All Astronautical Evolution posts in 2012:
Growth Options (1) (Feb.)
New in 2015:
Short story The Marchioness
2016: Stragegic goal for manned spaceflight…
2015: The Pluto Controversy, Mars, SETI…
2014: Skylon, the Great Space Debate, exponential growth, the Fermi “paradox”…
2013: Manned spaceflight, sustainability, the Singularity, Voyager 1, philosophy, ET…
2012: Bulgakov vs. Clarke, starships, the Doomsday Argument…
2011: Manned spaceflight, evolution, worldships, battle for the future…
2010: Views on progress, the Great Sociology Dust-Up…
Index to essays – including:
The Great Sociology Debate (2011)
Building Selenopolis (2008)
|(1) Growing into an Interstellar Civilisation|
|(2) News: Launch of the Institute for Interstellar Studies|
All content is by Stephen Ashworth, Oxford, UK,
unless attributed to a different signed author.
(1) Growing into an Interstellar Civilisation
The ten-billion-times difficulty
Paul Gilster reports on his Centauri Dreams blog that, just before setting out to go to this month’s 100 Year Starship Symposium in Houston, he received an e-mail from someone whose grasp of the difference between interplanetary and interstellar distances was less than perfect. “We’re already going to Pluto”, said the writer. “How much harder can it be to go to a star?” Gilster mused: “I could write a whole book in answer to that question. Wait – I already have...”
Regular reader Joy often posts comments from a more skeptical or reality-check point of view. This time she responded in the comments section:
Velocity × 1000 = energy × 1,000,000
x Crewed spaceflight duration 100 × longer than the longest space station missions
x Mass of vehicle 100 × anything we have orbited
I reckon it to be merely 10,000,000,000 times harder
Regular reader Astronist (a.k.a. Yours Truly) produced the following response to Joy’s calculation:
Joy said: “I reckon it to be merely 10,000,000,000 times harder.”
Given determination, patience and the resources of the Solar System, that shouldn’t be too much of a problem:
Present-day human population × 1,000,000 – this is John S. Lewis’s estimate (in his classic book Mining the Sky) for the population of a developed Asteroid Belt. Say 3% growth for 470 years.
Present-day wealth per person × 10,000 – this is 2% growth for 465 years.
Multiply these together to get an economy 1010 times more powerful than that of today, thanks to the power of that fashionable bête noire, exponential growth.
Taking the resource of solar power (380 × 1012 TW) as indicative of our actual physical room for growth (and remembering that the biggest growth factor for a starship identified by Joy was propulsion energy), an economy well over a trillion times larger than at present is conceivable (asteroidal matter for space colony construction can be expanded if necessary by dismantling small moons). Thus we would still at that point possess only 1% of the ultimate economic power of a fully developed interplanetary civilisation.
About the year 2500, therefore, Joy’s growth criterion could be met, assuming continued faith in material progress and success in finessing our way through all the stresses and strains of growth.
However, within the confines of a blog comment I did not have sufficient space to specify the practical details of how our global civilisation might grow to a multiglobal one with a million times the population and ten thousand times the wealth per head than today.
An omission which I shall now try to make good.
Scenarios for growth... or decline
In considering future growth in space, a number of different scenarios suggest themselves.
How will growth be driven forward?
This gives us three broad options to choose from.
Secondly: what will be the economic and social conditions on Earth over the next few centuries?
There are therefore another three broad options, making in combination nine distinct scenarios.
However, eight of these scenarios involves extremes of one sort or another: of monopoly by bureaucrats or buccaneers, of wealth or poverty. Others may wish to explore these. For the present I should like to develop further the “middle way” scenario: a creative community of public and private institutions acting in concert, yet with no overarching master plan, and a set of new technologies which both multiply wealth and introduce new problems, yet whose benefits on balance exceed their drawbacks.
This scenario is therefore based on the pattern of past history: progress arises as an evolutionary, system-level phenomenon, not one governed by any one institution or single clique of middle-aged men in smoke-filled rooms, and the new technologies of the past 200 years have on balance indeed benefited humanity despite all the problems they have brought in their wake.
While others may disagree, to me this seems both the most plausible vision of our future, and the one most likely to achieve the result of expanding civilisation to the stars.
A scenario for the ten-billion-times growth factor
Within this middle way scenario, I would envisage the following sequence of events for the future of manned spaceflight merging into Solar System colonisation.
This scenario thus completes the transformation of civilisation from monoplanetary to multiplanetary status, and sets up the conditions under which economic and population growth may now proceed without interruption until the limits of the carrying capacity of the Solar System are reached.
Clearly, those limits will one day be reached, and the transition to a low-growth society must be faced. Those who call for such a transition are correct. However, their timing is wrong. I estimate that growth can continue at typical present-day rates for a few thousand years. The society that will face the transition to a low-growth economy will therefore be very different from that of the present day.
At some point a few centuries in the future (I suggested the date 2500 above – as good a guess as any), the first starships will be able to depart, carrying our descendants to the stars. By this time, I assert in all seriousness, almost all of our descendants will be living permanently in space colonies. Why? Because we need to grow, and that is where the greatest opportunities for growth are.
Perhaps the biggest question so far unanswered is how humanity will change in coming centuries under the influence of genetic and information technologies. While genetics may modify us, principally in terms of improving disease resistance and extending our lifespans, information technologies, it is often claimed, have the potential to create a superior order of machine beings which are more intelligent than we are and more capable than natural humans in every way. Humans may be confined to Earth forever, or may even vanish completely, driven extinct by competition from the superior machine intelligence they have created.
This, however, is a topic for another essay.
(2) News: Launch of the Institute for Interstellar Studies
On 29 August Kelvin Long gave a talk at the British Interplanetary Society entitled “To the Stars: A Vision for Catalysing Interstellar Flight before the year 2100”. This talk is available to view on YouTube.
Kelvin gives a good summary of developments to date, and announces his latest venture, the Institute for Interstellar Studies. The Institute is now an active venture, with its own website and, on a related website, a growing Interstellar Index of literature, from scientific books and papers to science fiction, on the interstellar project, as well as a blog.
The latest blog entry records a planning meeting held in London a couple of days ago, with some photos of those present. (I am visible, seated on the left of Kelvin.)
The past few years – especially since the start of the Icarus project in 2009, but going back as far as NASA’s Breakthrough Propulsion Physics workshop in the 1990s and the resulting formation by physicist Marc G. Millis of the Tau Zero Foundation – have witnessed a flurry of renewed interest in interstellar spaceflight, but also a recognition of the magnitude of this ambition. It will be fascinating to observe how this plays out over the long term, and whether it can contribute to nurturing the confidence in human abilities and in the positive moral value of technological mankind which is needed if the scenario sketched out in the essay above is to come to fruition.