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Posted

It seems that Charlie is asking two different questions: 1) Is the Earth's core made of Hydrogen and 2) If it is made of iron, how did it form?

 

I'm quite certain that we've falsified the first question. Do you have any objections, Charlie?

 

The second question is more difficult to answer. Yet, we have lots of evidence for the mainstream theory of Earth formation. This is not to say that accretion and Solar System processes are completely understood and correct, but the main theory we have agrees with observations. An Earth inner-core composed of iron and nickel agrees with theory. A core of H2 does not match observations, from seismographs to ambient atmospheric readings.

 

So, why is an iron core puzzling? Is it puzzling because you can not account for its inception or is it puzzling because H2 is a better candidate in your view?

Posted

So the witch hunt continues. What part of “Where did all the iron supposedly in Earth's core come from” inspire Turtle's personal vendetta? Now, I've been the object of a personal vendetta that included never being able to work for a defense contractor or major USA industry since I blew the whistle on dangerous jet engines. Which why I ended up being an engineer for British Leyland cars. This current micro examination of every word and seeking some devious intent behind simple phrases is child's play.

 

[Turtle] Try your best shot again, so far you've been way off base.

 

I suggest Turtle takes the time to look up 'Epistle' as it seems to have scared him silly in that he thinks it smacks of Creationism. Epistle is a 'Directive sent to inform groups.' I don't have clue as to what Neil's religious beliefs might be and I don't intend to ask him. He did rip up the Creationists' views in his book and tried to get them to understand the Earth is a lot older and more complex than they claim.

 

[Turtle] Read a review of Neil's book first, then you won't make have to make stupid assumptions over misunderstanding one word in a book title. You will appear a lot less foolish in the future.

 

As for Neil, he is a real rocket scientist. Once Chief of the Titan Missile program in the Pentagon. He also suspects the many and varied claims about how Earth acquired an iron core, which supposedly vaporized the original hydrogen core, are largely illogical and details his reasons in this book. I'm also aware he has recently revised calculations for the density of materials in Earth's mantle, which allows for a much less dense core. [More Mantle density equals less Core density, thus even less possibility for the Core to largely be iron.] This paper should appear in a peer review journal in the coming months.

 

Oh yes, I've just been made aware of a fifth theory about iron replacing hydrogen in Earth's core; The Gravitational Collapse Theory. Don't have time to go into detail. May do so later this evening. Sorry, got to get back to my duties, but couldn't leave Turtle's latest tirade to fester any longer.

 

Still curious about any other more plausible theories on how Earth got such an extraordinary amount of iron it its core, if that be the case. Still trying to understand the water-iron theory. If anyone can explain it in simpler terms for a simple old car mechanic who started out repairing tractors on the family farm, please try.

 

Enjoy. Charlie

Posted

If you look at the chemistry of oxygen, atomic oxygen will gain stability by completing its octet, which amounts to getting electrons to occupy the entire P-orbital. O can do this by sharing electrons, such as in H2O, O2, CO2. It can also do this by forming oxides with metals where oxygen becomes O-2. There will then be a charge attraction to a cation such as M+, M+2, M+3, which has lost electrons (M is a metal), to form ionic compounds such as K2O, MgO, FeO, Fe2O3, Al2O3, etc.

 

Let us look at the elemental composition of the earth, as shown below. Although there is more weight of iron than oxygen, atomic iron has over three times the atomic mass oxygen. This implies there are roughly three oxygen atoms for every iron atom each which would like up to 2 electrons for the octet.

 

We also have Mg and Si as the next two big guns, with both having a higher atomic mass than O. If we leave out the Fe, as giving any electrons to O, to complete its octet, the atom count implies most of the O on the earth could not reach O-1 or O-2. This would cause is a potential on the earth for O to draw out electrons to complete its octet.

 

Earth | Moon

1 2 3 | 4

----------------------+------

Fe 34.6 29.3 29.9 | 9.3

O 29.5 30.7 30.9 | 42.0

Si 15.2 14.7 17.4 | 19.6

Mg 12.7 15.8 15.9 | 18.7

Ca 1.1 1.5 1.9 | 4.3

Al 1.1 1.3 1.4 | 4.2

Ni 2.4 1.7 1.7 | 0.6

Na 0.6 0.3 0.9 | 0.07

S 1.9 4.7 - | 0.3

 

If we leave out the iron, this drawing out of electrons to complete the octet should be causing other materials to become more positive but there is a limit, and the earth should have been generating covalent materials such as O2 to reduce the electron requirement of the O. But we assume the early earth had no O2. Another way the O could have been satisfied is with H to form H+, which combines with water to form the stable H3O+. This scenario would have made the oceans acidic, but the oceans are basic.

 

It reduces to two ways to get this to add up. First, the iron of the core already did its corrosion thing at the beginning and the core is form of iron oxide (ferric and ferrous) to satisfy the octet of oxygen. Magnetic lodestone is found in nature, which is iron oxide, so this scenario could still create a magnetic field.

 

The second alternative is the original metallic iron core is the process of rusting, with a current of electrons being drawn to satisfy the lingering requirement of the assumed amount of O. This could still maintain the magnetic properties of the core since both Fe and FeO are magnetic, but it could have an impact on field direction depending on where the current is stronger due the insulating effect of oxides.

 

Another thing to consider is magnetic iron is due to the outer electrons of iron having the same spin direction. Although this is stable, it is at higher energy than if one of the electrons had opposite spin for electron wave addition. This higher energy state is one step closer to ionization and could be a natural artifact of O sucking out electrons. The O with potential should stay closer to the iron core, since this is the best bet for electrons, since the crust material is mostly deplete of electrons in the form of stable mineral oxides.

