Talk:Twinkling

Comments
I think someone was confused by the phrase "atmospheric Schlieren measurements". This means Schlieren measurements of the atmosphere. There is no such thing as an "atmospheric Schlieren" as far as I know. Rnt20 20:00, 11 October 2005 (UTC)

Planets don't twinkle
Worth mentioning why?RayJohnstone (talk) 14:48, 13 March 2010 (UTC)

Planets don't twinkle (someone's replacement article)
This article on the appearance of stars and planets, replaces one I had written earlier. It relies on the false statement that the eye can form images of the planets which are circular discs. The eye has a scotopic resolution of approximately 3 arcminutes. (see http://en.wikipedia.org/wiki/Eye#Visual_acuity). Apparent planetary size varies (http://nssdc.gsfc.nasa.gov/planetary/planetfact.html) but is mostly about 0.5 arcminutes. The absolute largest is the crescent Venus at 1.1 arcminute. So the image of a planet is unresolved and is not a disc. I have replaced the article with the original.RayJohnstone (talk) 12:15, 26 November 2010 (UTC)


 * I somewhat doubt that the matter is as black and white as you perceive it. First of all, the difference between 3 arcminutes and 0.5 arcminutes (assumimg you did not mistype) is not so huge that the latter falling within the range of human variation implausible. Second, there is the question of how resolution is defined. Anyone that has ever read an eye chart is aware that there is no clear line that distinguishes the "resolvable" verses the "unresolvable"; and furthermore, the range in twinkle what is resolvable and what can be perceived as being something that is larger in 2 dimensions than a dimensionless POINT (such as a star) goes well beyond only what is resolvable. Only the ability to perceive planets as the latter would be needed for this to be the cause of the planets' lack of twinkle. Firejuggler86 (talk) 19:42, 10 November 2020 (UTC)

Merger Proposal (2014)

 * The following discussion is closed. Subsequent comments should be made in a new section.

I'm proposing merging the Twinkling article into Astronomical seeing, as the former is an effect of the latter. The discussion can be found here -- Primefac (talk) 23:15, 31 January 2014 (UTC)


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

There is no "denser layer" toward the horizon
The article has this statement that I think is misleading: "light rays near the horizon must penetrate a denser layer of and have longer paths through the atmosphere before reaching the observer". What is the "penetrate a denser layer" part based on?

Consider an observer standing at sea level: they can view something near the horizon and something near the zenith. If they could send a barometer along each light path that measures air density along the way, the way this article reads now seems to imply that the barometer going toward the horizon would measure absolute values that are higher (more dense) than the barometer going toward the zenith. Why would that be true? Why would we not expect both light paths to pass through exactly the same layers of air with the same densities, but the path toward the horizon would simply take a longer path through those same layers?

I propose removing the words "must penetrate a denser layer of and". The rest of the sentence makes it clear that a path toward the horizon is longer.

Mhrivnak (talk) 15:31, 10 July 2022 (UTC)