![]() | This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
It is messy, so I just created a sub-section.
More to the point, not all related content should go into an article, that is what links (sub-articles) are for. Could you imagine all the abortion related material going into abortion. It would be a very large and even more difficult article to manage. Since various religions speak to the age of the earth they are mentioned prominently in this article as alternatives to scientific inquiry. I will seriously consider your proposal to remove "non-scientific", and pose the question to other administrators. However, I doubt it will gain much traction, as it is firmly established (by the scientific community) that creation related science is pseudoscientific. But, within the specific context of a redirect message, it may be appropriate to remove it. - Roy Boy 800 21:29, 7 November 2005 (UTC)
Yes - further confirms means just that, the new evidence (read the references) add solid data that confirms the previous estimates at least back to the ages of those rocks. You obviously don't understand scientific evidence - it is not some inviolate truth - it is factual evidence based on the most recent and reliable techniques. As researchers press forward new evidence will no doubt push that 4.404 Byr even further back, that is to be seen. At present the available evidence does confirm that age to be accurate, within limits of experimental error. The further confirms is not POV, it is a statement of fact based on current research and is backed up by valid published, peer-reviewd research. The objective is to report what is the current state of our understanding from a scientific basis. And not to water the facts down to accomodate the anti-science bias of certain groups. The religious and mythical viewpoints are covered in the disamb articles listed - that is quite enough. - Vsmith 04:37, 10 January 2006 (UTC)
This is my first post and do not want to step on any toes or use inappropriate "wiki-manners", but it would appear that the mathematical calculation at the bottom of this article is flawed and needs to be removed for the following reasons.
Anyways, thanks to the person that posted it for injecting a quantitative flavour to the article, the effort is very much appreciated. I apologize for suggesting that it be taken out, but it appears to me to be fatally flawed. The appropriate substituion, perhaps, is what is known to isotope geochemists as the "geochron", or a age calculation based on the 207Pb/204Pb and 206Pb/204Pb values of meteorites and the earth (which, by the way, should really be mentioned in the article as this is the method by which the "scientific" age of the earth was first determined). The calculation, however, is both numerically (the equation is transcendental) and conceptually (why use the Pb isotopic composition of meteorites and ocean sediment?) complex and probably unsuitable for a general-knowledge encyclopedia.
If someone could check to make sure that I don't misunderstand the calculation and then delete it, that would be great. As this is my first post I am hesitant to eliminate something that clearly took someone a great deal of effort to produce. Rickert 21:19, 31 January 2006 (UTC)
Yes, you misunderstood the method. I made a typo, putting in 0.07 instead of 0.007, this is all. ati3414
And no, the equations don't have to be transcendental, they are linear, I just showed it. So plug in your favorite isotopes of Pb and you should get the same result. ati3414
If those numbers you've got are correct, then couldn't what you've got here just go inside the article in place of the old information? Homestarmy 23:39, 31 January 2006 (UTC)
Yes, it could except some idiot keeps editing it out. What I am giving here is a METHOD. After correcting my typo everything is copathetic. The short article shows that , contrary to what another guy keeps posting, it is PERFECTLY REASONABLE TO ASSUME EQUAL DISTRIBUTION OF ISOTOPES for U235/U238. I got sick of all this bs and I did my own page, don't dare to erase it. You can keep this one for yourselves.
Sorry, I am not being clear. In addition to the problems that the section faces based on it's two incorrect 235U/238U values, it has a more fundamental flaw: You cannot derive the age of the earth from 235U/238U systematics.
The premise of the calculation, that one can calculate an age of the earth using only uranium isotopic ratios is incorrect. With the corrected values I presented above, all one can do is calculate the 235U/238U of the earth at any time in it's history (or, I suppose, in the future). Although potentially useful, it has no place in an article on the age of the earth. Thank you for pointing out the lack of clarity in the previous post.Rickert 23:50, 31 January 2006 (UTC)
Thanks for responding quickly, Ati. Please do not take this as an attack on you. You have hit the nail on the head by drawing attention to the statement you have placed in quotation marks. The simple answer is that the assumption is invalid: There is no reason to assume that the isotopes had an equal abundance during the accretion of the earth or at any other time. Nucleosynthetic processes (i.e. stellar processes by which most of the heavy elements in our solar system were created) have no "reason" to create isotopic symmetry by balancing the amounts of one isotope with another. In fact, many processes operate to favour one isotope over another. An example is oxygen (although it is created by a slightly different nucleosynthetic process than uranium) for which 16O is present in excess of 400 times that of 18O. Since both isotopes are stable they represent a "primary" (that is, reflecting relative abundances at the accretion of the earth) isotopic signature, and suggest that the assumption of an isotopic "symmetry" is invalid. Similar arguments can be made for stable heavy elements (see some of the lanthanides, for example).
