Talk:Counter-Earth

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Furthermore, since none of the other planets has such a twin it would be extremely improbable if the Earth were the only planet to have one.

This sounds like "Since none of the other planets has a wikipedia, it would be extremely improbable if the Earth were the only planet to have one." It should be rewritten. Earth is quite improbable. -- Error

More like, "Since all of the other planets have gravity it would be extremely improbable if the Earth were the only planet not to have it." Some things are more improbable than others. --Lee M

Back to the article, is it true that the astronomical counter-earth was invented to save the phonomonea that the central fire could not be seen, a central tenet in pythoragean thought. (windsor ppt presentation--I am not a windsor student and do not feel comfortable putting this in--but seems like a definition of counter-earth should dominate this article. --Sam

Yes, the whole idea of a Counter-Earth was developed by Philolaus to support his new ideas about the non-geocentric cosmos and a Central Fire. You can learn more about this here. Mrwuggs 20:56, 7 November 2006 (UTC)

Contents 1 Orbital Feasibility 2 Just a guess 3 Merger 4 Wrong Section 5 Earth's orbit and rotation, a hypothesis?

[edit] Orbital Feasibility

According to the article the counter-earth orbit is just feasible. So would somebody please point out what is wrong with this analysis:

Consider the earth at the point where the line joining it to the sun forms an exact right angle with the major axis of its orbit. Counter-earth must be at the opposite side of the sun, at the point where it's line to the sun also forms a right ngle with the elliptical axis.

Now let us advance the earth until it is in the same position on the other side of the sun - i.e. the other point where it's line to the sun forms a right angle with the elliptic axis. In order for counter-earth to still be hidden it must now occupy the position that earth previously occupied. BUT this cannot be the case, because by Kepler's second law the areas swept by the arcs must be identical, and this is obviously not the case (one of the planets must be going round the long side of the ellipse).

So is counter-earth orbitally feasible or not? DJ Clayworth 20:27, 6 April 2006 (UTC)

The Earth's orbit is almost perfectly circular, and CE would stay hidden. It would orbit in exactly the same period.

The scientific analysis section seems to be clunky. It presumes CE in the L3 spot, which would make it uninhabitable as well as unstable. A 180 degree opposed orbit SHOULD be stable. Can someone clean up the section a bit so it reads more clearly on what is meant?Mzmadmike 02:19, 11 April 2007 (UTC)

CE in a 180 degree opposed orbit would be unstable due to L3 in close proximity and introduce its own L3 close to the earth making earths orbit unstable too. If CE was in earth's L3 it would be stable, but introduce its L3 close to earth an cause earth's orbit to become unstable, thus giving earth's L3 an unstable position and give an unstable CE. Sum - two identical objects can't have opposite obits around a third object. Eroen 17:49, 15 February 2008 (UTC) —Preceding unsigned comment added by 193.217.51.53 (talk)

[edit] Just a guess

I think it is plausible, however it will not be found in our lifetime.

As was noted, if it existed, it would have been found by observation from probes and gravitational perturbation of spacecraft and other bodies.Mzmadmike 02:20, 11 April 2007 (UTC)

