I don't know, but I would suspect it's the UV -- it has more energy, and turmeric's bright color implies that it's a little bit fluorescent. Most things that fluoresce under black light fade quickly in sunlight -- it's like the fluorescense takes something out of it chemically.
no subject
Date: 2005-10-27 03:31 am (UTC)no subject
Date: 2005-10-27 03:43 am (UTC)Do you happen to know whether it's the vis or UV light that causes it to degrade?
no subject
Date: 2005-10-27 04:55 am (UTC)