Shermer and the Drake Equation


To how many technological civilisations is our galaxy home at this moment? It would be nice to know, so we could estimate our chances of ever coming into contact with somebody out there. In 1961, astronomer Francis Drake suggested a number of parameters relevant to this issue, and summarised them in an equation that bears his name to this day. One of the parameters is the mean life-span of a technological civilisation.

In issue 2008:2 of Skeptic Magazine that reached me today, Michael Shermer has an interesting paper where he states that of Drake’s parameters, the mean life-span is actually one of the few that can be given an estimate from empirical evidence. Shermer calculates the mean length of historical civilisations on Earth and arrives at a figure of 420.5 years. This is in my opinion all backward. Shermer has mixed up the uses of the word “civilisation”. Says he:

“… I compiled the lengths of 60 civilisations (the number of years from inception to demise), including: Sumeria, Mesopotamia, Babylonia, the eight dynasties of Egypt, the six civilisations of Greece, the Roman Republic and Empire, and others in the ancient world, plus various civilisations since the fall of Rome, including the nine dynasties (and two Republics) of China, four in Africa, three in India, two in Japan, six in Central and South America, and six modern states of Europe and America.”

What Shermer has collected is the lengths of political blocks in the chronologies of areas with continuous complex societies. As he starts his list, “Sumeria, Mesopotamia, Babylonia”, he is simply dealing with phases in an unbroken sequence of civilisation that continues to this day in Mesopotamia. Likewise with the dynasties of Egypt and China. They weren’t independent new starts from a repeatedly cleaned slate, they were simply phases in the lives of cultures that are still with us today. (Strangely, Shermer quotes Thomas R. McDonough of the Planetary Society on this very point in an endnote, but makes no mention of it in his text.)

Extraterrestrials working on the Drake equation won’t be interested in the political details of small parts of Earth’s surface over time. They want to know the likelihood of being able to catch a transmission from somewhere in our solar system. So in fact, Earth’s world history offers us only a single data point to judge what Drake’s mean life-span might be like. If by “civilisation” we mean an agricultural society with cities, then we’re at about 11,000 years and counting. If instead, and more reasonably, we mean a society with radio broadcast technology, then we’re less than 107 years into our window of interstellar visibility, counting from the first trans-Atlantic transmission.

Anyway, the search for extraterrestrial intelligence by means of radio astronomy appears quixotic to me. Let’s say somebody in a far-off solar system is transmitting in our direction. Would we even be able to separate such a little ghost of a whisper from the roar of that person’s sun?

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Jeff Medkeff 1968-2008

One of Aard’s regulars, Jeff the Blue Collar Astronomer, died yesterday. He was diagnosed out of the blue with spontaneous (“cryptogenic”) liver cancer in early June. Jeff was 39. I learned the sad news from Wikipedia contributor Kwix this morning. Derek of Skepticality confirmed it on the JREF forum: “Jeff started to have some internal bleeding a couple days ago and was taken to the hospital. He died last night while sleeping.”

I met Jeff at The Amazing Meeting 5.5 in Fort Lauderdale in January. We became friends and I read his blog within hours of each posting. He was a programmer, an astronomer, a pro-bono science educator, a hard-nosed skeptic and an atheist. This random blow against a friendly and generous guy is a typical example of the non-plannedness of things.

I’m only three years younger than Jeff. His passing reminds me to live as if I had little time.

Update 8 August: Michael Shermer of Skeptic Magazine has accepted a joint book review of Jeff’s and mine for publication, on Bond & Hempsell’s A Sumerian Observation of the Köfels Impact Event. Jeff and I worked on the review immediately before he fell ill.

Book Review: Davidson, Doctor Eszterhazy

Having read what I had to say about Orsinian Tales, Ursula K. LeGuin’s 1976 collection of short stories set in an alternative Balkans, Dear Reader Tty suggested that I read Avram Davidson’s Doctor Eszterhazy stories. For this I thank him warmly: I have just finished the 1975 collection The Enquiries of Doctor Eszterhazy, and I loved every word of it.

As we meet him in the early 1900s, Engelbert Eszterhazy, seven times a doctor (counting two honorific titles), lives in the city of Bella, imperial capital of the Triune Monarchy of Scythia-Pannonia-Transbalkania. This realm covers parts of our world’s Austria, Hungary, Serbia, Romania and Bulgaria: Bella coincides roughly with Belgrade or Timisoara. The Triune Kingdom is (like its real-world counterpart) a kaleidoscopic mix of peoples and creeds, including many that are no longer with us in the real world and others that have yet to appear. So, for example, one of the three united kingdoms is dominated by Goths, another one by Avars, and up by the Austrian border live the Hyperboreans, headstrong country folk who will at the least provocation refuse to pay the imperial head-tax.

The stories are not easily sorted into a genre. There is some supernatural content, much history, even more alternative history, some sleuthing, ample humour and a wealth of rich world-building. Somehow it reminds me of Terry Pratchett. Eszterhazy is a more aristocratic, academic and easy-going version of Holmes, and instead of Watson he has all manner of funny characters out of the highest and lowest echelons of imperial society. Davidson’s style is shamelessly literate and effortlessly archaic with much erudition, all done in such a skilful way that the reader does not feel excluded by the many references to unheard-of-things. Half of them are fictional; the other half obscure bits of real-world history that will leave readers with that sort of inclinations feeling mighty smug and smart when, once in a while, they get it.

It’s been a long time since I read a book and didn’t want it to end. These eight stories on their all-too-brief 206 pages made me want to grow a mustache, wax it, buy a vintage pre-WW1 travelling suit-and-hat and take the first sleeper-train to Bella, there to join Doctor Eszterhazy in his enquiries.