Earth - What is the real age?

[Robittybob1]

Probably not. Nobody here has brought up core temperatures except you. It's not what we're discussing.

It is definitely the theme of the OP

 

...

Hence, in the past, the temperature at the center was much higher than 6000 °C.

However, the Earth has Iron inner core.....

Somehow that core temperature has been brought to the surface. I am questioning how when the OP refers to core temp the 6000 plus temps are made surface temperatures.

 

 

OK a bit further on David seems to be querying the Giant Impact theory:http://www.scienceforums.net/topic/88301-earth-what-is-the-real-age/#entry859800

 

 

Agree?

 

 

 

"There remain several questions concerning the best current models of the giant impact hypothesis, however.[6] The energy of such a giant impact is predicted to have heated Earth to produce a global 'ocean' of magma"

 

How could it be that it cools down dramatically in only 100 million years?

So is that is how the temperatures get to the surface?

 

I see he looks at the rate of cooling in the first 100 my compared to the following 4 by. http://www.scienceforums.net/topic/88301-earth-what-is-the-real-age/#entry859914

 

 

.... O.K.

Let's agree that the Earth had been cooled down from 6000 °C to 32 °C in 100 My. Hence, by average, the temperature had been decreased by 59.68 °C per My. As the space is still very cold, it is expected that the Earth will continue with its rapid heat lose. Therefore, after 110 M years the temperature should be around -68 °C and after 150 My -266.4 °C.

However, based on our knowledge, this isn't the case.

So, the Earth had been cooled down from over 6000 °C (or even 10,000 °C) to 32 °C in less than 100 My, and for 4.5 Billion years it holds the temperature at the same level (more or less). ....

Good question really.

Edited March 28, 2015 by Robittybob1

[swansont]

It is definitely the theme of the OP

"how long it should take the Earth to cool down from a full hot star at high temperature of over 6000 °C?" has very little to do with the core.

 

Somehow that core temperature has been brought to the surface. I am questioning how when the OP refers to core temp the 6000 plus temps are made surface temperatures.

The fact that the numbers are the same does not mean the "core temperature has been brought to the surface" It means that was the assumed temperature of the earth's surface when it formed.

[Robittybob1]

 

"how long it should take the Earth to cool down from a full hot star at high temperature of over 6000 °C?" has very little to do with the core.

 

 

The fact that the numbers are the same does not mean the "core temperature has been brought to the surface" It means that was the assumed temperature of the earth's surface when it formed.

OK but the only way you can get temperatures like that on the surface is from the hypothetical impact from Theia (as proposed by the Giant Impact theory). If the Iron catastrophe occurred after 500 m.y. it wasn't molten during the Earth's formation. You can't have it both ways.

[swansont]

OK but the only way you can get temperatures like that on the surface is from the hypothetical impact from Theia (as proposed by the Giant Impact theory). If the Iron catastrophe occurred after 500 m.y. it wasn't molten during the Earth's formation. You can't have it both ways.

 

It would really be helpful if you would read the thread before continuing. If you had, you would see that we were discussing — very early on — how the earth could cool significantly in ca 100 million years, and it was posited that it was at 6000 ºC. So what happened a few hundred million years later isn't really part of the discussion (and would also be in complete agreement with the earth not being molten at that later time).

 

Any disagreement with the OP's assertion that the early earth was a "full hot star" may be directed at the poster.

 

I see he looks at the rate of cooling in the first 100 my compared to the following 4 by. http://www.scienceforums.net/topic/88301-earth-what-is-the-real-age/#entry859914

 

Again, please read the thread. You will find commentary on how awful this analysis is.

[Robittybob1]

 

It would really be helpful if you would read the thread before continuing. If you had, you would see that we were discussing — very early on — how the earth could cool significantly in ca 100 million years, and it was posited that it was at 6000 ºC. So what happened a few hundred million years later isn't really part of the discussion (and would also be in complete agreement with the earth not being molten at that later time).

 

Any disagreement with the OP's assertion that the early earth was a "full hot star" may be directed at the poster.

 

Again, please read the thread. You will find commentary on how awful this analysis is.

Well yes I think the OP definitely used the wrong words there by calling the Earth a "full hot star" but at that temperature it would be radiating light as though it was "star-like" just because of its surface temperature.

Note: I don't expect the OP to convince me that the Earth's surface temperatures ever got as hot as this.

