Pangea

[dbcooper2]

This is just one of a few things that have just never seemed to be correct. A logical fallacy, if you will. An unexplained discrepancy in accepted science that has just never made sense. I do not wish to question the legitimacy of Pangea, there is overwhelming evidence to support the conclusion that all the current continents were, in fact, once part of one giant landmass connected together. That all seems a forgone conclusion.

My issue has always been in the physics of it. For billions of years this planet existed with one single giant landmass, on one side. While this in and of itself does seem to be a bit out of balance, like it's all weighted to one side, that of course would just be misconception as there is the water to counter balance. Except as I learned more I came to see that this couldn't be correct. For now instead of two large water masses, broken at each basic halfway point by land, you now have all the land concentrated in one location, with all the oceans one giant body unbroken for the rest of the globe. Now when you consider that this globe is spinning at a phenomenal rate, that water is a liquid and that centrifugal force does exist. Would you not then assume that this one body of water is being pushed up against one side of that side landmass? So now there is the entirety of the worlds land mass on one side of the globe, and add to that the weight of the water being pushed up against that landmass by the centrifugal force of the spinning planet, and you have a disproportnate amount of the mass of the planet on one side. Anyone who has used a washing machine and had a load get slightly out of balance can tell what happens when a little to much of the load gets to one side, and I'm certain the results would be quite similar. That's not to even bring up the effects that can happen from that much water all in one body, on a planet with a wobble to its rotation. (Ever carry a tub of water? The larger the surface area the container provides, the more sloshing you get, which can quickly become an issue.) This is just an overview of what has always just seemed illogical in the theory of the evolution of this planet.

It has always been overlooked, or seemingly so, perhaps it has been addressed and it's just not out in the mainstream easily accessible. Maybe it was just part of something that was so long ago no one thought to ask. Or perhaps they were all just to busy trying to prove or disprove the idea of Pangea or something else, that the simple physics of it just never occurred to anyone. What ever is the case, anyone who has ever breached the subject of Pangea I have asked this of, including numerous teachers in my youth, all to no response. So I bring it to this forum, and I hope to the correct section.

[Janus]

The combined mass of the continents is very small compared to the overall mass of the Earth, so their shifting would have a minimal effect on the Earth's rotation. Besides, 1 rotation per 24 hrs (0.00069 rpm) isn't what I'd call "spinning at a phenomenal rate".

Your analogy of a washing machine doesn't work either as with a washing machine the axis of rotation is fixed while with a free rotating body like the earth it is free to shift as mass is redistributed ( and as I noted above, this shift would be small due to the small portion of the Earth's mass the continents make up.)

 

Given the extreme slow rate at which the continents shift and the fairly slow rotation rate of the Earth, neither would you expect to be any "sloshing" effect of the Oceans as you seem to think.

 

All in all, I would have to say that your whole argument is very poorly thought out.

[studiot]

A lump on one side of the washing machine huh?

 

There is one place in a washing machine the washing stays away from.

The axis of rotation.

 

This represents a fundamental difference from the Earth's continents.

 

Pangea was not the first super continent, nor is it likely to be the last.

But look at today's globe.

The continents are lumped together, not equatorially or on one side of a spinning globe, but spread around the axis concentrated close to the poles.

 

http://www.nature.com/nature/journal/v482/n7384/abs/nature10800.html

Edited April 8, 2016 by studiot

[dbcooper2]

Though it seems insignificant and kinda slow, the earth's rotation speed is around 1000 mph. So as speeds go, that seems fairly ohenon

[swansont]

Numbers have to be used in context. As Janus pointed out, the mass in question is small, and the rotation rate is small, too. The amount of landmass above sea level is probably around 10^20 kg or so (surface area is 10^18 km^2, several hundred meter average thickness, covering a third of the earth). If it's 6x10^20, then that represents a part in 10^4 of all the mass. If your load of laundry is 10 kg, then this is a one gram imbalance. In a machine spinning once per day. Is that really a big problem?

[Strange]

 

A good, professional-quality bowling ball is smoother than the Earth.

https://what-if.xkcd.com/46/

 

OK. Slightly off topic. But worth it, if only for the line, "Fortunately for us, there are people who digitally scan bowling ball surfaces".

[Greg H.]

Though it seems insignificant and kinda slow, the earth's rotation speed is around 1000 mph. So as speeds go, that seems fairly ohenon

Not really. If you really want to see some impressive rotational speed take a look at Jupiter (28,000 miles an hour). But don't get too caught up in that big impressive number. What really matters is the RPM. A car tire (on average) rotates about 750 times a minute - this is why a weight imbalance causes such a drastic reaction The earth spins (as pointed out above) literally several orders of magnitude slower than a car tire, which means it is several orders of magnitude more tolerant to any weight imbalance.

