Earth’s magnetic field has reversed a number of times in its history

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Discussion Overview

The discussion revolves around the concept of Earth's magnetic field reversals, including the implications of these reversals, the terminology used to describe related phenomena, and the potential effects on life on Earth. Participants explore the meaning of "drift away" in the context of magnetic pole movement and inquire about the environmental impacts of magnetic pole flips.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested
  • Meta-discussion

Main Points Raised

  • Some participants express confusion about the term "drift away," seeking clarification on its meaning in the context of magnetic poles.
  • Others provide various interpretations of "drift away," suggesting it means to move slowly or aimlessly.
  • One participant notes that magnetic poles flip approximately every 200,000 years, with the last flip occurring 780,000 years ago, raising concerns about potential dangers to humanity.
  • Another participant argues that magnetic pole flips do not correlate with mass extinctions, which occur on a much longer timescale.
  • Some participants share resources, including links to videos and transcripts that explain magnetic pole reversals in simpler terms.
  • There is a mention of the South Atlantic Anomaly as a significant weakening of the magnetic field.
  • Questions arise about whether compasses will eventually point south due to magnetic pole shifts, with clarifications provided regarding the current positioning of magnetic and geographic poles.
  • One participant discusses the dual meanings of the word "drift," highlighting the complexity of English vocabulary.

Areas of Agreement / Disagreement

Participants generally agree on the terminology and implications of magnetic pole reversals, but there are competing views regarding the potential environmental effects and the relationship between magnetic flips and mass extinctions. The discussion remains unresolved on these points.

Contextual Notes

Participants express varying levels of understanding of English, which influences their interpretations of terms related to magnetic phenomena. The discussion includes references to external resources for further clarification.

Who May Find This Useful

Individuals interested in Earth's magnetic field, language nuances, and the implications of magnetic pole reversals may find this discussion beneficial.

momentum
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please see this English text ...The Earth’s magnetic field has reversed a number of times in its history. Before the poles actually flip, the magnetic field weakens and the magnetic poles drift away from “true” north and south.


>>>magnetic poles drift away from “true” north and south.

what does 'drift away' means ? I don't understand the meaning of 'drift away' ...I need english help ... any native speaker or someone knows better english ?N.B: is not the north pole of Earth's magnetic field a little distant away from geographic north pole ?
 
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Andre said:
Have you tried http://translate.google.com/#

drift away:

التغرب
отклонение
allunyar-se
游離

etc, etc

unfortunately my language is not listed there. ...so I did english to english conversion.

but anyway , I had a feel that it means dragging away , throwing away .
 
I also read

On average, the
magnetic north and south poles flip about
once every 200,000 years. The last time the
poles flipped was 780,000 years ago.
Therefore, the poles are in the process of
reversing.

really ? is it dangerous for human race ? what is the environmental effect for this if truly pole flips this way i.e south pole becomes north pole and north pole becomes south pole ?
 
momentum said:
unfortunately my language is not listed there. ...so I did english to english conversion.

but anyway , I had a feel that it means dragging away , throwing away .

More like, "move away from, slowly."
 
drift away -

wander away, meander away, going aimlessly in any direction, to stray away, deviate away.

Discussion about Earth magnetic fields should go in the Earth forum.
 
lisab said:
More like, "move away from, slowly."

like the clouds in the sky... drifting slowly.
 
runner said:
like the clouds in the sky... drifting slowly.

ahh...beautiful analogy addition ...simple , concise and exact hit ... I liked it ...thanks :)
 
  • #10
If you note the fossil record: periodic mass extinctions every 200,000 years (on average) do not exist. It seems reasonable to assert that a "magnetic pole flip" is not an event that devastates all living things.

Mass extinctions occurred on a far longer time scale than every 200,000 years. I'm defining mass extinction as an event that results in the extinction of 50% or more of the species living at the time. The last one of these was at the end of the Cretaceous, ~65 million years ago.
 
  • #11
Evo said:
I don't know how good your English is, but here is transcript of a show about magnetic pole reversal in laymen's terms.

A video showing how it would work.

http://www.pbs.org/wgbh/nova/magnetic/reversals.html

You can click on "transcript" to read the program.

http://www.pbs.org/wgbh/nova/magnetic/

thanks for the links .

you know I just need literal meaning ... no engineering stuff ...no complex mechanism needed...just simple meaning in simple English :)

I appreciate for the effort . And thanks for sharing your valuable time.
 
  • #12
jim mcnamara said:
It seems reasonable to assert that a "magnetic pole flip" is not an event that devastates all living things.

he he ... good good ... no apocalypse to come ... no 2012 kind of things :)
 
  • #13
So our compasses will one day point south?
 
  • #14
Hi momentum! :smile:
momentum said:
what does 'drift away' means ? I don't understand the meaning of 'drift away' ...I need english help ... any native speaker or someone knows better english ?

"drift away" means what a boat does when it has no power (no sails, no engine, no oars), but it isn't tied up …

if you forget to tie the boat to the jetty while you go off to get an ice-cream, you'll come back to find the boat moving very slowly away … and you can't stop it! :biggrin:

that's drifting!​

"Drifting" is used to describe any really slow movement …

for example "continental drift" is a few cm a year.
 
  • #16
leroyjenkens said:
So our compasses will one day point south?
Yes, but note that if you are near the geographic north pole, your compass already points south!

The magnetic north pole is not at the geographic north pole.
 
  • #17
300,000 years is what i saw on history channel today. they use the polarity in the rock formed on the ocean floor to determine which direction was...well...north per say...they didnt say when the last one was, but if its 200, or 300 thousand, and its been 700 thousand years...what gives here?
 
  • #18
Hello, momentum, I note that English is not your first language.

You might like to know that the word 'drift' has two nearly opposite meanings.

The meaning here is

'move in a casual or aimless manner'

drift into sleep
the leaves drifting about in the road

but drift is also used in the sense of driven (from drive) where something is directed by an outside force or agency.

a snow drift is a pile of snow collected (driven) by the wind
get my drift = the aim or purpose of a thought


There are a significant number of words in English that have more than one meaning. It can be quite confusing if some of these meanings are also opposite.
 

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