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General => General Technical Chat => Topic started by: RoGeorge on January 05, 2019, 02:58:35 pm

Title: Magnetic lines of the Earth - magnetic dip angle bigger than naively expected
Post by: RoGeorge on January 05, 2019, 02:58:35 pm
https://www.youtube.com/watch?v=Of-_BBHYwRE (https://www.youtube.com/watch?v=Of-_BBHYwRE)

 ^-^
Title: Re: Magnetic field lines of the Earth are mostly pointing downwords
Post by: CatalinaWOW on January 05, 2019, 04:19:28 pm
Didn't watch the video, but anyone who paid attention in a good physics class would know that the field of the earth is 3D, and is only parallel to the earths surface near the equator. 

Image using a compass in Newfoundland or in Alaska.   Both far north with strong vertical components.  And very different results due to the details of earths magnetic field.
Title: Re: Magnetic field lines of the Earth are mostly pointing downwords
Post by: RoGeorge on January 05, 2019, 05:11:39 pm
The surprise was that the angle is much bigger than I was expecting, because the magnetic core is much smaller than the whole Earth.  Also the tilt distribution is far from being uniform:

(http://i66.tinypic.com/5lowvl.jpg)
Title: Re: Magnetic field lines of the Earth are mostly pointing downwords
Post by: GeoffreyF on January 05, 2019, 05:17:58 pm
The surprise was that the angle is much bigger than I was expecting, because the magnetic core is much smaller than the whole Earth.  Also the tilt distribution is far from being uniform:

It's only a surprise because you formed an expectation without bothering to read the subject.  Your post is still pointlessly lacking in any effort at education.  I also suggest that you read up on how distortions occur with different types of map projection. 
Title: Re: Magnetic field lines of the Earth are mostly pointing downwards
Post by: RoGeorge on January 05, 2019, 05:46:47 pm
Well, it seems that magnetic lines tilted downward up to 30 degrees at the Equator is common knowledge for everyone but me.   ;D
Title: Re: Magnetic field lines of the Earth are mostly pointing downwards
Post by: chickenHeadKnob on January 05, 2019, 06:14:37 pm
Well, it seems that magnetic lines tilted downward up to 30 degrees at the Equator is common knowledge for everyone but me.   ;D

Understanding magnetic deviation+variation is basic component to all pilot training and quite evident, especially if you are a bush pilot in Canda's north or Alaska.
Title: Re: Magnetic field lines of the Earth are mostly pointing downwards
Post by: Gyro on January 05, 2019, 06:27:09 pm
This seems like a perfect opportunity for whoever it is around here, who has is location set to Antarctica, to pitch in a demo.  ;D
Title: Re: Magnetic field lines of the Earth are mostly pointing downwards
Post by: raptor1956 on January 05, 2019, 06:41:20 pm
Correct me if I'm wrong, but wouldn't there need to be a pretty much equal number of lines exiting the Earth as there is entering the Earth.  The magnetic poles are not coincident with the axis of rotation which complicates things a bit and the makeup of the Earth is not consistent with variations in the distribution of iron and other ferromagnetic materials.


Brian
Title: Re: Magnetic field lines of the Earth are mostly pointing downwards
Post by: duak on January 05, 2019, 07:24:25 pm
Fun fact: it's called magnetic inclination or dip: https://en.wikipedia.org/wiki/Magnetic_dip

More than you might want to read about the field:  https://en.wikipedia.org/wiki/Earth%27s_magnetic_field

In a book on the Hubble Space Telescope there was a reference to the South Atlantic Anomaly where it's computer would crash & then go into safe mode:  https://en.wikipedia.org/wiki/South_Atlantic_Anomaly

Title: Magnetic lines of the Earth - magnetic dip angle bigger than naively expected
Post by: RoGeorge on January 05, 2019, 07:47:29 pm
Thank you. Title changed to include the proper term:  magnetic dip.
Title: Re: Magnetic field lines of the Earth are mostly pointing downwards
Post by: cs.dk on January 05, 2019, 08:49:47 pm
This seems like a perfect opportunity for whoever it is around here, who has is location set to Antarctica, to pitch in a demo.  ;D

 :-DD :-DD :-+
Title: Re: Magnetic field lines of the Earth are mostly pointing downwards
Post by: CatalinaWOW on January 05, 2019, 09:38:17 pm
Given the accelerating rate and direction of motion of the magnetic north pole there could be a new thread started:

"The Russians are stealing the North Pole"