 

What is also interesting is going from Fe to Fe+2 to finally to Fe+3, might satisfy the O octet requirement. The moon has so little Fe, maybe the the Fe+3 stage would have formed earlier and could be why it lost if magnetic field.

Posted

All I see from Chuckles is rants about "stupid" scientists and their dogma for the past 2 years, including out of hand dismissal of the responses from Ecoglite, Pyrotex, Modest, Janus, etcetera, etcetera. If this was anything but a silly claim, then we'd be referencing peer-reviewed material supporting a hydrogen core. Show me the money. :) I strongly urge you all to read all of Mr. O's posts and see this is trolling pure & simple, whatever the motivation.

 

Science is always amendable, a fact which seems to only fuel Chuckle's disdain, and yet were it not for science there would be no discussion of a core at all. For what it's worth, some amendation of what we know about Earth's iron core. :turtle:

Computer simulations strongly support new theory of Earth's core

...In this new study the researchers present simulations of how seismic waves are reproduced in iron under the conditions that prevail in the core of the earth, showing a difference of about 12 percent depending on their direction-*which suffices as an explanation for the puzzling observations. First the trajectories of movement were calculated for several million atoms in strong interaction with each other. On this basis, the scientists were then able to determine that the progress of the sound waves was actually accurately described in the computer-generated model for iron under the conditions prevailing in the core of the earth.

 

“We found that the body-centered cubic structure of iron is the only structure that could correspond to the experimental observations,” says Börje Johansson, professor of condensed-matter theory at Uppsala University. ...

Posted

Earth | Moon

1 2 3 | 4

----------------------+------

Fe 34.6 29.3 29.9 | 9.3

O 29.5 30.7 30.9 | 42.0

Si 15.2 14.7 17.4 | 19.6

Mg 12.7 15.8 15.9 | 18.7

Ca 1.1 1.5 1.9 | 4.3

Al 1.1 1.3 1.4 | 4.2

Ni 2.4 1.7 1.7 | 0.6

Na 0.6 0.3 0.9 | 0.07

S 1.9 4.7 - | 0.3

 

It might be interesting to label these further. The columns are:

1 32.4% iron meteorite (with 5.3% FeS) and 67.6% oxide portion of bronzite chondrites.

2 40% Type I carbonaceous chondrite, 50% ordinary chondrite, and 10% iron meteorite (containing 15% sulphur).

3 Nonvolatile portion of Type I carbonaceous chondrites with FeO/FeO+ MgO of 0.12 and sufficient SiO2 reduced to Si to yield a metal/silicate ratio of 32/68.

4 Based on Ca, Al, Ti = 5 x Type I carbonaceous chondrites; FeO = 12% to accommodate lunar density; and Si/Mg = chondritic ratio.

 

Geol 456/656 - Composition of the Earth

I think you touch on a good point. Were earth to have a composition exactly equal to chondrites we would not expect a metalic iron/nickle core. I find this rather interesting. What we would get is described here:

 

Finally, it is worth reiterating that the division into layers depends critically upon the amounts of available oxygen and sulphur. If the Earth were made of literally carbonaceous chondrite material (as in Fig. 5.3), which is strongly oxidized, it would be almost entirely lithophilic with a small chalcophilic core (about 20% of its mass as FeS) and no free metal. Because the Earth has quite a large core (32% of its mass), it follows that, if in all other respects its chemistry is akin to carbonaceous chondrites, it mist have lost a few percent of oxygen. Thus, the overall oxidation state of a planet may determine the size of its core, whether there is a metallic region, and the position of the boundaries between the respective layers.

 

The Inaccessible Earth -- page 82

 

Of course, with a deficit of oxygen it's not unusual that Iron looses it's oxygen to silicates as it has a lower melting point and oxygen is a Lithophile element.

 

~modest

Posted

I don't think anyone is suggesting the earth was made up of chondrites. If it had been there would be much more carbon and water than we see on the earth. the collision that formed the moon can account for the loss of the water and even some oxygen (as part of the water) but not the loss of carbon. The feeding zone of the earth and the inner planets was evidently not composed exclusively of chondrites or even mostly of them. Possibly chondrites formed farther from the sun and were driven into the inner solar system from the area of Jupiter or beyond in the form of comet like bodies that evaporated into what we see as chondrites.

Posted
I don't think anyone is suggesting the earth was made up of chondrites. If it had been there would be much more carbon and water than we see on the earth. the collision that formed the moon can account for the loss of the water and even some oxygen (as part of the water) but not the loss of carbon. The feeding zone of the earth and the inner planets was evidently not composed exclusively of chondrites or even mostly of them. Possibly chondrites formed farther from the sun and were driven into the inner solar system from the area of Jupiter or beyond in the form of comet like bodies that evaporated into what we see as chondrites.

 

I should have been more clear, I'm not saying that it's in any way puzzling that earth's composition contains less oxygen than straight chondrites. On the contrary, I'd find it odd if it did. Especially, as you point out, considering Theia stripped away a disproportionate amount of oxides sending hardly any iron to the moon. What I found interesting was that a few percentage points of oxygen would completely do away with our metallic core.

 

~modest

Posted

I've read hypothesis that indicate the outer liquid core could contain a significant amount of sulfates, I see no reason some oxides might not be present as well. Is not he heat, 10,000 degrees plus, and the pressures at the core enough to squeeze out oxygen?

Posted

Charlie,

 

I think Turtle makes a very valid point. Your posts seem very hostile toward science and you quite often seem to disregard very good and direct answers that people are giving you.

 

If you consider the leftover ingredients of planet formation which are floating around the solar system; they are stony and iron/nickle meteoroids. They contain almost the exact elemental composition of the sun with the exception of Hydrogen and Helium (and a few other gas-forming elements). Pyrotex has given you a good explanation for this observation. In the hot accretion disc around our protostar hydrogen and helium did not condense—they remained gaseous.

