On Fri, 25 Jan 2013 15:07:07 +0000 (UTC), Joe Mastroianni
wrote:

On Fri, 25 Jan 2013 05:53:58 -0800, wrote:

Given my experiences with CFL, I
have good reason to doubt the longevity.
If they crap out
in two years, you're a big loser.

What makes incandescent bulbs wear out?
Oxidation of the filament, right?

No. The filament evaporates.

What makes CFL bulbs wear out?
Oxidation of the mercury inside?

No. There are a few wearout mechanisms but the worst seems to be
crappy capacitors. Fluorescents also have filaments (you can see the
ends get dark from the deposited metal).

What makes LED bulbs wear out?
(something must be wearing out or they'd last forever)

Heat. The junctions are pushing the limits of the material for any
useful amount of light. Cheap knock-offs are worse.