The message
from Pam Moore contains these words:

On Sun, 18 Sep 2005 20:30:37 +0100, Jaques d'Alltrades
wrote:


Sun can't burn the leaf through drops of water - 's against the laws of
physics.

But it can and does! That's why you shouldn't water in bright
sunshine, though sometimes the sun comes out too soon after rain and
the same thing happens.

Sorry - it can't, and it doesn't. The refractive index of water isn't
sufficient to concentrate the sun's rays that impinge on the centre of
the droplet significantly enough to raise the net amount or intensity of
light above what it would be without the droplet there.

Some light is reflected away externally, some is reflected internally
and is scattered, and some absorbed. The net result of it is to diminish
the amount of light, not intensify it.

Have you never burned a piece of paper by focusing the sunlight with a
lens? The drop of water acts as a tiny lens and burns the leaf.

Yes. The refractive index of glass is far higher than that of water, and
how far from the paper do you have to hold the glass? To get a similar
effect, the droplets would have to be much further away from the leaf.

The burning of leaves by sunlight on droplets is a long-established fallacy.

--
Rusty
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