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2098: "Magnetic Pole"

Posted: Mon Jan 14, 2019 9:49 pm UTC
by keithl
Image
Alt Text: People keep trying to come up with reasons that we should worry about the magnetic field collapsing or reversing, but honestly I think it's fine. Whatever minor problems it causes will be made up for by the mid-latitude auroras.

I worry that this will dissipate the inner van Allen belt before we get a chance to dissipate it ourselves, using thin sheets of orbiting material to change the pitch angle of all those energetic protons, and deflect them into the upper atmosphere at lower mid-latitudes. What a light show! Auroras are wasted over oceans, and at higher latitudes where it is too cold to spend all night watching them.

Re: 2098: "Magnetic Pole"

Posted: Mon Jan 14, 2019 10:29 pm UTC
by Archgeek
I worry that one of the mini-poles that models indicate are liable to form during a reversal event (which go on for centuries, if I recall) will manifest under a major metropolitan area, funneling energetic particles near to surface level and increasing the rate of various cancers significantly.

Re: 2098: "Magnetic Pole"

Posted: Mon Jan 14, 2019 10:38 pm UTC
by RogueCynic
I was going to make a snide remark about the poles reversing but was beaten to the punch. I guess I'll blame the drifting on global warming.

Re: 2098: "Magnetic Pole"

Posted: Mon Jan 14, 2019 10:56 pm UTC
by Flumble
I imagine the aurora is specks of vaporized Dalek. And inside the Earth's core there's a heavily time-dilated Doctor fuzzing and reversing the polarity, to protect us from adapted Daleks coming through.

Re: 2098: "Magnetic Pole"

Posted: Mon Jan 14, 2019 11:13 pm UTC
by Heimhenge
Even during a field reversal there might be a residual field from the inner core that gives us some protection. This article a NatGeo speculates that core could be a "permanent magnet" of sorts ... like one giant crystal lattice with all the magnetic domains aligned:

https://www.nationalgeographic.org/encyclopedia/core/

So the field reversals "recorded" on the magnetic tape of sea floor magma might have a constant bias underlying those reversals.

EDIT: I guess what it comes down to is "Despite the incontrovertible dipole flips in the geologic record, is there any evidence of increased radiation during those field transitions? It could show up as isotope spikes in ice cores ... the last flip was like 780,000 years ago, and the oldest ice cores go back 2.7 million years, but I couldn't find anything online correlating that idea.

Re: 2098: "Magnetic Pole"

Posted: Mon Jan 14, 2019 11:24 pm UTC
by Soupspoon
Heimhenge wrote:https://www.nationalgeographic.org/encyclopedia/core/

So the field reversals "recorded" on the magnetic tape of sea floor magma might have a constant bias underlying those reversals.

https://en.wikipedia.org/wiki/The_Core

A disastrous film.


:P

Re: 2098: "Magnetic Pole"

Posted: Mon Jan 14, 2019 11:50 pm UTC
by Archgeek
Heimhenge wrote:Even during a field reversal there might be a residual field from the inner core that gives us some protection. This article a NatGeo speculates that core could be a "permanent magnet" of sorts ... like one giant crystal lattice with all the magnetic domains aligned:

https://www.nationalgeographic.org/encyclopedia/core/

So the field reversals "recorded" on the magnetic tape of sea floor magma might have a constant bias underlying those reversals.

Well I'm disappointed -- I was going to ask if the bias field meant the total field strength was greater in one polarity than the other, or if it was orthogonal; but then I read the article, which speculates nothing of the sort, asserting that the inner core's well above iron's Curie point and so cannot host a magnetic field of that type.

(Don't even get me started on how weird it is that a bunch of stationary dipoles pointing the same way can generate a macro-scale magnetic field in the first place...at least the dynamo field makes sense without the aid of tensors.)

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 1:07 am UTC
by Heimhenge
Archgeek wrote:
Heimhenge wrote:Even during a field reversal there might be a residual field from the inner core that gives us some protection. This article a NatGeo speculates that core could be a "permanent magnet" of sorts ... like one giant crystal lattice with all the magnetic domains aligned:

https://www.nationalgeographic.org/encyclopedia/core/

So the field reversals "recorded" on the magnetic tape of sea floor magma might have a constant bias underlying those reversals.

