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PhysForum Science, Physics and Technology Discussion Forums -> Biology, Chemistry, Medicine, Other Sciences -> Biology -> Life First Started On Planet Mercury?
Last 10 Posts [ In reverse order ]
| Robittybob1 | Posted on Today at 12:41 AM | ||
| There is a force of gravity between the two bodies Earth & Moon (E&M). This force will cause an acceleration A = F/M (from F = M * A), from the acceleration we can find the new velocity V = A * t. The time is 10 years V then affects the period and radius for any extra energy will be converted to gravitational potential energy so the Moon's orbit with the Sun will alter and make the Moon orbit Faster (or slower) (which) at a different height The change in height will take (mgh) 50% of the extra energy in the system (the other 50% is in the Earth dynamics (even though we are saying for simplicity sake the Earth doesn't move). That is the bit I'm unsure of at the moment??? This means that even though the Moon slows down due to the Earth pulling it back (so to speak), but because it drops in toward the Sun, it will actually be orbiting faster and moving forward faster, this still means the time to conjunction will increase for the Earth won't be catching up to the Moon as fast. (all from the effect of slowing the Moon ends up making it go faster but on a different orbital radius. Have I got that logic right? |
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| Robittybob1 | Posted on Yesterday at 10:04 PM | ||
If the co-planet Moon is pulled toward the Earth how much does it speed up? does the speeding up significantly change the period of conjunction? I'm thinking it must. 16058 years is time taken for the natural difference in orbital period of the Early Moon-Early Earth to allow one complete lap, if they accelerate toward each other as they approach, some of this is reversed as it leaves the Earth, so that must mean the average velocity is higher and period is reduced. But by how much? The Moon gains speed on one leg, the Moon and the Earth move toward each other relatively (as well as orbiting the Sun, so I'm not suggesting anything goes backwards). The Moon would then slow on the going-away half of the orbit. I think that means the two halves are dynamically balanced. With our calculations we will use both the Early Moon-Early Earth as 42 times the current masses, remember. So you might agree the Earth and Moon at opposite sides of the Sun would have only minimal gravitational affect on each other. At the conjunction the tug will be the strongest. I know this isn't rocket science. Assuming it is a circular orbit there is a radius and the change in "theta" the angle between them.When the speed changes both theta and radius will change too. Since the Moon is much less massive than the moon we could look at the situation assuming all the changes affect the Moon only to begin with and when we feel happy with the results we will complicate the situation by having them both move. Earth:Moon mass ratio = 81.3:1 (Moon Earth mass ratio = 0.0123) Theta change per year = 360/16057 0.022420128 so we will look at 10 year blocks. This gives 0.22420128 degrees change in theta every 10 years and we will look at this finer when the rates become significant. There is probably more movement occurring in the last year prior to conjunction than in the first 5000 years after their greatest separation. So sensitivity in the later stages will be important. |
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| Robittybob1 | Posted on Yesterday at 9:07 AM | ||
Probably a bit like a double pendulum? - Just joking. Try and predict the motion! |
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| Robittybob1 | Posted on Yesterday at 8:23 AM | ||
| If it is possible to imagine it happening like this does that mean it is possible to put maths to the problem? I can't see why NOT but it will be interesting to see it. It is a matter of being able. Am I able to do it? Where do you start? |
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| Robittybob1 | Posted on May 18 2013, 09:19 PM | ||
| What are the dynamics of an orbiting body? How do they start off on an orbit? When is the energy and momentum too low? Or too high? Just because two celestial masses pass each other they don't go into orbit around each other do they? So if the Moon and Earth were orbiting the Sun, and every 16,000 years they pass each other what features would make the Moon begin orbiting the slowly rotating Earth? Starting rotation - we'll say 1 rotation per year (tidally locked to the Sun). Now that is radical isn't it? Could the Earth have been tidally locked to the Sun. Well I think it could! All the grains of dust of the protoplanetary disc would have had a tendency to be tidally locked and if the Earth is the accumulation of these components why not the Earth? Rotational momentum isn't going to appear from nowhere is it? Now whether the Earth is spinning or not could affect the ability of the Earth capturing the Moon. Did it need slowing down? Was it tidal deceleration of the repeated passing that slowed the Moon a little each time it passed? If it did the Earth would absorb this momentum and the Moon would fall into the Sun and orbit the sun at a faster rate. If