Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum Mansfield's Earth Formation Hypothesis: Evidence.

If you read it a year ago, why don't you read it again? Then we don't have to rely on your fairly selective memory.

BTW, still waiting for you have have the balls to deal with two papers which directly refute your claims:

McElhinney, M. W., Taylor, S. R., and Stevenson, D. J. (1978), "Limits to the expansion of Earth, Moon, Mars, and Mercury and to changes in the gravitational constant", Nature 271: 316–321,

http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/1999RG900016.pdf

Not too surprisingly, you keep dragging up red herrings to avoid the fact that your hypothesis has been throughly and totally discredited.

Bryan

If I made such a claim, you'd be able to provide a link to the post where I made it. Its not like I can delete my messages off of science-a-go-go, or edit them after a few days.

I.E. if I said it, there would be irrevocable proof of it. Provide it, or shut up.

But once again, we have a red herring here. Your hypothesis has been throughly and totally discredited by these studies:

McElhinney, M. W., Taylor, S. R., and Stevenson, D. J. (1978), "Limits to the expansion of Earth, Moon, Mars, and Mercury and to changes in the gravitational constant", Nature 271: 316–321,

http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/1999RG900016.pdf

Not too surpizingly, you still haven't had the balls to address the direct disproofs of your hypothesis.

Bryan

1) Do your own homework,

2) You are lying; the paper is only 23 pages long. Had you actually looked at the reference I provided you'd have at least picked up on the page numbers.

3) Still waiting for you have have the balls to deal with two papers which directly refute your claims:

McElhinney, M. W., Taylor, S. R., and Stevenson, D. J. (1978), "Limits to the expansion of Earth, Moon, Mars, and Mercury and to changes in the gravitational constant", Nature 271: 316–321,

http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/1999RG900016.pdf

Bryan

Nope. Its 59 pages. It must be a preprint or something.

Its a PDF so I probably downloaded it from the internet.

I'll search for some phrases from it.

Can't find it yet. But no worries, since it must be a preprint I can put it on the internet for all to see.

Also, I have quickly scanned the paper and there is absolutely no mention of your outrageous claim.

So, I suspect it is you who is lying,... and not me, contrary to your claim.

I will read it more thoroughly later today.

So you're going to base your "conclusions" on a paper which deviates quite obviously from the original?

I'd say I'm surprised, but that's about par for you, given your continued scientific failures.

Still waiting for you have have the balls to deal with two papers which directly refute your hypothesis:

McElhinney, M. W., Taylor, S. R., and Stevenson, D. J. (1978), "Limits to the expansion of Earth, Moon, Mars, and Mercury and to changes in the gravitational constant", Nature 271: 316–321,

http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/1999RG900016.pdf

Bryan

ImagingGeek,

The Earth’s mass is basically constant as I stated in my earlier post. And yes, from a great distance any variation in the Earth’s surface gravity could not be detected. However, your statement that there can only be small variations in surface gravity is incorrect. Depending on the amount of core(s) movement, there can be considerable changes in surface gravity; hence the theorized reason for large terrestrial and sea life.
Yes, today’s variations in surface gravity are being measured but these are not due to core movement but variations in crust and mantle densities. I have bypassed your comments on the scenario with no core movement and proceeded to the your statements concerning a shifted core (or cores).

Your wrote:
“Now, what about a shifting core? Once again, I would remind you that the earths mass, and thus total gravity, is constant. As such, all that can happen is the relative amounts of gravity felt on specific points of the surface can change.”
I agree.

“In the case of a shifting core, it is going to shift to correct an inequity in the earths mass”
No, it will shift to correct “rotational mass” or moment of inertia. For example, a movement of equal continental mass to each of the poles will have little or no effect on core movement but movement of that total mass to the equator would. It is the radius or distance to the rotational axis for the shifted mass that is significant.

“This will reduce the gravity felt on pangea and increase the gravity felt in the oceans.”
I agree.

“Assuming equilibrium is met (i.e. the earths center of mass is returned to its center of rotation), and the earth remains spherical, the gravity on the surface will be equalized - as in pangea will experience exactly 1.0G, and the ocean side will experience 1.0G.”
No, the shifting of the core(s), and therefore the shift in center of mass, has created the equilibrium. The center of mass will not coincide with the center of rotation. As long as Pangea remained basically intact, the differential surface gravity would remain the same.

Again, the reason why the oversized dinosaurs and sea reptiles and pterosaurs were able to develop was this lowered surface gravity and the reason they were gone near the K-T boundary was the rapid increase in surface gravity resulting from the breakup and dispersal of Pangea.

“Or, in other words, the tiny gravitational distortion formed by the thicker crust on the pangea side will be eliminated.”
See above explanation.

Laze

.
ImagingGeek:

I found a copy of the paper on the author's web-site.

Man, did google.com hide this paper away from the public.