Well I'm disappointed -- I was going to ask if the bias field meant the total field strength was greater in one polarity than the other, or if it was orthogonal; but then I read the article, which speculates nothing of the sort, asserting that the inner core's well above iron's Curie point and so cannot host a magnetic field of that type.

(Don't even get me started on how weird it is that a bunch of stationary dipoles pointing the same way can generate a macro-scale magnetic field in the first place...at least the dynamo field makes sense without the aid of tensors.)


DOH! I cited the wrong article. My apologies. Been reading a lot about this. Curie point notwithstanding, there may be a ferromagnetic crystal there:

https://www.psc.edu/science/Cohen_Stix/cohen_stix.html

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 1:47 am UTC
by qvxb
Wandering magnetic pole - Lech Walesa on vacation.

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 8:32 am UTC
by Rrhain
Well, there is something we use regularly that is connected to the magnetic press: Airplane runways. Runway numbers are based upon the angle the runway makes with magnetic north. It helps the pilot know where the runway is.

When the poles shift, the runways have to be renumbered.

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 10:43 am UTC
by jonhaug
Am I the only one to worry for all the magnetoreceptive bacteria and pigeon babies who now cannot find their way back home (or wherever they are heading)? (What did happen to those last time?)

https://en.wikipedia.org/wiki/Magnetoreception

/Jon

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 12:47 pm UTC
by da Doctah
qvxb wrote:Wandering magnetic pole - Lech Walesa on vacation.

Alexander Graham Kowalski - inventor of the telephone Pole.

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 3:26 pm UTC
by Archgeek
Heimhenge wrote:
Archgeek wrote:
Heimhenge wrote:Even during a field reversal there might be a residual field from the inner core that gives us some protection. This article a NatGeo speculates that core could be a "permanent magnet" of sorts ... like one giant crystal lattice with all the magnetic domains aligned:

https://www.nationalgeographic.org/encyclopedia/core/

So the field reversals "recorded" on the magnetic tape of sea floor magma might have a constant bias underlying those reversals.

Well I'm disappointed -- I was going to ask if the bias field meant the total field strength was greater in one polarity than the other, or if it was orthogonal; but then I read the article, which speculates nothing of the sort, asserting that the inner core's well above iron's Curie point and so cannot host a magnetic field of that type.

(Don't even get me started on how weird it is that a bunch of stationary dipoles pointing the same way can generate a macro-scale magnetic field in the first place...at least the dynamo field makes sense without the aid of tensors.)


DOH! I cited the wrong article. My apologies. Been reading a lot about this. Curie point notwithstanding, there may be a ferromagnetic crystal there:

https://www.psc.edu/science/Cohen_Stix/cohen_stix.html

Oh wow, aligned along the axis of rotation...so if there is a magnetic bias field, it's towards, oddly enough, true north or south. Neat.

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 5:42 pm UTC
by SuicideJunkie
da Doctah wrote:
qvxb wrote:Wandering magnetic pole - Lech Walesa on vacation.

Alexander Graham Kowalski - inventor of the telephone Pole.

Not to mention the honorable Sir Veigh, inventor of the Telephone Poll.

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 7:50 pm UTC
by xtifr
jonhaug wrote:Am I the only one to worry for all the magnetoreceptive bacteria and pigeon babies who now cannot find their way back home (or wherever they are heading)? (What did happen to those last time?)

https://en.wikipedia.org/wiki/Magnetoreception

/Jon

Yeah, that's my main concern. Ordinarily, it probably wouldn't that be a big of a deal, but we're sort of in the middle of a massive die-off anyway, and this is likely to be one more stress on an already overstressed ecosystem.

One of the biggest concerns is probably honey bees (which are already having plenty of problems, thank you very much). It may not be a big issue there, as they probably only care about relative directions, rather than absolute, so as long as they have a magnetic field, they may be ok, no matter which direction it points. But bees are pretty critical to a lot of things, so any risk there is one we should be taking seriously.

I'm also concerned about salmon, which are (among other things) a whole lot tastier than pigeons (IMO). They're also pretty important to certain ecosystems, as they carry huge amounts of tasty protein inland from the sea.

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 8:50 pm UTC
by Heimhenge
Archgeek wrote:
Heimhenge wrote:
Archgeek wrote:
Heimhenge wrote:Even during a field reversal there might be a residual field from the inner core that gives us some protection. This article a NatGeo speculates that core could be a "permanent magnet" of sorts ... like one giant crystal lattice with all the magnetic domains aligned:

https://www.nationalgeographic.org/encyclopedia/core/

So the field reversals "recorded" on the magnetic tape of sea floor magma might have a constant bias underlying those reversals.