 

So, we know the composition of these small planetesimals and they are literally the pieces that the earth was made from. Earth and the rest of the inner planets never accreted hydrogen because it isn't massive enough. As you pointed out extensively in another thread: earth looses hydrogen. It doesn't gravitationally accrete free hydrogen from the solar system.

 

The Jovian planets are different. They formed beyond the frost line (or "snow line") far enough from the sun that hydrogen compounds like water, ammonia, and methane could freeze. This would logically mean the planetesimals in the outer solar system had more material to work with (not being limited to stony and metallic elements and molecules). The Jovian planets would have formed faster and larger gaining enough mass to capture the light gasses hydrogen and helium.

 

Once a planet starts accreting the hydrogen and helium around it, it would grow extremely quickly since there's so much of it available. It seems quite clear that's what happened to the Jovian planets.

 

If you think there's a major problem with this hypothesis then you should outline the exact nature of this problem and how you think a hydrogen core fixes it. Railing against science and the people in this thread does not advance your cause.

 

~modest

Posted
I've read hypothesis that indicate the outer liquid core could contain a significant amount of sulfates, I see no reason some oxides might not be present as well. Is not he heat, 10,000 degrees plus, and the pressures at the core enough to squeeze out oxygen?

 

Your right, it could well be oxygen. Oxygen's solubility in liquid iron increases with pressure, so it is possible and I believe I've seen a theory proposing it. I'll edit it onto this post if I can find it.

 

~modest

 

**** edit ****

 

Here we are:

 

The solubility of oxygen in metallic thus increases with increasing pressure... Our results are consistent with a geochemical model for the core containing 5.8 wt% oxygen and 1.9 wt % sulfur as proposed by McDonough and Sun (1995) [5].

 

OXYGEN SOLUBILITY IN IRON MELTS AT HIGH PRESSURES AND TEMPERATURES: EXPERIMENTAL CONSTRAINTS ON TERRESTRIAL PLANETARY CORE FORMATION.

Posted

Let us do this a different way. Say we took the earth and atomized it, at high temperature, and let it cool. Based on the atomic composition that is assumed, what would we get? Under those conditions there is enough O to oxidize the iron. Therefore, if the iron in the core is not oxidized, wouldn't that give O a potential?

 

One work around this is to atomize the earth and feed in electrons from an external source to saturate the requirement of O, so it will leave the iron alone. But I don't know of any huge source of bare + charge or electron deficient molecules.

 

There is another possible work-around. The octet requirement of O is something that is stronger at ambient conditions compared to high temperature. At room temperature one can not make atomic O for more than a milli-sec before it tries to strip off or share an electron. But at higher temperature or energy, atomic O can be made because the octet electrons remain ionized.

 

What that suggests is if there was an iron core, and O was at high temperature it would have less affinity for the electrons of iron. But one would also have to assume if the O is octet ionized iron is having a problem holding onto all its electrons. But with O not in need for these electrons they remain part of the metallic iron matrix.

 

As the atomic oxygen cools closer to the surface, the potential for the octet electrons increases, with a maximum near ambient (more or less). If there is any hydrogen trying to escape the crust, the O will takes its electrons. As the surface materials lose their ability to supply electrons to O (saturated), there could be a potential remaining. Plants making O2 is one way to lower this potential or the spontaneous generation of O2 would be another way to help lower the O potential. Another way could be to conduct electrons from the core since the iron has plenty of electrons to spare.

Posted

HB, if iron was the only element involved you might have a point but I think other elements have higher affinity for oxygen than iron and subsequently there would still be lots of iron left over. We do have free oxygen in our atmosphere but it not anywhere near enough to oxidize even a large percentage of the iron in the earth. All the rest of our oxygen is taken up by other elements many of which have a higher affinity for oxygen than iron. The oxygen in silicon is simply unavailable to any chemical reaction plausible in the earth. i don't see where you would get the oxygen to oxidize the iron in earths core.

Posted
Let us do this a different way. Say we took the earth and atomized it, at high temperature, and let it cool. Based on the atomic composition that is assumed, what would we get? Under those conditions there is enough O to oxidize the iron. Therefore, if the iron in the core is not oxidized, wouldn't that give O a potential?

 

One work around this is to atomize the earth and feed in electrons from an external source to saturate the requirement of O, so it will leave the iron alone. But I don't know of any huge source of bare + charge or electron deficient molecules.

 

Yeah, I agree with MTM. Also, even if you only consider iron I still believe the quote above is not correct. The mantle can be oxidized by simple disproportionation of iron:

 

[math]6FeO \rightarrow 2Fe_2O_3 + 2Fe[/math]

 

creating plenty of metal iron for the core while the charge remains neutral.

 

~modest

Posted

Modest: You wrote, “I think Turtle makes a very valid point. Your posts seem very hostile toward science and you quite often seem to disregard very good and direct answers that people are giving you.”

 

With all due respect and you seem to be a considerate and thoughtful person, please note that I have been appreciative and complimented several members who offered information instead of insults. Also, please consider the fact, repeat, fact, that, in an earlier thread, I only asked forum members to just consider a possible alternative to the “mainstream geology” belief that Earth has an iron core.

 

I must observe the fact, repeat, fact, that in recent times, geologically speaking, many people were executed or put under house arrest for suggesting Earth was not the center of the universe. So I glad I'm only being called names in this forum.

 

I must confess, as I have done many times, I am not a trained scientist, just an old car mechanic living in a mobile home on isolated acreage on the Colorado plains. I'm trying to keep my wife free of a nursing home, with good days and bad, 24/7 and always stressful. Then I found this website and thought I might find some release from the mind numbing daily grind with the intellectual stimulation I once enjoyed investigating mechanical failures in my younger days. [Court certified expert witness in same.]