Robin Canup has a few papers listed here:

http://www.boulder.swri.edu/~robin/rcpapers.html

"Simulations of a late lunar-forming impact" is here:

http://www.boulder.swri.edu/~robin/c03finalrev.pdf

I have read the paper thoroughly.

As I suspected, the paper you quoted does NOT claim that the proto-Earth-Theia collision released 10^24 Joules.


Also, nowhere in it, is your earlier claim that the proto-Earth-Theia collision released 10^27 Joules.

You made your earlier claim of 10^27 Joules, here:

http://www.scienceagogo.com/forum/ubbthreads.php?ubb=showflat&Number=34629#Post34629

It appears that ImagingGeek just makes up his "facts" from thin air.

preeath, you are coming close to lacking civility again. If you can't follow the math, don't call people names or impugn their character.

It varies slightly from the one at iccarus, none the less

Funny that, seeing as the data is integral to table 1 and figure 11. Funny, as well, in that they extensively quote the original calculation [Nature 412, 708-712 (16 August 2001)].

I guess you should have read more closely, and perhaps tried using some of those math skills you claim to have.


Why so I did. And in this case I have made a mistake - 10^24kJ is the impact energy.

But my mistake still doesn't help you none:
1) You're imaginary impact is still several orders of magnitude greater than the one which formed the moon (10^4 times greater, to be exact)

2) Your hypothesis has been completely disproven by at least two publications, which you insist on ignoring:
McElhinney, M. W., Taylor, S. R., and Stevenson, D. J. (1978), "Limits to the expansion of Earth, Moon, Mars, and Mercury and to changes in the gravitational constant", Nature 271: 316–321,

http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/1999RG900016.pdf

And here we see the fundamental difference between the scientific approach (i.e. mine) and the kook (your) approach - I own upto my errors, and correct for them. The kook (i.e. pre-earths) approach is to whine about minutia, and to ignore contradictory data.

Now, pre, do you have the guts to actually address those two papers which DIRECTLY DISPROVE YOUR HYPOTHESIS?

Better make it quick - I leave for the cottage in ~14 hours for four days of fishin, swimmin' and bbqin'.

Bryan

Which is a round about way of saying exactly what I said. In the event you have an uneven distribution of mass perpendicular to the axis of rotation, there will be a force applied along the plane of rotation (i.e. perpendicular to the axis of rotation). In the event of a solid earth this force would result in precession of the earths axis of rotation.

No, that is incorrect. With the core centered, and pangea off to one side, you start off in disequlibrium - mass is not evenly distributed along the plane of rotation, which creates a precessionary "force" across the plane of rotation. In this case you have "extra" gravity on pangea, due to the increased amount of mass beneath pangea, relative to the earth on average. As per newtons 3rd law, in the disequlibrium state described above, you also have an equal, but opposite force that would push the core away from the pressesion of pangea. I'll attempt to draw, all images representing a line drawn across the plane of rotation, as seen from above:

P = pangea
) = oceanic crust
o = core
- = unit of distance
<> = forces
^ = location of axis of rotation (axis would extend out of your screen)
. = place holders, since this forum removes superfluous spaces

Starting position (not at equlibrium). More gravity will be found at pangea, due to the additional mass on that side of the rotational plane:
P-----o-----)
......^

Force on the above system due to rotation(top)and the opposite force on core (bottom, newtons 3rd law and all that):
<<P-----o-----)>
........^
........< >>

Distribution & force after core moves:

<P------o----)>
........^
.......< >

In the bottom case we have equilibrium - mass is distributed evenly across the plane of rotation, thus eliminating precessionary "force". Because the mass is now evenly distributed along the plane of rotation, surface gravity is also equal along the plane of rotation. Assuming a perfect sphere, this will be roughly 1G.

Sorry, that doesn't work for a number of reasons:
1) In disequlibrium, there would be less than a half-percent change in gravity on pangea. At equilibrium, that change goes away. In the former case the difference is so small (0.4%, or 0.004G) as to be meaningless in a biological context.

2) Pangea broke up ~150MYA, with the major breakup complete around 100MYA. The dino's went extinct and the KT boundary formed 65MYA. So the timing doesn't fit.

3) Assuming a slow breakup of pangea, the ~100MY period of time it took would have been more than sufficient for the dino's to evolve along with changes in gravity. Instead, we see even the largest of dino's making upto the KT boundary intact, and then suddenly disappearing.

4) There is no known mechanism which could lead to a rapid breakup and leave the crust intact. There is also a boat-load of evidence for a slow breakup of pangea.


5) The mineralogy of the KT boundary is consistent with chondritic meteorites, and not with the earths mantle, providing further evidence for the meteoric extinction model, and further evidence against a geological mechanism.

