Halcyon days are here again

'The Gods their shapes to winter-birds translate,
But both obnoxious to their former fate.
Their conjugal affection still is ty'd,
And still the mournful race is multiply'd:
They bill, they tread; Alcyone compress'd,
Sev'n days sits brooding on her floating nest:
A wintry queen: her sire at length is kind,
Calms ev'ry storm, and hushes ev'ry wind;
Prepares his empire for his daughter's ease,
And for his hatching nephews smooths the seas.'

from the Metamorphoses of Ovid translated by John Dryden et al

The storms of the past few weeks have blown themselves out for now, and in their place is the pellucid stillness of the approaching shortest day. The Halcyon Days are here, the name given to the weeks either side of the winter solstice when the wind dies and the sea flattens.

The Greeks of antiquity told a tale of a bird of light that made a floating nest on the sea each midwinter. The tale survives in Ovid's great poem Metamorphoses. He relates how, out of grief for her drowned husband, Alcyone threw herself into the sea but was lifted up and turned into a bird by the gods. Husband and wife, both now birds, are reunited and each winter build a nest on the sea to lay a clutch of eggs. It is fortunate that Alcyone's father, Aeolus, is the keeper of the winds and they are held in check for the seven days it takes for the eggs to hatch.

The bird of light is most usually identified as a kingfisher and this is recalled in its generic name Alcedo, a latinised form of the Greek Halcyon. It is perhaps a strange coincidence that midwinter is the time of year when kingfishers are most likely to be seen at our coasts, when the inland rivers where they usually fish may be frozen. And whatever the truth of Ovid's tale, it is certainly the case that the solstices, the pivots of our solar year, are more often than not periods of welcome tranquility in our generally unstable weather.

Halcyon Days: winter calm on the Dundee waterfront

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.