 

Sadly, I find I'm being called names based on assumptions and misunderstandings or misreadings and my request for the consideration of hydrogen as an alternative is considered worthless and silly. Hardly scientific reasoning on someone's part. So whence comes the “Hostility?” Do you seriously believe defending one's self from unfair, even illogical and highly personal attacks is Hostility?

 

However, at least I know I don't know it all, but I'm very curious, a trait which has gotten me into trouble more than once. Apparently, questions about dogmatic beliefs are not always appreciated by the insecure and ignorant in many fields, including political and legal.

 

So you have Turtle making valid points. About what? I only asked in this thread if there were other theories about how such an enormous excess of iron, compared to the cosmos, got into Earth's core, besides the only two theories of which I was familiar. Which, in all honesty, I sincerely consider both of them illogical, even absurd, more science fiction than any logical, physical possibility. Something which is becoming increasingly clear from recent NASA observations.

 

I was taught Earth formed from within a spinning cloud of elements, mainly hydrogen, and, as with any rotating fluid, gaseous or semi-solid mass, the heaviest elements will always be forced outward, leaving the lightest elements in the center. Thus, Earth originally having a hydrogen core is what I was taught in the 1950s and then again in the 1970s, albeit seldom clearly stated; usually mentioned as lighter elements.

 

I was also taught that an enormous swarm of iron-rich micro-planets later attacked a smaller proto-Earth in a concentrated bombardment, adding to its mass and making it totally molten. Then, even though early Earth was still spinning to the extent that many believe it was still largely disk shaped, only iron, with some nickel, somehow flowed inward against centrifugal force and displaced the original hydrogen core, vaporizing it and forcing it to vent to the surface where it was blown away by solar winds. Have I got this right? Don't want to leave myself open to any more insults.

 

The point I'm making is that such a scenario is physically impossible, largely due to the presence of the Sun and Jupiter's much greater gravitational attraction and the total lack of any similar swarms being evident anywhere in the cosmos, as per recent astronomical observations.

 

Do you think the Grand Bombardment is a viable theory as to how Earth's original hydrogen core was replaced by an enormous excess of iron? I don't.

 

Then, I learned later in life that the Grand Bombardment was wrong, albeit taught to hundreds of thousands of students as the primary mainstream geology theory at that time as to how Earth came to have an iron core. Now we are to believe a Mars sized planet, which was largely iron, somehow wandered into Earth's orbit and they collided. They supposedly melted together and the smaller planet's immense, proportionally, iron core was transferred into proto-Earth, again vaporizing Earth's original hydrogen core and forcing it to vent into space and be lost. At least this is how I read the latest reviews of this theory in Winkipedia.

 

However, there is no mention of how the smaller planet obtained an iron core far greater in proportion to its size than the core which ended up as Earth's iron core in a combined mass. There is also no mention as to how it was able to wander freely through our solar system, unaffected by the Sun's or Jupiter's gravity. There is also no mention of how it was able to travel in an orbit different from Earth's, even though all the other planets in our solar system travel in the same direction. Thus, I, at least, believe the 'theory' to be good science fiction, albeit physically illogical to the point of being absurd.

 

This is my personal opinion, based on the lack of information as to how any Mars sized planet, largely composed of iron, was formed and how it came to be on an opposing orbit to Earth's and how it was able to avoid the gravitational attraction of the Sun and Jupiter; both of which have obviously never experienced any similar event, if their lack of iron is to be considered valid evidence.

 

Do you think the Earth-Theia collusion scenario is a valid theory as to how Earth acquired its iron core?

 

One forum member suggested Earth might have been “lucky enough” to have condensed from a primordial ring of iron-rich dust. Seems a better theory than both of the above to me, but highly unlikely since nothing like a ring of iron-rich dust has ever been observed. Again, not to say such can't exist.

 

Modest: You wrote, “Pyrotex has given you a good explanation for this observation.”

 

Please remember I complimented Pyrotex for his detailed explanation and I promised to attempt, with my admittedly limited scientific education, to try to understand it better. It may in fact be a more plausible explanation of how Earth came to have at least some iron in its core. This qualification is made because it has been proven that iron-nickel becomes too dense at core pressures to be the only elements in Earth's core. Therefore, lighter elements are currently being considered for inclusion in Earth's core, which will complicate his explanation; most often mentioned is hydrogen.

 

In fact, it now appears that hydrogen, compressed at core pressured over time, may become sufficiently dense enough to be near the density required to be Earth's core. IF this proves to be true and that Earth's mantle is heavier than originally calculated, the iron core theory may be in trouble. Heavier mantle equals lighter core, for which iron becomes too dense now. However, I'm not holding my breath on this or expecting to live long enough.

 

Modest: You wrote, “If you consider the leftover ingredients of planet formation which are floating around the solar system; they are stony and iron/nickle (sic) meteoroids.”

 

Some may consider this to be a fair assumption, but it is based only on the fragments of meteoroids which have survived during their passage through our atmosphere. While there are other types of meteorites, I suspect the original mass of stony meteorites which enters our atmosphere is many fold times greater than the mass which survives and lands on Earth. Whereas, I suspect the original mass of iron/nickel meteorites which survive entry through our atmosphere is not anywhere near as reduced by their passage. Therefore, it seems likely that the iron/nickel found on Earth's surface is only an insignificant portion of the total mass of the alleged “leftovers” floating around the solar system.

 

And, again, I believe the Sun and Jupiter would have attracted the vast majority of these leftovers long ago, should they have existed in any useful quantity; yet the Sun and Jupiter show little evidence of acquiring anything near the mass of iron attributed to these alleged “leftovers.”

