Sun-Exposed Cable in Black Conduit

[JohnW2]

I suspect that it's "complicated".

Indeed. As I wrote:

Indeed so - that's the 'equilibrium' we're talking about. However, I think that one needs quite a bit more information before one can draw any conclusions.

As I implied, but did not say explicitly, a crucial question is the difference between white and black in relation to UV absorption and IR radiation - which, as you imply, are almost certainly quite different.

P s. I was reading a bit yesterday and it mentioned that National Rail paint the rails white in certain hot spots to reduce solar heating - on the assumption that they'd not spend money without checking first, it woukd seem to work.

No need to 'read' - there have been several clips of them doing just that on national TV news for the past few days. However, even if my initial (probably incorrect) thoughts had been correct, in that the main effect of white would be to slow the rate of temp rise, even that would have been of value (given that intense solar radiation is only experienced for a few hours at a time).

Also, similar reading. In hot places they tend to have white roofs.

Sure - but, again, one doesn't really need to 'read' - just go to Spain/wherever and look at the houses (and you'll probably struggle to find a black one ).

I have often wondered how it has arisen that many Muslim women in very hot countries go around totally encased in black, whilst the males are generally white-clad - has that perhaps culturally evolved as a male-invented form of 'torture of women', or what?

Kind Regards, John