6) There is a crater (Chicxulub Crater) which is both of the right age, and right size, as was predicted for the dino-killing impact. Once again, consistent with conventional science, and in direct opposition to your alternate answer.

7) There is no geological evidence consistent with large-scale or rapid changes in the makeup of the earth around 65MYA.

8) There is no mechanism by which earths irridium, which is largely locked up in the core, to move to the surface. To get it to the surface would require sufficient force to destroy the earths core, or lift a portion of it to the surface. No irridium = no KT boundary.

9) There is no biological need for lower gravity - biophysical analysis of even the largest dino's (sauropods; see the references in my older post) shows that their physiology was more than sufficient to support their mass given earth-normal gravity. Same is true for the largest of flying petrosaurs - aeronautic analysis has shown that the second largest would have had no trouble flying at earth-normal. The largest isn't much bigger, and is expected to have very similar physics.

Like I've been saying, the evidence is against you model. The math shows that any variation in gravitational force will be small - a half % of 1G max. There is no evidence suggesting a catastrophic breakup

Bryan

EDIT: as I mentioned to pre, I'm gone the next few days for some R&R. Please reply, and I'll try to get back to you early next week.

ImagingGeek,
You wrote:
“Which is a round about way of saying exactly what I said. In the event you have an uneven distribution of mass perpendicular to the axis of rotation, there will be a force applied along the plane of rotation (i.e. perpendicular to the axis of rotation). In the event of a solid earth this force would result in precession of the earths axis of rotation.”
This is correct but what you stated originally was not, which was that
“In the case of a shifting core, it is going to shift to correct an inequity in the earths mass”


Your wrote:
“Assuming equilibrium is met (i.e. the earths center of mass is returned to its center of rotation), and the earth remains spherical, the gravity on the surface will be equalized - as in pangea will experience exactly 1.0G, and the ocean side will experience 1.0G.”
I responded:
“No, the shifting of the core(s), and therefore the shift in center of mass, has created the equilibrium. The center of mass will not coincide with the center of rotation. As long as Pangea remained basically intact, the differential surface gravity would remain the same.”

You responded:
“No, that is incorrect. With the core centered, and pangea off to one side, you start off in disequlibrium - mass is not evenly distributed along the plane of rotation, which creates a precessionary "force" across the plane of rotation. In this case you have "extra" gravity on pangea, due to the increased amount of mass beneath pangea, relative to the earth on average. As per newtons 3rd law, in the disequlibrium state described above, you also have an equal, but opposite force that would push the core away from the pressesion of pangea.”

My response:
You are making a basic logic error here......according to theory being discussed, the core(s) cannot be at center with Pangea formed. If our current continental distribution with core(s) centered were to reform into a Pangean state, the core(s) would gradually shift off center. Therefore, your initial conditions of “disequilibrium” is invalid. If you meant to state that as Pangea formed, the disequilibrium created precessionary forces resulting in a shift of the core(s) away from Pangea, then I would agree with that.


Re: Your drawing depicting the plane of rotation of Pangea:

Again, your first and second drawings depict an invalid condition (i.e., centralized core(s) with Pangea formed). I won’t comment on this one.

Your third drawing depicts the shifted core(s) along with Pangea.
You wrote:

“In the bottom case we have equilibrium - mass is distributed evenly across the plane of rotation, thus eliminating precessionary "force". Because the mass is now evenly distributed along the plane of rotation, surface gravity is also equal along the plane of rotation. Assuming a perfect sphere, this will be roughly 1G.

My response:
Not true. We do have equilibrium now that the core(s) have shifted off center and therefore, by definition, we do not have mass distributed evenly across the plane of rotation.
Therefore, surface gravity will not be 1G on Pangea but will be less depending on the amount of the core(s) shifting.


I wrote:
“Again, the reason why the oversized dinosaurs and sea reptiles and pterosaurs were able to develop was this lowered surface gravity and the reason they were gone near the K-T boundary was the rapid increase in surface gravity resulting from the breakup and dispersal of Pangea.”

You wrote:
“Sorry, that doesn't work for a number of reasons:
1) In disequlibrium, there would be less than a half-percent change in gravity on pangea. At equilibrium, that change goes away. In the former case the difference is so small (0.4%, or 0.004G) as to be meaningless in a biological context.”

My response:
Based on my last response, surface gravity on Pangea would be lower, the lowest near the equatorial regions. The ratio of current G to Pangea’s lowest G would be d^2/r^2 where r is the current radius and d is the distance from the shifted center of mass (due to the core shift) to the center of mass of Pangea.


