Pandora's low gravity mirrored on the early Earth?

[Mike Philbin]

Neal Adams - Conspiracy of Science - Earth is growing (http://mikephilbin.blogspot.com/2008/09/neal-adams-conspiracy-of-science-earth.html) is one of my favourite explanations of seismic/volcanic activity on our planet, and the really fun thing is Neal Adams isn't even a scientist, he's a cartoon artist.

Anyway, why bring this up here? Pandora has low gravity, hence the size of the Na'Vi etc...

If earth was SMALLER in the past, as Adams suggests, would this go to explain why the DINOSAURS (sorry Creationists) were able to grow to such a HUGE STATURE, as standard?

Earth had low gravity, because it was smaller back then?

[Aihwa]

Yes, because a cartoonist obviously has qualifications.

[Theorist]

well, I don't think you mean growing in size, simply meaning volume, meaning a larger raidus. If you mean growing in mass, ignore what I'm saying

The force of gravity =

F = M(earth)xM(object)xG(gravitationalconstant)/R^2 (where R is the distance from the Earth's center of mass to the object in questions center of mass)

So, if earth were smaller in radius, the gravitational effects would be stronger. If earth were larger in radius, gravity would be weaker. So, if it were smaller, I would have had a larger gravitational effect.

However, if the earth were to increase in rotational velocity (ie: days were shorter because the Earth spins faster, like 22 hours maybe) the effects of gravity would be weaker. If Earth were to spin slower, gravity's effects would be more noticeable, because of "Centripetal Force" F = mV^2/R

[applejuice]

Actually, a faster spinning Earth should be an Earth with a smaller radius, if we consider its mass constant. The Japan quake made the Earth spin a bit faster, a microsecond but no mass was lost or gained in the process, more likely, the Earth's mass distribution changed. This is because of the angular momentum conservation, just like a spinning skater, when she extends her arms, she slows her angular speed, if she brings her arms closer to her body, she spins faster. As for the mega fauna existent in Earth millions of years ago, it was not necessarily due to a weaker gravity force but because mega fauna evolved in the seas, where, effectively, the effects of gravity are diminished because of buoyancy. The most evident proof of that are the ocean creatures, like the cetaceans.

Edit: One more important thing, given the magnitude of the Gravitational Constant (10^-11) the main contributor to Earth's gravity is the quantity of matter it has. Earth is a quite dense planet, composed mostly of Iron and Nickel, if mass is being created in the core of the Earth, then, necessarily, its angular speed MUST decrease and, with more mass, more gravity, and with more gravity, our Moon should be coming closer to us, but it is going away from us...

[Eternal Enigma]

With the presence of more gravitational force any life on Earth at that time would have to be able to cope with such gravity. To do this any living thing would have to have a much larger overall body mass to accommodate the muscle mass necessary for movement in such an environment. This would explain why dinosaurs were able to be as large as they were. If you move forward in time with the Earth becoming larger (in size not mass) the reduction of the gravitational forces would explain how life was able to become smaller as you move forward through the prehistoric timescale.

Less gravity = less muscle necessary to move = less overall mass of an animal.

If the gravitational force was a hundred times greater than it is now (or more) humans would be unable to do much of anything because we would lack the muscle mass necessary to move in such an environment. We would then have to adapt and become larger. Since our muscles would become larger it only makes sense that in order to hold up our muscles our bones would become larger and denser. Now does the size of the dinosaurs make more sense?

For plants this would work in the opposite direction… less gravity would allow trees to reach unimaginable proportions while animals could be much smaller. That’s not saying that larger animals couldn’t exist, but with the theory of evolution in place it would make it less likely. Animals would have adapted to the reduced gravity, which would have resulted in smaller overall mass.

Also I’ll touch on the moon moving away…

If the moon is moving away from us (2 inches per year) and has been doing so for 70 billion years (or longer) then by the time humans came along the moon wouldn’t have existed at all. It would have been long gone over such an immense time span. It would be 70 billion years away. The moon is still here and still appears to be the same perspective size as the Sun like it always has. There’s no evidence showing our moon being any closer than it is right now. We wouldn’t want it to be closer because of how it would affect things on Earth. For instance the “super moon” suggests that the moon suddenly jumped towards Earth just for one night. If this really happened we would have experienced apocalyptic tsunamis hundreds of feet high and buildings would have collapse. Those who weren’t killed (billions dead) would have had a disaster like what we see in Japan, but on a global scale.

I said all of that without incorporating unnecessary math. ^_^

[applejuice]

Conservation of angular momentum should be enough to demonstrate that the Earth-Moon system is a constant-mass one. If it wasn't, all the calculations on Moon receding and the Earth slowing because of it, would simply not fit. But they do.

