It's The h2g2 Post's birthday, but how significant is it this time? We traditionally recognise some sort of importance in anniversaries which are 'round numbers', particularly those which end in zeroes. Yet, eleven isn't round, so is there any reason we should celebrate it?
Eleven itself doesn't mean a lot. It's a prime number, but it's not the lowest or the highest. It does some pretty things if you multiply it - 22, 33, 44, etc – but these are just a consequence of our decimal number system. The number nine would do the same thing if we worked in base eight.
Yet, though the number itself may not be so interesting, some particular quantities of eleven certainly are. Take distance for example. Eleven kilometres happens to be the approximate depth of the deepest point below the sea - in the Mariana Trench in the Pacific Ocean.
Ever been held in a long queue of planes circling round and round, waiting to land? This is because air traffic controllers have to keep aircraft a certain distance apart in order to minimise the effects of turbulence caused by the wake vortices from the aircraft in front. The safe distance for the largest airliners is, you've guessed it, eleven kilometres.
In terms of speed, eleven kilometres per second is the approximate escape velocity we need a rocket to achieve to leave our earth's gravitational attraction.
But, returning to our anniversary, we are celebrating eleven years, and it's this particular period of time which has perhaps the most interesting significance.
When we say the h2g2 Post has existed for 11 years, what we really mean is that our Earth has made exactly eleven orbits of the sun since the first issue of The h2g2 Post appeared on the site. Yet there's a more significant astronomical event which has happened. The sun itself has been through just over one complete solar cycle in that period. Its magnetic field switches polarity during this time, and its ancient cycle of sunspots, solar flares and magnetic storms begins all over again.
But has this celestial phenomenon affected us here on Earth? Well, there's an unusual coincidence which occurs with many of man's greatest constructions. These days, newspapers are littered with scandals relating to engineering projects which are inevitable late, over budget, and poorly built. Two which have proved their worth, however, are the ship canals which were cut through the isthmi1 at Suez and Panama. These channels revolutionised global trade in the age before air travel. Both canals had something of a long history behind them, but it's generally accepted that the final constructions of each took more or less eleven years to complete.
It's also a popular timescale for UK canal projects. The Trent and Mersey Canal took eleven years to complete from the time Josiah Wedgwood ceremonially cut the first sod2. In Northern Ireland, the Newry Canal took a similar amount of time.
But man also constructs things of great beauty. One of the most iconic of world buildings is the Taj Mahal at Agra, India – Shah Jehan's memorial and mausoleum to his favourite wife, Mumtaz Mahal. Not everyone agrees, but many believe this great edifice took eleven years to construct.
Finally, in literature, one of the greatest epic poems ever written took eleven years to complete. I'm referring to Virgil's Aeneid, which tells the story of the wanderings of the hero Aeneas, and beautifully describes the Trojan Wars and beyond. As Laocoön once said:
Equo ne credite, Teucri
Quidquid id est, timeo Danaos et dona ferentes.
(Do not trust the Horse, Trojans
Whatever it is, I fear the Greeks even when they bear gifts.)
And so, whether or not we can blame solar cycles for it, it seems that eleven years is a great period over which to be constructing things of both utility and beauty – like The h2g2 Post, for example.