You wrote:
“2) Pangea broke up ~150MYA, with the major breakup complete around 100MYA. The dino's went extinct and the KT boundary formed 65MYA. So the timing doesn't fit.
My response:
Pangea started to breakup earlier than 150mya. About 200mya the nascent Atlantic Ocean began to form accompanied by the massive flood basalt volcanism known as CAMP. It might be a matter of semantics, but “breakup” doesn’t fully describe the situation. There was rifting or separation, both latitudinally and longitudinally in different degrees well beyond 150mya. 65mya the continents were pretty much separated and moving apart rapidly, some rotating also. It is this rapid, non-uniform, primarily longitudinal movement that caused a corresponding shift of the core(s) back toward their original, centralized location. And, according to this theory, caused pulses of increases in G, resulting in extinction.

You wrote:
“(3) Assuming a slow breakup of pangea, the ~100MY period of time it took would have been more than sufficient for the dino's to evolve along with changes in gravity. Instead, we see even the largest of dino's making upto the KT boundary intact, and then suddenly disappearing.”

My response:
What you see is the largest (and tallest) sauropods disappear at the end of the Jurassic in North America and a shift of the largest sauropods (i.e., the titanosaurs) into S. America as Pangea moved north, thereby shifting the lowest gravity region south. The titanosaurs were different with wide lower bodies, shorter necks and wider stance, all evolutionary characteristics that could be the result of increasing gravity. As the K-T approached all of the larger dinosaurs disappeared. It is inaccurate when someone writes that the dinosaurs were thriving up to an instant in time.

You wrote:
“4) There is no known mechanism which could lead to a rapid breakup and leave the crust intact. There is also a boat-load of evidence for a slow breakup of pangea.”
My response:
Again it is a matter of semantics. “Rapid” in geologic parlance could mean millions of years.
The breakup of Pangea was rapid compared to its formation.

You wrote:
“5) The mineralogy of the KT boundary is consistent with chondritic meteorites, and not with the earths mantle, providing further evidence for the meteoric extinction model, and further evidence against a geological mechanism.”
My response:
I don’t deny that a meteorite struck the Earth around 65mya and neither does Vincent Courtillot who admitted this in ‘Evolutionary Catastrophes’, where he emphasizes the fact that hot spot volcanoes have accompanied almost all of the major extinctions. The Deccan Traps volcanic activity coincided with the K-T.

You wrote:
“6) There is a crater (Chicxulub Crater) which is both of the right age, and right size, as was predicted for the dino-killing impact. Once again, consistent with conventional science, and in direct opposition to your alternate answer.”

My response:
Yes, there is a crater there but where is the bone pile? If the cataclysm was so devastating, there should have been entire herds, rookeries, etc. of dinosaurs that were buried alive.......where are they? I don’t know of a single one discovered just below the clay layer.


You wrote:
“7) There is no geological evidence consistent with large-scale or rapid changes in the makeup of the earth around 65MYA.”
My response:
Not sure what you stating. 65mya was the point at which geologists/paleontologists decided to change the name of the era from Mesozoic to Cenozoic. Had to be a significant change at that time.

You wrote:
“8) There is no mechanism by which earths irridium, which is largely locked up in the core, to move to the surface. To get it to the surface would require sufficient force to destroy the earths core, or lift a portion of it to the surface. No irridium = no KT boundary.”
My response:
Courtillot believes iridium can come from hot spot volcanos. If I remember correctly, he gives examples of where iridum has been found but no signs of impact.

You wrote:
“9) There is no biological need for lower gravity - biophysical analysis of even the largest dino's (sauropods; see the references in my older post) shows that their physiology was more than sufficient to support their mass given earth-normal gravity. Same is true for the largest of flying petrosaurs - aeronautic analysis has shown that the second largest would have had no trouble flying at earth-normal. The largest isn't much bigger, and is expected to have very similar physics.”
My response:
I question the validity of the biophysical analysis that you cite. These are computer models and I’m sure you know what GIGO stands for. You were unwilling to accept the study done by a Japanese scientist using extant sea birds, which are probably as close to the flying, egg-laying, mostly fish hunting, believed-to-be warm blooded pterosaurs. I would put more faith in his study than a computerized model based on someone’s guess as to the flesh and bone, lifestyle, etc. of dinosaurs.

You wrote:
“ Like I've been saying, the evidence is against you model. The math shows that any variation in gravitational force will be small - a half % of 1G max. There is no evidence suggesting a catastrophic breakup”
My Response:
See my earlier post where I give the ratio of current G to G with shifted core(s). Surface gravity may have been 30% to 50% of current values.

Laze

ImagingGeek, why don't you just admit that your number of 10^27 joules is totally wrong.

Why don't you just admit it like a man and get on with life.

FIRST COMMENT:

YOU ARE OBVIOUSLY WRONG.

As has been pointed out to you before, a release of 10^24 kilojoules = 10^27 joules, for the proto-Earth-Theia collision is obviously wrong.

The amount of energy for each kilogram of Earth is;

= 10^27/(the mass of Earth)

= 10^27/(5.97369 x 10^24) = 167.4 joules.

So, how much will 167.4 joules of energy heat each kilogram?

