What is geometrical reversal ?

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What is geometrical reversal ?

Post by Blr243 » 09 Oct 2019, 4:14 pm

In relation to our earth , magnetism As I have been useing a compass for nav lately , a bit of my research has led me to this topic. But I don’t understand it. It’s doing my head in. I understand that once it happened over 100 year period but sometimes it can take 12000 yrs to occur. And it doesn’t necessarily happen on a regular basis. Does our planet flip over upside down or is it just our magnetic field reverse so that my compass needle will point to the south instead of the north? Some of you may be as confused as me. Others might get it. I’m lost
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Re: What is geometrical reversal ?

Post by Die Judicii » 09 Oct 2019, 4:33 pm

I'm just as much in the dark as you Mate,,,,,,,,, but,

"once every 12.000 years" I'm guessing its not much to worry about, unless it happens in this day and age,,, whereas the good news is,,
that you will only have to deal with it once.
:lol:
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Re: What is geometrical reversal ?

Post by JSS » 09 Oct 2019, 4:48 pm

Are you talking about polar magnetic reversal? I looked into it once before and no-one not even NASA could explain it in any sort of way that was even remotely understandable. So based on Einsteins quote "If you can't explain it simply, you don't understand it." I don't think anyone knows how the hell or why it happens.

This is about as close to english as the most plausible guess gets.

Hypothesized triggers
Some scientists, such as Richard A. Muller, think that geomagnetic reversals are not spontaneous processes but rather are triggered by external events that directly disrupt the flow in the Earth's core. Proposals include impact events[40][41] or internal events such as the arrival of continental slabs carried down into the mantle by the action of plate tectonics at subduction zones or the initiation of new mantle plumes from the core-mantle boundary.[42] Supporters of this hypothesis hold that any of these events could lead to a large scale disruption of the dynamo, effectively turning off the geomagnetic field. Because the magnetic field is stable in either the present North-South orientation or a reversed orientation, they propose that when the field recovers from such a disruption it spontaneously chooses one state or the other, such that half the recoveries become reversals. However, the proposed mechanism does not appear to work in a quantitative model, and the evidence from stratigraphy for a correlation between reversals and impact events is weak. There is no evidence for a reversal connected with the impact event that caused the Cretaceous–Paleogene extinction event.
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Re: What is geometrical reversal ?

Post by Blr243 » 09 Oct 2019, 6:36 pm

D j. I take you did not get any dogs these last few days ? JSS. thanks for your effort but I think it might be one of those things that I don’t understand for a while
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Re: What is geometrical reversal ?

Post by Blr243 » 09 Oct 2019, 6:38 pm

Other than my compass I actually have another 8 different techniques for finding my quad bike in the dark so I’ll b right for a bit
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Re: What is geometrical reversal ?

Post by Stix » 09 Oct 2019, 6:44 pm

Blr243 wrote:Other than my compass I actually have another 8 different techniques for finding my quad bike in the dark so I’ll b right for a bit

EIGHT...!!
What are they...?...easy enough to briefly explain...? :unknown:
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Re: What is geometrical reversal ?

Post by Blr243 » 09 Oct 2019, 7:53 pm

Physical natural methods I would say BREEZE If I get disoriented in the dark after a bit of shooting action and the breeze is consistent I can tell direction with the breeze ....STUBBLE ROWS FROM THE PREVIOUS CROP they run east west There are 2 BLUE FLASHING LIGHT FARM BEACONS one is to the south west the other to the south east ...THE STARS. I LOOK FOR THE CROSS if I’m a bit temporary bushed. But mostly if I see pigs in my binos I look at the star s directly above them. Then I walk 200 m looking at the stars to help me stay on track. Then I do a bino check again then I shoot them piggies. ...I have a small rechargeable solar powered light sitting on top of my quad ( garden light ) as soon as I shoot a pig I turn round and head back to that light. THERMAL BINOS I use them to find my quad as it’s usually still hot and it shows up anyway after it cools down. I can also see the grain silos in the south east direction I have a COMPASS hanging on my neck I use it when I get in the s**t or I twist the dial to get a bearing and use it for navigating to and from pig mobs if it’s overcast and I can’t see the stars ... I use GOOGLE EARTH or similar to see ecxactly where I am in realation to the edges of my paddocks and where my quad is. And finally I have a gps dog tracking collar on my quad. If I’m really tired at 3 am and I can’t think properly and it’s overcast I can dig my gps tracker receiver out of my mini back pack and it will lead me straight back to my quad where my dog sits upright intently focused on the dark looking for any sign that I might be heading back to him for an ammo top up or a snooze. ....I never usually think too much about navigation in the day because we just seem to have a general awareness of where we are but on black nights beteeen dusk and dawn I have to pay more attention to it. It’s a major part of my hunt plan
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Re: What is geometrical reversal ?

