Category Archives: Astronomy

Moon Shadow

In which The Author digs out an old book

A couple of weeks ago, one of my Facebook pals shared a link about an eclipse in the UK this month. I hadn’t seen any mention of it myself, so I decided to look into it. There is in fact an eclipse due, on Friday 20 March, just two days after my birthday. I wondered why I hadn’t come across it in my old copy of The Guinness Book of Astronomy Facts and Feats (2nd edn) by Patrick Moore, published in 1979. (He was plain old ‘Mr Moore’ back then, by the way.)
The answer turned out to be more straightforward than I’d thought. Sir Patrick’s listings stopped at the total eclipse of 11 August 1999. It was logical enough, I suppose, to declare a cut-off point at the end of the century, rather than spend pages and pages listing all the forthcoming eclipses for decades to come.
Eclipses are more common than you might think. In fact, the maximum possible number in any one year is seven, made up of solar and lunar eclipses. As Sir Patrick himself pointed out, ‘in 1935 there were 5 solar and 2 lunar eclipses, and in 1982 there will be 4 solar and 3 lunar’.
Of course, whether you get to see any of them depends on a combination of factors. Your own location on the Earth’s surface is the key to how much you’ll get to witness. I vaguely remember standing in the yard of Comin School in Trecynon, looking into the sky through a piece of smoked glass. I think that must have been the partial solar eclipse of 11 May 1975, when I was nine years old.
Here in the UK we didn’t get any more Moon-on-Sun action until the summer of 1999. This was really exciting, because it would be a total eclipse – always assuming that you were right at the south-western tip of Cornwall at the time. Here in South Wales, we could look forward to about 95% totality.
Even though I knew I wouldn’t be anywhere near Lands End, I swapped a day off work (it was a Wednesday) for the occasion. I left the house in good time and took my little viewer up to the playground near the old Dare-Aman Line, where a gang of local kids had gathered to watch it for themselves. We spent our time passing the viewer around, taking turns to watch the eerie spectacle of the sun gradually being nibbled away. The birds stopped singing and it quickly became much cooler as the shadow of the moon advanced across the solar disc. I sketched out a quick diagram on a piece of paper to show what was happening, and the whole occasion turned into an impromptu science lesson.
Next Friday’s eclipse is also set for fairly early in the morning. Always assuming it doesn’t piss down, I’ll probably head for high ground and take my viewer with me again. I might even try and set up a camera obscura and photograph the solar disc at various stages. That had been my plan on the previous occasion, but it was far too breezy. We’ll have to see what happens on the day. Unlike eclipses, we still can’t predict the weather with any reasonable accuracy.
According to Sir Patrick,
The first known prediction was made by the Greek philosopher Thales, who forecast the eclipse of 25 May 585 BC. This occurred near sunset in the Mediterranean area, and is said to have put an end to a battle between the forces of King Alyattes of the Lydians and King Cyaxares of the Medes; the combatants were so alarmed by the sudden darkness that they concluded a hasty peace.
Here, for your entertainment and edification, are some more highlights from his book:
The longest possible duration of totality for a solar eclipse is 7m 31s. This has never been actually observed, but at the eclipse of 20 June 1955 totality over the Philippine Islands lasted for 7m 8s.
The shortest possible duration of totality may be a fraction of a second. This will happen at the eclipse of 3 October 1986, which will be annular among most of the central track, but will be total for about a tenth of a second over a restricted area in the North Atlantic Ocean.
The first recorded solar eclipse seems to have been that of 2136 BC (22 October), seen in China during the reign of the Emperor Chung K’ang. The Chinese believed that eclipses were due to an attack on the Sun by a hungry dragon, and they endeavoured to scare the dragon away by making as much noise as possible. (It always worked!) There is a story – probably apocryphal – that on this occasion the two Court Astronomers, Hi and Ho, were executed for their negligence in failing to predict the eclipse.
The first official American total eclipse expedition was that of 21 October 1790, when a party went to Penobscot, Maine; it was led by S. Williams of Harvard, and was given ‘free passage’ by the British forces, but unfortunately a mistake in the calculations meant that the party remained outside the track of totality!
The only emperor to have died of fright because of an eclipse was Louis of Bavaria, in 840 (his three sons then proceeded to engage in a ruinous war over the succession).
The only astronomer to have escaped from a besieged city in a balloon to study a total eclipse was Jules Janssen. The eclipse was that of 22 December 1870, and Janssen flew out of Paris, which was surrounded by the German forces. He made his way safely to Oran, but clouds prevented him from making any observations.
The longest totality ever recorded was during the eclipse of 30 June 1973. A Concorde aircraft, specially equipped for the purpose, flew underneath the Moon’s shadow and kept pace with it, so that the scientists on board (including the British astronomer John Beckman) saw a totality lasting for 72 minutes! They were carrying out observations at millimetre wavelengths, and at their height of 55 000 feet were above most of the water vapour in our atmosphere, which normally hampers such observations. They were also able to see definite changes in the corona and prominences over the full period. The Moon’s shadow moves over the Earth at over 3000 km/h.
The first attempt to show a total eclipse on television from several stations along the track was made by the BBC at the eclipse of 15 February 1961. The track passed from France into Italy and Jugoslavia, and thence into Russia. The attempt was successful; totality was shown from St Michel in France (commentator, Dr Hugh Butler); from Florence in Italy (C. A. Ronan); and from the top of Mount Jastrebec in Jugoslavia (myself). This must also have been the most peculiar way in which a television commentator has spoken to the technical crew. I talked French to a Belgian astronomer, who relayed it in German to the senior Jugoslav, who passed it on to his companions in Serbo-Croat. This was no doubt why, at one stage, we showed pictures of mountain oxen chewing the cud rather than the eclipsed Sun!
I doubt whether next week’s eclipse will produce any stories as interesting or bizarre as those.
But you never know.
On the morning of 11 August 1999, I bumped into an old hippy mate of mine from the Carpenters days – a casualty of heavy alcohol and drug abuse during his younger days – walking his dog Poppy along the line. Later that same morning I saw him wandering through Aberdare – on his own.
My first thought was, ‘Oh, no! He’s sacrificed Poppy to bring back the warm yellow god in the sky!’

