From Centauri Dreams:
The assumptions we bring to interstellar flight shape the futures we can imagine. It’s useful, then, to question those assumptions at every turn, particularly the one that says the reason we will go to the stars is to find other planets like the Earth. The thought is natural enough, and it’s built into the exoplanet enterprise, for the one thing we get excited about more than any other is the prospect of finding small, rocky worlds at about Earth’s distance from a Sun-like star. This is what Kepler is all about. From an astrobiological perspective, this focus makes sense, as we want to know whether there is other life — particularly intelligent life — in the universe.
But interstellar expansion may not involve terrestrial-class worlds at all, though they would still remain the subject of intense study. Let’s assume for a moment that a future human civilization expands to the stars in worldships that take hundreds or even thousands of years to reach their destination. The occupants of these enormous vessels might travel in a tightly packed urban environment or perhaps in a much more ‘rural’ setting with Earth-like amenities. Many of them would live out their lives in transit, without the ability to be there at journey’s end. We can only speculate what kind of social structures might emerge around the ultimate mission imperative.
Moving Beyond a Planetary Surface
Humans who have grown up in a place that has effectively become their world are going to find its norms prevail, and the idea of living on a planetary surface may hold little interest. Isaac Asimov once wrote about what he called ‘planetary chauvinism,’ which falls back on something Eric M. Jones wrote back in the 1980s. Jones believed that people traveling to another star will be far more intent on mining asteroids and the moons of planets to help them build new habitats for their own expanding population. Stephen Ashworth, a familiar figure on Centauri Dreams, writes about what he calls ‘astro-civilizations,’ space-based cultures that focus on the material and energy resources of whatever system they are in rather than planets.
Ashworth’s twin essays appear in a 2012 issue of the Journal of the British Interplanetary Society (citation below) that grew out of a worldship symposium held in 2011 at BIS headquarters in London. The entire issue is a wonderful contribution to the growing body of research on worldships and their uses. Ashworth points out that a planetary civilization like our own thinks in terms of planetary resources and, when looking toward interstellar options, naturally assumes the primary goal will be to locate new ‘Earths.’ A corollary is the assumption of rapid transport that mirrors the kind of missions used to explore our own Solar System.
Image: A worldship kilometers in length as envisioned by space artist Adrian Mann.
An astro-civilization is built on different premises, and evolves naturally enough from the space efforts of its forebears. Let me quote Ashworth on this:
“A space-based or astro-civilisation…is based on technologies which are an extension of those required on planetary surfaces, most importantly the design of structures which provide artificial gravity by rotation, and the ability to mine and process raw materials in microgravity conditions. In fact a hierarchical progression of technology development can be traced, in which each new departure depends upon all the previous ones, which leads ultimately to an astro-civilisation.
The technology development Ashworth is talking about is a natural extension of planetary methods, moving through agriculture and industrialization into a focus on the recovery of materials that have not been concentrated on a planetary surface, and on human adaptation not only to lower levels of gravity but to life in pressurized structures beginning with outposts on the Moon, Mars and out into the system. Assume sufficient expertise with microgravity environments — and this will come in due course — and the human reliance upon 1 g, and for that matter upon planetary surfaces, begins to diminish. Power sources move away from fossil fuels and gravitate toward nuclear and solar power sources usable anywhere in the galaxy.
Agriculture likewise moves from industrialized methods on planetary surfaces to hydroponic agriculture in artificial environments. Ashworth sees this as a progression taking our adaptable species from the African Savannah to the land surface of the entire Earth and on to the planets, from which we begin, as we master the wide range of new habitats becoming available, to adapt to living in space itself. He sees a continuation in the increase of population densities that took us from nomadic life to villages to cities, finally being extended into a fully urbanized existence that will flourish inside large space colonies and, eventually, worldships.
An interstellar worldship is, after all, a simple extension from a colony world that remains in orbit around our own star. That colony world, within which people can sustain their lives over generations, is itself an outgrowth of earlier technologies like the Space Station, where residence is temporary but within which new skills for adapting to space are gradually learned. Where I might disagree with Ashworth is on a point he himself raises, that the kind of habitats Gerard O’Neill envisioned didn’t assume high population densities at all, but rather an abundance of energy and resources that would make life far more comfortable than on a planet.
This reminds me of an old Analog article I read back in the 1970s by Larry Niven titled “Bigger Than Worlds” in which Niven gave several examples of structures that evolved into massive structures from interstellar vessels to Ringworlds and Dyson Sphere, all of which were safer than natural planets.
Of course this goes by the assumption if human goes by the “expansion” route, or the “evo devo” route proposed by Jon Smart.
From Centauri Dreams:
One of the benefits of constantly proliferating information is that we’re getting better and better at storing lots of stuff in small spaces. I love the fact that when I travel, I can carry hundreds of books with me on my Kindle, and to those who say you can only read one book at a time, I respond that I like the choice of books always at hand, and the ability to keep key reference sources in my briefcase. Try lugging Webster’s 3rd New International Dictionary around with you and you’ll see why putting it on a Palm III was so delightful about a decade ago. There is, alas, no Kindle or Nook version.