[Wanderlust]

The size and gravitation of the Earth have remained roughly constant (2.8%) throughout its history. The increase due to cosmic dusts and impacts is negligible in the terms of what this hypothesis proposes. The dinosaurs and other large prehistoric animals were huge due to the incredible amounts of vegetation available to them, high levels carbon dioxide allowed for more plant abundance. This has also been observed in humans, people/popuation groups who have better nutrition usually are bigger. The average height in the middle ages (poor nutrition eras) was around 5". Increased oxygen levels also allowed them to have more energy to support large sizes.

Gravitation could also have an effect on the size of life, but not on Earth since there has not been much variation in Earth's gravity field for the time life has been on it. Lighter gravity would allow for larger/taller species. Pandora is a moon that has lighter gravity (that would be relatively constant) than the Earth which allows for taller plant species. Don't forget the Na'vi seem to be very well nourished as well.

In regards to the moon. Its orbit moves outward from the earth 3.8 cm a year. Thi may seem like alot, but it has only resulted in a few thousand kilometers in a couple hundred million years. The current orbit is 360,000 The tidal force of Moon's gravitation acting on the Earth pulls up a tidal bulge. Since the Earth is rotating much more rapidly than the Moon can orbit, the planet's rotation pulls the tidal bulge ahead of the Moon. The added mass of the bulge leading the Moon pulls on it gravitationally, imparting energy and resulting in an ever-increasing orbital radius; at the same time, the friction caused by the Earth rotating through the tidal bulge results in a continually-decreasing rotational period.

This increase in moon distance has been directly observed through a mirror/lazer system. The mirrors were deployed during the Apollo missions.

[Eternal Enigma]

Humans who eat excessively gain mass in fat. I’ve yet to see 50ft tall muscle bound humans due to over eating or because of an abundance of food availability.

In low gravity environments it takes less energy to move therefore you do not need to eat as much regardless of the abundance of food available. Since it takes less effort to move in low gravity environments you wouldn’t need massive muscles. So the overall muscle mass would be reduced because according to evolution it would be unnecessary. That’s not to say that larger animals couldn’t thrive in these types of environments it just suggests that animals being the size of buildings would be less likely to occur in low gravity environments. The size would be completely unnecessary from an evolutionary standpoint.

In high gravity environments you must have large muscles in order to move or you’re going to be a pool of lard lying lifelessly on the ground. It’s as simple as that. Animals in lower gravity environments need less muscle mass to move and the result is smaller overall mass. You guys are good at looking stuff up so look up what happens to astronauts with long-term exposure to zero gravity. They lose muscle mass (regardless of how much they eat or workout) and they lose bone density. It takes less effort for them to move and the result is the loss of muscle mass and bone density due to not having to hold up their body weight. Astronauts can lose up 60% of their muscle mass or more in just 6 months. This can translate into a 14% loss in bone density. Now, if a trip to outer space resulted in astronauts being exposed to excessive gravity they would come back to Earth with more muscle mass and more bone density because of all the effort it would take them to move about. Over a prolonged period of exposure in time humans would then be born larger to adapt to such an environment. Unfortunately due to data based on what’s currently seen in astronauts during their time in zero gravity I would imagine that humans would become invertebrates as an environmental adaptation. If you don’t need it you don’t use it and if you don’t use it you lose it.

The Earth of the past would have been much denser and the result would have been a higher level of gravity even though the size of the planet was much smaller. The Earth growing larger in size creating less density while slowing down rotation reducing the level of gravity to whatever degree could explain how living things on Earth went from being very large down to the “evolutionary” results we see in the many much smaller diverse species of today including us. It also would explain how the moon is able to drift away. If the Earth’s gravitational pull isn’t as much as it once was…

The moon…

I’ll try some math… I don’t know any of the fancy types of math, but I’ll try this…

The fact is we have no idea what the real timeline is so I’m only basing this on 70 billion years with the idea that our moon is and always has been moving away from Earth at the same rate each year.

1 Mile = 1.609344 kilometers (according to a conversion table)

1 Mile = 160,934.4 centimeters (according to a conversion table)

1 Mile = 63,360 inches (common knowledge)

3.5 cm = 1 and 1/16 of an inch… (according to a conversion table)

It is 406,700 km to the moon = 252,711.663 miles (according to a conversion table)

It should be 100% movement (1 inch per year) X 100% of the time on the timeline. In this case 70 billion years is the timeline.

1 inch per year X 63,360 inches = (1 Mile) which takes 63,360 years to achieve.

Over the course of 70,000,000,000 years the moon would move 70 billion inches.

63,360 (1 mile) will go into 70 billion (years) 1104797.97979798 times.

That translates into 1,104,797 miles, which is almost three times the distance of 252,711 miles where the moon is now. The moon would be about the size of a pencil eraser held at arms length right now if it has always been moving away from Earth at a constant rate.