this went on too long the Moon would end up going the same rate as the Earth, but one could assume the Early Earth continued to pick up mass and hence increased it gravitational strength on the Moon as it passed. Now we are going to cast our thoughts right into the Moon Earth situation at that time. As the moon approached the Earth an enormous tidal bulge would appear on both the Earth and the Moon. This is a one sided bulge for neither the Earth or the Moon are rotating to any degree. So the center of mass of both the Earth and the Moon would move closer together, the G forces increased. Lifted to a higher orbit the Moons relationship to the Sun is disrupted. Normally the centrifugal force balances the gravitational force, but note the outward forces are greater than the Sun's attraction and if the earth can hold on it has captured the Moon. The Moon slows further as more momentum is transferred to the Earth, and with the gravitational pull of the Earth the Moon is flung into an elliptical orbit around the Earth. Now the thing to appreciate is that the Moon is lifted up behind the Earth and thrown over the top of the earth (when viewed from the Sun's perspective) |
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| Robittybob1 | Posted on May 18 2013, 10:17 AM | ||
| The one thing that surprises me about the theory is how the Earth could accrete all its mass and not have quite a high rotation rate. But to get the yo-yo Capture Theory to work it seems that you need an Earth that is not rotating that fast otherwise you won't get the momentum added to the Earth, during the Lunar deceleration phase, to throw the Moon out later. When a torus contracts does it create a spinning mass? Maybe it doesn't for to begin with the torus had only orbital momentum not rotational momentum, so if it contracts it was still going to have the same total orbital angular momentum, so where was I thinking the rotational angular momentum going to come from? No, I am now convinced that a torus can contract into a planet without a massive resultant rotational momentum. There would be particles slamming into the Earth but the momentum they had, had been borrowed from the Primordial Earth's momentum in the first place. Does that make sense? Look a meteorite is attracted toward the Earth it gains speed but the speed is balanced by an equal momentum gain of the Earth toward the meteorite. So after the collision the two momentums cancels each other out. So if the meteorite was in the same orbit and started off at zero relative motion (no additional momentum) the net effect is zero. Even though there is energy released there is only a small additional momentum due to the particles coming together due to the delay. |
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| Robittybob1 | Posted on May 18 2013, 04:05 AM | ||
There would be no prospect of life on Earth after that. There are so many possibile theories but they all end up with problems of being unable to account for the inclination of the Moon or the tilt of the Earth. I'm wondering about the sense of trying to solve it from a home computer. It seems to be a problem too difficult to solve. 2 things I haven't seen discussed much: 1. The tidal acceleration/deceleration. 2. None assume the Earth was much more massive like my theory or Herndon's. I am thinking the Earth and Moon must have been interacting even before they formed properly so some of the core materials could have transferred while they were is in the primordial state. If the Moon can accrete while orbiting the Earth surely it will form while it was orbiting the proto-sun. May have been slightly later than the Earth. One thing is a must and that is the Moon formed prior to the Sun going thermonuclear. The capture may have occurred before or after this. |
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| Capracus | Posted on May 18 2013, 02:40 AM | ||
| In this version of the impact theory Theia is consumed in the process. Giant Impact Theory of Lunar Formation Gains More Credibility
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| Robittybob1 | Posted on May 18 2013, 12:50 AM | ||
I have just skimmed through this study "A New Disintegrative Capture Theory for the Origin of the Moon" available at http://arxiv.org/abs/1204.0980 It seems unlikely that I can match the level of detail in that study, but it might not be totally impossible, but it will take 5 years of study to understand something like that. So to answer your question, it was my understanding of the YouTube video I linked to the other day. Did you look through it? It was an hour long and it is hard to refer to a section in a video. I'm not sure how to do that. I'll get back to you later when I gone through it again. I'm struggling to find but the one refers to the same study "Harvard Scientists Suggest Moon Made From Earth" http://www.youtube.com/watch?v=z732iuzcxG8 Here was the one: http://www.youtube.com/watch?v=CFX4b2qRsXI "Earth-Moon Resonances - Matija Cuk (SETI Talks)" There were no non-Earth type isotopes found in Moon rocks. So where is the evidence of Theia? |
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| Capracus | Posted on May 18 2013, 12:25 AM | ||
Explain your reasoning. |
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