Did I say information was proliferating? Dave Turek, a designer of supercomputers for IBM (world chess champion Deep Blue is among his creations) wrote last May that from the beginning of recorded time until 2003, humans had created five billion gigabytes of information (five exabytes). In 2011, that amount of information was being created every two days. Turek’s article says that by 2013, IBM expects that interval to shrink to every ten minutes, which calls for new computing designs that can handle data density of all but unfathomable proportions.
A recent post on Smithsonian.com’s Innovations blog captures the essence of what’s happening:
But how is this possible? How did data become such digital kudzu? Put simply, every time your cell phone sends out its GPS location, every time you buy something online, every time you click the Like button on Facebook, you’re putting another digital message in a bottle. And now the oceans are pretty much covered with them.
And that’s only part of the story. Text messages, customer records, ATM transactions, security camera images…the list goes on and on. The buzzword to describe this is “Big Data,” though that hardly does justice to the scale of the monster we’ve created.
The article rightly notes that we haven’t begun to catch up with our ability to capture information, which is why, for example, so much fertile ground for exploration can be found inside the data sets from astronomical surveys and other projects that have been making observations faster than scientists can analyze them. Learning how to work our way through gigantic databases is the premise of Google’s BigQuery software, which is designed to comb terabytes of information in seconds. Even so, the challenge is immense. Consider that the algorithms used by the Kepler team, sharp as they are, have been usefully supplemented by human volunteers working with the Planet Hunters project, who sometimes see things that computers do not.
But as we work to draw value out of the data influx, we’re also finding ways to translate data into even denser media, a prerequisite for future deep space probes that will, we hope, be gathering information at faster clips than ever before. Consider work at the European Bioinformatics Institute in the UK, where researchers Nick Goldman and Ewan Birney have managed to code Shakespeare’s 154 sonnets into DNA, in which form a single sonnet weighs 0.3 millionths of a millionth of a gram. You can read about this in Shakespeare and Martin Luther King demonstrate potential of DNA storage, an article on their paper in Nature which just ran in The Guardian.
Image: Coding The Bard into DNA makes for intriguing data storage prospects. This portrait, possibly by John Taylor, is one of the few images we have of the playwright (now on display at the National Portrait Gallery in London).
Goldman and Birney are talking about DNA as an alternative to spinning hard disks and newer methods of solid-state storage. Their work is given punch by the calculation that a gram of DNA could hold as much information as more than a million CDs. Here’s how The Guardian describes their method:
The scientists developed a code that used the four molecular letters or “bases” of genetic material – known as G, T, C and A – to store information.
Digital files store data as strings of 1s and 0s. The Cambridge team’s code turns every block of eight numbers in a digital code into five letters of DNA. For example, the eight digit binary code for the letter “T” becomes TAGAT. To store words, the scientists simply run the strands of five DNA letters together. So the first word in “Thou art more lovely and more temperate” from Shakespeare’s sonnet 18, becomes TAGATGTGTACAGACTACGC.
The converted sonnets, along with DNA codings of Martin Luther King’s ‘I Have a Dream’ speech and the famous double helix paper by Francis Crick and James Watson, were sent to Agilent, a US firm that makes physical strands of DNA for researchers. The test tube Goldman and Birney got back held just a speck of DNA, but running it through a gene sequencing machine, the researchers were able to read the files again. This parallels work by George Church (Harvard University), who last year preserved his own book Regenesis via DNA storage.
The differences between DNA and conventional storage are striking. From the paper in Nature (thanks to Eric Davis for passing along a copy):
The DNA-based storage medium has different properties from traditional tape- or disk-based storage.As DNA is the basis of life on Earth, methods for manipulating, storing and reading it will remain the subject of continual technological innovation.As with any storage system, a large-scale DNA archive would need stable DNA management and physical indexing of depositions.But whereas current digital schemes for archiving require active and continuing maintenance and regular transferring between storage media, the DNA-based storage medium requires no active maintenance other than a cold, dry and dark environment (such as the Global Crop Diversity Trust’s Svalbard Global Seed Vault, which has no permanent on-site staff) yet remains viable for thousands of years even by conservative estimates.
The paper goes on to describe DNA as ‘an excellent medium for the creation of copies of any archive for transportation, sharing or security.’ The problem today is the high cost of DNA production, but the trends are moving in the right direction. Couple this with DNA’s incredible storage possibilities — one of the Harvard researchers working with George Church estimates that the total of the world’s information could one day be stored in about four grams of the stuff — and you have a storage medium that could handle vast data-gathering projects like those that will spring from the next generation of telescope technology both here on Earth and aboard space platforms.
I am not a geneticist or biologist of any kind so I can’t write a good review about the technology or wisdom of such a storage method other than to say that biological systems tend to break down over long periods of time, even small dots of DNA.
I can understand the information carrying capacity of DNA; livings things require googols of information in order to operate their bodies and reproduce, so putting vast amounts of generic info into DNA does make sense.
I would suggest making a virtual model of a DNA molecule, storing it in a crystal and loading the info that way. It would last longer IMO.