Talk:Secular phenomena

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Worst article?[edit]

Could this be the worst article in WP? It reads like a definition, and leaves me longing for examples that would make this idea clear. I thought I knew a little about astronomy (I got an A in it in college), but I'm unclear on a perturbation in an orbit that doesn't repeat because its period is too long to observe, if that is what secular really means. Just doesn't make sense to me as written.

Here is an example of secular in the literature of cosmology/astronomy. David spector (talk) 03:14, 16 January 2010 (UTC)[reply]

Planetary orbits and fringe cosmology[edit]

I've removed the following text multiple times now:

Jet Propulsion Laboratory has an important role in providing scientific efemeris data. In spite of methods to deal with perturbations of numerous asteroids, most of whose masses and orbits are poorly known, remains a tiny secular trend, causing the JPL to revise its published ephemerides at intervals of 20 years. Russian astronomers have taken notice of this problem. [1][2]

Kolesnik has followed this up with an ambitious undertaking, which can be condensed in an empiric formula, that may help solving JPL's problem.[3]

The net result is that the planet accelerates in its orbit, while slowly falling toward the sun. The relation for the change in angular velocity is given by

where 1/ is the Hubble time and ω is the increasing angular velocity. This tiny change will cause the Earth to fall roughly 22 meters closer to the Sun per year. [4] One theoretical explanation claims that this secular acceleration is of a cosmological origin. [5]

this is a spillover from a wider dispute/attempt to insert fringe cosmological theories into wikipedia. The issues with this particular passage are first and foremost that the reference claiming that "Russian astronomers have taken notice of this problem", a research paper by Kharin and Kolesnik (I found it available here), does not in fact mention this "problem" anywhere. Moreover, JPL revises its ephemerides much, much more often than every 20 years, mostly to account for increasing knowledge regarding small solar system bodies and the orbits of and trajectories of the various man-made objects in the solar system. They even keep a log of updates and changes, which can be seen here; note that the most recent change was March 18 (including updates on the ephemerides for some of Saturn's smaller satellites), and the one before that on February 15, much less than 20 years. As such, there doesn't seem to be any evidence at all that there is such a secular effect, or that such an effect could even be noticed given the current confidence levels in the ephemerides, much less that this represents the scholarly consensus on the matter. Without that, the addition of Maserliez's fringe theories is totally unwarranted without even venturing into the discussion of whether it would properly considered to reflect consensus itself (it certainly does NOT). This text has no place in this article, and would only be appropriate in an article about Maserliez or his work, and only then if presented as that alone, and not a well-accepted and understood theory in modern physics and cosmology. siafu (talk) 20:06, 4 May 2011 (UTC)[reply]

Didn't this get considered (and rejected) at Secular variations of the planetary orbits? Also, note that an abstract presented at a conference is not a WP:RS: pretty well anything can be William M. Connolley (talk) 20:39, 4 May 2011 (UTC)[reply]

Secular phenomena create variations in the orbits of the Moon and the planets[edit]

This article seems a bit broken / confused. It starts secular phenomena are contrasted with phenomena observed to repeat periodically - so SP are things like the orbits of the planets, or the moons acceleration. In which case they don't "create" variations, they are variations.

But anyway, secular variation just means time-trending, not periodic or recurring non-periodic. Why is this article hijacked for just-astronomy? William M. Connolley (talk) 08:01, 17 July 2011 (UTC)[reply]

  1. ^ Kharin, A. S. and Kolesnik, Y. B.; On the Errors of the Ephemerides Derived from Optical Observations of Planets. (1990), IAU SYMP.141 P.189, 1989.
  2. ^ Georgij A. Krasinsky and Victor A. Brumberg, Secular Increase of Astronomical Unit from Analysis of the Major Planet Motions, and its Interpretation Celestial Mechanics and Dynamical Astronomy 90: 267–288, (2004).
  3. ^ Yuri B. Kolesnik; Analysis of the secular variations of longitudes of the Sun, Mercury and Venus from optical observations, in Highlights of Astronomy, Vol. 12, as presented at the XXIVth General Assembly of the IAU - 2000 [Manchester, UK, 7 - 18 August 2000]. Edited by H. Rickman. San Francisco, CA: Astronomical Society of the Pacific, ISBN 1-58381-086-2, 2002, p. 330 – 333.
  4. ^ Y. B Kolesnik;On the Relationship Between Dynamical Time and Atomic Time, Astrophysical Ages and Times Scales, ASP Conference Series Vol. 245. Edited by Ted von Hippel, Chris Simpson, and Nadine Manset. San Francisco: Astronomical Society of the Pacific, ISBN: 1-58381-083-8, 2001., p.83
  5. ^ Masreliez C. J.; Scale Expanding Cosmos Theory II–Cosmic Drag, Apeiron Okt (2004)