Talk:Pulsar

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[edit] Merge Radio pulsar & X-ray pulsar into Pulsar

The following discussion is archived. Please do not modify it. Subsequent comments should be made in a new section.


User:Quarl has suggested merging both accretion powered pulsar and rotation powered pulsar into the general pulsar article on the Astronomy WikiProject talk page.

70.51.8.30 05:21, 3 March 2007 (UTC)

[edit] Survey

[edit] Discussion

  • We have smaller articles on types of pulsars than either X-ray or radio pulsar, they can be expanded to a fair degree, I would keep them separate and make pulsar into a better overview of pulsars in general. It should overview most types of pulsars, including magnetars, AXP, SGR, short duration GRB, millisecond pulsars, etc. 70.51.8.30 05:27, 3 March 2007 (UTC)

I agree, I don't see a reason by those two should be selected out in particular for merging. Why not also merge magnetars since their mechanism of action is different? Rather each of the individual branch articles should be improved and the pulsar article should be grown with material common of all pulsars - pulsar origins, physics involved, observation methods, history,etc. – Meowist 20:28, 8 July 2007 (UTC)

The above discussion is preserved as an archive. Please do not modify it. Subsequent comments should be made in a new section.


[edit] "Religious interpretations"

I took out this:

Some modern Islamic scholars believe that the Qur'an has mentioned the pulsars: "[I swear] by Heaven and the Tariq! And what will convey to you what the Tariq is? The Star Piercing [the darkness]! " (Qur'an, 86:1-3). The Arabic word "Tariq," comes from the root "tarq," whose basic meaning is that of striking hard enough to produce a sound, or hitting. Bearing in mind the word's possible meaning as "beating," "striking hard," our attention may be being drawn to this scientific fact.

Because it's not referenced. The footnote posing as a reference for it read this:

This is not the only scientific fact mentioned in the Quran; many other scientific facts in the variance science fields (e.g. Astronomy, biology, medicine,…etc), which were discovered in the 19th and 20th centuries, are mentioned in the Quran. Harun Yahya. miracles of the quran.

A website authored by one person is not "some modern Islamic scholars". The claim that people believe that the Qur'an is unequivocally referring to scientific principles for which the ancients had no scientific measures is quite extraordinary, and requires extraordinary citation. As it stands, this reads as one man's theory, if not outright promotion.

I see Harun Yahya already has an article; his theories are more appropriately discussed in that article rather than adding backreferences to every other "scientific fact" supposedly appearing in the Qur'an. 82.95.254.249 13:11, 23 June 2007 (UTC)

I deleted a similar block:

Strangely enough the Quran, Muslims' holy book revealed more than 1400 years ago, speaks about pulsars in chapter 86. The original Arabic word used for these stars is 'Tariq'. The verses go on describing the Tariq as the piercing star. Those who translated the word Tariq into other languages did not translate it accurately but most native speakers of Arabic know the meaning of Tariq as 'someone or something knocking on a door or striking with a hammer'.[citation needed]

[edit] More scientific details needed

A few examples of things that should probably be in this article. I've searched the web, and can't find them, so anyone with knowledge, please contribute:

  • Radiated spectrum: are they broadband pulses, or narrowband? A few articles I found suggested narrowband, but none made any general conclusions.
    • If they're narrowband, are their peak frequencies scattered all over the spectrum? Or do pulsars tend to radiate within a small range? Also, if narrowband, does the peak frequency remain constant over time?
    • It may also be instructive to include a plot of intensity vs. frequency for an example pulsar.
  • Pulse duration vs. non-radiating period. The article mentions periods of 1.5ms to 8s, but for how much of that time are they "pulsing"? I realize that that probably depends on distance from the Earth, so maybe a better metric is the solid angle size of the radiated cone. Is this about the same size for most pulsars, or does it vary greatly?
  • Is there any noticeable precession of the radiation (or rotation) axis?

The above would help describe what a pulsar is/does, not just the history behind their discover. Thanks to any who can contribute. —Ryan McDaniel 22:17, 6 July 2007 (UTC)

Just flagged this as "attention=yes" on the Physics template; this article needs attention I can't give it. If this is not a proper use of that attribute, I apologize. —Ryan McDaniel 21:14, 11 July 2007 (UTC)

[edit] Discovery of pulsars before Jocelyn

Apparently, the US Air Force detected pulsars a couple of months before Jocelyn Bell discovered them; see [1]. Unfortunately, I can't find a better reference for it than that, hence why I'm commenting here rather than adding it to the article. Mike Peel 10:46, 19 August 2007 (UTC)

Patrick1982 added some interesting new text [2] about Charles Schisler's discovery of pulsars pre-dating that of Bell & Hewish. While there is nothing to doubt Schisler's claim, his result is not unique. Several other groups had discovered pulsars beforehand, but either had not realized what they had found, or did not follow up on it - see for example [3]. I think a discussion of Schisler's and other preceding work (not the least of which would be Minkowski's identification [4] of the stellar remnant in the Crab Nebula in 1942) has a place somewhere in this article, but certainly the main credit for the discovery should go to those who followed through with their discovery and who were in a position to publish their result. Let's discuss this further on the talk page before changing the main article. Tubbs334 11:36, 7 September 2007 (UTC)

I can understand your reasons for reverting back to the previous version. However in my opinion it is wrong to just leave this new information out of the article, treating it like it "did not happen". I think that my formulation did not weaken the credit atribution towards Bell & Hewish. In fact, I did not even change that paragraph, I simply added a new one.
But perhaps it would be best to add a small paragraph at the bottom of the discovery section, or perhaps even at the end of Subsequent history, as an 'additional footnote in history'. I think a publication in Nature, and the subsequent media coverage that was given to it (it was in every newspaper), justifies this. And this can be extended/reformulated to include other pre-discovery's. --Patrick1982 23:16, 8 September 2007 (UTC)
Patrick1982, I agree with you 100%. This should be in the article, and I am not concerned about protecting Bell & Hewish's legacy. But it shouldn't be presented as "we used to say that Bell discovered pulsars but the correct answer is now Schisler", since the full situation is more complex. I think a subsequent "footnote" is a good way to do it, as you propose. Tubbs334 14:12, 9 September 2007 (UTC)


[edit] Time standard?

Shouldn't something be said in this article about how pulsars have been proposed for use as an independent check (or alternative time standard) on terrestrial atomic clocks? (See Barycentric Coordinate Time.) I would say it myself if I knew how, but I was trying to do some initial research and found nothing in this article; I think there used to be something about this in one of the various articles about various sorts of pulsars, but haven't found it yet, and really, this is the article that I think it ought to be mentioned in. arkuat (talk) 07:32, 21 February 2008 (UTC)