posted on Feb, 7 2011 @ 06:22 PM
The force of gravity is proportional to the mass of the object and inversely proportional to the square of the distance between the two objects. So
let's do a quick back of the envelope computation.
Let's assume the comet will be 100 km in diameter and about the same density as the moon (that would be one massive comet, but we'll err on the size
of caution here -- I don't actually know how big it will be).
The moon is about 3500 km wide. Mass is proportional to volume, assuming constant density (as we are), and volume is proportional to the cube of the
diameter.
The comet is going to come within 0.3 AU compared to the moon's approx 0.003 AU.
So the effect of the comet will be (3500/100)^3 * (0.3/0.003)^2 = 428,750,000 times less than that of the moon (assuming I didn't make a mistake in
my calculations or feed in grossly inaccurate info -- it's possible I did).
Moreover, whilst there are some good theories as to how the earth's magnetic field is generated, no one currently knows for sure. There are computer
models of different possibilities which seem to broadly agree with the general characteristics of the earth's magnetic field. It seems that it's
probably sustained by churning of the molten outer iron core caused by convection and also the rotation of the earth.
However, it is not possible to predict much of anything about it, as it is chaotic. We certainly don't know how to predict reversals, as we have zero
data to work with (no one has every seen one because the last one was hundreds of thousands of years ago).
We do know that the measured dipole moment of the earth's magnetic field has been diminishing since it was first measured in the early 1800's, and
we know the north and south poles move about pretty chaotically (more rapidly in the last few years than in the decades before it). No reason to
suppose that anyone has even the foggiest clue when the next reversal will be.
Certainly no reason to suppose that a comet will have anything to do with it.
I call hoax, as this conspiracy has absolutely zero evidence associated with it so far, and common sense suggests someone made it up just for the
LOLs.
Having said that, we are about 400000 years overdue for a pole reversal, there is a comet on its way and March 15th is a date that occurs this year.
Those are apparently three facts which can be checked, all of which are very likely completely unrelated.