Professor John Raven FRS will be giving a special talk to postgraduates at the University of Bristol.  His research interests are very broad including climate change, biogeochemical cycles, astrobiology and evolution.

Tea/Coffee and cake will be provided.

Please can you let Amanda Woodman-Hardy know if you will be attending so she can make sure there is enough cake to go around.  Email amanda.woodman-hardy@bristol.ac.uk

Prof Raven is a member of the Royal Society of London and the Royal Society of Edinburgh.  He graduated with a PhD. from Cambridge University and has been a leading researcher plant research, with specific emphasis on algae, for almost 40 years. He is currently the Boyd-Baxter Professor of Biology at Dundee University and a member of staff at the Scottish Crop Research Institute.  In 2005, Prof Raven was the chair of the Ocean acidification Royal Society Report. 

Nb.  This event is only open to postgraduates at the University of Bristol.

Abstract

Black smokers in the deep ocean where no solar radiation penetrates emit aqueous solutions at not more than 600 K, generating black-body radiation with a peak photon emission at 6120 nm and just under one ten millionth of these photons below 1100 nm and so usable in photochemistry, including photosynthesis. With radiation < 1100 nm also supplied by sonoluminescence, chemiluminescence and bioluminescence, there is the possibility of photosynthesis by the anoxygenic photosynthetic green sulfur bacteria. Brown dwarfs are stellar bodies of spectral type L and T which can potentially have planetary systems, but are too small to sustain nuclear fusion and so rely for radiation emission of gravitational and radioactive energy. Despite the decreasing energy supply some brown dwarfs can continue emitting black body radiation with a an effective temperature of 600 - 2500 K, with peak photon emission at 6120 - 1470 nm and just under one ten millionth to almost one tenth of there photons below 1100 nm. Earth=like planets orbiting in the continuously habitable zone of Early L brown dwarfs (2500 K) could potentially support about one-tenth of the photosynthesis found on Earth, while for late T brown dwarfs (600 K) the potential photosynthesis is less than one ten millionth that of Earth.