A Baby Earth

Why does the planet act like a giant magnet? One scientist is building his own Earth to find out

By Christopher Maag Posted 09.12.2008 at 9:57 am 8 Comments

Field of Dreams: geologist Lathrop hopes this 30-ton spinning orb will generate a magnetic field just like Earth's Courtesy Santiago Andres

Dan Lathrop needs a bigger Earth. His old one is two feet across and 500 pounds, about 20 millionths the size of the real thing. And after four years of tests, it failed to generate a magnetic field similar to the real Earth’s, which shields us from the sun’s radiation and guides some navigation systems by pointing compasses north.

Lathrop, a physics and geology professor at the University of Maryland, thinks one key to creating a magnetic field is size. A bigger orb with more hot metal churning inside it, mimicking Earth’s iron core, could provide the mass needed to make a planet-shaped magnet. So he has spent $1.6 million in grant money building a fake Earth that is 10 feet tall and weighs 30 tons.

Our planet’s magnetic field has reversed directions hundreds of times throughout its history and has weakened 10 percent since monitoring began in the 1830s. Is it preparing for another reversal, which could make the field even weaker and expose us to harmful solar particles?

Sun Shield: As Earth's iron core rotates, it generates a magnetic field that deflects solar radiation: Paul Wootton

To find out, Lathrop spent the summer testing his new orb and its rotating mechanism. This fall, he will fill it with molten sodium, set it spinning at 90 miles an hour, and see what happens. Although scientists in Europe have produced electromagnetic fields by pushing liquids through pipes or mixing them in cylinders, none of these setups resembled a planet. “We have some inkling about how the Earth generates its electromagnetic field,” Lathrop says. "But we can’t predict what the field will do next."

If Lathrop’s baby Earth succeeds in creating its own field, it could help scientists develop predictive models that would reveal what will happen to the planet’s magnetic field (and whether we should stock up on sunscreen).

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8 Comments

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Zengrath

09/12/08 at 11:55 am

First global warming, then colliding particles engulfing the earth, next reversing magnetic poles??? What's with all the bad news lately!

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scubasdsteve87

09/12/08 at 7:09 pm

Has anybody else noticed the SPF levels on sun tan lotion and how the numbers keep going up? Ever wonder why? This might be a good explanation.

I know im stocking up on the stuff...

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acme

09/13/08 at 10:00 am

Oh didnt you get the report on how SPF sunscreen lotion is super bad for the coral reefs...not joking here, its just ironic that now we cant even protect ourselves from harmful rays without killing something else, which sustains our CO2 levels...it has become a matter choosing our fate, rather than preventing it, sorry to sound dessimistic but why are we not killing massive amounts of industry? a 70:1 garbage ratio is unacceptable, for more info view this quick video on www.storyofstuff.com

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njdevil

09/13/08 at 5:11 pm

yeah, a 70:1 garbage ratio and dead coral reefs are pretty bad. but then again, if more and solar rays start hitting the earth, which is sort of what this article is about in case you actually didn't read it, those problems will seem pretty insignificant pretty quick. sunscreen or not.

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luke123abc

09/15/08 at 5:22 am

yeah this article is rather awesome. umm, the on the pole switching thing, i dont know the exact time, but the mayans believed "the end of the world" to be in 2012. 2012 may not sound far off, but that may very well be the date for it.

it would really be nice to know how the core really works

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dontbother

09/18/08 at 11:06 am

"Has anybody else noticed the SPF levels on sun tan lotion"

SPF does not factor in UVA protection.

Also, it won't be the UV radiation that kills us. More than likely we will not be able to effectively block gamma and X-ray radiation if our poles reverse.

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bbowers

07/25/09 at 9:36 pm

Doubt it will work. The earth's magnetic field is relatively weak considering the size of the earth. the magnetic field his contraption would create most likely wouldn't be detectable, if it would even create one.

http://beecherbowers.com

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iraqistan

10/05/09 at 4:49 pm

I always wondered why the core is said to be Iron. I would think there would be large quantities of more dense elements like uranium and such. I mean sure theres way more Iron than the other stuff but a nuclear core would make way more sense to me. Heat generated from the fissile material compressed together by gravity sustaining temperature. Radiation working in conjuction with molten outer iron and nickle layers spinning. But i havent been able to persue higher learning yet so I depend on POPSCI readers to explain.