Friday 13th October 2023 The Astrophysics of Earth: light-life interactions beyond photosynthesis (video recording and extended paper)

Dr Robert Fosbury

Friday 13th October 2023 7.30 pm in the BRLSI, can be attended either in the BRLSI or remotely on Zoom

Lecture 2 of 4 on the theme ‘Conserving the Planet’ in association with the Herschel Museum of Astronomy

Image shows a chart of spectra and the effect on life © Bob Fosbury

Sunlight is the dominant energy source for Earth’s biosphere. There will be evolutionary advantages for life that make the most effective use of available photons before they finally degrade to heat and radiate back into space. Photosynthesis in cyanobacteria and in plants uses water, carbon dioxide and sunlight to synthesise the sugars that build plant structures. These can be used directly as food for animals to eat but can also be captured and stored for long periods as ‘fossil fuels’.

It has taken over two centuries to gain an understanding of the how photosynthesis works and yet we are only just beginning to appreciate the ways by which light interacts with animal life. Apart from the obvious use of light for vision — the evolution of which is thought to have driven the Cambrian explosion in life’s complexity — we now know that light performs other functions, many of which require photons with colours beyond the visual range but still reaching the biosphere from the Sun. Research is revealing which colours have beneficial effects and which are damaging. Over billions of years, the biosphere has adapted to thrive under the solar spectrum modified during its transmission through the atmosphere. The introduction of artificial lighting on a huge scale over the planet during recent decades is breaking this adaptation in ways that are damaging to life, including humans. This understanding allows us to suggest new lighting strategies that should have very significant health benefits and which could be less costly than the current extravagant overuse of energy-efficient but environmentally damaging white lights.

Robert (Bob) Fosbury is currently an emeritus astronomer at the European Southern Observatory and an honorary professor at the Institute of Ophthalmology at UCL.

A link to a video recording of this lecture is available here.

A link to an extended paper on this subject titled Light-life interactions beyond photosynthesis by Robert Fosbury and Glen Jeffery is available as a PDF file here.