Saturday, July 28, 2007

The Killing Star

Re-reading Pellegrino and Zebrowski’s book “The Killing Star”. The basic idea is that the earth is subject to a pre-emptive attack by unknown aliens who deploy relativistic kinetic weapons. The description of what would happen if a car-sized object travelling at 92% of the speed of light impacted the earth is well done. (It would look like a lance of fire from sky to horizon, and the impact of the photons themselves would be like a hard slap in the microsecond or so before you vaporised). In the attack described there are many, many such objects.

Considered as a novel, “The Killing Star” is mediocrity raised to a very high power. Characterisation is perfunctory, and the plot indulgently undulates and wanders like Chesterton’s rolling English road. The book is better seen as a concept paper on evolutionary theory applied to extra-terrestrial intelligence.

About a third of the way through there is an epistolary section, composed of purported emails between the likes of Isaac Asimov and Gregory Benford with NASA SETI scientists, set in the mid-80s. In the best Asimov tradition three ‘laws’ are proposed.

1. Any alien species we encounter will prefer its own survival over ours.

2. Any alien species we come to deal with will be the local top dog: smart and aggressive.

3. They will apply the same approach to us.

The authors draw a game-theoretic-like conclusion. In this situation, the strategy with maximum payoff is to wipe the other ‘top dog’ out while you still can, with as little risk to yourself as possible. In what might be called the ‘Pearl Harbour’ doctrine, it turns out that as soon as you detect an alien intelligence, you should hit them so hard, and then exterminate any remnants so that no representative survives to exact a genocidal revenge.

All stirring stuff, and a welcome antidote (as they themselves note) to the Carl Sagan school of galactic benevolence. It did spark a couple of questions.

Q1. Could evolution ever produce an intrinsic star-faring species in the sense that birds, insects and bats are intrinsic air-faring species while we do it with technology? This idea was explored in Brian Aldiss' book “Hothouse”.

Q2. There is something weird about human evolution. A basic principle of evolution is parsimony. A species has just enough capability to be optimal for its niche. Any extra (and superfluous) muscle, sensory capability or brainpower atrophies if not needed. Evolved creatures are optimised to their niche.

This was true also for human hunter-gathers (who do not traverse either the air or space). What seems to have happened was that the intelligence which was designed to optimise social hunting-and-gathering was applied (as if by side effect) to invent agriculture and pastoralism (domestication of animals).

The consequence was social surplus product: the ability to support classes which didn’t have to engage in subsistence labour, and who then drove an explosion of technologically-driven capability over 12,000 years. These capabilities of civilisation are based on a substrate of evolution (social intelligence) but are not the direct products of it.

On this basis, the answer to question 1 would be that - as in 'Hothouse' - it is possible to imagine a space-faring species which attained this capability through direct evolution, but such a capability would owe nothing to smartness and such a species would most likely not be capable of projecting the kind of threat Pellegrino and Zebrowski are concerned with. Most likely the bullies on the galactic block are just as smart, vicious and scary as they suggest. (So where are they, then?)