The Earth's core: the enigma 1,800 miles below us

http://www.nytimes.com/2012/05/29/science/earths-core-the-enigma-1800-miles-below-us.html

by ValentineC • 14 years ago

81 24 14 years ago

politician• 14 years ago

"It’s a place where pressures bear down with the weight of 3.5 million atmospheres, like 3.5 million skies falling at once on your head."

I shouldn't be overly critical, but, well, that one's not working for me.

trafficlight• 14 years ago

Yeah, what exactly does the weight of 1 sky falling on your head feel like? Feels pretty decent to me.

InclinedPlane• 14 years ago

1 megabar (roughly 1 million atmospheres) is equivalent to a thousand tonnes of pressure on every square centimeter of your body.

fghh45sdfhr3• 14 years ago

It’s a place where the term “ironclad agreement” has no meaning, since iron can’t even agree with itself on what form to take.

This is good writing to most people. It is fun and interesting, etc. But my brain hates it.

Surely You're Joking, Mr. Feynman! is the kind of fact heavy writing I prefer. But me and people like me are in the minority.

draggnar• 14 years ago

It is funny how regarding the polarity flip they just say "don't worry, you'll be dead.". Ok that may be true, but what would happen? If the rate of polarity switch is exponential, 10% in the last century could end up being, oh dec 12 2012? Even if that is just a silly mayan thing, what would theoretically happen? We get pelted by radiation?

ChuckMcM• 14 years ago

Generally the models have it becoming fairly distorted in various ways and then strengthening again in the opposite polarity. It never goes to 'zero' because there isn't a model where the core stops moving. But there could be some 'local' poles in addition the primary poles. Think of it 'aurora borealis at the equator' kind of weird but not 'sleeting sheets of coronal mass ejecta raining death on helpless flora and fauna.'

Of course nobody really knows, we have models, we have guesses, we have theories. I've not seen any credible theories that result in the field going away but it doesn't mean they aren't out there.

jpxxx• 14 years ago

As I understand it, the opposite polarity isn't a guarantee. The weakened magnetic poles wander for a period of time. Once the magnetic field reasserts itself, the magnetic poles return to the physical poles, and if they're opposite, so be it.

Retric3• 14 years ago

Also, your ancestors went though this millions of times while living long enough to have kids. So, while it may be unpleasant chances are it's just going end up with lightly different lights in the sky and at worse a small increase in cancer risk.

ktizo4• 14 years ago

Polarity flips take thousands of years, as far as I know. In the middle bit you have loads of poles floating around and the ionosphere is much weaker and very confused, so you get a hell of a lot more radiation at the earth's surface. I also read that there is a minor north pole floating around the South Atlantic at the moment, which could presumably have you sailing in circles if relying on compasses.

kijin• 14 years ago

> there is a minor north pole floating around the South Atlantic at the moment, which could presumably have you sailing in circles if relying on compasses

That sounds very interesting. Any sources?

By the way, I can almost imagine the beginning of the next Roland Emmerich disaster movie. A ship sinks while traveling in circles. Some clever scientist investigates the accident and deduces that the poles are going to switch next week. Nobody listens, so he must single-handedly save the world as well as his family.

chc• 14 years ago

1. The most immediate thing that would happen if that were the case is we'd already know. We could tell if the magnetic field were quickly changing. A lot of instruments people use every day would be affected by major changes in the magnetic field.

2. The magnetic field could completely disappear and we wouldn't get bombarded by radiation. The atmosphere itself protects us from radiation. Remember all that talk in the '90s about the ozone layer and how we'd get irradiated if it disappeared? That's in the atmosphere. The magnetic field doesn't do much for that AFAIK.

3. Based on the same evidence that leads us to believe the polarity switches, we believe it doesn't happen quickly. We are talking about a geological timescale here. The field won't flip by the end of the year any more than a new mountain will appear by then.

4. I think the biggest consequence if the field suddenly flipped is that we would have to fix a lot of navigational equipment.

5. You're more likely to get killed by the consequences of silly superstitions — say, based off a calendar ending on a particular date — than you are from a magnetic field polarity reversal.

ktizo4• 14 years ago

In rough agreement with you, but have a quibble about your second point. As far as I understand it, while the lower atmosphere does provide significant protection, the ionosphere does have a substantial role to play as well.

Here is a very brief outline of this from everyone's favourite experimental nutter-magnet/atmospheric testing facility, HAARP: http://www.haarp.alaska.edu/haarp/ion3.html

[edit] Just thought and realised that the ionosphere is very little to do with the issue. I should really be talking about the magnetosphere and how it helps protect us from highly energetic particles in the solar wind. So my quibble still stands, but my reasoning was a big steaming pile of monkey poo.

mistercow• 14 years ago

>As if the inside story of our planet weren’t already the ultimate potboiler, a host of new findings has just turned the heat up past Stygian.

I hope, when old media finally dies, that this sort of "clever" news-writing dies with it.

MPSimmons• 14 years ago

The author of this piece REALLY wants to write fiction. I can appreciate the florid tones in a human interest piece, or in an epic tale, but time and time again, I found myself wanting more information where instead, I got a bit of fluff.

It was well-written fluff, but still. Facts, please!

JonnieCache• 14 years ago

The BBC did a great Horizon documentary on The Core recently where they visited some researchers and looked at some shiny machines which attempted to replicate the conditions at the core and grow iron crystals or something. It talks about local variations in the earth's magnetic field as well. I recommend it.

cnbeuiwx• 14 years ago

I would go for D) Scientists dont have a clue.

Because despite all human hubris, we are pretty much in the dark ages. When we have learned how to sustain ourselves without raping the planet, then maybe we can at least be called civilized. Although still a very primitive species.

Humans dont like viewing themselves as primitive and limited, but we very much are. We are unaware of the alien species constantly being around us, we think 90% of the DNA is "junk" because we dont understand what it does, we call space "empty" because we dont see whats there, etc.

Its all very much based on hubris and ego. Very very primitive. I often feel like Im watching a society that is completely nuts. Valuing paper more than the planet that is giving us life every second of every day (!).

Ok, rant over... its just mind boggling...

rsanchez1• 14 years ago

I think you have that tin foil hat on a little too tightly.

lukifer• 14 years ago

Everything is primitive, in that it is the origin for the things to come. The way I think of the situation is that our species and its civilization are frightfully young, with all the arrogance and naïveté that entails. Here's hoping we're not the kind of teenager that kills ourselves by crashing the family car.

redwood• 14 years ago

If heat is coming up 3x faster than expected, isn't there a good chance that this could have a material affect on global climate? Perhaps this is yet another significant piece of the chaotic climate record.

The Earth's core: the enigma 1,800 miles below us

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