Surprisingly (for me), he ended with an argument that we could colonise the planet. But forget heroic terraforming efforts, and forget the hellish conditions on what we normally think of as the surface. Venus becomes surprisingly attractive if one redefines the rock surface as its ocean bottom, and thinks instead of aerostats hovering at about 55 km altitude, in the clouds, where the atmospheric pressure and temperature approximate Earth-surface norms.

Since at the rock surface the venusian atmosphere is no longer gaseous, but is rather a supercritical fluid (neither liquid nor gas), it is actually technically correct to think of Venus as enveloped in a global carbon dioxide ocean.

Since the atmosphere of Venus is predominantly carbon dioxide, breathable Earth air, which is lighter, becomes a lifting gas. An inhabitable air-filled base or indeed an entire city can thus float effortlessly at this altitude, sending rugged robotic miners down to the rocks on the ocean bottom below for silicon and metals for further material construction.

Crucially, the gravity, at 90% of Earth’s, is not likely to pose any health problems for humans (it is not yet clear whether sustained human life on Mars, with only 0.38 of Earth’s gravity, is physiologically possible). And since the mass of atmosphere above the 1-bar altitude is about equal to that on Earth, cosmic and solar radiation are screened out to Earth surface norms. Thus two of the major problems of extraterrestrial colonisation are solved without needing technological intervention.

However, questions may remain about the stability of floating cities against possible vertical and horizontal convection-driven air currents. Clearly, we need some experience with making “air-landings” at the 55 km level and observing how airships deployed here move around the planet, especially in view of the rapid rotation of the upper atmosphere relative to the body of the planet.

Geoffrey Landis may be found at http://www.geoffreylandis.com/.

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(2) Progress at Reaction Engines

I hear that Reaction Engines’ test programme on their pre-cooler is going well.

Recent report from Jonathan Amos here.

David Shukman, BBC science editor, here.

Interview with Alan Bond, recorded late 2011, posted on YouTube April 2012. This is an informative and wide-ranging interview, with Alan giving clear descriptions of both the technical problems of single-stage to orbit, and the broader strategy issues.

Alan is scheduled to give a lecture at the Institute of Engineering and Technology in London on 8 May, which I am planning to attend (online registration needed).

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(3) The anti-human ideology: Bob Zubrin fights back

Last December, I wrote about the conflict between optimistic and pessimistic future visions of mankind: optimism based on the enormous possibilities for growth of our civilisation into space, versus pessimism based on the three horsemen of the popular apocalypse: peak oil, climate change and socialism.

A version of this piece was published by the British Interplanetary Society e-publication Odyssey (issue 13, March 2012). Odyssey is available to all free of charge from Mark Stewart; details on the BIS website.

Now the well-known space advocate, author and founder of the Mars Society, Dr Robert Zubrin, has published a new book focusing on another aspect of this conflict: the campaign for population control in pursuit of the notion that growing populations lead to poverty. According to his detailed account, this campaign has been pursued in a spirit of ignorance of history, dishonesty, tyrannical force, cruelty, and racism of a kind that we thought was defeated in 1945. A major essay drawn from the book is now accessible on the website of The New Atlantis.

A sample:

“Around the world, the population control movement has resulted in billions of lost or ruined lives. We cannot stop at merely rebutting the pseudoscience and recounting the crimes of the population controllers. We must also expose and confront the underlying antihumanist ideology. If the idea is accepted that the world’s resources are fixed with only so much to go around, then each new life is unwelcome, each unregulated act or thought is a menace, every person is fundamentally the enemy of every other person, and each race or nation is the enemy of every other race or nation. The ultimate outcome of such a worldview can only be enforced stagnation, tyranny, war, and genocide. The horrific crimes advocated or perpetrated by antihumanism’s devotees over the past two centuries prove this conclusively. Only in a world of unlimited resources can all men be brothers.”

I urge everyone to give careful consideration to what Zubrin has to say, and to use every opportunity to counter this pernicious and unhistorical notion that a growing human population must be stopped in order to save the planet (or at least to save the privileged position of its current rulers).