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The Oort Cloud theory, while generally accepted in the scientific community, has come under some criticism. [[R. A. Lyttleton]] questioned the procedures behind adopting a comet shell model in a 1974 research paper: |
The Oort Cloud theory, while generally accepted in the scientific community, has come under some criticism. [[R. A. Lyttleton]] questioned the procedures behind adopting a comet shell model in a 1974 research paper: |
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<blockquote>"The procedures adopted as theory for a shell of comets are shown to be invalid. Any plot of numbers of Long-period comets against 1/a will automatically exhibit a peak at small values of this parameter, and cannot be inverted to demonstrate a high volume-density of aphelia in space. The positions of actual aphelion-points show no sign of any concentration at any range. Further, the aphelion-distance undergoes large almost random changes owing to planetary perturbations at each return, and present values can yield no indication of original positions. That a group of some forty, or even twenty, comets selected for other reasons would all be coming in for the first time has such evanescent probability as to be an entirely inadmissible assumption...The plain conclusions emerge that the shell-theory is devoid of any support by facts, and that the alleged shell of comets is non-existent. "-R.A. Lyttleton <blockquote/><ref>{{cite web |url=http://www.springerlink.com/content/x188306l63458j53/ |title= THE NON-EXISTENCE OF THE OORT COMETARY SHELL|author=R.A. Lyttleton |date=1974 |work=The non-existence of the Oort cometary shell |publisher=Institute of Astronomy, Cambridge, England; and Jet Propulsion Laboratory, |accessdate=6 November 2010}}</ref> |
<blockquote>"The procedures adopted as theory for a shell of comets are shown to be invalid. Any plot of numbers of Long-period comets against 1/a will automatically exhibit a peak at small values of this parameter, and cannot be inverted to demonstrate a high volume-density of aphelia in space. The positions of actual aphelion-points show no sign of any concentration at any range. Further, the aphelion-distance undergoes large almost random changes owing to planetary perturbations at each return, and present values can yield no indication of original positions. That a group of some forty, or even twenty, comets selected for other reasons would all be coming in for the first time has such evanescent probability as to be an entirely inadmissible assumption...The plain conclusions emerge that the shell-theory is devoid of any support by facts, and that the alleged shell of comets is non-existent. "-R.A. Lyttleton <blockquote/><ref>{{cite web |url=http://www.springerlink.com/content/x188306l63458j53/ |title= THE NON-EXISTENCE OF THE OORT COMETARY SHELL|author=R.A. Lyttleton |date=1974 |work=The non-existence of the Oort cometary shell |publisher=Institute of Astronomy, Cambridge, England; and Jet Propulsion Laboratory, |accessdate=6 November 2010}}</ref> |
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:[[Young earth creationist]] Danny Faulkner claimed that comets should be all gone if the universe is billions of years old: |
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<blockquote>"Comets are continually being lost through decay, collisions with planets, and ejections from the solar system. If the solar system were billions of years old, then all comets would have long ago ceased to exist if they were not continually being replaced"-(Faulkner 2001).<ref>{{cite web |url=http://orgs.usd.edu/esci/age/content/creationist_clocks/comets_disintegration.html |title=Faulkner on Comets |author=Danny Faulkner |date=2001 |work= |publisher= University of South Dakota|accessdate=8 November 2010}}</ref></blockquote> |
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{{reflist}} |
{{reflist}} |
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:The article already says that the Oort cloud comets formed at planetary distances and then were sent out into the shell by planetary action. I don't really understand what the difference is. <b>[[User:Serendipodous|<font color="#00b">Serendi</font>]][[Special:Contributions/Serendipodous|<sup><font color="#b00">pod</font></sup>]]<font color="#00b">[[User talk: Serendipodous|ous]]</font></b> 07:55, 7 November 2010 (UTC) |
:The article already says that the Oort cloud comets formed at planetary distances and then were sent out into the shell by planetary action. I don't really understand what the difference is. <b>[[User:Serendipodous|<font color="#00b">Serendi</font>]][[Special:Contributions/Serendipodous|<sup><font color="#b00">pod</font></sup>]]<font color="#00b">[[User talk: Serendipodous|ous]]</font></b> 07:55, 7 November 2010 (UTC) |
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:::::I will add more quotes from his paper that detail his explanation (See Above)..--<span style="background:burlywood; color:red;font-size:small;;font-family:Arial;">[[User:Terra Novus|Novus]]</span><span style="background:yellowgreen; color:white;font-size:small;;font-family:Arial;"> [[User talk:Terra Novus|Orator]]</span> 09:02, 8 November 2010 (UTC) |
:::::I will add more quotes from his paper that detail his explanation (See Above)..--<span style="background:burlywood; color:red;font-size:small;;font-family:Arial;">[[User:Terra Novus|Novus]]</span><span style="background:yellowgreen; color:white;font-size:small;;font-family:Arial;"> [[User talk:Terra Novus|Orator]]</span> 09:02, 8 November 2010 (UTC) |