Post by Oldbloke » 09 Oct 2019, 9:12 pm

".I have a small rechargeable solar powered light sitting on top of my quad ( garden light ) as soon as I shoot a pig I turn round and head back to that light."

What a grouse idea. Ill remember that.
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Re: What is geometrical reversal ?

Post by No1_49er » 09 Oct 2019, 10:29 pm

Blr243 wrote:In relation to our earth , magnetism As I have been useing a compass for nav lately , a bit of my research has led me to this topic. But I don’t understand it. It’s doing my head in. I understand that once it happened over 100 year period but sometimes it can take 12000 yrs to occur. And it doesn’t necessarily happen on a regular basis. Does our planet flip over upside down or is it just our magnetic field reverse so that my compass needle will point to the south instead of the north? Some of you may be as confused as me. Others might get it. I’m lost

Have you been doing your head in by watching this? https://www.youtube.com/watch?v=1VPfZ_XzisU
Salient point starts at around 10 min.
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Re: What is geometrical reversal ?

Post by Die Judicii » 09 Oct 2019, 10:45 pm

Blr243 wrote:D j. I take you did not get any dogs these last few days ? JSS. thanks for your effort but I think it might be one of those things that I don’t understand for a while


Your not wrong Mate, in fact I haven't been out since the 1/4 moon.
Have been too busy setting up a spare tank for Bore water only, and plumbing it up via a pressure pump, that feeds only
the laundry for clothes washing and the toilet.

Times are getting real bad, and am down to only 1 1/2 tanks of rainwater

Next step unless we get rain,,,,,, is buying drinking water. :thumbsdown:
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Re: What is geometrical reversal ?

Post by Die Judicii » 09 Oct 2019, 10:59 pm

JSS wrote:Are you talking about polar magnetic reversal?

This is about as close to english as the most plausible guess gets.

Hypothesized triggers
Supporters of this hypothesis hold that any of these events could lead to a large scale disruption of the dynamo, effectively turning off the geomagnetic field. Because the magnetic field is stable in either the present North-South orientation or a reversed orientation, they propose that when the field recovers from such a disruption it spontaneously chooses one state or the other, such that half the recoveries become reversals.


I think that a similar thing happens albeit on a minuscule scale with a dynamo eg: DC Welder.

There are certain things that happen whereas it chooses (of its own accord) which terminal is positive or negative.

ie: when inserting new brushes, or changing the drive direction, upon initial start up, sometimes the normally positive terminal suddenly becomes negative.
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Re: What is geometrical reversal ?

Post by JSS » 10 Oct 2019, 7:41 am

Die Judicii wrote:
JSS wrote:Are you talking about polar magnetic reversal?

This is about as close to english as the most plausible guess gets.

Hypothesized triggers
Supporters of this hypothesis hold that any of these events could lead to a large scale disruption of the dynamo, effectively turning off the geomagnetic field. Because the magnetic field is stable in either the present North-South orientation or a reversed orientation, they propose that when the field recovers from such a disruption it spontaneously chooses one state or the other, such that half the recoveries become reversals.


I think that a similar thing happens albeit on a minuscule scale with a dynamo eg: DC Welder.

There are certain things that happen whereas it chooses (of its own accord) which terminal is positive or negative.

ie: when inserting new brushes, or changing the drive direction, upon initial start up, sometimes the normally positive terminal suddenly becomes negative.


DJ you've probably just outsmarted all the worlds scientists and come up with the most simple and understandable explanation of what the hell happens. Should have known you'd sort it for us after seeing your results on your shooting platform.
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Re: What is geometrical reversal ?

Post by Blr243 » 10 Oct 2019, 9:25 am

No 1 49 , I did have a look at your link. And even though I did not understand all of it I considered it quite worthwhile because it helps me to understand movement and stabilisation and inertia etc in a great range of things in life ....the tennis racket example was a great tool they used in an effort to help us understand it all
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Re: What is geometrical reversal ?

Post by Stix » 10 Oct 2019, 1:37 pm

No1_49er wrote:
Blr243 wrote:In relation to our earth , magnetism As I have been useing a compass for nav lately , a bit of my research has led me to this topic. But I don’t understand it. It’s doing my head in. I understand that once it happened over 100 year period but sometimes it can take 12000 yrs to occur. And it doesn’t necessarily happen on a regular basis. Does our planet flip over upside down or is it just our magnetic field reverse so that my compass needle will point to the south instead of the north? Some of you may be as confused as me. Others might get it. I’m lost

Have you been doing your head in by watching this? https://www.youtube.com/watch?v=1VPfZ_XzisU
Salient point starts at around 10 min.


A pretty cool video No1_49er... :)
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