Photosynthesis - in pitch darkness?

Bacteria have been discovered which can carry out photosynthesis at the bottom of the ocean, miles away from any sunlight.

The newfound bacteria use sophisticated antenna systems that act like a microscopic satellite dish to collect light, the researchers said. Tests show the microbes indeed depend on photosynthesis. Visible light is just one aspect of the electromagnetic spectrum, which includes radio waves, infrared "heat," and X-rays. Instead of sunlight, the deep-sea microbes use geothermal radiation. "This shows that photosynthesis is something that is not limited only to the very surface of our planet," Blankenship said. "It lets you consider other places where you might find photosynthesis on Earth as well as on other planets."

Infrared light had not been considered a good candidate for photosynthesis because of its low energy per photon and its long wavelength. However, it's an energy source, and wherever energy is packaged in any remotely available form, some life form can evolve a way of tapping it.

We may yet find life that taps the energy of nuclear reactions.