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::::::Yes, he makes the case that there is no Oort cloud, but as far as I can tell he makes no case as to how the long-period comets are appearing in our skies. <b>[[User:Serendipodous|<font color="#00b">Serendi</font>]][[Special:Contributions/Serendipodous|<sup><font color="#b00">pod</font></sup>]]<font color="#00b">[[User talk: Serendipodous|ous]]</font></b> 09:11, 8 November 2010 (UTC) |
::::::Yes, he makes the case that there is no Oort cloud, but as far as I can tell he makes no case as to how the long-period comets are appearing in our skies. <b>[[User:Serendipodous|<font color="#00b">Serendi</font>]][[Special:Contributions/Serendipodous|<sup><font color="#b00">pod</font></sup>]]<font color="#00b">[[User talk: Serendipodous|ous]]</font></b> 09:11, 8 November 2010 (UTC) |
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:::I added a quote from Faulkner that gives the Young-earth creationist solution to the problem.--<span style="background:burlywood; color:red;font-size:small;;font-family:Arial;">[[User:Terra Novus|Novus]]</span><span style="background:yellowgreen; color:white;font-size:small;;font-family:Arial;"> [[User talk:Terra Novus|Orator]]</span> 09:22, 8 November 2010 (UTC) |
Revision as of 09:22, 8 November 2010
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Argument from Ignorance
...Doesn't the whole concept of the Oort Cloud fall under the Wiki definition of "Argument from Ignorance"? >_> ~Dah Cheese —Preceding unsigned comment added by 76.179.137.176 (talk) 03:43, 23 August 2010 (UTC)
- The argument from ignorance is "It has never been disproven, therefore it must be true." The key word there is must. "It has never been disproven, therefore it may be true (or in the case of the Oort cloud, very likely is true, given the evidence), is not an argument from ignorance. Serendipodous 19:48, 23 August 2010 (UTC)
However, it is taught and put forth in particularly this article as binding and very real truth, with no alternative at all proposed or theorized. At least it seemed that way when I read it. ~Dah Cheese —Preceding unsigned comment added by 76.179.137.176 (talk) 01:33, 28 August 2010 (UTC)
- The very opening line says, "hypothesized spherical cloud of comets". It then goes on to say it may lie roughly 50,000 AU from the Sun and that there has been "no confirmed direct observations of the Oort cloud". As the modern accepted theory what-else do you want it to say without getting off topic? -- Kheider (talk) 04:41, 28 August 2010 (UTC)
Absolute Magnitude
It seems to me that the two normalizations of absolute magnitude can cause confusion. In "Structure and composition" and reference 14, the 1 AU distance normalization is used. Perhaps this could be clarified by stating non-stellar absolute magnitude. Filiulodimeapatro (talk) 04:10, 21 September 2010 (UTC)
- Absolute magnitude in this sentence links to Absolute_magnitude#Solar_System_bodies_.28H.29. Ruslik_Zero 15:39, 21 September 2010 (UTC)
Criticism Section
The article needs a little bit of coverage of criticism to insure that it is upholding the principle of scientific falsifiability. My suggestion is below--Novus Orator 03:06, 7 November 2010 (UTC)
Criticism
The Oort Cloud theory, while generally accepted in the scientific community, has come under some criticism. R. A. Lyttleton questioned the procedures behind adopting a comet shell model in a 1974 research paper:
"The procedures adopted as theory for a shell of comets are shown to be invalid. Any plot of numbers of Long-period comets against 1/a will automatically exhibit a peak at small values of this parameter, and cannot be inverted to demonstrate a high volume-density of aphelia in space. The positions of actual aphelion-points show no sign of any concentration at any range. Further, the aphelion-distance undergoes large almost random changes owing to planetary perturbations at each return, and present values can yield no indication of original positions. That a group of some forty, or even twenty, comets selected for other reasons would all be coming in for the first time has such evanescent probability as to be an entirely inadmissible assumption...The plain conclusions emerge that the shell-theory is devoid of any support by facts, and that the alleged shell of comets is non-existent. "-R.A. Lyttleton
- Young earth creationist Danny Faulkner claimed that comets should be all gone if the universe is billions of years old:
"Comets are continually being lost through decay, collisions with planets, and ejections from the solar system. If the solar system were billions of years old, then all comets would have long ago ceased to exist if they were not continually being replaced"-(Faulkner 2001).[2]
- ^ R.A. Lyttleton (1974). "THE NON-EXISTENCE OF THE OORT COMETARY SHELL". The non-existence of the Oort cometary shell. Institute of Astronomy, Cambridge, England; and Jet Propulsion Laboratory,. Retrieved 6 November 2010.
{{cite web}}
: CS1 maint: extra punctuation (link)- ^ Danny Faulkner (2001). "Faulkner on Comets". University of South Dakota. Retrieved 8 November 2010.
- The article already says that the Oort cloud comets formed at planetary distances and then were sent out into the shell by planetary action. I don't really understand what the difference is. Serendipodous 07:55, 7 November 2010 (UTC)
- What Novus Orator means is that some (such as Lyttleton) view this hypothesis as implausible, and that this fact should be mentioned in the article. CielProfond (talk) 18:41, 7 November 2010 (UTC)
- Does it offer an alternative explanation? Plus, that paper is 36 years old; I would prefer a more modern objection, since science tends to reject older hypotheses. Serendipodous 18:43, 7 November 2010 (UTC)