Additionally, with the correct present day 235U/238U (listed in my first post) the "time" that is calculated using the (completly valid!) equations in the article (the time at which the two isotopes had equal abundances) is approximately 5.9 Ga: older than the currently accepted age of the solar system (either 4.6 Ga or 4000a, depending on your POV). :) Rickert 01:07, 1 February 2006 (UTC)
That's bs, the number comes out 4.4 and this seems to CONFIRM the equiprobable hypothesis as an interesting side effect of the simple methos that I put forward. I wish you took your first post elswhere because it is dead wrong.
Ah, I understand then. Well then, we should at least see if Ati knows about this, if he knows how those numbers work, maybe he has something to say on this. Homestarmy 00:12, 1 February 2006 (UTC)
I've removed the section here for discussion. It appears to be original research.
We can verify both the above method and the correctness of the equiprobable distribution by replacing in the above calculations U235 with U234.
U234 has a half life of 2.45x10^5 and N234/N238=0.000055. Therefore:
a234=ln2/0.000245 (6)
and
Solving (7) we obtain :
IF YOU DO NOT LIKE THE RESULT , AT LEAST ACKNOWLEDGE THAT THE METHOD IS GOOD. I GAVE YOU A MATHEMATICAL WAY OF CALCULATING.
THERE IS EVERY REASON TO CONSIDER AN EQUIPROBABLE DISTRIBUTION OF ISOTOPES AT THE TIME EARTH WAS FORMED. IF YOU DON"T LIKE IT, PLUG IN YOUR FAVORITE NUMBER. Have at it!
ati3414
Discuss below please. Vsmith 00:40, 1 February 2006 (UTC)
Well, there are two arguments. One is that the calculation has nothing to do with the age of the earth (the assumption is demonstrably wrong). The other is the one that Vsmith just pointed out. If this is a new formulation (correct or not) it is inappropriate for a Wikipedia article.
Rickert
01:09, 1 February 2006 (UTC)
It looks like ati got the ratio between U isotopes right, and it also says 2.3 billion years not 3.2, im afraid im lost again :/. Though I do understand the part about not knowing what the original ratio was when the earth was supposedly created via big bang theory and stuff, how can we assume that it was equiprobable distribution, or that there were such heavy elements at all? Homestarmy 01:12, 1 February 2006 (UTC)
It is 4.4 after replacing the 0.07 with the correct value of 0.007. I wish you could read more carefully.
I still can't think of any reason why both uranium isotopes would of come into existance on earth at the same exact time the earth supposedly pullled together or something. Homestarmy 14:20, 1 February 2006 (UTC)
Hi Homestarmy. You are correct. Isotopes of heavy elements like U are produced during supernovae events, and it is common for isotopes of the same element to have markedly different abundances. The following link [1] has a list of the abundances abundances of stable isotopes of each element. With a few very minor caveats, these represent the original abundances of of the isotopes on the earth when it was accreted because they are neither produced nor do they decay. Note the differences in isotopic abundances for each element. Rickert 14:33, 1 February 2006 (UTC)
Why should I be civil when you are uncivil in erasing my contribution?
Hi. A couple of new comments on the new calculation, just to clear things up and make sure no one is confused.
Most likely you made an error. The point is that the distributions of isotopes are not exact and the method is used as a means to show the order of magnitude, not the exact age. No wonder the creationists are having a party with this page ....
Why don't you read my text carefully, I used an apples to apples replacement of U235 with U234, same type of data.
Yeah, I got it. Your remark on stable Pb has nothing to do with what I was trying to show you which is based on radioactive decay. Thank you.
Thanks everyone. Rickert 14:33, 1 February 2006 (UTC)
Try "Instant Physics-from Aristotle to Einstein, and Beyond" bu Tony Rothman,page 147. The bit with using two different isotopes and the exact math are mine. OK? ati3414
"Instant Physics-from Aristotle to Einstein, and Beyond" page 147, by Tony Rothman
Try reading. I simply put the text into mathematical formulas. I also used two different methods to arrive to the same result.
Thank you. How do you explain that you get a very similar result by replacing U235 with U234? A coincidence? Why are you so hung up agains the equiprobable distribution at the initial point? Seems to work perfectly fine. And if you don't like my approach, why don't you or any of the other critics produce a calculation that would shut down the creationists? There must be one. Adios .
See Wikipedia:Articles for deletion/How to calculate Earth's Age. Seems our friend ati3414 is forking the content elsewhere. Vsmith 17:42, 1 February 2006 (UTC)
I was just trying to build my own page, I was fed up with the bs on this page.
