Last night I was part of a panel of 4 people discussing various aspects of the 1972 Sci-fi film “Silent Running“.
This event was organised by BRASS, the Cardiff University centre for Business Relationships, Accountability, Sustainability and Society. It was run as part of Cardiff University’s sustainability week.

The other participants were Dr. Chris North (also of the School of Physics and Astronomy in Cardiff University), Dr. Rob Thomas of Cardiff University’s School of Biosciences, and Chris Barber, founder and head of the International Space School Education Trust (ISSET).
The film’s plot is that a fleet of space ships have left Earth, which has become uninhabitable to plant life. The space ships are out by Saturn, having left the Earth carrying enormous geodesic domes carrying plant life and animals. The film focuses on one ship in particular, Valley Forge (which, historically, is a site in Pennsylvania near the Delaware river where George Washington regrouped in 1777-78 in the war of independence against Great Britain).
The film’s main character is Freeman Lowell (a combination of Freeman Dyson and Percival Lowell perhaps?). He tends to the plants and animals in these geodesic domes (or “forests” as they are referred to in the film), so when he and his fellow crew members are ordered to jettison the forests and return to spaceship to commercial use, he is horrified and decides to rebel against the orders.
After the film, the 4 panel members, our moderator Lorraine Frater of BRASS and the film’s audience went to a separate room to begin the discussion. I was, unfortunately, the first to say my piece. Given one of the themes of the film, I decided to talk about terra-forming.
Here is a link to the PDF slideshow I prepared: 20111102_Silent_running_chapter
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As you can see from these slides, I started off by trying to put human beings’ brief history on Earth into context. In slide 2 I show a graphic to get this idea across. If one were to compress the 4.6 billion year history of Earth into just 24 hours, then human beings only make an appearance in the last 20 seconds on this timescale!
What many people don’t realise is that, for most of the history of the Earth, the planet would have been uninhabitable to humans. Green plant life didn’t start oxygenating the atmosphere until roughly 1.5 billion years ago. However, human beings have evolved to live in the conditions which now exist, and so if we have to abandon our planet, we would need to be able to create an environment elsewhere which is able to support our needs. This is the idea of terra-forming.
We may, of course, make the Earth uninhabitable to our species through our own folly, but eventually the Earth will become uninhabitable to all life when the Sun swells up to become a red giant. This is not going to happen for about another 4.5 billion years, so a whole 24 hours more on our compressed timescale. Given that we have only been around for 20 seconds on this scale, it is maybe a little naive to think we will survive much longer than a few tens of seconds more, or a few minutes at most.
Nevertheless, NASA and other space agencies have held workshops on terra-forming, with Mars being the most likely candidate. The gravity of Mars is similar, the temperature is not too different, so compared to most other locations in the Solar System it is the best candidate for terra-forming. However, currently the atmosphere of Mars is some 96% CO2, with most of the remainder being Nitrogen. There is no oxygen to speak of in the atmosphere, whereas the 20% oxygen in our atmosphere is essential for most multi-cellular life. In order to oxygenate either the entire atmosphere of Mars, or even some geodesic domes on its surface, we would need green plant life to use photosynthesis to do the work for us.
Personally, I don’t think there are no aspects of terra-forming which are beyond our understanding, but much of it is beyond our present technology, or beyond the money governments would be willing to spend. In my opinion, it would be very stupid to invest money on terra-forming at the expense of fixing our problems here on Earth. We have only been around for 20 seconds on our Earth’s 24-hour timescale, and yet in that 20 seconds we have increasingly put the planet and its ecosystem under a lot of strain. The planet will survive whatever mess we make of it. The question is, will we have the vision and sense to realise that we cannot continue to abuse the environment without serious consequences to the Earth’s habitability ensuing?
Hi Rhodri, great to meet you and your wife at the film evening! I’ve enjoyed reading your blog article about it here -I’ll see if I can add mine below yours
Best wishes, Rob
Thanks Rob. Great to meet you too. Yes, feel free to add anything here, or if you want to do a “guest posting” let me know via email & we can sort something out.
[...] few weeks ago, as I metioned in a previous blog, I was on a panel discussing the science fiction film Silent Running. Also on the panel was Dr. Rob [...]