[pavelcherepan]

Well yes I think the OP definitely used the wrong words there by calling the Earth a "full hot star" but at that temperature it would be radiating light as though it was "star-like" just because of its surface temperature.

Note: I don't expect the OP to convince me that the Earth's surface temperatures ever got as hot as this.

 

As it was stated on multiple occasions in the thread, oldest zircons have been dated around 4.4 bya and since those have survived until now in their original state means that at no point in history these have been subjected to a temperature above the melting point of zircon - 1855^oC and thus here you have the upper boundary for the crust temperatures from 4.4 bya onwards.

 

Also, as been already pointed out before, ratio of oxygen isotopes in these zircons shows that at the time of their formation temperatures were low enough to support liquid water on the surface. So if the surface were molten completely, it had to cool down relatively fast to support these known facts.

 

And the upper bound for the formation of the Earth comes from dating of meteorites and lunar samples, since its implausible to assume that the Earth has formed before the rest of the Solar System.

 

So here you have them facts and they correlate well with each other and whatever the mechanism of cooling was (although I think physicists here gave some really good insights on the process) it had to happen within these time frames.

 

http://www.sciencemag.org/content/308/5723/841.short

Edited March 29, 2015 by pavelcherepan

[David Levy]

 

It would really be helpful if you would read the thread before continuing. If you had, you would see that we were discussing — very early on — how the earth could cool significantly in ca 100 million years, and it was posited that it was at 6000 ºC. So what happened a few hundred million years later isn't really part of the discussion (and would also be in complete agreement with the earth not being molten at that later time).

 

Any disagreement with the OP's assertion that the early earth was a "full hot star" may be directed at the poster.

 

Again, please read the thread. You will find commentary on how awful this analysis is.

 

 

Yes, I read it carefully, but unfortunately it seems that the science didn't take in the account for the fast Earth heat dissipation (100 My) the following main factors:

Atmosphere on Earth, Crust heat conductance and Sun radiation

Please advice if you confirm this verification.

Edited March 29, 2015 by David Levy

[pavelcherepan]

Yes, I read it carefully, but unfortunately it seems that the science didn't take in the account for the fast Earth heat dissipation (100 My) the following main factors:

Atmosphere on Earth, Crust heat conductance and Sun radiation

Please advice if you confirm this verification.

 

David, please read rules about discussing your ideas in Speculations forum, if you haven't already done so and particularly pay attention to rule 1. Please provide evidence to back your idea, because so far we haven't seen any evidence, just random baseless speculations with no scientific backing. Do you want to discuss or just want to postulate that current knowledge is incomplete?

[David Levy]

 

David, please read rules about discussing your ideas in Speculations forum, if you haven't already done so and particularly pay attention to rule 1. Please provide evidence to back your idea, because so far we haven't seen any evidence, just random baseless speculations with no scientific backing. Do you want to discuss or just want to postulate that current knowledge is incomplete?

 

It's unbelievable.

I ask you a simple question and you direct me to speculation.

Please be aware that I didn't say even one word of speculation.

Therefore, let me repeat my question:

Did the science take in the account of the fast Earth heat dissipation (T4 formula) the following factors:

Atmosphere on Earth, Crust heat conductance and Sun radiation

Yes or no?

Why is it so difficult to answer?

Edited March 29, 2015 by David Levy

[pavelcherepan]

I ask you a simple question and you direct me to speculation.

Please be aware that I didn't say even one word of speculation.

 

This thread has been moved to speculations if you haven't noticed it yet. My guess that would be because you're arguing against accepted scientific theories without ever providing evidence and yet demanding explanations for your random ideas.

 

 

Did the science take in the account of the fast Earth heat dissipation (T4 formula) the following factors:

Atmosphere on Earth, Crust heat conductance and Sun radiation

Yes or no?

Why is it so difficult to answer?

 

 

It's easy to answer but you obviously haven't read any papers that other posters have linked before. Please go through the thread and check information that you've been given.

 

Please refer to these:

 

http://www.scienceforums.net/topic/88301-earth-what-is-the-real-age/?p=859805

also this article from post 4:

http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1988LPICo.681...20G&db_key=AST&page_ind=0&data_type=GIF&type=SCREEN_VIEW&classic=YES

 

http://www.scienceforums.net/topic/88301-earth-what-is-the-real-age/?p=859809

 

There's plenty of information in these links and remember - it's pretty lame to ask a question and not read the answer you've been given.