Well, 1000 joules will heat one kilogram one degree centigrade (i.e., the specific heat for the Earth is 1000 Joules/kg°K)

So each kilogram is heated by the collision by 167.4/1000 = 0.1674 degrees.

So, ImagingGeek claims that the proto-Earth-Theia collision will raise the temperature of the entire Earth by ONLY 0.1674 of a degree. Which is obviously wrong.

SECOND COMMENT:

Your reference, the paper "Simulations of a late lunar-forming impact," does provides a figure for the energy and it is many orders of magnitude greater than 10^24 kJ.

Guess what it is?

So how come you couldn't find it? You didn't even try? Forget where it was?

No,... you just never knew where it was.

Now you know it is there, why don't you find it and report back.

Hey Preearth would your idea still work if the continents all melted and reformed? Is there any reason why they must have remained mostly intact but spread out?

No logical error was made - it was a hypothetical situation intended to produce the maximum gravitational deviation possible. The whole point was to create the situation most likely to produce the effect you claim, and then analyze the impact that would have.

Secondly, your assumption could very well be wrong. No one has ever measured the rate the earths core moves in response to an uneven distribution of mass - or even if it occurs. Keep in mind that the force on the core will be less than the force pretty much anywhere else within the earth (as the core will be at/close to the center of rotation). Likewise, the mantle is very viscous and may be nearly solid near the core itself. As such, it is very well possible that the movement of the core to correct for shifts in mass may be slower than the continental drift forming those disequlibria. If the rate of continental drift forming those disequlibria occurs faster than shifts in the position of the core, you would end up with something close to the model I analyzed.



But I will - the pictures, as drawn, reflect the absolute maximum amount of deviation you could get. And while the "real-world" may not have occurred to the maximum extent, those deviations from equilibrium are the only way in which you could create a gravitational abnormality.



Sorry, you are wrong.

In the first picture we have a disequlibria - there is more mass between the axis of rotation and pangea than there is from the axis of rotation and the anipode to pangea. This occurs because the core is centered at the axis of rotation, while pangea (with its greater mass) is off to one side.

That unequal distribution of mass also creates a gravitational disequilibrium in pangea compared to its antipode.

In picture 3 we have restored equilibrium - the core is now off-set towards pangea's antipode. Since the core is denser than the mantle, this shifts mass towards pangea's antipode. The net effect is the amount of mass (i.e. in kg) between the center of rotation and pangea is now the same as the amount of mass between the center of rotation and pangea's antipode.



1) Your math is wrong, ergo your last response is invalid.

2) Even if we take your case at face-value, without values your claims are meaningless - you would need pretty large movement of the core to get a d2/r2 ratio to provide a 1-2% change in surface gravity.



Still doesn't fit the fossil record. The major periods of breakup were not associated with mass-extinctions, but rather increases in species diversity:




Three points:
1) The shifts in body shape you claim occur were not universal across all large caldes - which is what would have to happen if gravity was the cause.

2) Large sauropods are found at all elevations near the KT-boundary; picking the one continent where there numbers appear to have dropped doesn't bolster your argument, but instead is a clear-cut case of you cherry-picking data to "prove" your model.

3)Sauropods are found upto the KT boundary, but not beyond it. So it is fair to claim they all disappeared at the KT boundary.


But in this context, rapid can be very well defined. For your model to work the breakup must occur faster that the core can shift.

You've provided no values, so we cannot put a limit on "rapid". None-the-less, the geological record and fossil record do not agree with your hypothesis. Pangea broke up over a >100 million year period; not exact consistent with a model that requires rapid shifts.



Cut-and-pasting from wikipedia, I see. But your complaint doesn't alter my criticism one bit - the evidence for a earth-altering impact that occurred when the dinos went extinct is very strong. Had you read all of the wikipedia article you copied from, you'd have noticed this sentence:

Due to the volcanic gases and subsequent temperature drop, the formation of the traps is seen as a major stressor on biodiversity at the time. This is confirmed by a mass extinction topping 17 families per million years (about 15 families per million years above the average)[5]. Sudden cooling due to sulfurous volcanic gases released by the formation of the traps and localised gas concentrations may have been enough to drive a less significant mass extinction, but the impact of the meteoroid that formed the Chicxulub Crater (which made a sunlight blocking dust cloud that killed much of the plants, called an impact winter) made this one of the most pronounced mass extinctions in the Phanerozoic.[6]

Or, in other words, the traps were insufficient to drive the mass extinction - and there is good evidence they were also caused by a meteorite, not changing geology.


Couple of points:
1) Asteroid impacts would not necessarily create conditions that lead to good fossilization, which would be a pre-requisite for increased numbers of fossils. In fact, the K-T mineralogy suggests that the impact resulted in acidification, which degrades, not preserves, fossils.

