Earth's Magnetic Field Flippage

Well, don't know whether to break out the tin-foil hat or go full body with it! :laugh:

BBC - Earth's Magnetic Field Weakening

I'm a little not up to speed on this as they say it flips every 200k years, but the last major flip was over 700K years ago...

However, while this is one of those why worry, there isn't anything you can do about it, if we're without our mag-blankie for a period of time, will make the ozone-hole look like a stroll in the park...

Well. Time to start building an underground bunker. Lol :lol:

Your average speaker magnet has about 2T. An MRI machine runs something like up to 3T through your body, and not only don't you suffer no lasting damage, you don't even feel the field flowing through you at all despite your electrochemically functioning nervous system.

The earth's magnetic field peaks at below 70µT. That's something like three times one in a million your average speaker. Apart from vaguely shielding us from solar winds (peaking at energies as high as fifteen orders of magnitude below the work you need to lift a chocolate bar by a yard, with a magnetic field still measured another three orders of magnitude below that of earth's) and cosmic rays (something like ten orders of magnitude below the chocolate bar; the atmosphere does much more of a job shielding us against that), it is quite literally of no consequence to us whatsoever. Now, there are other animals who can sense magnetic fields and they might be slightly confused and startled for a moment when the polarity switches, though no harm will come upon them through it either.

Gisteron wrote: <snip>..it is quite literally of no consequence to us whatsoever.....

So, my impression that it shields us from nasty energetic sun-bursts is a misunderstanding? No sunburns will be worsened by it's weakening/loss?

No electronics will be toasted by the "shields-down" of temporarily losing the magnetic blanket?

It does, and they will but the effect is more or less negligible as far as I know (and I shall stand corrected, if I'm wrong). As for electronics, no, the electromagnetic fields they generate on their own are way stronger than earth's, anyway. Orders of magnitude stronger, in fact. Earth's could flip all the time or not be there at all, and the electronics wouldn't give a rodent's bum either way.

Disclaimer; AFAIK...

I read somewhere the reason Mar's probably losts its atmosphere is that its core stopped turning, and the magnetic field collapsed... allowing the Solar wind to literally blow away the atmosphere - its vital to protect us from the Sun. Luckily Earth's core is much larger then Mar's and should keep on turning. A field reversal would at least allow us to print maps the correct way around (upside down with Australia at the top)
:silly:

Sidetrack... Did you know the North pole is actually the South pole and vice versa!

Logic being that a magnets north pole points north, but since a north pole on a magnetic is attracted to a south pole, its actually pointing to the Earths south pole!!!! Which we call a north pole because our magnet's north pole points in that direction - another example of human-centric distortion to facts.

What if, say, yesterday, the magnetic polarity started shifting. How long would it take to reverse?
Centuries?
Decades?
Millennia?

James Burke in The Day the Universe Changed gives the timeline polarity occurring five times every million years.

Alan,

It's not clear, initially theories indicated a millennia or more, but newer information indicates it can happen within a century or less...