This "reducing magnetic filed" information is true or no?

Question

"The direction and intensity of the dipole change over time. Over the last two centuries the dipole strength has been decreasing at a rate of about 6.3% per century. At this rate of decrease, the field would reach zero in about 1600 years. However, this strength is about average for the last 7 thousand years, and the current rate of change is not unusual."

http://en.wikipedia.org/wiki/Geomagnetic_secular_variation

This information is true or not?
And what is true information?
magnetosphere how much reducing per 100year?

Answer 1

2013 + 1600 = 3613.



When I did the calculations over thirty years ago (when teaching about magnetism), I had calculated roughly the same dates (3500 plus or minus a few hundred).



The sentence

"At this rate of decrease, the field would reach zero in about 1600 years."

is misleading



Earth's magnetic field is a collection of many fields, and we often model it using two "categories": the dipole field and the random field.



This calculation only deals with the dipole component, not the other one.



The dipole field seems to reset itself after each event, and the magnetic moment seems to reset around 10 units. (Last time it reset was 41,000 years ago, and the entire field reset value was closer to 11).



The moment is presently roughly around 7 (or 7.5, depending who you ask) and the next "event" will likely begin when the moment is down to 4 units (which seems to be what happened on previous occasions). The dipole component represents roughly 60% of the total field, while the "chaotic" component is the other 40%



The discussion (about the decrease of 6.3% per century) seems to deal only with the dipole portion.



The dipole field is easy to "imagine" as a giant bar magnet near the centre of Earth. The chaotic field is a bit tougher to imagine. The best I can do is this: imagine a giant bag full of fridge magnets placed at random in the bag. There will definitely be a magnetic field around the bag, but is will not be well oriented... it will be chaotic.

Answer 2

Yes, its scientifically accurate.



The current rate of change of the magnetic field is 6.3% per century (6.3% per 100 years). But there is evidence that the rate of change can change.

Answer 3

field, not filed. Sorry, "magnetosphere how plenty decreasing consistent with 100year?" is meaningless English. you will be able to desire to spice up your English, or publish on your community language. The magnetosphere is not diminishing in radius, notwithstanding if it is your query. In English, the be conscious "authentic" has a which means implying absolute information. technological realize-how is incapable of discerning absolute truths, so any query about what is "authentic" is not one that are spoke back scientifically. you ought to publish interior of the faith and Philosophy part if you pick "reality". Is the assistance precise consistent with what is at present familiar? Is that your query? sure.

Answer 4

Probably not, there's been a magnetic field of Earth for most of the planet's life.... It comes and goes - if it went to zero for a long time, we wouldn't like it.....