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June 4, 2008 4:42 PM   Subscribe

Later this year, geophysicist Dan Lathrop's DIY Planet Earth will be filled with liquid sodium, weigh in at 26 tons, and will be spun-up to 80mph at its equator in an effort to discover how the earth's magnetic field is generated. Currently undergoing tests, even those can be pretty impressive.
posted by Kronos_to_Earth (34 comments total) 7 users marked this as a favorite

 
filled with liquid sodium, weigh in at 26 tons, and will be spun-up to 80mph

"And we figured it'd look so pretty if we floated it out into the middle of a pond."
posted by hangashore at 4:54 PM on June 4, 2008 [4 favorites]


If this geomagnetism experiment fails, I hope the lab next door has an Apple 2 handy.
posted by tss at 4:55 PM on June 4, 2008


"We are essentially trying to build planetary cores in the lab."

And hey, even if it doesn't work, we'll be able to do about a year's worth of laundry in this thing!
posted by flapjax at midnite at 4:58 PM on June 4, 2008 [2 favorites]


"The Earth's magnetic field is anything but simple," he says, pointing out that the field has flipped directions many times over the ages.

Fascinating.
posted by Mblue at 5:31 PM on June 4, 2008


I somehow read that at first as them filling THE GUY with liquid sodium. And I was like...whoa, this guy is hardcore. Or liquid core, anyway.
posted by DU at 5:33 PM on June 4, 2008


Given that the Earth's core is believed to be primarily iron, why sodium? Sure, it's got a low melting point but generating liquid sodium is a royal pain and then there's that pesky little reactivity thing that Hangshore alluded to.

I thought it might have something to do with orbital filling, but even that doesn't make any sense.
posted by Kid Charlemagne at 5:34 PM on June 4, 2008


The youtube comments on that second link are incredibly intelligent! What's going on? Do I have a brain tumor? Are we in the matrix?

Maybe we should start posting misspelled racist graffiti here to keep the universe in balance.
posted by jewzilla at 5:35 PM on June 4, 2008


Given that the Earth's core is believed to be primarily iron, why sodium?

The youtube comments on that second link are incredibly intelligent!

The first is answered by the second! Survey says....MAGNETOHYDRODYNAMICS
posted by DU at 5:41 PM on June 4, 2008


Every time I hear about someone doing anything at all with tons of liquid sodium, I feel like running for the hills. Christ, that stuff is dangerous!
posted by Class Goat at 5:52 PM on June 4, 2008


During the test, the sphere makes truly excellent Krell-machine moaning sounds. Sounds like Big Science to me!
posted by The Tensor at 5:58 PM on June 4, 2008


All mad science experiments would be improved by having one of things that makes a spark and goes "Bzzzt." Still, pretty impressive.
posted by steef at 6:02 PM on June 4, 2008


..one of things that makes a spark and goes "Bzzzt."

That's good during the experimentation phase, but at implementation time most customers prefer an amplified bing machine.
posted by DU at 6:10 PM on June 4, 2008


Oh, earth, you're too wonderful for anybody to realize you!
posted by subgear at 6:31 PM on June 4, 2008


Every time I hear about someone doing anything at all with tons of liquid sodium, I feel like running for the hills. Christ, that stuff is dangerous!

Don't worry, according to the article:
Water can actually make things worse — Lathrop's team has disabled the sprinkler system.

Sounds like they have it all under control...
posted by meinvt at 7:07 PM on June 4, 2008


I totally saw this thing in one of the weird labs in that Buckaroo Banzai movie, but I think they were actually using it to do laundry. Lab coats, lasers, ectoplasmic interdimensional slime, you know how it goes.
posted by loquacious at 7:10 PM on June 4, 2008


"and will be spun-up to 80mph at its equator"

What they don't say is that he will be using the back left tire on his jacked-up pickup truck to do it, or who will be holding his beer at the time. Yee-haw, earth science!
posted by Eideteker at 7:18 PM on June 4, 2008 [1 favorite]


Hey, if it works, his mom will be so proud, she can stick the refrigerator on IT!
posted by not_on_display at 7:53 PM on June 4, 2008 [2 favorites]


That's a great photo of him in the first link, the slightly-squinty, manically smiling expression that says "mad scientist".
posted by XMLicious at 7:56 PM on June 4, 2008


I was initially confused when it talked about the pole being in Canada, I then realized they were talking about the magentic pole.
posted by cell divide at 8:51 PM on June 4, 2008


Class Goat--

...every time?

Is this common for you?
posted by effugas at 9:16 PM on June 4, 2008


Effugas, not common, because I don't hear about such things very often.
posted by Class Goat at 10:09 PM on June 4, 2008


Most of the time, lab equipment is a bunch of boring plastic phials, or machined aluminum tubes with random wires sticking out, sitting there, doing science quietly and all to itself.

Then there's this, which is easily the coolest science experiment special effect in a movie I've seen all year - only it's not a movie at all, it's real. They are using that massive, spinning, thrumming, ominously bronze-colored sphere to do real science, and not just any science! Science investigating mysterious magnetic fields on a planetary scale!

What's better? It's filled with a superheated substance that explodes when it gets wet.

"They said my plan to recreate the core of the earth was mad! Laugh at me, will they? I'll show them... I'll show them all!"
posted by Slap*Happy at 10:20 PM on June 4, 2008


Oh no, the magnetic sphere reversed the polarity of observing internet communities.