 

Modest: You wrote, “So, we know the composition of these small planetesimals and they are literally the pieces that the earth was made from. Earth and the rest of the inner planets never accreted (sic) hydrogen because it isn't massive enough.”

 

Well, I believe this is just an assumption as no one really knows if these small planetesimals are the pieces from which Earth was made. According to NASA observations, suns, planets and moons began as swirling masses in clouds of cosmic dust and gases, evolving into spinning disks and then into solid masses; during which time the heavier elements in every mass, prior to solidification, would be forced outward and lighter elements inward because of centrifugal force. Simple physics. My Cream Separator Theory.

 

In fact, NO such planetesimals have ever been observed. This is not to say they don't exist, just never been observed. Meanwhile the above evolution of suns, planets and moons appears to be an ongoing and observable process which makes good sense and is both logical and physically possible.

 

Modest: You wrote, “As you pointed out extensively in another thread: earth looses (sic) hydrogen.”

 

That I did, but I'm just not sure what this prior thread has to do with my current question in this thread as to how Earth acquired an iron core. Seems to me, changing the issue is a popular way in this forum to avoid answering questions.

 

Modest: You wrote, “If you think there's a major problem with this hypothesis then you should outline the exact nature of this problem and how you think a hydrogen core fixes it.”

 

While this is not the question I asked in this thread, I did this in detail in other threads to which you can refer. Again, changing the issue or subject matter does not answer my question in this thread.

 

Modest: You wrote, “Railing against science and the people in this thread does not advance your cause.”

 

Seems to me the others have been railing against my questions and opinions, so I have largely been on the defensive instead of learning the facts and information I expected to obtain to satisfy my curiosity. Sad commentary about what some people claim to call scientific method. Most only seem to want to demonize anything not in [their] mainstream beliefs.

 

What amazes me is the manner in which Turtle attacks me for being devious and a Creationist, largely on the basis of his misunderstanding of an aside on a book by Neil Christianson, “The Epistle to the Creationists.” Turtle must be a Christian, as he appears to believe “Epistle” in the title refers to the Bible. In fact, Epistle means 'Directive to a group' and the book is largely about Neil's research into the history of the belief in Earth having a hydrogen core and it was critical of Creationists.

 

While hardly a Creationist myself, being more agnostic/atheist, I do know a lot of Creationists. While active with the Boy Scouts, I can report that all the Creationists I have met have been good people and fine parents, and apparently just as biased in their beliefs as others. Fortunately, their sons largely admit their parents are a bit kooky and I believe few will adhere to their parent's beliefs as they grow older. I can say this with some authority as I have held most positions in the BSA, including that of Commissioner. Wonder if Turtle was ever a Boy Scout? Sure doesn't act like one.

 

Unfortunately, Turtle apparently brags that he will expose and reject anything which indicate a Creationists was asking devious questions [trolling?] in his website. What a bigoted, biased bully. I note he is listed as a “Sponsor.” I also note that no other member has dared to openly criticize Turtle for his hurtful and false assumptions, personal insults and such, albeit you and a few others seem to have wisely counseled that some of my views might be worth considering. For this, I thank you and them, but I must view many of the others as cowardly by comparison. Seem to me, 'Sponsor' Turtle may have 'bought' himself a forum in which he can bully those with whom he disagrees without fear of complaint from other members. I suggest this is not a good thing for those seeking to participate in the expressed intent of this forum as being a scientific and social gathering.

 

Well, my curiosity is still with me, even though many my age don't know what day it is. So my question is still the same, which I may ask of another forum where there might be more tolerant, understanding and less biased members. Goodbye.

Posted

CharlieO dude, please give us some links to the evidence that drives your ideas. I've read the wikki article about Orpheus colliding with the earth to form the moon., No where does it mention Orpheus having an extra big iron core or the earth having a hydrogen core that is replaced by it. So far you have proposed many things about an hydrogen core, all of them so far defy physics. A compressed hydrogen core does not just stay that way. It takes tens of thousands of miles of atmospheric pressure and a thousands of miles of liquid metallic hydrogen pressure to make metallic hydrogen in nature and if that pressure is removed the hydrogen goes back to being a gas. I am easy to get along with , just provide some evidence for your ideas, I've never heard of them, At no time in my life have i been told earth got it's iron core form some later bombardment. I am 54 years old, i have been paying attention. lets see some of this info. if your info is compelling I would be more than willing to talk about the possibilities but so far all you offer is third hand "info" that doesn't hold together.

Posted
...What amazes me is the manner in which Turtle attacks me for being devious and a Creationist, largely on the basis of his misunderstanding of an aside on a book by Neil Christianson, “The Epistle to the Creationists.” Turtle must be a Christian, as he appears to believe “Epistle” in the title refers to the Bible. In fact, Epistle means 'Directive to a group' and the book is largely about Neil's research into the history of the belief in Earth having a hydrogen core and it was critical of Creationists.

 

While hardly a Creationist myself, being more agnostic/atheist, I do know a lot of Creationists. While active with the Boy Scouts, I can report that all the Creationists I have met have been good people and fine parents, and apparently just as biased in their beliefs as others. Fortunately, their sons largely admit their parents are a bit kooky and I believe few will adhere to their parent's beliefs as they grow older. I can say this with some authority as I have held most positions in the BSA, including that of Commissioner. Wonder if Turtle was ever a Boy Scout? Sure doesn't act like one.

