“Can heat alone be used to stimulate photosynthesis instead of sunlight?”
The Contributors above quite properly discuss the different types of heat, the mechanics of photosynthesis and the sun’s radiation spectrum.
My point is that the OP probably does not understand the science at all. Heat (to him/her) is what comes from the furnace or a fire. “instead of sunlight.” can reasonably be interpreted as - “in the dark”.
A photon does not have a temperature. No single particle (with the exception of a black hole) has a temperature. A collection of many photons (or other particles), however, can.
That labeling is wrong. It is no more nor less correct to call infrared “heat” than it is for any other part of the spectrum.
I read the OP as asking if biochemical processes in life could extract energy (that is, perform some form of ‘photosynthesis’) from “heat”.
Heat, in layman’s terms, may be imagined as infra-red light or as a heat gradient.
So if the question is rephrased that way:
Can we imagine plants on some exoplanet thriving of it’s red dwarf suns IR output. I think yes, based on pictures of black plants in some Scientific American article I read a ways back. Chronos also points out that the black bosy radiation of even a cool star will include some energetic photons, but I don’t *think *that that’s whet the OP is looking for.
Do we have any examples of life using a heat gradient to generate energy? Can we imagine that? ( I don’t *think *that the thermal vent bacteria count, as they metabolize a chemical emitted by the vent, rather than generate energy from a heat gradient.)
Assuming OP isn’t insisting on some photonic definition of heat (such as IR), what’s being asked for is a hypothetical organism powered by thermosynthesis: a biological heat engine.
The wikipedia article says that there are no known examples of functional biological thermosynthesis, and I certainly can’t think of any. But it seems like a viable biochemical approach, at least for simple (unicellular or small colonial) creatures in settings with the availability of appreciable thermal gradients.
Yeah, except that it is hard to have a “hot end” and a “cold end” when you are a microscopic creature or organelle.
It’s been awhile, and it’s not a plant, but I think I recall reading about an oceanic alga that could photosynthesize off EM radiation that was just barely into the infrared. hence, not visible light. But close. The visible spectrum goes to 700 nm, by convention, and this alga has an absorption peak at 706.
I suppose that counts as photosynthesis not using light, but only technically. Let me see if I can find the cite.
Can heat alone be used to stimulate photosynthesis instead of sunlight?
The options are “heat” vs “sunlight” which makes it pretty clear that the OP envisions these two things as being significantly different from each other. In other words, “heat” is defined as something other than visible light. Since the range of frequencies used for photosynthesis fall within the visible spectrum, the answer, in the sense of the OP, has to be, “no.”