Edited March 29, 2015 by pavelcherepan

[Robittybob1]

 

... its implausible to assume that the Earth has formed before the rest of the Solar System. ...

 

 

I don't think you should put limits on this aspect. I have favoured a progressive building of the Solar System hence Earth could have been the 3rd planet to form and meteorites could be from the later built planetesimals. It is all on a very close time frame, so I am not confident it can be differentiated on the information known to date.

I don't think you should put limits on this aspect. I have favoured a progressive building of the Solar System hence Earth could have been the 3rd planet to form and meteorites could be from the later built planetesimals. It is all on a very close time frame, so I am not confident it can be differentiated on the information known to date.

Edit: Tell me why that deserves a minus 1 please.

Edited March 29, 2015 by Robittybob1

[swansont]

 

Please be aware that I didn't say even one word of speculation.

 

 

Oh, please.

 

"This might be an indication that the earth was a full hot star"

 

You speculated there would be linear temperature reduction as the earth cooled. That Venus is hot because it has no magnetic field.

 

Mainly, you've taken an attitude that the science is wrong while clearly demonstrating no understanding of the science involved.

 

Why is it so difficult to answer?

 

You were given references. Those count as answers. Spoon-feeding is not a service we provide.

[pavelcherepan]

I don't think you should put limits on this aspect. I have favoured a progressive building of the Solar System hence Earth could have been the 3rd planet to form and meteorites could be from the later built planetesimals. It is all on a very close time frame, so I am not confident it can be differentiated on the information known to date.

 

Such a situation would require one external event to trigger the formation of the Earth and so accurate that it didn't affect anything else, and another event to trigger formation of all other planets. How would it fare against Occam's razor?

Edited March 29, 2015 by pavelcherepan

[Robittybob1]

 

Such a situation would require one external event to trigger the formation of the Earth and so accurate that it didn't affect anything else, and another event to trigger formation of all other planets. How would it fare against Occam's razor?

I would need to do that in another thread but the mechanism is simple so it meets Occam's razor demands.

Edited March 29, 2015 by Robittybob1

[David Levy]

 

You were given references. Those count as answers. Spoon-feeding is not a service we provide.

 

There is no need for spoon, as the evidences are clear.

The science didn't take in their account for the fast Earth heat dissipation ALL the following factors: Atmosphere on Earth, Crust heat conductance and Sun radiation.

Please also be aware that as the Earth is drifting away from the Sun, it is expected that 4.5 By ago the Earth was closer to the sun. Therefore, the total heat from sun radiation was higher.

In any case, without taking in account the impact of all the factors, T4 formula is not realistic. Hence, it is needed to set more accurate calculation/formula!

Edited March 29, 2015 by David Levy

[imatfaal]

!

Moderator Note

 

David

 

Please start providing argument through reason and from a factual basis - your continued use of blank assertion together with the argument from incredulity/ignorance will lead to the thread being locked.

 

As always do not response to this moderation within the thread

 

[David Levy]

Thermal Aspects of Lunar origin by giant impact

https://books.google.com.au/books?hl=en&lr=&id=8i44zjcKm4EC&oi=fnd&pg=PA179&dq=%22giant+impact%22+%26+%22cooling%22&ots=7J7G5oM4kO&sig=wwNA70Ueg5akNq0HCdlX_wD6fPU#v=onepage&q=%22giant%20impact%22%20&f=false

 

It is an excellent example how the Crust heat conductance could affect the heat dissipation of the Moon.

In pg 181 it is stated:

"Interestingly, lava takes on Hawaii typically show effective radiating temperatures of around 500 K (because of thin skin overlying…)

"To summarize, substantial bodies (1M or even 0.5 M) must be extensively partially molten in order to lose heat efficiently, and would be even more molten if they failed to lose heat efficiently. The cooling time is on the order of accretion time (100my) or longer.

"From the number mentioned previously, it is evident that an incoming mass of order 1 M has sufficient energy to melt all of Earth".

Hence, If we take in account this factor by itself, the cooling time (for the moon) is in order of 100 My or more.

Therefore, it is clear that the cooling time for the Earth must be significantly longer as it's mass is about 80 times the mass of the moon. So if we just multiply it by 80, the cooling time must be more than 8000 My or 8 By.

If we add to this the other factors, than the cooling time must be even much longer!

Edited March 29, 2015 by David Levy

[Greg H.]

Please also be aware that as the Earth is drifting away from the Sun, it is expected that 4.5 By ago the Earth was closer to the sun.

