that's what causes the heat, surely.
and thereby also the light, by black body radiation.
( Moon Girl Technologies horrendous beanbag, Fri 12 Jun 2009, 20:31, archived)

yea and what will cause the eventual passing away of the lovely little lamp
r.i.p little light giver, jesus loves you
( mongychops, Fri 12 Jun 2009, 20:37, archived)