2) The extinction was not thought to be instantaneous, but rather thought to occur over several thousand years. Once again, that would not produce large fossil beds, but rather dwindling rates of fossil production. Geologically, that is very fast, ergo appearing as an immediate loss of fossils.

3)There are several references in the scientific literature showing an abrupt end to dinosaur fossilization at the KT boundary; consistent with a rapid, but multi-generational extinction:

Archibald, J.D. 2000. Dinosaur abundance was not declining in a "3 m gap" at the top of the Hell Creek Formation, Montana and North Dakota. Comment. Geology 28(12): 1057-1184.

Bohor, B.F., D.M. Triplehorn, D.J. Nichols, and H.T. Millard, Jr. 1987. Dinosaurs, spherules, and the "majic" layer: A new K-T boundary clay site in Wyoming. Geology 15: 896-899.

Bryant, L.J. 1989. Non-dinosaurian lower vertebrates across the Cretaceous-Tertiary Boundary in Northeastern Montana. University of California Publications in Geological Sciences 134.

Moreover, at least one of the kinds of deposits you expect (i.e. jumbles from instantaneous mass-death) have been found:
Bourgeois, J.T., T.A. Hansen, P.L. Wilberg, and E.G. Kauffman. 1988. A tsunami deposit at the Cretaceous-Tertiary boundary in Texas. Science 241: 567-570.



What I mean is that your model of rapid gravitational changes would be accompanied by specific geological evidences: changes in the formation of sedimentary rocks, changes in paleomagnetic data (whose traces are directly proportional to the strength of gravity at the site of formation), etc.

These changes are not seen. I provided links in a previous post relating to paleogravitaitonal measures; if the changes you claimed occured, we would see them in those recored - there would be significant deviations in those measures is rocks of the same age, located in different regions of the earth. That simply is not seen.



Some irridium is present in volcanic flows. However, the concentrations are much lower than what is found in the KT boundary, nor is there any volcanic mechanism by which it could be distributed as evenly across the earth as it is in the KT boundary, and thirdly, irridium in volcanic flows is always associated with volcanic material - be it solidified magma or volcanic particulates in sedimentary rock. This is not seen at the K-T boundary, where instead the irridium is contained within a layer consistent with condritic meteors that lacks significant amounts of volcanic dust/minerals.



Maybe you should check out those links I provided, because:

1) The fact that large petrosaurs could fly was validated experimentally - as in they made, and flew, a scale model.

2) Those computer models you so readily dismiss are known to be extremely accurate - the same models are used to design planes, trains and automobiles, and are know to replicate the real world to an extremely high degree of accuracy.

3) Your Japanese group also used a computer model - but one of highly questionable relevance. They took a range of measurements from existent birds and then used to measures to derive a cutoff for where birds can no longer fly. Compare that to the models used by other groups - models which apply the well-understood physics of aerodynamics and materials to predict the aerodynamic qualities of any object.

Not to mention, petrosaurs are not birds - morphologically & aerodynamically they are very different. Likewise, their environment was different as well - high O2 levels as one example.

So why would you consider the Japanese computer model better than the ones used to design and build airplanes - computer models, which as I mentioned above - have been validated through the construction & flight of a model petrosaur.

Or, take the example of the model used for suaropods - they took known strengths of biological materials, known morphology of the sauropods, accepted ranges of sauropod masses and mass distribution, and known newtonian physics and simply calculated the force.

What is questionable about that? How is that less valid than measuring various physical traits of things that fly and then saying anything that lacks those traits cannot fly?



And you provided ZERO evidence to support that sized shift. In fact, we can prove it to be impossible - the inner core accounts for ~2% of the earths mass, while the outer core accounts for ~30%. Keep in mind that for a constant mass, the only factor that will change gravity is distance - GM/r2. For these calcs' I'll treat the cores as point masses - a process which will maximize the gravitational difference; in the real world the actual differences will be less. So the max change in gravity would be:

Inner core:
r with core centered = 1 earth radius, core sitting on the bottom of the oceanic plate = 2 earth radi.

Fgunshifted = G(0.02)/12 = 0.02G of gravity from the core, therefore 0.98G from stuff inbetween

Fgshifted = G(0.02)/22 = 0.005G from core, for a total of 0.98+0.005 = 0.985G

That 1.5% less gravity on pangea; ignoring any "extra" gravity from pangea itself.

Outer + Inner core:
Fgunshifted = G(0.32)/12 = 0.32G of gravity from the core, therefore 0.68G from stuff inbetween

Fgshifted = G(0.32)/22 = 0.08G from core, for a total of 0.68+0.08 = 0.76G.

So the absolute maximum theoretical gravitational change possible, under the impossible assumptions that:
a) the inner + outer core is located on the bottom of the sea opposite pangea,
b)the mass of the 2 cores is concentrated into an infinity dense point,
c) no mass fills the space previously occupied by the core
d) pangea has no "extra" gravity due to its mass

The maximum loss of gravity you can have is 0.24G.