 

Unfortunately, Turtle apparently brags that he will expose and reject anything which indicate a Creationists was asking devious questions [trolling?] in his website. What a bigoted, biased bully. I note he is listed as a “Sponsor.” I also note that no other member has dared to openly criticize Turtle for his hurtful and false assumptions, personal insults and such, albeit you and a few others seem to have wisely counseled that some of my views might be worth considering. For this, I thank you and them, but I must view many of the others as cowardly by comparison. Seem to me, 'Sponsor' Turtle may have 'bought' himself a forum in which he can bully those with whom he disagrees without fear of complaint from other members. I suggest this is not a good thing for those seeking to participate in the expressed intent of this forum as being a scientific and social gathering.

 

Well, my curiosity is still with me, even though many my age don't know what day it is. So my question is still the same, which I may ask of another forum where there might be more tolerant, understanding and less biased members. Goodbye.

 

:mickmouse: Guess we can't go any further afield than we already have, so here goes. All of the above quoted has nothing to do with the topic. You have no basis Charlie to assume anything about me along the lines of your above speculation. What's more, it has no more bearing on the topic than your personal anecdotes. If you're not a creationist that's peachy, but there is plenty of reason to have suspected you. Still, the point is your attacks on science regardless of your motivation. Considering the above condemnation of my hyperbole it's a little like the pot calling the kettle black aint it?

 

So anyway, you came here looking for attention for your ideas and now I have assured that you have it. Carpe diem Chuck and you're welcome. :ideamaybenot:

Posted
Unfortunately, Turtle apparently brags that he will expose and reject anything which indicate a Creationists was asking devious questions [trolling?] in his website. What a bigoted, biased bully. I note he is listed as a “Sponsor.” I also note that no other member has dared to openly criticize Turtle for his hurtful and false assumptions, personal insults and such, albeit you and a few others seem to have wisely counseled that some of my views might be worth considering.

 

I am a moderator of these forums and I did, in fact, tell Turtle that his questioning of your motives (in particular: assuming they have something to do with creationism) is inappropriate. I'm now also telling you that it is completely inappropriate to call another member a bigot. If you have a problem with a member you can report their post by clicking the red square above it, or you can private message me or any staff member and we will deal with the problem.

 

I now suggest that we all focus on the science of this topic and avoid any further conversation of an ad hominem nature. Discussing each other's motives and trading insults is just not a beneficial discussion. In that spirit, I'm going to selectively reply to the science portions of your message, Charlie.

 

I was taught Earth formed from within a spinning cloud of elements, mainly hydrogen, and, as with any rotating fluid, gaseous or semi-solid mass, the heaviest elements will always be forced outward, leaving the lightest elements in the center.

 

I think this is the foundation of the problem. You are correct that more massive elements move to the outside of a spinning disc with more force than lighter elements. The force responsible is the centrifugal force which is:

[math]F_C=\frac{mv^2}{r}[/math]

As the mass (m) gets larger, so too does the force ([math]F_C[/math]). This means that something with more mass is exerting more outward force when spinning in a circle than something with less mass. An example of this is when you put blood in a centrifuge and it segregates according to density such that the heavier parts throughout the fluid make an aggregate toward the bottom of the test tube.

 

This cannot happen when the earth formed, and I assure you, Charlie, you will find no textbook saying it can.

 

In the case of a spinning disc or a centrifuge a mechanical force holds the material to the spinning device. In the case of a forming planet it is gravity which holds materials to the protoplanet. The force of gravity is:

[math]F_G=\frac{GMm}{r^2}[/math]

This means the downward force ([math]F_G[/math]) increases with mass (m). For any given element spinning in the forming protoplanet there are two major forces affecting it: gravity and centrifugal force, and they are both proportional to mass. If the centrifugal force is the greater of the two then the element will be flung away from the forming planet. In that case a planet won't form, so gravity must be the greater force. Since the force of gravity increases with mass, substances with greater density will sink toward the bottom while lighter elements float toward the top.

 

Gravity must be the major force and it will segregate a fluid by density such that heavier substances move toward the center and lighter elements are pushed toward the exterior.

 

Thus, Earth originally having a hydrogen core is what I was taught in the 1950s and then again in the 1970s, albeit seldom clearly stated; usually mentioned as lighter elements.

 

I don't know much about the gravitational instability models of planet formation of the 50's and 70's. I've just read some of Kuiper's 1951 paper (yes, that Kuiper) advocating that kind of thing. All I can say is that the current favored model is not that of gravitational instability and collapse of hydrogen and helium and it was never really considered seriously for the terrestrial planets. Nonetheless: even where such a model makes some sense (as with Jupiter) it's not in any way unusual for the heavier rock and metal to sink to the core.

 

I was also taught that an enormous swarm of iron-rich micro-planets later attacked a smaller proto-Earth in a concentrated bombardment, adding to its mass and making it totally molten. Then, even though early Earth was still spinning to the extent that many believe it was still largely disk shaped, only iron, with some nickel, somehow flowed inward against centrifugal force and displaced the original hydrogen core, vaporizing it and forcing it to vent to the surface where it was blown away by solar winds. Have I got this right?

 

This is not correct according to modern planet formation models (Solar Nebular Disc Model). Earth never had a hydrogen core. I'll also point out again that "somehow flowed inward against centrifugal force" shows a misunderstanding of physics. No freely self-gravitating collection of material can arrange itself in such a way that lighter elements are attracted with greater force than heavier elements. I think your belief otherwise is the source of many of your disagreements with earth's structure and formation.

 

The point I'm making is that such a scenario is physically impossible, largely due to the presence of the Sun and Jupiter's much greater gravitational attraction and the total lack of any similar swarms being evident anywhere in the cosmos, as per recent astronomical observations.