[Janus]

Though it seems insignificant and kinda slow, the earth's rotation speed is around 1000 mph. So as speeds go, that seems fairly ohenon

It's not just he speed that counts; it also the the radius of the circle in which you are traveling. Drive around a hair pin curve at 30 mph and you'll definitely feel it. Take a gentle turn on the freeway at 80 mph and you won't even notice it. Centripetal acceleration is found by v^2/r, so a speed of 1000 mph (444 meters/sec) at a radius of 6378000 meters gives an acceleration of 0.03 m/s^2 or .003g, not highly significant.

 

Another example of why speed alone is not significant:

 

The Earth orbits the Sun at ~30 km/sec, but because of the large radius of the orbit, the centripetal acceleration is only 0.006 m/sec^2(0.0006g). This is 1/5 as much as that calculated above for the spinning Earth, even though the speed is over 67 times greater.

[dbcooper2]

I see what you are saying with the mph vs rpm, that does put the speeds more into perspective. And as far as surface mass, I do understand that a majority of the earths mass is not surface, and I guess if you take the tectonic plates that everything rides on, distance from surface of ocean to the bottom of the tectonic plates is the same as surface of the land mass to bottom of tectonic plates is possibly the same? (Not really certain if that is true) and the main portion of the earth's mass is below that and fairly evenly distributed, if all that is true then the balance wouldn't be an issue really. Just always seemed peculiar. I know in geology (high school edition, many years ago) they taught us that the water levels in bodies of water were effected by the rotation of the planet, even though there were tides created by moon and sun, if you take out tide effects and just saw the water itself, it wasn't level due to planet rotation. So basically the planets spin. So, I think it's Western side is always higher then Eastern, bit dislexic so things sometimes get flipped in my brain and I don't realize it's backwards, but I think that's correct, planet spins to the east, so force pushes water to the west. All bodies of water are pushed to their Western side, before tides and currents are figured in. That just always made it seem like one continuous body of water would mean a much more significant mass shift to the west. Unlike now where the shift is broken up and stays kinda balanced out.

 

Always thought if Pangea had been some sort of balanced out, with an opposing land mass, it just made more sense. Also seemed to make dinosaurs more reasonable, since that's another total wtf altogether. I mean I have seen a few proposed theories over the years, and the last I found recently is far better then anything before, but still seems strange. The theory that the air was much thicker in the distant past so that it had a consistency similar to modern day oceans, creating an actual buoyancy that helped to counter gravity and allow some significantly raised limits on how large land animals could grow. But if the air was similar to water, even though it was air, wouldn't be more like a liquid then a gas? And wouldn't that show in evolution, high percentages of land creatures have some type of aquatic features, nothing really drastic, just some fins and webbing type stuff that would increase balance and movement. Just things similar to that. Other ideas seem far less outlandish now then they did before. Things like if the bottom of tectonic plates to surface of planet is not a significant portion, then if the astroid the caused the extinction of the dinosaurs had a more sideswipe and knock off just some tectonic regions, or just hit so hard and so direct that the force went through and just popped some off. Like you would get from serious force applied to an object and just carrying through to effect the exact opposite side. As stated above, the majority of the planets mass is below tectonic area, so not some huge decrease in mass, but in diameter and surface area, not only causing a planet wide extinction event, but moving the surface closer to center of gravity as the remaining regions moved around to close up the hole, like possibly 1/8 - 1/3 give or take. That would cause an increase in surface gravity since mass would be fairly similar, the distance from center of gravity would really be the most significant difference. That might just account for variance in creature growth from then to now. And it may help clear up that whole lone gunman Pangea supercontinent that has just always bothered me. On a plane that is always so well balanced from the micro on up to the whole food chain and ecosystem, (minus humans and things done by them, built by them, caused by them, etc.) That whole one single supercontinent for billions of years just seemed so out of balance and odd. Even the ecosytems we can reconstruct from pre dinosaur extinction was balanced and symmetrical, that single continent never looked balanced.I mean I know it sounds insane, and I need to go dig up some figures and calculate surface gravity differences and the growth size limits for those kind of gravity differences, but it could work.

 

It would also be a reasonable counter to that whole growing planet proposed hypothesis that I just never liked, but had some points that grew on you. (Hahahaha) Like their computer model of shrinking the globe to remove the oceans and fitting all the current continents including Antarctica neatly together into not a supercontinent, but just a tiny earth with only some large lakes instead of oceans. (Yea, I know, computer models are much like statistics, they can be made to present things in a way that says what you want it to, like how news programs are always saying there has been a 12% increase in the number of this from 1995 to 2015. And never put into proper perspective by including that the population has grown by over 200% in that same time, making that growth % an actual decrease overall. Computer simulation can be done similar.) And the growth marks on the bottom of basically the entire Pacific ocean floor, and a good bit of the Atlantic as well. And the damn core samples from some reputable, referenceable geolological something or other, that really do show significant differences between age of land on bottom of ocean floors and the surface land masses. Some girth could be lost, some shrinkage of diameter, but it wouldn't just seal shut with remaining plates, 1) plate movement is really slow 2)may not be enough to just shrink shut completely without significant core loss and there by mass loss. So there would have to be some new growth. Might work. Sorry I know this isn't really the type of science board for crazy ideas, just kinda came together as I wrote it. I'll be back.