If you simply move the cores, so that the outer edge of the outer core sits against the oceanic crust opposite pangea, and assume the material that fills the space has the median density of the mantle, your maximum change becomes ~0.1G

So once again, basic physics and a basic grasp of math disproves your model.

Bryan

Because it isn't - and I provided the citations to prove so. The very fact you are unable to counter that claim by pointing out the "true" values used in those studies I cited is proof positive that you cannot counter those claims directly.



We've covered this already. Even today, the median temperature of the earth (~4800K) is more than sufficient to melt the entirety of the surface, if it were distributed evenly (the lithosphere melts somewhere between 900K and 1300K, but currently averages ~500K). Ergo, to melt the earths surface you need to either:

a) provide sufficient energy to mix the lithosphere and upper mantle, or

b) provide enough heat to directly melt the lithosphere.

1027J is more than sufficient to achieve a or b.



The fact you are unable to point this out yourself pretty much shows us you are not able to find this information yourself. Keep in mind you are claiming I've falsely presented the data in my citations. Therefore the burden of proof is on you to show it is the case.

As I stated earlier, the 10^24kj value is used extensively in the impact models. To be more accurate, it is the median value they used that produced a moon, as their models covered a huge range of impact energies, starting temperatures, and impactor mass ratios.

All of that said, I'm going to assume you think the angular momentum is equal to the impact energy. I hope that's the case, because it would be the final proof that you simply stopped reading at the first big number you came across.

Bryan

ImagingGeek, why don't you just admit that your number of 10^27 joules is totally wrong.

Why don't you just admit it like a man and get on with life.

FIRST COMMENT:

YOU ARE OBVIOUSLY WRONG.

As has been pointed out to you before, a release of 10^24 kilojoules = 10^27 joules, for the proto-Earth-Theia collision is obviously wrong.

The amount of energy for each kilogram of Earth is;

= 10^27/(the mass of Earth)

= 10^27/(5.97369 x 10^24) = 167.4 joules.

So, how much will 167.4 joules of energy heat each kilogram?

Well, 1000 joules will heat one kilogram one degree centigrade (i.e., the specific heat for the Earth is 1000 Joules/kg°K)

So each kilogram is heated by the collision by 167.4/1000 = 0.1674 degrees.

So, ImagingGeek claims that the proto-Earth-Theia collision will raise the temperature of the entire Earth by ONLY 0.1674 of a degree. Which is obviously wrong.

ImagingGeek claims that a 0.1674 degree rise in temperature for the proto-Earth-Theia collision, is, in fact, correct.

Excuse me everyone, but surely this proves beyond a shadow of a doubt that ImagingGeek is stupid.

ImagingGeek, why don't you just admit that your number of 10^27 joules is totally wrong.

Why don't you just admit it like a man and get on with life.

SECOND COMMENT:

Your reference, the paper "Simulations of a late lunar-forming impact," does provide a number for the energy and it is many orders of magnitude greater than 10^24 kJ.

Guess what it is?

So how come you couldn't find it? You didn't even try? Forget where it was?

No,... you just never knew where it was.

Now you know it is there, why don't you find it and report back.



Yes, I claim that you have falsely presented the data in your citations.

You continually LIE to me and everyone. I don't appreciate it.

Usually your LIES are of the sort where you deliberately answer the wrong question and claim to have answered the question posited,... usually they are not as blatant as this LIE.



Actually, the burden of proof is on you.

It is you who claimed the paper "Simulations of a late lunar-forming impact," STATED that the proto-Earth-Theia collision generated,...

1) 10^24 joules of energy. You later changed this number to
2) 10^27 joules.

The paper does not state either of these numbers.

All you have to do to prove you are not guilty of falsely presented data, is to provide the section of the paper where it supports your claim, but you have not, and apparently cannot, do this.

You can't show the paper supports either of these numbers because you LIED about the paper stating such a number, in the first place.



Who said I was unable to find this information myself (apart from you)? I was waiting for you to point it out so that it won't be so embarrassing for you. But since you LIE as readily as you tell the truth,... you have chosen to try and LIE your way out of it.

In fact, I can give the number that you cannot give. It is 2.95 x 10^31 joules.

Robin Canup states that for an impactor 0.13 the size of Earth, the (specific) impact energy per unit projectile mass is 3.8 x 10^11 ergs/g = 3.8 x 10^4 joules/g = 3.8 x 10^7 joules/kg.

Hence the total impact energy = (mass of the impactor) x 3.8 x 10^7

= 0.13 x (mass of the Earth) x 3.8 x 10^7

= 0.13 x 5.97369 x 10^24 x 3.8 x 10^7 = 2.95 x 10^31 joules.