[edit] Merger

Suggestion: Counter-Earth merge with Antichthon

An orpahned discussion can be found at :Talk:Antichthon#Merger

• Support -- I realize now that a copy and paste merger is the wrong way to merge things, but seriously, there is no reason why this should be two pages. Although the copy/paste job was improperly done, that was just the way this article should look. This page seems ideal for a speedy merger. Mrwuggs 19:40, 28 September 2006 (UTC)
• Oppose – Oppose your merger — your merger is wrong. Antichthon is the absolute wrong title to use for a merged counter-Earth article. Oppose merger from Antichthon — because that article is lengthy. 132.205.44.134 02:06, 29 September 2006 (UTC)
• Oppose. "Counter-earth" might have been distantly inspired by Pythagorean concepts, but it's considerably different from Antichthon. --Akhilleus (talk) 03:15, 29 September 2006 (UTC)
• Support merge to Counter-Earth - It looks like the Counter-Earth and Antichthon articles contain complementary information that should be combined under one heading. Since Counter-Earth appears to be a more common name, I suggest using Counter-Earth. I would oppose merging both under the name Antichthon. GeorgeJBendo 09:00, 29 September 2006 (UTC)
  • Comment: No source is provided for the assertion that "It was hypothesized by the Pythagorean school as Antichthon and was periodically speculated about..." I find this connection dubious, so I'm adding a "citation needed" tag. Even if a citation is provided, I still oppose the merger, because the ancient concept is significantly different than the modern science fiction trope. --Akhilleus (talk) 14:12, 29 September 2006 (UTC)
• Mildly oppose. Like George J. Blendo, I would strongly oppose merger under "Antichthon" because "Counter-Earth" is a broader, more general term able to accomodate both. But I agree with Akhilleus that there are enough differences in the articles, and since they are already fairly well connected up with each other readers can easily get a more complete picture, and keep the somewhat different usages straight, by having both articles. Gene Nygaard 15:28, 7 October 2006 (UTC)
• Oppose These are two completely different concepts which happen to have the same philosophical end result: "a planet never visible from Earth". It is important to link the two articles in that respect, but they shouldn't be merged. GreyWyvern 18:39, 12 October 2006 (UTC)
• Support Under Counter-Earth. Antichthon should be its own section, clearly, but the articles don't need their own space-- especially for a topic that, conceptually, is identical. Counter-Earth is descriptive, Antichthon is specific; seems clear to me. --mordicai. 05:21, 3 November 2006 (UTC)
• Support I agree with mordicai. I also agree with Akhilleus that a distinction needs to be made between the ancient theory and the science fiction idea. I suggest that Antichthon and the science fiction stuff be put under the same article (titled "Counter-Earth") in the context of an analysis of the changes in the idea over time (or, to be truly accurate, the changes in the way the idea is applied and interpreted). Galanskov 19:15, 23 November 2006 (UTC)
• I've gone ahead and added a lot of the stuff in the Antichthon article to the Counter-Earth article. There is now essentially nothing in the former that is not in the latter. I believe that the Antichthon article should now be redirected to Counter-Earth. (I've ensured a distinction is made between the ancient theory and the science fiction motif). Unless someone raises an objection I'll go ahead and make the change in two weeks. Galanskov 23:33, 23 November 2006 (UTC)
• Thank you, Galanskov. Your helpful additions have finally made possible a merger that should have happened long ago. Mrwuggs 17:02, 29 November 2006 (UTC)
• You're welcome. Thank you for suggesting the merger. Galanskov 16:04, 30 November 2006 (UTC)
• The merger has been carried out. Thank to all who have participated in this discussion. The ideas you presented here were essential to merging the two articles. Galanskov 04:33, 7 December 2006 (UTC)

[edit] Wrong Section

The information about Mela's spherical Counter-Earth is, at least in my opinion, probably better situated in the "Need for a Counter-Earth" section than in the "Scientific Analysis" part. Galanskov 23:44, 23 November 2006 (UTC)

[edit] Earth's orbit and rotation, a hypothesis?

The ideas of a flat earth, Counter-Earth, and Central Fire were all eventually superseded by the hypothesis which is currently held by the scientific community, that is, of a spherical earth rotating around both its own axis and the sun.

Is this idea really just a hypothesis? I would think that all the spacecraft that have left earths orbit, been effected by the Sun's gravity, effected and captured by gravity of other objects, experienced Impairment and loss of Line of site of line-of-site, usually by design or prediction, would be more than sufficient to prove the earth orbits the Sun. In addition, satellites that orient themselves to the position of the Sun, keep cameras pointed at the earth and have located at least one other moving object in space, would confirm the earths orbit of the Sun. and its rotation around it's axis.--Zerothis 06:58, 16 February 2007 (UTC)

You're right. The better word would be 'theory.' Thank you for pointing this out. Galanskov 04:12, 17 February 2007 (UTC)

Is it even a theory? There are certainly fine points in gravitational theory and orbital mechanics to debate, but I think it's pretty well established FACT that the Earth revolves around the Sun. Are there ANY reputable scientists in dispute? Perhaps call it an "understanding"?Mzmadmike 02:23, 11 April 2007 (UTC)

In science, a 'theory' is a widely accepted explanation for natural phenomena for which ample empirical evidence exists and which has been rigirously tested. Therefore, a 'theory' (such as gravity) pretty much is a fact. Galanskov 05:22, 11 April 2007 (UTC)

In the most basic sense, a scientific fact is an objective and verifiable observation; in contrast with a hypothesis or theory, which is intended to explain or interpret facts.^[1] Thus, theory is not fact. I have an hypothesis that there is no such thing as "scientific fact". It seems wikipedia agrees with me, since that link goes nowhere at this moment--Zerothis (talk)