 

Say what?

[swansont]

Thermal Aspects of Lunar origin by giant impact

https://books.google.com.au/books?hl=en&lr=&id=8i44zjcKm4EC&oi=fnd&pg=PA179&dq=%22giant+impact%22+%26+%22cooling%22&ots=7J7G5oM4kO&sig=wwNA70Ueg5akNq0HCdlX_wD6fPU#v=onepage&q=%22giant%20impact%22%20&f=false

 

It is an excellent example how the Crust heat conductance could affect the heat dissipation of the Moon.

In pg 181 it is stated:

"Interestingly, lava takes on Hawaii typically show effective radiating temperatures of around 500 K (because of thin skin overlying…)

"To summarize, substantial bodies (1M or even 0.5 M) must be extensively partially molten in order to lose heat efficiently, and would be even more molten if they failed to lose heat efficiently. The cooling time is on the order of accretion time (100my) or longer.

"From the number mentioned previously, it is evident that an incoming mass of order 1 M has sufficient energy to melt all of Earth".

Hence, If we take in account this factor by itself, the cooling time (for the moon) is in order of 100 My or more.

Therefore, it is clear that the cooling time for the Earth must be significantly longer as it's mass is about 80 times the mass of the moon. So if we just multiply it by 80, the cooling time must be more than 8000 My or 8 By.

If we add to this the other factors, than the cooling time must be even much longer!

 

 

So what part of "cooling time is on the order of accretion time (100my) or longer" is inconsistent with the cooling time being around 100 million years?

[pavelcherepan]

I would need to do that in another thread but the mechanism is simple so it meets Occam's razor demands.

 

Please do. In another thread.

[Robittybob1]

 

 

So what part of "cooling time is on the order of accretion time (100my) or longer" is inconsistent with the cooling time being around 100 million years?

David Levy - that would be OK as long as you are both talking of the Moon, but not if one is talking about the Moon and the other about the Earth.

The sentence does not specify what body/bodies it is being discussed.

Edited March 29, 2015 by Robittybob1

[swansont]

David Levy - that would be OK as long as you are both talking of the Moon, but not if one is talking about the Moon and the other about the Earth.

The sentence does not specify what body/bodies it is being discussed.

 

The book, as viewed from the link, appears to be using an "earth mass" symbol.

[Robittybob1]

 

The book, as viewed from the link, appears to be using an "earth mass" symbol.

The sentence that is interesting is this one:

 

"From the numbers mentioned previously, it is evident that an incoming mass of order 1 M has sufficient energy to melt all of Earth".

Theia was supposed to be a Mars sized planet, so quite a bit of its kinetic energy would have been used up in tossing sufficient material up into space to accrete later into the Moon. (That process seems unlikely to be 100% efficient so one could imagine 10 times more stuff being thrown up and the majority later raining down again.) So with the energy balance of that there is plus side and a minus side. Have you ever seen the figures for a Theia sized impact rather than a 1 M sized mass? There must be a huge difference in that Mars being only 11% the mass of Earth.

Looking at the ratios they are saying the equivalent 90% the mass of Theia remains on Earth and only 10% goes into the formation of the Moon.

Earth 5.972E+24

Mars 6.39E+23 Ratio Earth : Mars 9.345852895 Ratio Mars : Earth 0.10699933

 

Moon 7.35E+22 Ratio Earth : Mars 8.13E+01 Ratio Mars : Earth 1.23E-02, Ratio Moon : Mars 1.15E-01

Edited March 30, 2015 by Robittybob1

[David Levy]

David Levy - that would be OK as long as you are both talking of the Moon, but not if one is talking about the Moon and the other about the Earth.

The sentence does not specify what body/bodies it is being discussed.

 

Yes, it is the Moon

 

The title of this article is: "Thermal Aspects of Lunar origin by giant impact"

"The bulk of the evidence and modeling suggests hot initial conditions for nearly all the lunar."

"Our goal here is to assess whether the moon we know is compatible with the Moon that might form following a giant impact."

"leading to bodies of the 1M (lunar mass) as the building blocks for making Earth."

Edited March 30, 2015 by David Levy

[Robittybob1]

Thanks for clearing that up David.

 

So looking at those ratios if an incoming mass the size of the Moon is enough to melt the Earth what would a Mars sized mass (that is a mass 8.7 times as large) do?

Edited March 30, 2015 by Robittybob1