Remember, Roberto Bugiolacchi stated that the proto-Earth-Theia collision released 3 x 10^31 J.

So, ImagingGeek has been shown to have falsely presented data from the source he quoted.

Sorry, that's not how it works in the real world. You're claiming malfeasance on my part - both in the scientific world and in the legal world it is upto you to provide the evidence that I have done something wrong.


VICTORY IS MINE!!!

I have to thank you pre - you just demonstrated beyond any shadow of a doubt that you are either:

a) lying, or
b) incapable of understanding the material in front of you

You've also shown that you cannot come up with the right answer, even when every clue you need is laid out before you (hint - re-read my post where I refer to figure 11 and table 1).

Maybe you should have read that whole footnote, instead of grabbing the first big number you found:

Including consideration of latent heat should be most important for impacts whose specific impact energy per unit projectile mass, EI, is comparable to the heat of vaporization for rock, Ev ~ 1011ergs/g, and less important for impacts with either EI << Ev or EI >> Evergs/g, comparable to Ev. Also of a similar magnitude is the specific energy difference between an orbit with a = 1.5R&#8853; and the Earth’s surface, ~ 2 x 11 ergs/g. It is thus not surprising that accounting for the latent heat budget results in a somewhat lower yield of orbiting material for simulations using M-ANEOS than those using Tillotson for similar impact conditions.


Emphasis (bold) is mine. Had you bothered to read the paper, of even that whole footnote, you'd have known that the whole point of this paper was to refute the models based on impact energies like those described by Tillotson (who, BTW, is the one who first claimed 1011ergs/g).

I know pre will ignore this, but the whole point of this paper was to account for issues that previous models of lunar formation could not address. The earlier models, like Tillotsons, assumed a direct impact with huge energies - 1011ergs/g or more. Cameron showed in his nature paper (citation provided 2-3 posts ago) that this kind of impact was incapable of producing a moon due to the amount of vaporized material (which condenses poorly) and the orbital distribution of the debris (which are not ring-like, but rather spherically distributed).

The whole point of Camerons nature paper, which was refined by Canup in this paper, was that the impact had to be a glancing one - lower energy, impacting near the limb of the earth. This is the only way you can get an orbiting ring of material, in which the material is comprised almost entirely of crust, and in which the material is of a suitable size distribution to allow the moon to form in the time it took the moon to coalesce (vaporized particles are smaller, thus have less gravity, and thus take much longer to coalesce).

In figures 11 and 12, this paper outlines a range of impactor size, velocities and impact angles which can produce the moon. To actually get the energy absorbed by the earth, due to these simulated impacts, you need to do a bit of math of your own - table 1 outlines successful combinations (i.e. mass, velocity and impact angles which can produce a moon-like object). All of the values you need are in there - the speed and mass of the impactor (from which you can calculate input energy) the speed and mass of the resulting debris field (from which you can calculate the energy not absorbed by the earth). The difference between the two is the amount of energy absorbed by the earth - approx 1027J, +/- an order of magnitude across the various conditions.

What can I say - this was a test of pre's self-proclaimed math skills. He failed.

Now I'm sure at this point pre is frantically writing another post in which he'll call me a liar and other names, while not providing one iota of evidence that I'm wrong. But in the vauge hope he may of read this far, I re-issue my challenge for the 7th (I think) time:

How do you account for these two studies which directly refute your hypothesis?

McElhinney, M. W., Taylor, S. R., and Stevenson, D. J. (1978), "Limits to the expansion of Earth, Moon, Mars, and Mercury and to changes in the gravitational constant", Nature 271: 316–321,

http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/1999RG900016.pdf

For some reason, I suspect instead of answering that question pre's just going to call me names again...

Bryan

.
What's the old saying that goes something like;

When the JACKASS fails completely in his argument, he loudly claims complete victory, in the hope that those who hear his claim are foolish enough to believe him.

You must take the people on this forum for complete idiots.

Somehow I don't think they are as stupid as you think they are.

LIE 1) The impact energy is stated to be 10^24 joules.

When it is pointed out that in the past he had claimed the impact energy was 10^27 joules, behold a new lie,...

LIE 2) The impact energy is stated to be 10^27 joules.

Without ever backing up any of his claims,...

LIE 3) the jackass claims victory.

By the way,... do you remember this?





Which part of Paul's observations concerning you didn't you understand, Bryan?

1) your inability to understand the least of his concepts,... or,...

2) well should you ever cross that threshold bryan, I for one would make sure the door lock was changed and you were not given a key,... or,...

3) I've toyed with the concept that you think backwards bryan,... which can be compared to your understanding of newtons laws.

By the way, what happened to Paul?

One day he was the first or second most prolific poster, the next he wasn't even on the Top Posters list.

By the way Bryan, I think you are a total moron and the less time I waste on you, the better.