FAKE, FAKE, FAKE!!1!
posted by Free word order! at 1:20 AM on June 5, 2008


I, too, am in the WHY SODIUM DAMN?! camp. Okay, mercury would be no fun, and probably costly. I'm sure cost is a factor in most of the other metals, but ... I would think that the prohibitive cost of compensating for the danger of molten sodium would outweight the benefits from a low materials cost. No indium-bismuth alloy? Wood's metal? Cerrosafe? You can even mix potassium and sodium to make them liquid at room temperature. That would seem to satisfy any "one free electron" requirement and it wouldn't have to be REALLY FREAKING HOT.
posted by adipocere at 5:09 AM on June 5, 2008


The magentic pole is in San Francisco. Or T-Mobile headquarters, whichever.
posted by seanmpuckett at 5:16 AM on June 5, 2008


adipocere -

This is so when they unleash it on an unsuspecting populace, Superman can't just go and hit it, because it would spray molten sodium over all the innocent bystanders, with the added benefit that it would be immune to his super-breath!

This is a science experiment that works for me on so many levels.
posted by Slap*Happy at 6:48 AM on June 5, 2008


A sodium fire can't just be put out with water. Water can actually make things worse — Lathrop's team has disabled the sprinkler system.

That's an understatement**. Sodium + water--> FIRE! It seems to me that they've made a very nice bomb. Glad the sprinklers are off, but this still sounds a bit off. Wouldn't the sodium being liquid make it more prone to reaction, should something go awry and it comes into contact with water? Are they just being extremely careful? The part where they spin the thing adds to my alarm.

** Skip ahead to about 1:30 to avoid lecture and camera issues. The short and sweet version.
posted by Tehanu at 8:11 AM on June 5, 2008


I watched that second video and I gotta ask, are we sure he isn't a Mad Scientist or maybe an Evil Genius or something? Because that big spinning ball filled with liquid sodium... that sounds a bit like some Bond villain weather-machine, planet destroying shit right there.
posted by quin at 8:43 AM on June 5, 2008


I'm saying. Superman would fly the fuck away from this thing. Every chemistry professor covers this. If they do demos, it's the most exciting lecture all year, unless there's another one with liquid nitrogen. One professor I know blew tiles off the lab ceiling doing this. It's one of the first things chemistry students try if they can get access to a little sodium-- they run outside and throw it into a snowbank, a pond, a puddle, a bucket. They blow shit up for fun with a little bit of this stuff. And that's mostly harmless. But this is a lot of it. And liquid. And spinning.

I did find their lab webpage. They seem to be tracking the media coverage. Maybe they'll address the sodium concern.
posted by Tehanu at 9:15 AM on June 5, 2008


I would have gone with solder, myself. But the melting point is a lot higher. (Sodium melts at 98 degrees C; solder somewhere in the range of 200 degrees C.)
posted by Class Goat at 9:20 AM on June 5, 2008


Everyone is making a big deal over the dangers of molten sodium. By way of comparison, consider that the reason the outer core of the earth remains molten is because of the radioactive decay of thorium, uranium, and radioactive potassium in the mantle. To heat other metal with similar conductivity to their molten state and then spin it around is a non-trivial engineering problem.

But this is a very exciting experiment, if it works. It isn't immediately obvious why Earth even has a a magnetic field, as Mars and Venus do not. The magnetic field prevents the solar wind from blasting away the atmosphere, so without a magnetic field, there would be no life on Earth.
posted by Pastabagel at 10:22 AM on June 5, 2008


Sodium filled valves. It's not as crazy as it sounds, they have a pretty good margin of safety.
posted by IronLizard at 10:34 AM on June 5, 2008


I got to visit Experimental Breeder Reactor I (EBR-1) a couple years ago. It had a liquid sodium-potassium coolant system which has since been used in a lot of other reactors. I imagine there's a lot of experience with handling liquid sodium out there. In one of the links I read that they were using sodium for this experiment because of its high conductivity.

EBR-1 is awesome, by the way.
posted by pombe at 11:59 AM on June 5, 2008


But this is a very exciting experiment, if it works. It isn't immediately obvious why Earth even has a a magnetic field, as Mars and Venus do not. The magnetic field prevents the solar wind from blasting away the atmosphere, so without a magnetic field, there would be no life on Earth.

Which, of course, explains why Venus has no atmosphere, right?

As to why Earth has a magnetic field, I didn't think it was a huge mystery. The details, of course, remain to be worked out, but the general reason is because the Earth has a lot more metal than Venus or Mars, and because a combination of radioactive decay and tidal flexing has kept the core particularly hot and fluid.

And all of that is because the Earth got hit by something about the size of Mars early in its life, gaining a lot more metal and losing rock, which eventually coalesced into the Moon.

Actually, when comparing the Earth to Venus, the interesting question is why the Earth has so little atmosphere. Air pressure at the surface of Venus is 90 times that of Earth. Where did ours go?

I've thought a lot about that, and it seems to me that the Moon is the key to regulating Earth's atmosphere. Tidal flexing keeps plate tectonics going, which means volcanoes keep erupting, producing new atmosphere. Meanwhile, the Moon acts like a gravitational vacuum cleaner. When air molecules rise to the point between Earth and the Moon which is equipotential gravitationally, they can go into orbit around the Moon, and thus get a free ride to the far side of the moon, outside the Earth's magnetic field, where the solar wind can blow them away.

The interesting thing is that those two effects scale differently. The amount of atmosphere is not a factor of the amount of vulcanism. But when our atmosphere is thicker, then the Moon sucks more of it away. So over the long term (tens of millions of years) there's a tendency to reach an equilibrium where the amount of new atmosphere resulting from volcanoes equals the amount removed by the Moon.
posted by Class Goat at 1:31 PM on June 5, 2008


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