![]() | This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
It is messy, so I just created a sub-section.
More to the point, not all related content should go into an article, that is what links (sub-articles) are for. Could you imagine all the abortion related material going into abortion. It would be a very large and even more difficult article to manage. Since various religions speak to the age of the earth they are mentioned prominently in this article as alternatives to scientific inquiry. I will seriously consider your proposal to remove "non-scientific", and pose the question to other administrators. However, I doubt it will gain much traction, as it is firmly established (by the scientific community) that creation related science is pseudoscientific. But, within the specific context of a redirect message, it may be appropriate to remove it. - Roy Boy 800 21:29, 7 November 2005 (UTC)
Yes - further confirms means just that, the new evidence (read the references) add solid data that confirms the previous estimates at least back to the ages of those rocks. You obviously don't understand scientific evidence - it is not some inviolate truth - it is factual evidence based on the most recent and reliable techniques. As researchers press forward new evidence will no doubt push that 4.404 Byr even further back, that is to be seen. At present the available evidence does confirm that age to be accurate, within limits of experimental error. The further confirms is not POV, it is a statement of fact based on current research and is backed up by valid published, peer-reviewd research. The objective is to report what is the current state of our understanding from a scientific basis. And not to water the facts down to accomodate the anti-science bias of certain groups. The religious and mythical viewpoints are covered in the disamb articles listed - that is quite enough. - Vsmith 04:37, 10 January 2006 (UTC)
This is my first post and do not want to step on any toes or use inappropriate "wiki-manners", but it would appear that the mathematical calculation at the bottom of this article is flawed and needs to be removed for the following reasons.
Anyways, thanks to the person that posted it for injecting a quantitative flavour to the article, the effort is very much appreciated. I apologize for suggesting that it be taken out, but it appears to me to be fatally flawed. The appropriate substituion, perhaps, is what is known to isotope geochemists as the "geochron", or a age calculation based on the 207Pb/204Pb and 206Pb/204Pb values of meteorites and the earth (which, by the way, should really be mentioned in the article as this is the method by which the "scientific" age of the earth was first determined). The calculation, however, is both numerically (the equation is transcendental) and conceptually (why use the Pb isotopic composition of meteorites and ocean sediment?) complex and probably unsuitable for a general-knowledge encyclopedia.
If someone could check to make sure that I don't misunderstand the calculation and then delete it, that would be great. As this is my first post I am hesitant to eliminate something that clearly took someone a great deal of effort to produce. Rickert 21:19, 31 January 2006 (UTC)
Yes, you misunderstood the method. I made a typo, putting in 0.07 instead of 0.007, this is all. ati3414
And no, the equations don't have to be transcendental, they are linear, I just showed it. So plug in your favorite isotopes of Pb and you should get the same result. ati3414
If those numbers you've got are correct, then couldn't what you've got here just go inside the article in place of the old information? Homestarmy 23:39, 31 January 2006 (UTC)
Yes, it could except some idiot keeps editing it out. What I am giving here is a METHOD. After correcting my typo everything is copathetic. The short article shows that , contrary to what another guy keeps posting, it is PERFECTLY REASONABLE TO ASSUME EQUAL DISTRIBUTION OF ISOTOPES for U235/U238. I got sick of all this bs and I did my own page, don't dare to erase it. You can keep this one for yourselves.
Sorry, I am not being clear. In addition to the problems that the section faces based on it's two incorrect 235U/238U values, it has a more fundamental flaw: You cannot derive the age of the earth from 235U/238U systematics.
The premise of the calculation, that one can calculate an age of the earth using only uranium isotopic ratios is incorrect. With the corrected values I presented above, all one can do is calculate the 235U/238U of the earth at any time in it's history (or, I suppose, in the future). Although potentially useful, it has no place in an article on the age of the earth. Thank you for pointing out the lack of clarity in the previous post.Rickert 23:50, 31 January 2006 (UTC)
Thanks for responding quickly, Ati. Please do not take this as an attack on you. You have hit the nail on the head by drawing attention to the statement you have placed in quotation marks. The simple answer is that the assumption is invalid: There is no reason to assume that the isotopes had an equal abundance during the accretion of the earth or at any other time. Nucleosynthetic processes (i.e. stellar processes by which most of the heavy elements in our solar system were created) have no "reason" to create isotopic symmetry by balancing the amounts of one isotope with another. In fact, many processes operate to favour one isotope over another. An example is oxygen (although it is created by a slightly different nucleosynthetic process than uranium) for which 16O is present in excess of 400 times that of 18O. Since both isotopes are stable they represent a "primary" (that is, reflecting relative abundances at the accretion of the earth) isotopic signature, and suggest that the assumption of an isotopic "symmetry" is invalid. Similar arguments can be made for stable heavy elements (see some of the lanthanides, for example).
