In article ,
Rafael Almeida wrote:
wrote:
In article ,
Rafael Almeida wrote:

Ivan Kobrinsky wrote:

For this feat they are using completely special light.
Instead of the sun the green sulfur bacteria use the weak
jets of hot sources of the deep sea for their photosynthesis.

Hum... photo-synthesis, photo is greek for light, right? The bacterias
you described seems to use the heat energy to do whatever is done and
not light energy, therefore it couldn't be called photosynthesis, could
it? I'm not a biologist and i don't even know much about it, but that
just seemed wrong.

It seemed strange to me too, but if these hot water jets are as hot as
350C, they would be hot enough to emit some near-infrared and even a
bit of red light by black-body radiation, at the tail end of the curve.

Still, even if it emits a little red light the energy source would be
heat, as the generates little light. For what i know any eletromagnetic
wave that we can't see is just eletromagnetic wave, not light

Well, if the reaction is the usual one in photosynthesis, where a photon
is the energy source, even if it isn't a photon of human-visible light,
I think we'd probably have to call it photosynthesis. There are lots of
ways of acquiring usable energy from temperature differences, including
steam engines, etc, but I don't think any living organisms use them. If
anyone knows of one, please correct me! I suppose a deep ocean vent,
where water at 4C is adjacent to water at 350C would be a place to look
for such bizarre and hard to imagine adaptations.

I'm very curious to know more about these bacteria, and whether energy
from this light source is a significant source of energy to them, or an
adjunct to the well-known chemosynthesis based on oxidizing H2S popular
with Archaeobacteria in unusual environments. I hope Ivan can provide
us with some sources of information.