Out with a bang

So that's that then. The season of Edinburgh festivals is over for another year. It ended, as it always does, with an exhilarating firework display to music on the castle rock. There can surely be few more dramatic settings for such a show, and for those not fortunate enough to have tickets to Princes Street Gardens the city centre has many fine vantage points from which to coo and gasp. This year, in keeping with the theme of the International Festival, the music was chosen for its eastern flavours; the composers, mostly Russian, drawing their inspiration from the Orient. Each year the most appreciative cooing and gasping is reserved for the waterfall, a magnesium white cascade that tumbles and bounces down the bare black rock.

For me the Firework Concert is one of those punctuation marks in the calendar by which time is notched. Whatever the weather it signals the end of summer. As the echoes of the last detonations fade, as the streets clear of spectators and the convoys of road sweepers get to work, there is no longer any denying it - autumn has been heralded in. The concert starts at nine o'clock. A month earlier and it would have been unthinkable to start so early but by now the days are shortening alarmingly. Our wobbly Earth has lurched onwards, like a homebound drunk, veering to the winter side of the street

By Monday morning the streets had returned to normal and Edinburgh's daily traffic of suited commuters and shoppers and schoolchildren went on their way. The city is never without tourists but things get decidedly quieter for a while after the fireworks. At Haymarket railway station and in the queues for the airport shuttle it suddenly seemed as if everyone was heading for the exits. And just as suddenly it again becomes possible to book a table in a restaurant and the buses run more or less to time without throngs of disorientated sightseers asking for directions. It doesn't last long. There is just time to draw breath before the first Christmas displays appear in shop windows. No sooner has the temporary seating on the Castle Esplanade - for the past month home to the Royal Military Tattoo - been removed than the skating rink and big wheel will arrive in the gardens. And so the Edinburgh year rolls on.

Invariably the tourists I meet seem genuinely wowed by my home city. They have travelled the globe to be here and Edinburgh doesn't disappoint. Despite the weather doing its level best to rain on everyone's parade, despite the eyesores of the perennially stalled tram project, and the rash of lowest-common-denominator gift shops selling every imaginable Scottish cliché, despite the litter and traffic and scaffolding and street clutter, they are left with an overwhelming impression of an elegant city. I feel very proud and privileged to sit with a coffee in the Canongate, or to stroll along the Water of Leith to Stockbridge and be able to say 'I live here'.

Edinburgh is a wealthy city. But much of its money is sterile and corporate, sealed off behind faceless legal and financial institutions. Tourism brings money too, lots of it. But more importantly the tourists bring vibrancy and colour and life. During the summer festivals the streets are buzzing with their excitement. There's a certain class of Edinburgh resident who gets very sniffy about the festivals but I am not one of them. Of course there's plenty of mediocre art among the thousands of shows on offer, some of it very hammy, some of it pretentious and excluding, but there is also a lot of fun, energy, talent and idealism to be found.

So, summer 2011 goes out with its traditional bang. It won't be long before next season's programmes start arriving through my letterbox. All those things to choose from and all on my doorstep. That's something I hope never to grow complacent or nonchalant about.

The unruly sun

'BUSY old fool, unruly Sun,
Why dost thou thus,
Through windows, and through curtains, call on us?
Must to thy motions lovers' seasons run?'

From The Sun Rising  John Donne

Today is Midsummer's Eve and for days the local newspapers have carried advertisements from country hotels inviting us to bonfire parties in their gardens. In true Scottish tradition the thunderclouds have been brooding all day but no doubt the venues are well prepared with marquees from which spectators can enjoy their rib roast and solstice-themed cocktails while staying dry.'Experience all the excitement of a real Celtic fire festival!' one advertisement enticed. I suppose in these challenging times they can't be blamed for trying but it was tempting to let them know that Midsummer bonfires have little to do with the Celts. While undoubtedly pagan, the parts of Britain with the strongest traditions of bonfires in June are Norse or Anglian, not Celtic.

So Midsummer is upon us, that curious time after the solstice when the sun, at the extreme limit of its station, appears to hover unmoving and undecided in the sky, rising and setting at almost the same time each day. It is, after all, what the word solstice means, from the Latin solstitium, or 'sun-halting'. Like its counterpart at the other end of the year, 24 June has been conveniently commandeered by the Christian calendar as the Feast of John the Baptist who, the Gospel of St Luke tells us, was born six months before Christ and 'jumped in the womb' on learning of the Virgin's conception.

At school we learned that the summer solstice occurs each 21 June and like much else we learned at school, while generally true it is not universally so. In fact the solstice may fall on 20 June (as it last did in 2008) and may be as late as 22 June (although this last occurred in 1971 and won't happen again in any of our lifetimes). This year, in Britain, it fell a little after 6.16pm on the date my school approved of, although those of us living in the northern half of the country could be forgiven for not noticing as it poured with rain and barely seemed to get light all day.

The mathematics behind the precise calculation of the solstice is complex, so perhaps my school should be excused for wanting to keep things simple. But I can't help thinking the lack of punctuality exhibited by something as big as the sun would have been a cause for some consternation among my teachers. It was hardly setting the right example!

With the mixed blessing of hindsight, it seems now that much of my schooling was a sequence of learning and unlearning in this way. We were taught absolute truths only to have them dismantled a term or two later once we were deemed ready for subtler lessons. Thus we learned that electrons orbit around the nucleus of an atom in distinct 'shells', so many electrons to each. Our calculations of valency and compound formation relied on this certainty. Well, no actually, it's not like that at all.

It wasn't so bad a preparation really. The rest of my life, too, has involved as much unlearning as learning. But the trouble with unlearning is that it is often painful, reluctant and incomplete. We don't like to let go of what we thought we knew. We don't want to hear that Shakespeare didn't write every word of his own plays or that Columbus didn't discover America, or that water doesn't go down the plughole the opposite way in the southern hemisphere any more than we don't want to hear that our friends will sometimes let us down or our government doesn't have our best interests at heart.

Anyway, I digress. To get back to the solstice, the problem (if indeed that's how we choose to see it) of the unreliable timing isn't anything to do with the sun. The Earth wobbles on its axis like a spinning top, its orbit is disturbed by the gravity of other planets and, above all, our calendar is just not clever enough. An average orbital year is 365.242199 days. Our Gregorian calendar gets as close as it can. Its sophisticated cycle of leap (intercalary) days in years divisible by four, but not if they are divisible by 100 unless they are also divisible by 400 (still with me?) is a big improvement on its Julian predecessor. But it still means we'll be about a day awry every 3,300 years. Further refinements have been proposed but never adopted, perhaps because a further consideration then comes into play, the spinning of our Earth is slowing down so days are set to get longer!

But that's quite enough arithmetic. Celtic or Norse, Julian or Gregorian, our forebears knew better than to reduce the solar calendar to mere numbers and fractions and we should follow their instincts. Sunsets and sunrises remain high on may people's lists of their most memorable experiences, eclipses and other solar special effects even more so for those lucky enough to see them. We may no longer be attuned to the stations of the sun quite as we once were but there's no questioning the power of our own private star to stir wonder and awe in us.  I'm sure gatherers at damp hotel bonfires will have a good time this evening whether the skies are clear or not, but I wish them at least a glimpse of the star of the show.