From Stephen Webb’s If the Universe Is Teeming with Aliens … WHERE IS EVERYBODY?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life. Aside from wildlife documentaries, thought experiment science is the only kind that interests me, and the Fermi Paradox is by a good margin my favorite area here. In addition to Webb’s book I’d also recommend Milan Cirkovic’s The Great Silence: Science and Philosophy of Fermi’s Paradox and Duncan Forgan’s Solving Fermi’s Paradox. There’s also a very good Youtube channel that routinely offers proposals of a more speculative sort. The host, John Michael Godier, also maintains an equally good interview podcast called Event Horizon that frequently touches on the Fermi Paradox in conversation with a range of mostly physicists.
Solution 23 Information Panspermia
The Armenian mathematical physicist Vahe Gurzadyan has posited an interesting hypothesis:(Footnote 1) we might inhabit a Galaxy “full of traveling life streams”—strings of bits beamed throughout space. The argument goes as follows.
We know that strings of characters can contain information. Consider two strings, each containing a trillion characters. The first string starts “101010 …” and continues in that way until the trillionth character is reached; the second string starts “x9Y$m& …” and carries on in a seemingly randomly pattern. The Kolmogorov complexity (Footnote 2) of strings such as these is defined as the minimum length in bits of a binary-coded program that describes the string. The Kolmogorov complexity of the first string is small because one requires only a short program to describe it: in words, the program could be something along the lines of “Print alternating sequence of 1s and 0s, starting with 1 and ending after the trillionth digit”. The Kolmogorov complexity of the second string is large because there’s no obvious way of compressing the information it contains; any program describing the string would likely be as long as the string itself. Gurzadyan argued that the Kolmogorov complexity of the human genome—indeed, of the totality of terrestrial life—is relatively low. There’s a vast amount of genetic information contained in the millions of species on Earth, but the program that describes that information might be much smaller.
Suppose we wanted to communicate all the genomic information contained in terrestrial life. Communication takes energy: the more bits we have to transmit, the greater the energy requirements. If we wanted to send a file containing all of Earth’s genetic data then the cost in energy would be prohibitive; if instead we sent a program that could recover that information then the energy cost would be small. This is the same argument that says transmitting a trillion digits is much more costly than transmitting the string “Print a trillion alternating 1s and 0s”. Gurzadyan showed that with an Arecibo-like antenna it would be possible to transmit the genomes of terrestrial organisms throughout the Milky Way galaxy.
Gurzadyan, then, imagines a type of what might be called “information panspermia”. He describes the possibility of a Galaxy in which ETCs establish a network of self-replicating Bracewell–von Neumann probes and life is propagated not by sending the genomes themselves but by sending the programs that can recover the genomic information. In other words the probes, which could be many light years away from their home planet, would receive coded strings and from those strings reconstitute the full panoply of that planet’s life. Even now, life might be raining down on us. But it would be a strangely desiccated form of life: not living creatures, but rather ghostly strings of information that have the potential to become living.
Gurzadyan says this idea can eventually approach a solution to Fermi’s paradox. However, I’m not entirely sure how this is so. The hypothesis certainly has implications for SETI: perhaps we should be analyzing radiation for evidence of bit strings? However, if ETCs are indeed spreading their form of life via a Galaxy-wide network of Bracewell–von Neumann probes then why, as we’ve already argued, aren’t they already here? They’ve had plenty of time to reach us but, unless you believe that terrestrial life is the result of the unpacking of a transmitted bit string, we see no signs of them. To my mind, Gurzadyan’s hypothesis, rather than being a solution to the Fermi paradox, is a particular example of how directed panspermia might be made to work. (What perhaps could resolve the paradox is if ETCs either won’t or can’t make self-replicating probes. In that case, might they send out life streams anyway, like dandelion “clocks” in the wind, hoping that occasionally someone somewhere will catch one and reconstitute the life they contain?)
And the footnotes since they add good references, should anyone have the interest.
- For details of the argument that the universe might be full of low-complexity bit strings, see Gurzadyan (2005 – Kolmogorov complexity, string information, panspermia and the Fermi paradox. Observatory 125:352–355).See Scheffer (1993 – Machine intelligence, the cost of interstellar travel and Fermi’s paradox. Q J R Astro Soc 35:157–175) for an earlier and thorough defense of the notion that “information transfer” is a much cheaper option for interstellar travel than physical travel. Scheffer resolves the Fermi paradox by arguing that the first civilization to colonize its galaxy will have done all the hard work; for any emerging society it will be overwhelmingly attractive to join the existing civilization rather than try to physically colonize the galaxy. There will be a single,unified civilization. If that first civilization in our Galaxy didn’t bother to contact Earth, for whatever reason, then subsequent societies won’t have bothered either.
- The idea that a measure of the complexity of a system can be the length of an algorithm that produces that system is due to Andreii Nikolaevich Kolmogorov (1903–1987), who was one of the outstanding mathematicians of the twentieth century. For an appreciation of just some of Kolmogorov’s output, see for example Parthasarathy (1988 – Obituary: Andreii Nikolaevich Kolmogorov. J Appl Prob 25:445–450)
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