphere.

[Meldread]

5. What about Venus?

It is about the size of Earth and can hold an atmosphere but has a very weak magnetic field.

[WindRavenX]

6. No plate tectonics

...This is so absolutely crucial, that many astrobiologists think that plate tectonic could be THE determining factor in whether a planet can sustain conditions for complex life; a magnetic field is needed in order for this.

If you're interested more in this, check out the bible of astrobiology, Rare Earth: Why Complex Life is So Rare In The Universe"

[Meldread]

7. Thanks, I'll look into it.

...however... couldn't life on a planet with high solar radiation just evolve to withstand / become immune to it? Or perhaps life would evolve to use the radiation in some useful way? Certainly Earth Life wouldn't make it, but alien life...?

[WindRavenX]

8. Well, that's the big question

Based on our limits of understanding the boundaries for life, DNA/RNA and nucleic acids really can't withstand solar bombardment...so if another form of life could exist on another system that isn't DNA based and is able to withstand intense radiation- then who knows.
Based on what we know...it seems very unlikely that any life- even simplistic bacteria, including the extremeophilic bacteria- can develop in high radiation.
But there's a lot we don't know =)

[Meldread]

3. Ditto. I was under the same impression.

Either you an I are psychic and don't know it, or these guys are late. :P

[Up2Late]

9. Duh, I could of told them that.

And how the Hell did they supposedly "Prove" this, when we can't even drill past the Crust?