Well I'm disappointed -- I was going to ask if the bias field meant the total field strength was greater in one polarity than the other, or if it was orthogonal; but then I read the article, which speculates nothing of the sort, asserting that the inner core's well above iron's Curie point and so cannot host a magnetic field of that type.

(Don't even get me started on how weird it is that a bunch of stationary dipoles pointing the same way can generate a macro-scale magnetic field in the first place...at least the dynamo field makes sense without the aid of tensors.)


DOH! I cited the wrong article. My apologies. Been reading a lot about this. Curie point notwithstanding, there may be a ferromagnetic crystal there:

https://www.psc.edu/science/Cohen_Stix/cohen_stix.html

Oh wow, aligned along the axis of rotation...so if there is a magnetic bias field, it's towards, oddly enough, true north or south. Neat.


Yeah, I thought that was totally sensible. The inner core had to be random at first, as it assembled during the "iron catastrophe". Then, over the eons, as the outer core churned above it, the inner core gradually picked up the average orientation of the outer core's field. Whenever the inner core actually solidified/crystallized, that would determine the polarity. Article wasn't clear about that detail though.

Re: 2098: "Magnetic Pole"

Posted: Tue Jan 15, 2019 9:19 pm UTC
by mathmannix
SuicideJunkie wrote:
da Doctah wrote:
qvxb wrote:Wandering magnetic pole - Lech Walesa on vacation.

Alexander Graham Kowalski - inventor of the telephone Pole.

Not to mention the honorable Sir Veigh, inventor of the Telephone Poll.

also, Fisher Price, inventor of the Telephone Pull...
Image
(Hey, they're homophones where I come from...)

Re: 2098: "Magnetic Pole"

Posted: Wed Jan 16, 2019 5:02 pm UTC
by cellocgw
Got this far and nobody posted "Fucking Magnetic Poles: How Do They Work?"

Oh, well.

I'll award 2 DarkNets to anyone who can combine magnetic pole flip with a bobcat or a velociraptor

Re: 2098: "Magnetic Pole"

Posted: Wed Jan 16, 2019 8:59 pm UTC
by xtifr
cellocgw wrote:I'll award 2 DarkNets to anyone who can combine magnetic pole flip with a bobcat or a velociraptor

I got nuthin' on bobcats, but I know of no reason not to think that velociraptors use magnetoreception, so the shifting of the poles could affect their migratory patterns, putting some of our cities at risk.

Re: 2098: "Magnetic Pole"

Posted: Sat Jan 19, 2019 12:04 am UTC
by Steve the Pocket
SuicideJunkie wrote:
da Doctah wrote:
qvxb wrote:Wandering magnetic pole - Lech Walesa on vacation.

Alexander Graham Kowalski - inventor of the telephone Pole.

Not to mention the honorable Sir Veigh, inventor of the Telephone Poll.

Who served under Lord Duvall, master of ally Sir Veigh.

OK, this has gone on too far already.

Re: 2098: "Magnetic Pole"

Posted: Sun Jan 20, 2019 4:47 am UTC
by Cougar Allen
Um ... so what happens to this single crystal permanent magnet when the Earth's magnetic field changes polarity? Does the whole inner core flip over? Does it flip polarity without physically moving? As far as I know the Earth's magnetic field has equal strength in both polarity modes.

Re: 2098: "Magnetic Pole"

Posted: Sun Jan 20, 2019 4:38 pm UTC
by Heimhenge
Cougar Allen wrote:Um ... so what happens to this single crystal permanent magnet when the Earth's magnetic field changes polarity? Does the whole inner core flip over? Does it flip polarity without physically moving? As far as I know the Earth's magnetic field has equal strength in both polarity modes.


The (second) article I cited doesn't say, and I didn't follow up with any of its references. But I can't imagine the inner core/crystal flipping polarity ... don't see a mechanism for that to happen. Perhaps it just exerts a permanent bias on the overall field, which is far from symmetric. See this interesting thread over on StackExchange:

https://earthscience.stackexchange.com/ ... y-stronger

That said, I expect the larger part of Earth's field is generated by the outer core dynamo. And I think the inner core's field would be at least partly shielded by the largely ferromagnetic outer core.