 

In fact, the gravitational instability scenario where earth starts as a self-collapsing collection of gas is generally considered impossible—as you say. In order for this to happen the collapsing material would need to fight the tidal forces of the sun. The density of the material in the accretion disc would need to be greater than the "Roche density" given by:

[math]\rho_R=\left(\frac{2 \beta R_0}{a}\right)^3[/math]

where (a) is the distance to the sun. The density needed varies inversely with the cube of the distance to the sun. Given estimates for the mass of the protoplanetary disc, it seems very unlikely that planets as close as earth can form from direct gravitational collapse as you describe above. Even for a planet as far as Jupiter the protoplanetary disc would need to be .3 times the mass of the sun now which is very massive given astronomic observations. It seems unlikely that the gas giants were formed that way and it seems (as you say) physically impossible in the case of earth.

 

Do you think the Grand Bombardment is a viable theory as to how Earth's original hydrogen core was replaced by an enormous excess of iron? I don't.

 

It does not seem possible (as I say above) that earth can ever have had a hydrogen core. There is therefore no need to replace one. Earth's early bombardment has nothing to do with replacing the core.

 

Then, I learned later in life that the Grand Bombardment was wrong, albeit taught to hundreds of thousands of students as the primary mainstream geology theory at that time as to how Earth came to have an iron core.

 

A google search for "grand bombardment" and earth gives 111 results—so, I doubt there is such a thing. The only bombardment I know of is the "early bombardment" revealed by structures on the moon. It took place after earth's formation and has nothing much to do with the content of the core. Do you have a link or reference to a book or publication to that which you're referring?

 

Now we are to believe a Mars sized planet, which was largely iron, somehow wandered into Earth's orbit and they collided. They supposedly melted together and the smaller planet's immense, proportionally, iron core was transferred into proto-Earth, again vaporizing Earth's original hydrogen core and forcing it to vent into space and be lost. At least this is how I read the latest reviews of this theory in Winkipedia.

 

This is not correct. In the theory to which you refer both bodies had iron cores. Essentally, they had equivalent compositions. You should read this:

However, there is no mention of how the smaller planet obtained an iron core far greater in proportion to its size than the core which ended up as Earth's iron core in a combined mass.

 

The proposed impact has been extensively molded. When two objects like mars collide, a great deal of material from the upper layers of each body is left in orbit forming a large moon. Its composition has little iron because the cores of the two impacting bodies mostly does not obtain orbit.

 

There is also no mention as to how it was able to wander freely through our solar system, unaffected by the Sun's or Jupiter's gravity. There is also no mention of how it was able to travel in an orbit different from Earth's, even though all the other planets in our solar system travel in the same direction. Thus, I, at least, believe the 'theory' to be good science fiction, albeit physically illogical to the point of being absurd.

Pluto's orbit crosses that of Neptune and there are many solar bodies with eccentric orbits.

 

This is my personal opinion, based on the lack of information as to how any Mars sized planet, largely composed of iron, was formed and how it came to be on an opposing orbit to Earth's and how it was able to avoid the gravitational attraction of the Sun and Jupiter; both of which have obviously never experienced any similar event, if their lack of iron is to be considered valid evidence.

 

It is not suggested to have had an opposing orbit to earth nor to have a composition significantly different from the current combined Earth / moon system. The reason it is a favored theory is because it is the only model which has successfully explained the formation of Earth's moon. It's also very likely that the Sun and Jupiter have both had similar events. You are incorrect about the Sun and Jupiter not having the required iron content. The most current estimates for the total mass of elements in Jupiter other than hydrogen and helium is between 11 and 45 times the mass of Earth. That is certainly enough to account for a couple mars-sized impacts of terrestrial material. As for the sun, it is estimated to have 0.14% iron by mass which is [math]2.78 \times 10^{27}[/math] kg. That's 467 times the mass of earth. There's simply no way of saying that planets with iron cores couldn't have plunged into the sun.

 

I realize you're not meaning to, but all your arguments so far have been against a strawman. I hope you are receptive to their critique.

 

Do you think the Earth-Theia collusion scenario is a valid theory as to how Earth acquired its iron core?

 

I believe it is a valid hypothesis, but is not a theory for how Earth acquired its iron core. It would be more accurate to say "the hypothesis explains why earth's core is as large as it is".

 

One forum member suggested Earth might have been “lucky enough” to have condensed from a primordial ring of iron-rich dust. Seems a better theory than both of the above to me, but highly unlikely since nothing like a ring of iron-rich dust has ever been observed. Again, not to say such can't exist.

 

The best current model of solar and planet formation is the Solar Nebular Disc Model. It explains that planetesimals about 1 kilometer in average size condensed after which the planets accreted from that material.

 

It may in fact be a more plausible explanation of how Earth came to have at least some iron in its core. This qualification is made because it has been proven that iron-nickel becomes too dense at core pressures to be the only elements in Earth's core. Therefore, lighter elements are currently being considered for inclusion in Earth's core, which will complicate his explanation; most often mentioned is hydrogen.

 

No, the most-often mentioned is not hydrogen. It is oxygen and sulfur. Geophysical evidence would be consistent with 5.8 % oxygen and 1.9% sulfur which you can see from the paper I linked yesterday in my post to Moontanman. Notice from a landmark paper in 1952 written by Francis Birch:

The velocities in the core and inner core are also reviewed. The inner core is most simply interpreted as crystalline iron, the outer part as liquid iron, perhaps alloyed with a small fraction of lighter elements. The density and compressibility of iron at high pressures are estimated with the aid of the experimental compressions of the alkali metals...

 

So, It has been known for almost 60 years that the outer core is slightly less dense than iron/nickel alone. By the way, there's a quote in that paper which I find funny and you'll like, so I'll quote:

Unwary readers should take warning that ordinary language undergoes modification to a high-pressure form when applied to the interior of the Earth. A few examples of equivalents follow

  • Certain = Dubious

  • Undoubtedly = Perhaps

  • Positive proof = Vague suggestion

  • Unanswerable argument = Trivial objection

  • Pure iron = Uncertain mixture of all the elements

 

In fact, it now appears that hydrogen, compressed at core pressured over time, may become sufficiently dense enough to be near the density required to be Earth's core.

