[dreadgeek]

Originally Posted by LadyFlamezzz

I watched the big documentary on the supposed event and I came away with this idea....true enough the milky way does have a black hole in the center which we all know the gravitational pull of a black hole, right? The alignment with our core <earth> has to have some kind of effect much like that of a full moon accept greater. The oceans waters will rise creating floods. To what degree who knows. The cycle of life could be changed drastically if the earths movement is changed to the .1 degree they said it would, it would create a counter clockwise rotation flipping the poles. I don't think this would be an over night event though. It would take years and years causing a gradual altering of the entire life cycle on the planet.

just my three cents

I hate to ruin the party here (well, sort of) but there's a couple of things I think need to be clarified here because the supposed 'science' behind the 2012 idea is actually a misunderstanding of the science.

I'll take these one-by-one:

1. Black hole at the center of the galaxy: Is there a black hole at the center of the galaxy? Yes. Does that black hole have any gravitational effect on the Earth? No. At least none that is measurable. Why? Because gravity falls off according to the inverse square law. What this means is that, like all other measurable fields, the strength declines as a *square* of the distance to the source of that field. Even though the supermassive black hole at the center of the galaxy has a gigantic gravitational field, it is not strong enough to have any effect on our local neighborhood. What holds our solar system in its little neighborhood of the Milky Way is the angular momentum of the solar system in relation to the rest of the galaxy, NOT the supermassive black hole itself. To give you a sense of the gravitational forces effecting Earth consider the following three celestial bodies: the Sun, the Moon, and Jupiter. Obviously the Sun, being the center of gravity for the solar system has the largest effect. The Moon has an effect on the Earth which causes the tides. Jupiter, which is the next largest gravitational body in the Solar system, has an effect ONLY in as much as it acts like a gigantic vacuum cleaner hoovering up Oort cloud objects (read comets) and asteroids before they reach the inner solar system.
2. Polar shift: Here the misunderstanding is caused by mistaking the magnetic North pole from the arbitrary geologic point we label the North pole. These are not the same thing. As it turns out, what we *call* the North pole happens to correlate with the magnetic North pole but that has not always been the case. At various points in the Earth's history, the magnetic poles have flipped and the magnetic poles do 'wander' a bit because of geophysics of the Earth's core (which is what causes the Earth's magnetic field). However, these flips are ONLY of the magnetic poles and not the *physical* (arbitrary) points on the map we call the North and South poles. That would require rotating the Earth 180 degrees on its axis. Could this happen? Highly doubtful and any force that COULD do that would sterilize the surface of the Earth. How can we be so certain of this? Two events, one in the very distant past and one in the relatively recent past (on geologic terms not human terms) demonstrates why. At some point, the object that became the Moon slammed into the early Earth almost shattering the planet and creating the Earth-Moon gravitational system. This impact most likely created the 23 degree axial tilt of the Earth (the Earth does not, in fact, rotate perpendicular to the plane of orbit but at an angle which is what gives us seasons). The other event is the last *major* impact the Earth went through which was the K-T extinction event which wiped out the dinosaurs. In that event an meteor about the size of Manhattan island (6 miles in diameter or so) slammed into the Earth. This impact was so traumatic that crystals on the *other* side of the planet from the impact have a 'shock mark' through them! It rang the planet like a bell and through up huge amounts of material into the atmosphere and wiped out 50 - 70 % of all life on the planet. But it did not effect either the angular momentum (rotation) or the orientation (axial tilt) of the Earth at all! Even if we took every single nuclear weapon on the planet, piled them all up on one side of the planet and detonated them simultaneously it would not change the axial tilt of the Earth.
3. Alignment with the galactic plane: Where to begin with this one? The simplest thing is that every December the Earth-Sun system lines up with the approximate center of the galaxy with no effect. There is nothing special about the galactic plane itself and Earth is not about to cross the galactic plane at any rate. The last time we did was several *million* years ago.
4. Solar follies: The last one is the idea that a massive solar flare will flip the Earth on its axis. Most of why this is *impossible* I've already covered in the polar shift section. However, it might be useful to just inject that a solar flare would NOT have the mass necessary to move the Earth at all because the Earth is hugely massive. Think about it this way. Imagine that you are in, say, a 747 on the tarmac. Someone shines a gigantic spotlight on the airplane. Will this cause the plane to move? No. Do all of those photons striking the plane actually put pressure on the plane? Yes, as a matter of fact they do but the amount of pressure compared with the mass of the plane is negligible. The same is true of any *conceivable* solar flare. Any flare that was large enough to cause us worry would not be because it would cause the Earth to change its axial orientation. Rather it would be that it would ionize the atmosphere shutting down our very complex electronic civilization. However, the magnetic field of the Earth protects us from the worst of those effects.
5. Meteor strikes: Might we be hit by a meteor in 2012? This is *possible* however, there are no *known* objects that will make a close pass to the Earth in 2012. The next near close pass of a major object is Apophis in 2029. That pass will be VERY close, beneath the orbit of geosynchronous orbit satellites (25K miles or so) but it is not expected to hit the Earth in 2029. However, there is a non-zero probability that it will pass through a *very* small region labeled the 'keyhole' which if it does, it *will* hit the Earth in 2035 when it is on its way out of the solar system. However, the 'keyhole' is a region of maybe only a five or ten miles. To give you a sense of context, imagine standing in New York City and trying to shoot a basket hanging somewhere in central China!

The whole 2012 thing is hype and nothing more. It sells books, it sells movie tickets but there is nothing to it. Dec 21 2012 will come and go and Dec 22 2012 will come and go. People who have made their money on the 2012 hysteria will have their money and they will then go on to pretend that they DIDN'T make predictions that failed to come true and will then start hyping the Apophis event in 2029. There is NO scientific basis for believing that anything at all interesting will happen on Dec 21 2012 unless humans do something incredibly stupid but that isn't the kind of thing we're discussing here.

Cheers
Aj