Talk:Ultraviolet

UV Light, Infrared Light and Visible Light relations

If UV light is higher, is visible light brightness and infrared light heat also higher too? Can one type type increase without increasing the other types? For example does a UV index of 8 have the same sunlight brightness on the ground and same color temperature regardless of the angle of the sun in the sky and horizon? RedProofHill123 (talk) 18:11, 12 October 2022 (UTC)

In general, the ratios of UV, visible light and infrared emitted by a source can be in any proportion. I'm not aware of a hard and fast rule relating the "UV Index" given in the weather report to the amount of visible light and infrared coming from the Sun on that day; since atmospheric layers that absorb UV may have no effect on visible light or IR, there may not be a strict correlation (aside from the obvious that after sunset there's no visible, IR or UV). --Wtshymanski (talk) 02:02, 25 October 2022 (UTC)

UV Light effects on sleep cycles

Any thought to adding a sub-section on the effects of UV light on the sleep cycle: https://www.nature.com/articles/s41433-020-01132-2 Egreena42 (talk) 23:20, 5 December 2022 (UTC)

Ultraviolet

Read article 2402:3A80:1BDC:F388:0:0:D7D:DC6C (talk) 01:40, 5 February 2023 (UTC)

Consistency, is it UV-X or UVX ?

This might sound like nit picking, but I came across the issue because I had a problem reading the article.

In the introduction one of the paragraphs mixes wavelength and UVB before the term UV is described. As I do not know the range of UVB wavelengths I used my browser search for UVB in the article, but it found no wavelength ranges for the term.

However I found the table of the UV subtypes which uses the terms UV-A, UV-B and UV-C.

Which is correct or more commonly used? I believe UVX is more common, but I am an electronics and software engineer not an optics engineer or physicist. The article should use only one or the other.

Note also that when I searched the article for UV<minus>B only 3 hits were found. The dash or minus used in the table must be a different character. When I take that term UV‑B and search for it I get 17 hits. Whereas UVB gets 23 hits. Therefore the term without the dash is more common in the article. The fact that the character used for the dash in UV-X is not consistent and the minus character available on a standard keyboard is not the character most commonly used in the article would indicate that no dash or minus would be better.

I also suggest, in the introduction, before the terms are described, that either only wavelengths and frequencies should be used, or UVA, UVB and UVC terms and wavelength ranges should be described before the terms are used. Alternatively the wavelength range should be included in brackets wherever the terms are used before they are described in the article.

If I hear nothing I will change the EM spectrum to be consistent with the rest of the article and add a paragraph to describe UVA, UVB & UVC in the introduction. Lkingscott (talk) 10:01, 6 February 2023 (UTC)

I also came across the issue of searching for "UV<hyphen>C" and found only a few hits. When I copied the other version of "UV-C" to Word, I found that it was a 'non-breaking hyphen' (U+2011) in there. The fact that there are (as of now) only 4 with a true hyphen, 9 with the non-breaking hyphen, and 15 with *no hyphen at all*, I'm going to be bold and remove all the hyphens (normal or not), so users can find what they are looking for when they search.

If this is not acceptable to others, PLEASE put back the hyphens, BUT be consistent, so when a user sees a term they want to search for, they can actually FIND it.

Thanks! WesT (talk) 19:20, 7 August 2024 (UTC)

The authoritative reference:

• International Organization for Standardization. "ISO 21348 definitions of solar irradiance spectral categories." Environment 5 (2007): 6-7.

does not use hyphens, so UVA, UVB etc is correct per the reference.

BTW the same ref uses IR-A IR-B and IR-C so the usage is not accidental and the omission of hyphens is not univerisal. Johnjbarton (talk) 00:32, 8 August 2024 (UTC)

What is UVB?

This article uses the term "UVB" 23 times, but never defines it or explains it. I think it's reasonable to infer that UVB has some relationship to ultraviolet, since the "UV" in "UVB" probably stand for "ultra violet".

Of course, I could search the web to learn what "UVB" means, but this article ought to explain it. Preferably before using the term 23 times. — Lawrence King ^(talk) 05:30, 27 September 2023 (UTC)

Ultraviolet#Subtypes. --Wtshymanski (talk) 19:07, 11 October 2023 (UTC)

Origin of UV-A, B, and C designations?

I don't have a reference for this, but I somewhat recall that the UV-A, UV-B, and UV-C nomenclature came from medicine, where UV-A and UV-B lamps had different therapeutic uses, and UV-C lamps were used for sanitizing air, surfaces, etc. 2600:4041:DF:9600:1885:6FC0:C62A:5345 (talk) 19:25, 14 October 2023 (UTC)

References to UV wavelengths without explanation

UVA, UVB, and UVC are referenced a lot on this page in a way that suggests the reader should already be familiar with these topics. This usually wouldn't be a problem, but there's no solid definition of their differences and defining characteristics, just their behavior in certain conditions. A new section defining and discussing them could be very helpful, particularly since those terms redirect to this page. 65.129.38.23 (talk) 01:52, 26 October 2023 (UTC)

What is an "aJ"?

The table in Subtypes has an unsourced column of photon energies in two units, eV and "aJ". The link points to photon energy which explains eV. Nothing is said about "aJ". I assume its is an SI prefixed joule but it should be explicitly described here and sourced. Johnjbarton (talk) 15:19, 15 September 2024 (UTC)