 

This is false. As Pyrotex has shown, metallic hydrogen has a density of around 1 gram / cm at core pressure (the source of which I quoted in an earlier post). To satisfy earth's total volume and mass it would need to be between 10 and 13.

 

IF this proves to be true and that Earth's mantle is heavier than originally calculated, the iron core theory may be in trouble. Heavier mantle equals lighter core, for which iron becomes too dense now.

 

This would be inconsistent with evidence and well-established physics for a couple reasons. If the core were composed of a lighter liquid than the mantle then the material of the mantle would sink into the core displacing it. The mantle would not be the heavier of the two for very long. Also, seismic data constrains the density of the mantle and core. As the density of the materials change so too does the speed of seismic waves traversing them. Here, for example, are the velocities of p waves:

-

At about 2890 km the p waves encounter a large increase in density accompanied by a drastic slowing from about 14 to about 8 km/s.

 

There really is preponderant evidence which agrees with current theories and disagrees with your proposed alternatives.

 

Modest: You wrote, “If you consider the leftover ingredients of planet formation which are floating around the solar system; they are stony and iron/nickle (sic) meteoroids.”

 

Some may consider this to be a fair assumption, but it is based only on the fragments of meteoroids which have survived during their passage through our atmosphere. While there are other types of meteorites, I suspect the original mass of stony meteorites which enters our atmosphere is many fold times greater than the mass which survives and lands on Earth. Whereas, I suspect the original mass of iron/nickel meteorites which survive entry through our atmosphere is not anywhere near as reduced by their passage. Therefore, it seems likely that the iron/nickel found on Earth's surface is only an insignificant portion of the total mass of the alleged “leftovers” floating around the solar system.

 

I'm not sure what you're trying to say here. My point is that Earth's composition and isotope ratios are remarkably close (near-indistinguishable) from chondritic meteorites. The current favored model of planet formation essentially says Earth is made from these things. They don't have large abundances of hydrogen and helium so it's only natural that Earth doesn't either.

 

And, again, I believe the Sun and Jupiter would have attracted the vast majority of these leftovers long ago

 

Yes, I'm sure they have. The leftover asteroids and meteoroids from the inner solar system and the leftover comets from the outer solar system are often being thrown into the sun, out of the solar system, or bumping into planets. There's still a lot of it out there (NASA is tracking 6,000 asteroids with near earth orbits right now), but the vast majority (even when including the asteroid belt) is certainly gone.

 

should they have existed in any useful quantity; yet the Sun and Jupiter show little evidence of acquiring anything near the mass of iron attributed to these alleged “leftovers.”

 

I already addressed the metalicity of the Sun and Jupiter. I'll add that we watched Shoemaker-Levy 9 hit Jupiter in 1994 and a few weeks ago NASA tracked an SUV-sized asteroid until it hit the earth and they went to Sudan and collected pieces of it and they're studying them now. It is really fascinating what we can learn from these things and it has a lot to do with planet formation.

 

Modest: You wrote, “So, we know the composition of these small planetesimals and they are literally the pieces that the earth was made from. Earth and the rest of the inner planets never accreted (sic) hydrogen because it isn't massive enough.”

 

Accrete means "To grow together, combine; To adhere; to grow (to); to be added". It's a very common word used in astronomy. The planets, for example, formed from an accretion disc surrounding the sun from which they accreted mass.

 

Well, I believe this is just an assumption as no one really knows if these small planetesimals are the pieces from which Earth was made. According to NASA observations, suns, planets and moons began as swirling masses in clouds of cosmic dust and gases, evolving into spinning disks and then into solid masses; during which time the heavier elements in every mass, prior to solidification, would be forced outward and lighter elements inward because of centrifugal force. Simple physics. My Cream Separator Theory.

 

I hope you see the value of bringing these ideas to a science website. In 2007 you presented this idea that the centrifugal force would move heavier elements toward the outside of a forming planet. This notion was immediately corrected by a very qualified physicist in this post. I'll quote him:

Where is your evidence that that Earth was spinning so m/ch faster in its youth? (as in enough for the centrifugal effect to become the
major
factor.)

 

In order for the centrifugal effect to cause the separation of elements as you suggest (the cream separator effect), it would have to be stronger than the gravity holding the Earth together, in which case the Earth would have never formed in the first place.

 

The centrifugal effect acts outward from the axis of spin, not from a central point. The separation would happen like the rings of a tree rather than the layers of an onion. Thus you would see all the heavy elements at the equatorial regions of the crust and lighter elements as you approached the poles. We do not.

 

A few months later you persisted with the notion and I corrected it in this post. Please try to be receptive to the feedback you're getting. Your description of mass separation is not possible. If heavier elements have less inward force than lighter elements then the centrifugal force must be the dominant factor at which point the elements must exceed the escape velocity of the body.

 

If you are going to continue repeating this claim then you need to provide a scientific source by way of a link or a specific reference to some published media to back it up. This is a site rule at Hypography.

 

In fact, NO such planetesimals have ever been observed. This is not to say they don't exist, just never been observed.

 

By the common definition, asteroids and comets greater than 1 km are planetesimals.

 

I know this post covers a lot of ground. It might be useful to just focus on just a couple topics. I'm most curious about your reception to heavy elements in Jupiter and your understanding of centrifugal force and gravity as far as floating and sinking materials. If you could explain in depth or find a source for why you think Jupiter can't have a couple earth masses worth or iron or by what physical forces lighter elements can float downward, I think that would be a beneficial area of discussion rather than a carpet response. But, I leave that, of course, up to you.

 

~modest

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