Sinusoidal Path Theory / Pole Shift Surface Effects

[DancesWithBears]

Hello All,

I am new here, so forgive my ignorance if these topics have already been discussed (links please), but I have a couple of questions which I am hoping someone can answer ...

1) Is anyone familiar with the "Sinusoidal Path Theory" - and it's relevance to periodic mass extinctions ?

2) In relation to that - Are we heading towards or away from the center-line of teh Orion arm and how far away are we in terms of distance or time ?

3) What would the likely surface effects be should Earth's poles shift - and how long might that last.

Regards,
"Dances With Bears"

[apodman]

1) Here's a link: http://lxrdesign.biz/EXTINCT.htm

Worth a look IMO. Note however that the listed mass extinctions are already well explained by meteorites in two cases and by historical geological conditions impacting climate in at least one other case. Note also that, while the linked page contains points I think are valid, there are some items that I wouldn't personally endorse as truth expressed correctly (so let the buyer beware). And of course it's sketchy, not a fully developed theory.

2) According to an illustration at the link above, we're presently in the center of the arm.

3) I don't know why the Earth's poles would shift.

[Chris Peterson]

1) Is anyone familiar with the "Sinusoidal Path Theory" - and it's relevance to periodic mass extinctions ?

Our orbit within the Milky Way takes us slightly above and below the central plane, but not with a periodicity associated with mass extinctions. There is some evidence of periodicity in extinctions, but the actual number of events isn't great enough to make a very strong statistical case, and at least a couple of extinctions seem to have been caused by purely geological events. It is possible that some periodic external influence disrupts bodies in the Oort cloud and sends them our way, increasing the impact rate. But there isn't much evidence supporting this idea.

3) What would the likely surface effects be should Earth's poles shift - and how long might that last.

What do you mean by the "poles shift"? If you mean the orientation of the Earth's rotation axis with respect to the ecliptic, that is very stable. It hasn't changed significantly in billions of years, and will remain stable for billions more, because the Moon stabilizes it. If you are referring to the reversal of the magnetic poles, this happens once or twice every million years or so. It probably has a minimal impact at the surface. In mid-reversal the Earth's magnetic field is very small, and if this interval persists for long a greater number of ionizing particles will reach the surface. This could affect cloud formation, and therefore climate, and it could have some impact on life- either by increasing mutation rates or even killing off some species. Magnetic pole reversals are not associated in the fossil record with mass extinctions, however.

[Orca]

I am not sure if anyone has researched this already, but a thought occurred to me in a physics class.

The topic was magnetism and we were discussing the Earth's magnetic field and its apparent tendency to swap poles every so often. The physical evidence for the reorientation of the magnetic poles exists in the form of lavas; the atoms in iron-rich basalts align themselves with the current configuration of the magnetic poles when the rock is molten. When the rock solidifies the atoms maintains alignment.

The concern with a reversal in the magnetic poles is, how weak will the magnetic field get? How will it impact life on Earth?

Here's my thought: compare the data from the lava with the corresponding dates in the fossil record. If past pole swaps have had an appreciable effect on living things could this be detected in the fossil record by referencing pole swaps in the lava?

[Chris Peterson]

Here's my thought: compare the data from the lava with the corresponding dates in the fossil record. If past pole swaps have had an appreciable effect on living things could this be detected in the fossil record by referencing pole swaps in the lava?

This has been done. A few researchers have claimed to connect a handful of individual extinctions to a period of geomagnetic pole reversals, but others have contested those observations. It is safe to say that reversals are not responsible for major extinctions. Evidence of any effect at all in the fossil record is subtle at best.

[apodman]

Real:

http://en.wikipedia.org/wiki/Cataclysmi ... hypothesis
http://en.wikipedia.org/wiki/Pole_shift_hypothesis
http://en.wikipedia.org/wiki/True_polar_wander

Not Real:

http://survive2012.com/index.php/geryl-pole-shift.html
http://dec212021.blogspot.com/2009/09/g ... shift.html

[Orca]

Here's my thought: compare the data from the lava with the corresponding dates in the fossil record. If past pole swaps have had an appreciable effect on living things could this be detected in the fossil record by referencing pole swaps in the lava?

This has been done. A few researchers have claimed to connect a handful of individual extinctions to a period of geomagnetic pole reversals, but others have contested those observations. It is safe to say that reversals are not responsible for major extinctions. Evidence of any effect at all in the fossil record is subtle at best.

We don't know what the effects will be on large populations of humans, though. But if other life has "survived the storm" without major incident, we are most likely looking at risks such as increased cancer rates but not constant, deadly levels and the ionization of the atmosphere. Whew. I can sleep now. I am curious as to the length of time it takes the field to get to full strength again after a swap; I imagine that the longer we go with our shield down the worse off we'll all be.

At least we will get a hell of an Aurora show!

[Chris Peterson]

We don't know what the effects will be on large populations of humans, though. But if other life has "survived the storm" without major incident, we are most likely looking at risks such as increased cancer rates but not constant, deadly levels and the ionization of the atmosphere.

Seems reasonable. One of the species that has survived the storm is our own: our ancestral species certainly went through many geomagnetic pole reversals.

At least we will get a hell of an Aurora show!

I'm not so sure about that. Without magnetic field lines to focus the flow, I might expect a diffuse worldwide aurora that could be much less impressive than the current polar auroras.