This is only if you’re looking at a time span of 70 billion years and it’s really difficult to determine actual time so who knows it could much more extensive I was just picking a number. Also I’ll add that this is based off of the moon being formed right up against the primary point of origin, which would be Earth. Now it would be difficult to imagine the moon forming and being in physical contact with Earth so if the moon was already 50,000 miles away before it began to drift away then over the period of 70 billion years the moon would be 1,154,797 miles away right now. It doesn’t sound like much, but when you apply perspective change to what we see the moon would look much different than it does now. Seeing a solar eclipse wouldn’t be as “spectacular” as it is. It would be a “solar what was that supposed to be?”

Eventually the moon would approach the edge of the Earth’s gravitational pull, so if this theory is true “we” may eventually see the moon’s rotation/orbit change and one day “we” may be able to witness (through a telescope) the moon slowly leave Earth orbit. The moon would drift away and there would be nothing we could do about it. I would imagine that moment would be sad because it would be like losing an old friend. I highly doubt we’ll have to worry about this in our lifetimes. Over the course of an average human life cycle “75 years” the moon would only have moved 75 inches (75 in = 190.5 cm), which is 6’3” (1.92024 meters).

I will go on to say that some of what I covered are things that I absolutely do not believe in, but what I believe in is not as important as what I can come up with if I open my mind and take what I know apart. I’ve come to the realization that something I believe may be completely incorrect based off of something I realized while coming up with all of this. That's why I enjoy things that provoke thought.

[Mike Philbin]

Guys,

I'm basing this theory on the CORE 'lo-grav' CONCEPT of the film we all know and love far too fondly.

You're all dissing the basic foundation of WHY NA'VI ARE BLUE GIANTS, you realise this, right?

[Wanderlust]

Humans who eat excessively gain mass in fat. I’ve yet to see 50ft tall muscle bound humans due to over eating or because of an abundance of food availability.

It does not work that way. That is over individual time. Nutrition affecting population stature happens in a species evolution over successive generations. The human height average has increased and continues to increase as the generations pass.

The hypothesis of less gravity and its effect do not work on Earth because the gravity has remained relatively constant since life has been on earth.

Btw, the moon isn't expected to 'leave' earth orbit for billions of years, perhaps not even till after the sun dies. Some hypothesize that i would not happen at all, that it would reach an 'equilibrium', though i would have to do some research to find sources for it.




I will go on to say that some of what I covered are things that I absolutely do not believe in, but what I believe in is not as important as what I can come up with if I open my mind and take what I know apart. I’ve come to the realization that something I believe may be completely incorrect based off of something I realized while coming up with all of this. That's why I enjoy things that provoke thought.

Nice. :)




Guys,

I'm basing this theory on the CORE 'lo-grav' CONCEPT of the film we all know and love far too fondly.

You're all dissing the basic foundation of WHY NA'VI ARE BLUE GIANTS, you realise this, right?

What!?

[Theorist]

Just a few things, 70 billion years is way too long a time. The Universe is widely accepted to be 13.6 to 13.7 billion years old. Our solar system is roughly 5, and Earth is roughly 4.6 to 4.7 Billion years. The moon is believed to have been part of the Earth at one time, but when the Earth was just molten magma rock, an asteroid hit the Earth, knocking a chunk of magma into space. (Roughly 4.2 billion years ago) Due to the effects of gravity, this magma formed a rough sphere, and cooled. All the while, it had been sent into orbit around Earth.

And, an orbit is simply when something is moving Fast enough around the Earth, so that although it is falling (yes, the moon is falling inwards towards the Earth. Always has been since it has been there), the moon moves forward enough, so that as it moves forward, the Curvature of the Earth causes the ground to "dip" fast enough so that although the moon is falling towards the center of the Earth, it moves forward fast enough so that the curvature of the Earth "falls" before it, causing the Moon to not crash into the Earth.

Also, as far as gravity meaning big/small organisms, it's really situational. Lighter Gravity would cause a trend towards larger organisms (plants and Animals). However, low gravity doesn't mean life gets bigger, because the Genes to make organisms bigger have to be there, and be more beneficial than the small genes.

Also, eating more can add muscle mass, not just fat. It depends on the organism. Humans are a bad example, because we eat very high fat foods, and do not move around very much.

[visualizer]

The growing earth theory is utter BS. One of the most important reasons you don't see many large animals is because more intelligent species (like homo sapiens and previous species) hunted them for food. Sure, they were very difficult to hunt, but the reward was huge. And since intelligent species expanded across the globe pretty quickly, large animals constantly receded until they no longer existed. And nowadays there isn't enough room and/or time for large animals to evolve because of our "brilliant" ability to alter Earth and all of its ecosystems :/

[Mother of the Forest]

I think the Earth had a ****-ton more oxygen back then. Lolz.