PeakOil is You
Is earth growing?
Re: Is earth growing?
by The Practician » Wed 17 Aug 2011, 12:35:04
$this->bbcode_second_pass_quote('seahorse3', 'I') was curious about certain "facts" put forth in the video, to see if those are in fact "facts." The video states as fact that all the continents, including the poles, fit perfectly together. Is that true? The video then states as fact that the sea floor is 70 millions years old while the continental land masses are over 100 million years old, thus implying the earth is expanding. Is it fact that the sea floor is much younger than the continents? It states the gorge marks on the ocean floor point direction of movement (east and west). True? The video states that certain forest in the upper continents are all of the same type, even though now separated by oceans and that remnants of those forest have been found in the north pole (I believe it said). Is that a fact?
My plate tectonics is a little rusty, but I am pretty sure the sea floor is generally younger than the land masses, as it is on the sea floor where the surface of the earth is created-- where the plates are "spreading apart" this does not necessarily imply the earth is expanding however, because there are also "subduction zones, like the coastal area of BC where I live, where the crust dives under the opposing plate back into the mantle.
As for the Taiga, Yeah, i think its pretty much the same in Canada/alaska and Russia, certainly less genetically diverse than the tropical rainforests of south america vs. africa. They were probably connected longer than the lower continents. I see no reason they could not have extended further into the arctic circle during a warmer period of the earths climate.
- The Practician
- Lignite
- Posts: 270
- Joined: Wed 20 Jul 2011, 22:08:02
Re: Is earth growing?
by Sixstrings » Wed 17 Aug 2011, 12:54:34
$this->bbcode_second_pass_quote('seahorse3', 'W')ell, I'm still interested in verifying the "facts" put forth in the video that I posted earlier. The benefit of forums like this is people with vast experience and knowledge in particular areas. I'm not even close to a geologist, so, I would hope that some of our resident geologist would indulge me for a second here. There are many things I find interesting for fun.
All due respect, you don't have to be a geologist to know the earth can't grow.
Fill a cup halfway with sugar. What you have is a half cup of sugar. That's a quantifiable amount of mass. It will never, ever, grow to a full cup unless more mass is added.
The planet is mass. It can't grow unless you add in mass from an external source. I.E. a very large planet colliding with us, setting the whole crust afire in molten lava, melting down the crashing planet too, plus an explosion, and when it all cools down you've added some extra mass by combining the two planets and now you have a nifty moon with the leftover bit.
That's only way to add mass to a planet. Other than planets still growing in a nebula.
-
Sixstrings - Fusion
- Posts: 15160
- Joined: Tue 08 Jul 2008, 03:00:00
Re: Is earth growing?
by ian807 » Wed 17 Aug 2011, 13:10:31
$this->bbcode_second_pass_quote('Oakley', 'T')he gravitational force at the surface of the earth places a limit on the size of land animals with elephants being the largest today. Elephants are significantly smaller than the largest known dinosaurs of 65 million years ago, which were huge by comparison; these dinosaurs could not possible have lived if the gravity was the same or greater back 65 million years ago. Their massive bodies could not have been supported by their bone structure. The logical conclusion is that gravity was less 65 million years ago.
Ummmm..., no.
The far simpler and more likely solution is that larger dinosaurs like the brontosauri, were largely aquatic, like hippos, sea turtles or walruses. Most of their weight was supported by water. They probably only came out of the water to bear young, again, much like hippos, sea turtles or walruses.
In today's relatively oxygen poor environment, animals don't grow as large. After we manage to de-sequester all of the carbon in the earth's crust and enough of this turns into biomass, this situation may change. Who knows, humans may even live to see it.
-
ian807 - Tar Sands
- Posts: 899
- Joined: Mon 03 Nov 2008, 04:00:00
Re: Is earth growing?
by The Practician » Wed 17 Aug 2011, 13:28:02
$this->bbcode_second_pass_quote('Oakley', '')$this->bbcode_second_pass_quote('steam_cannon', '
')Yep and if they post poor quality ideas they are going to openly get knocked down. I know you're responding to my bold text about this being a geology and economics website. Of course we don't need to discuss only Geology or Economics. Personally I think other topics that relate to the community are worth discussing. But tinfoil hat topics like the old "out of this world" section took away from the forums quality and the subject of peak oil in general which has had a lot of good research go into it. So I'm glad the "out of this world" section is gone and I'd rather the open discussion section doesn't turn into the same thing. Tinfoil science is bad science and conspiracy talk makes me itch.
')Yep and if they post poor quality ideas they are going to openly get knocked down. I know you're responding to my bold text about this being a geology and economics website. Of course we don't need to discuss only Geology or Economics. Personally I think other topics that relate to the community are worth discussing. But tinfoil hat topics like the old "out of this world" section took away from the forums quality and the subject of peak oil in general which has had a lot of good research go into it. So I'm glad the "out of this world" section is gone and I'd rather the open discussion section doesn't turn into the same thing. Tinfoil science is bad science and conspiracy talk makes me itch.
Perhaps the world is more complex than your single minded attribution of dinosaur size to higher oxygen levels alone. I say single explanation because the second explanation you offer, genetics, simply begs the question and is not an answer at all; genetics is simply the means through which their size is transmitted from generation to generation. I seriously doubt that oxygen alone would explain why the largest land animal today is 7 tons while some of the dinosaurs were estimated to be 90 tons. Bone and muscle have limitations which place limitations on size; what those limitations are is better left to the minds of those who study kinesiology and paleontology.
Often it helps to understand things better to think of extremes. What do you think land animals would look like on a planet with 50 or 100 times the gravity of earth? Do you think that even in an environment more rich in oxygen that such creatures even the size of elephants, much less dinosaurs, could exist under those surface gravity conditions? I think your dismissal of gravity as a possible factor defies logic.
"The deepest sin against the human mind is to believe things without evidence"-- Oakleys Sig, believe it or not.
There is no evidence to suggest that the earths gravity was significantly less in the time of dinosaurs as it is today. Your insistence that it must defies Physics: earths mass would have to have been significantly less than it is now, and there is just no evidence to suggest that was so, even when you factor in the millon or so kg in mass the earth gains a year from space dust and the like. The limitations of muscle and bones you vaguely refer to have a lot to do with how efficiently they can exchange gases and nutrients. It follows that significantly higher concentrations of oxygen in the atmosphere would allow larger animals. C02 concentrations were also much higher back then, which must have been quite the boon to certain plant life. I have read that one of the benefits to being large is having a large and complex digestive tract that can break down and exctract the most nutrients from low quality sources, like the leaves of trees. This goes a long way towards explaining why are largest land animals today inhabit environments with an emphasis on quantity rather than quality. The big herbivorous dino's probably had a lot of trees to eat, because the CO2 rich atmosphere would have been a boon to them, and they also had a lot of oxygen in the air to make running their larger bodies possible.
- The Practician
- Lignite
- Posts: 270
- Joined: Wed 20 Jul 2011, 22:08:02
