Quote:
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
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Lady Flamezz:
I thought I'd add a bit more about the supermassive black hole at the center of the galaxy and why it has no measurable effect on us. In order to understand the full implications of this, it's necessary to dive a bit deeper into gravity--what it is and how it works.
So....
Gravity is the warping of space-time by the presence of mass. The more massive an object is, the more gravitational influence it has. One implication of this is that, EVERYTHING with mass has SOME gravitational influence. That includes you, me, and everything else. However, your mass compared with the mass of the Earth is absolutely negligible so for all practical purposes we can ignore the mass of living things for the kinds of applications we're talking about. Another reason why we can ignore the mass of living things is that gravity is a field and ALL fields obey the inverse square law. To understand this falling off, let's take an ideal situation.
Imagine a sphere that has mass. At distance 1R from the sphere, let's say that there are 9 'lines of force' radiating out in all directions contained in a box that we'll label B1. The lines of force in B1 will be F-F-F-F-F-F-F-F-F At distance 2R there will be *four* foxes which will have a pattern like B1: F-F-F B2: F-F-F B3: F-F B4: F-F. At distance 3R: there will be *nine* boxes with one line of force. The more F's in a box the greater the force. So a box with 9 lines of force in it has a greater amount of force than a box with one line of force.
The reason I explained this was to give you some way of visualizing what is happening with the gravitational force between the supermassive black hole at the center of the Milky Way and the Earth. Now, we are 30,000 light years from the galactic center. A light year is 5,878,488,057,210 miles. That is an incomprehensible distance! To put it into scale, it takes light about 8 minutes to traverse the 93 million miles from the Sun to Earth. Moving at that speed it takes 30,000 years to traverse the distance between the Sun and the galactic center. Gravity propagates through space at the speed of light. Now, what I'm trying to get you to visualize is this: the gravitational effect of the galactic center is negligible while still being non-zero. However, it is so negligible as to not be worth considering for ANY applications that we're likely to use. (The only one I can think of where we would need it is to account for what is caused 'gravity lensing' when dealing with an object on the *other* side of the galaxy from us.)
The gravitational force of the galactic center has NO effect on the tides (which are effected by the Moon pulling on the crust of the Earth slightly deforming it and causing the water to rise).
The axial tilt of the Earth does not stay precisely at 23 degrees, by the way. It actually precedes at MORE than the .1 degree you mention (it actually changes about 1 degree over a 72 year cycle).
As far as the Earth ever reversing its rotational direction that will NEVER happen. The angular momentum of the Earth (angular momentum is what keeps you upright when riding a bike) has so much energy in it that any force that would change that angular momentum enough to effect our rotation so drastically would literally shatter the Earth into pieces.
Cheers
Aj