Additionally, with the correct present day 235U/238U (listed in my first post) the "time" that is calculated using the (completly valid!) equations in the article (the time at which the two isotopes had equal abundances) is approximately 5.9 Ga: older than the currently accepted age of the solar system (either 4.6 Ga or 4000a, depending on your POV). :) Rickert 01:07, 1 February 2006 (UTC)
That's bs, the number comes out 4.4 and this seems to CONFIRM the equiprobable hypothesis as an interesting side effect of the simple methos that I put forward. I wish you took your first post elswhere because it is dead wrong.
Ah, I understand then. Well then, we should at least see if Ati knows about this, if he knows how those numbers work, maybe he has something to say on this. Homestarmy 00:12, 1 February 2006 (UTC)
I've removed the section here for discussion. It appears to be original research.
We can verify both the above method and the correctness of the equiprobable distribution by replacing in the above calculations U235 with U234.
U234 has a half life of 2.45x10^5 and N234/N238=0.000055. Therefore:
a234=ln2/0.000245 (6)
and
Solving (7) we obtain :
IF YOU DO NOT LIKE THE RESULT , AT LEAST ACKNOWLEDGE THAT THE METHOD IS GOOD. I GAVE YOU A MATHEMATICAL WAY OF CALCULATING.
THERE IS EVERY REASON TO CONSIDER AN EQUIPROBABLE DISTRIBUTION OF ISOTOPES AT THE TIME EARTH WAS FORMED. IF YOU DON"T LIKE IT, PLUG IN YOUR FAVORITE NUMBER. Have at it!
ati3414
Discuss below please. Vsmith 00:40, 1 February 2006 (UTC)
Well, there are two arguments. One is that the calculation has nothing to do with the age of the earth (the assumption is demonstrably wrong). The other is the one that Vsmith just pointed out. If this is a new formulation (correct or not) it is inappropriate for a Wikipedia article.
Rickert
01:09, 1 February 2006 (UTC)
It looks like ati got the ratio between U isotopes right, and it also says 2.3 billion years not 3.2, im afraid im lost again :/. Though I do understand the part about not knowing what the original ratio was when the earth was supposedly created via big bang theory and stuff, how can we assume that it was equiprobable distribution, or that there were such heavy elements at all? Homestarmy 01:12, 1 February 2006 (UTC)
It is 4.4 after replacing the 0.07 with the correct value of 0.007. I wish you could read more carefully.
I still can't think of any reason why both uranium isotopes would of come into existance on earth at the same exact time the earth supposedly pullled together or something. Homestarmy 14:20, 1 February 2006 (UTC)
Hi Homestarmy. You are correct. Isotopes of heavy elements like U are produced during supernovae events, and it is common for isotopes of the same element to have markedly different abundances. The following link [1] has a list of the abundances abundances of stable isotopes of each element. With a few very minor caveats, these represent the original abundances of of the isotopes on the earth when it was accreted because they are neither produced nor do they decay. Note the differences in isotopic abundances for each element. Rickert 14:33, 1 February 2006 (UTC)
Why should I be civil when you are uncivil in erasing my contribution?
Hi. A couple of new comments on the new calculation, just to clear things up and make sure no one is confused.
Most likely you made an error. The point is that the distributions of isotopes are not exact and the method is used as a means to show the order of magnitude, not the exact age. No wonder the creationists are having a party with this page ....
Why don't you read my text carefully, I used an apples to apples replacement of U235 with U234, same type of data.
Yeah, I got it. Your remark on stable Pb has nothing to do with what I was trying to show you which is based on radioactive decay. Thank you.
Thanks everyone. Rickert 14:33, 1 February 2006 (UTC)
Try "Instant Physics-from Aristotle to Einstein, and Beyond" bu Tony Rothman,page 147. The bit with using two different isotopes and the exact math are mine. OK? ati3414
"Instant Physics-from Aristotle to Einstein, and Beyond" page 147, by Tony Rothman
Try reading. I simply put the text into mathematical formulas. I also used two different methods to arrive to the same result.
Thank you. How do you explain that you get a very similar result by replacing U235 with U234? A coincidence? Why are you so hung up agains the equiprobable distribution at the initial point? Seems to work perfectly fine. And if you don't like my approach, why don't you or any of the other critics produce a calculation that would shut down the creationists? There must be one. Adios .
See Wikipedia:Articles for deletion/How to calculate Earth's Age. Seems our friend ati3414 is forking the content elsewhere. Vsmith 17:42, 1 February 2006 (UTC)
I was just trying to build my own page, I was fed up with the bs on this page.