[studiot]

 

I'll be back

 

Perhaps when you do you will pick out a short list of key points you would like answered.

 

 

Meanwhile I recommend looking at

 

The Emerald Planet

 

by David Beerling

 

It is the only book dedicated to a geological history of the Earth's atmosphere (and to a lesser extent the hydrosphere) that I know of.

You might find some suprises there.

[dbcooper2]

Apologies, what began as an attempt to defend my position on the point of Pangea being the only unbalanced thing in an otherwise beautifully balanced world, I got interrupted 337 times and realized while looking up some figures on the mass distribution of planetary mass that the Pangea was irrelevant after seeing some proportional data on the actual insignificance of mass from bottom of tectonic plates up compared to the core areas below. It would be much more symmetrical and balanced if there had been another continent opposite Pangea,but oh well.

 

Pales in comparison to the realization that the impact from the asteroid that caused planet wide extinction could just as easily also be the reason for the whole dinosuar paradox. An impact of that nature could very easily have dislodged some tectonic plates, they just float on the planet, their not attached. Gravity is all that's holding them on, and it really is the weakest of forces. Grab a magnet, pick up something metal with it and the magnet just over powered gravity. And the loss of all the tectonic plates isn't really a super significant loss in mass, is in circumference though. It isn't any change in sequence of events, or established theory. Still goes dinosaurs, asteroid,extinction, tectonic drift, reevolution of life (mammals), some number of ice ages, and then here we are. Very generalized timeline, btw. The only addition would be the dislodging of some tectonic plates, and that's not really a big stretch. Their not attached, float on a liquid, there are numerous ways of impacting that could dislodge some floating rock chips that are proportionally light. Could happen without really any significant mass loss, would just be a circumference change. Tectonic plates now would be floating on less liquid buffer over the planet cores, which makes sense. The liquid buffer would have gone with the plates below it, the rest spreads as the remaining plates spread. No real reforming the inner cores with the significant portion of mass and the shape would be the same. The surface would just be closer to center of gravity, causing a higher effective surface gravity, and lower the overall size and size limits for land animals. How's it go? The simplest most direct and uncomplicated answer is ussually correct? Anyway, still trying get enough of the right data to calculate how much circumference would have to change, been one of those days, raining like mad, internet going in and out, somebody needing something non-stop. I will be back with some numbers to say how significant of a circumference change would be required, go from there.

[quote name="studiot" post="917159" timestamp="1461010203

 

The Emerald Planet

 

by David Beerling

 

It is the only book dedicated to a geological history of the Earth's atmosphere (and to a lesser extent the hydrosphere) that I know of.

You might find some suprises there.

 

While I haven't read that book in particular, I have done some reading on the idea of a hydrosphere and the much thicker atmosphere, not like our modern sea water, but approaching the consistency of a liquid, and the idea is really cool. I even read some of the scientific theory with the nessacery buoyancy formulas and the probable ppm content that would be needed to breach that whole muscle strength/ muscle mass threshold that make dinosaurs a bit of a riddle. One that the creationist cult leader pretending to be a scientist has seized upon and exploited to further propogate his ridiculous science trying to use the Bible as a literal historical record and sell his 6000 year old universe bs. I like the hydrosphere theory, it's reasonable, logical, nonevasive, and not just a load of bull. I think it is really the only really possible, scientific, plausible theory I have ever scene to address the whole riddle of dinosaur existance. The only thing that really gave me pause was its lack of any evolutionary evidence. That evolution, he is one merciless, calculating, unforgiving dude who will exploit any teeny tiny little thing he can turn to an advantage, and he had a really long go at it with the dinos. They had a huge chunk of history that they dominated, and their evolution was extensive. It just seems that if the atmosphere was think enough to be referred to as a hydrosphere and had enough buoyancy to provide lift for these megalithic creatures, he would have used that in their evolution. Some type of dorsal fin down their backs,the added balance would be possibly a game changer. And some type of flippers or webbed upper appendages to increase movement speed and mobility and dexterity. I mean, not an absolute that it should be there, just seems if there was air thick enough to be referred to as a hydrosphere evolution would have explored that shamelessly. Not any type of expert on either evolution or dinos, just seems that evolution would have worked with that, and I don't recall ever having seen anything that would make me think it had. Still not gonna discount it as possible, just a pause in my thoughts on it. It is sure way better then the whole well all the continents were one giant landmass so they had more room to grow and get big I got as a curious kid asking why nothing was that big any more. And it is light-years beyond the creationist cult leader fake scientist dude. It's still a viable option, just got some questions on its validity.