Scientists who believe in the Old Earth hypothesis seem to all agree that our Moon was formed or captured by the Earth's gravity approximately 4,500,000,000 years ago. Astronomers and planetary scientists have measured our Moon's orbit and distance from Earth between 225,600 miles at perigee to 252,000 miles at apogee. This distance is increasing at approximately 4 cm (1.6 inches) every year. Old Earth scientists adhere to the axiom 'the present is the key to the past' or uniformitarianism that natural laws, speeds and functions remain constant throughout time. Simple mathematics then would locate our Moon at approximately 120,000 miles from Earth when it was formed or captured. What would be the effect on Earth's tides if the Moon was that near? What other effects (other than a shorter month) would that have on the Earth?
I think the moon would be moving away from the earth at a faster rate early in its history. Yes, tides would have been huge then. Also the day would be very short. Maybe 8 hours or so. The stresses on the moon would be huge. Maybe enough to keep the core of the moon molten, like some of the moons of Jupiter now.
Likely our moon had incredible effect on the Earth during the fist billion years of it's existence. It is also likely the planet had far less liquid at that time and was relatively molten. This probably meant a fluid surface that shifted regularly before solidifying somewhat. As the crust cooled and the moon moved further away in orbit, the combination of Cometary impact and water vapor allowed for ocean formation which furthered the cooling to an extent. Over another couple billion years the surface became cooled enough to allow for a solid crust and tectonic plate formation which created basins for the liquid water to settle and begin erosion of the crust. This began the process of soil development which eventually created a base for organic material to develop complexity...the rest is pretty strait forward.
Some think the Moon was formed in a collision with another planet (Theia). If so, the Moon was at a distance of 0 from the Earth when formed, and it would have been quite a messy affair. Supposedly this event also gave Earth it's characteristic 23 degree tilt that defines the 4 seasons. Eventually the Moon and Earth would go in orbit around each other, like a double planet. As the Moon moved further away the barycenter would move closer to the Earth and both orbits would slow down. The Earth and Moon would both be molten during this time and experience nasty tidal forces. - - - Updated - - - What causes the tides other than gravity?
Yes, today that's the most shared hypothesis about the genesis of our moon. The impact of an other proto planet against e very young earth caused the expulsion of a huge amount of materials towards the orbital region. We can imagine the earth, just after the impact, as a semi molten sphere, very hot, with a wide disc of fragments, dust, pieces of rock ... it was that disc, aggregating itself, to form the moon.
If it's moving at a faster rate historically then you have even LESS time for the Moon to go from its impossible early orbit to its current orbit. Understand? There isn't enough time for the moon to have drifted toward tidal lock like they say that is what the moon is doing. - - - Updated - - - Why would a disk aggregate around a single object? All the mass is moving together, what would pull it all toward one center of a very disperse orbit? The asteroid belt didn't coalesce around a single object. You obviously haven't thought this through very well.
Why? By moving consistently 4 cm further away from the earth the moon would have had roughly 9,5 billion years to reach its current orbit, if my calculations are correct.
your calculations dont consider absurdities such as a moon orbiting the earth at 1 cm above the surface. https://www.physicsforums.com/threads/how-fast-can-an-object-spin.701153/ I am trying to figure out just how close could the Moon get to the Earth before physical impossibilities occur such as becoming "unbound" (a condition where the angular momentum or the force of the spin exceeds the gravitational attraction).
Exactly, if I had a better math background I suppose I could figure out for myself just what reasonable limits exist on the closeness of the moon... Although we have one other POTENTIAL record called Tidalites...which could infer distance by periodicity of the tides in supposedly ancient rocks. Either way what I am suggesting is let's say the Moon could only be half as close as it currently is...at that distance the moon has some 4.5 billion years of play. If it's less..even less. But there is another feedback that is problematic, the moon is drifting away into tidal lock, which simple physics tells us that the closer it is the faster the move toward tidal lock. So ~4cm/year is the SLOWEST it has ever moved away from the Earth...so we are dealing with the very possibility that the time the Moon has existed and been in orbit is Absurd.
Wait, the asteroid belt is a kind of fossil relic of ancient proto planets and meteors. The volume of such a belt is enormous, while the belt of fragment around the earth was in a very little volume [in comparison to the asteroid belt]. Anyway note that also some asteroids there are the result of aggregation, so imagine the moon. Then, the mechanic of the impact generated a not symmetric distribution and this favored the aggregation [you don't have to imagine an uniform disc like the ones around Saturn, there was a quite dense cloud of material above the region of impact and it became to orbit, collecting the other material becoming more and more dense and big ...]. Take a look at this simulation: http://it.wikipedia.org/wiki/Formazione_della_Luna#mediaviewer/File:Big_Slash.gif
Might I recommend you get a hobby other than Physics and Orbital dynamics? It is very likely your understanding and confusion come about due to visualizing our current moon as the proto version. It also seems you do not quite grasp distances and gravity.
Your post prompts another impossibility of 4 -5 b.y.a of the universe, how could a smallish moon at near zero temperature still have a molten core? (I think you meant to write a shorter month.) The supposition that the moon's regression was once greater does not fit in with other uniformitarianism rules used by evolutionary cosmologist and has not been proved by any geological discoveries. - - - Updated - - - That does make for a good sci-fi story, but does not fit with any current scientific evidences.
The collision theory for the formation of the Moon has been rejected since lunar rocks and soil were brought back and analyzed from the surface in 1969.
Please note the use of the word "Likely", which designates possibility with supporting evidences. It is also abundantly clear from your postings that your understanding and knowledge of "Current Scientific Evidence" has very much to be desired. I do appreciate the compliment on my hypothesis however...I very much enjoy Sci Fi.
They aren't correct. 1.6 inches per year times 4.5 billion years = 7.2 billion inches divided by 63,360 inches per mile
I will refer you to the same lunar rock sampling analyzed in 1969 proving the Moon and Earth rocks have different compositions. - - - Updated - - - Do you have a doctorate degree in Physics or Orbital Dynamics?
I can tell you love sci-fi. So do I (definitely not a Treki type sci-fi fan.) Please read again what I posted above. Lunar samples and time/distances do not allow for the two bodies to be related. - - - Updated - - - Are you going to provide that evidence or do we simply take your word for it?
No...nor have I claimed to, I do however seem to comprehend some of the complexities at a level above your own. By the way...our moon composition bares great resemblance to the outer crust of the Earth: "Studies shown that the Moon's composition closely resembles that of Earth's crust and mantle. From this, scientists concluded that a Mars-sized body hit Earth within a few million years of its formation. The impact vaporized much of the material in Earth's crust and mantle and blasted them into space, forming a ring around the planet. This material quickly coalesced to form the Moon -- Earth's steady companion in its never-ending trek around the Sun." http://stardate.org/astro-guide/ssguide/moon
Actually, you have that backward. The examination of lunar samples is the whole reason the collision theory cam about.
Sorry no, I won't. I don't feel like retracing stuff from the internet that I've read somewhere in the past because you'll refute the parts you don't like anyway. Besides I just mentioned the opposing evidence because I acknowledge that your guess about the origin of the moon is as good as mine. I don't feel the need to prove you wrong, and I couldn't. Peace.
