Talk:Red edge

Wavelength not known?

The Planetshine article says, "While the red edge is almost certainly the easiest way to directly detect life on earth via Earthshine observations, it could be extremely difficult to interpret a similar feature due to life on another planet, since the wavelength of the spectral feature is not known in advance (unlike most atomic or molecular spectral features)."

Why is the wavelength not known? It would be really helpful if this article could elaborate on that and provide an explanation.

Conversely, if the wavelength really is known, somebody should correct the Planetshine article. 71.219.224.128 (talk) 20:21, 13 February 2010 (UTC)

Unless they borrowed it from earth, other planets would have their own version of photosynthesis, presumable with its own protein and absorption spectrum. Gah4 (talk) 22:26, 19 May 2021 (UTC)

Illustration

This article really needs an illustration. I've sent an inquiry off to one of the NASA webmasters to see if I can use an image I found on their site -- we'll see what happens. -- Phyzome is Tim McCormack 04:04, 22 September 2007 (UTC)

You usually don't need permission for NASA pictures (see for example : Image:Mercury_3.jpg right here in wikipedia). Pro bug catcher (talk • contribs). 18:17, 30 November 2007 (UTC)

If you already knew then great (and I was useless, but checking). Pro bug catcher (talk • contribs). 18:20, 30 November 2007 (UTC)

I knew, but... it's that "usually". In this case, I couldn't tell if the graphic was done by NASA or one of their commercial partners. -- Phyzome is Tim McCormack 15:39, 1 December 2007 (UTC)

This phenomenon is more commonly known as the "red drop effect", especially outside of astrobiology. I think it would be useful to include some information about the experiments leading up to its establishment as a known principle. Also useful to include is the relationship of this to the discovery of two photosystems in plants. I'll look into this and come back with some concrete material to add. --Taingalls (talk) 19:58, 2 February 2008 (UTC)

That would be excellent, Taingalls. -- Phyzome is Tim McCormack 21:00, 2 February 2008 (UTC)

Proper sentence?

"This effects in that rapid change that can be from 5% to 50% reflectance between 680 nm to 730 nm."

I can't make out the subject and predicate of this sentence. I can't even find the verb. 208.54.85.204 (talk) 21:00, 7 May 2014 (UTC)

Retroreflector#Cat's_eye

I suspect the reflection is more like Retroreflector#Cat's_eye than corner cube. Though it is also more diffuse than a true retroreflector. Gah4 (talk) 22:28, 19 May 2021 (UTC)

Potential future exploitation of Red Edge

At present, irrigation of arid and semi-arid regions is hampered by the limited amount of suitable water and the onerous cost of converting fluid high in dissolved substances (as from the sea, or around petroleum deposits) to potable water. But if abundant cheap energy (as we dream of obtaining from nuclear fusion) becomes available so as to make exploitation of the saltiest or most polluted water as easy as exploiting a freshwater body today . . . and if Earth's climate continues to warm . . . then we can expect present-day xeriscaping practices to be discarded as great irrigation projects spread across deserts. The goal will be to minimize Earth's heating by covering as much land as possible with infrared-reflecting green plants. Tony (talk) 01:07, 16 August 2023 (UTC)