Here Comes the Sun

In which The Author has more technical problems

I made several fruitless attempts, spread over a two-hour window, to get online in Aberdare Library this morning and afternoon.
Regular readers won’t be surprised to learn that, of course. The ongoing piss-poor wifi provision in what should be the one place where it is available in this technophobic town is a regular bone of contention for me. Just a couple of weeks ago, I emailed my local councillors within Rhondda Cynon Taf CBC to bring the problem to their attention. So far, only one of the three has had the courtesy to reply. Kudos to Cllr. Ann Crimmings of Aberdare West for taking the time to look into the situation. (Mind you, given the local population’s three-tier technical hierarchy, which I’ve discussed in I Want to Believe and elsewhere, it’s quite possible that the other two have yet to check their emails.)
When I first mentioned the lack of signal to Steven G., he told me that he’d already rebooted the server once this morning, about half an hour before I arrived. It hadn’t done any good, evidently, as the network steadfastly resisted all my attempts to log on. Steven vanished into the main office and returned a few minutes later, looking even more harassed than usual.
‘They’ve done something, so it should work in a few minutes,’ he told me. (Do you see how lightly the technical terms trip off his tongue?)
Anyway, I waited five minutes or so, tried connecting again, and didn’t even get the login screen which you need to negotiate first. By now Steven had gone for his lunch, and Judith was sitting at the desk. I decided that I wouldn’t mention the problem to her. I’d already earned a place in her bad books on my way into the building.
As part of the ongoing de-accessioning process in Rhondda Cynon Taf (see A Turn-out For the Books), the library service has decided to sell off pretty much its entire stock of CDs and DVDs. They were stacked up on trestle tables in the recess by the main doors, and Judith and Aled were standing nearby while a couple of people browsed.
‘Aye aye?’ I said casually, ‘the closing down sale’s started, has it?’ Judith gave me a sour sideways glance, and I followed it up with, ‘Oh, sorry – that was in rather poor taste, wasn’t it?’
Actually, Aberdare Library should be fairly safe from the first wave of public service cuts which RCTCBC are planning. For now, anyway. The same can’t be said for the smaller branches (see A Further Turn-out For the Books), hence the ongoing stock clearance.
[A digression: Martin H. and I had a closer look through the sale tables when we were leaving a couple of hours later. It occurred to us that we must be part of the first generation of humans who have lived through an entire wave of technology, right from its inception to its virtual obsolescence. We can still remember the birth of CDs in the early- to mid-1980s. We saw TV presenters rolling them across the studio carpets, and even smearing jam on the playing surfaces, to demonstrate their resilience in the face of adversity. (Little did we know that the smallest speck of fluff or partial fingerprint would fuck things up badly.) Now, just about three decades on, we’re seeing their slow death, as downloads and online listening replace the physical object altogether.
In Snap, Crackle and Pop I wrote a long piece about vinyl records, and the altogether different experience involved in the acquisition of music in those days. It’s somewhat ironic, therefore, that my own vinyl collection is pretty much redundant following the failure of my stereo system. Just over a week ago, to thank me for being there (almost) at the start of the whole story, Andy Tillison very kindly sent me a zip file containing Gold, Frankincense and Disk Drive’s newly-reissued debut LP Where Do We Draw The Line? (see Our Friends in the North.) I haven’t been able to listen to it since the technical breakdown.
Ironically, Andy had had to remaster the tracks from another surviving vinyl LP and encode them digitally to get them out to a new audience. It’s not quite gone full circle, but it’s still well over 180º from where we started.]
Anyway, I gave up trying to access the Library’s wifi and tried using the MyFi instead. For some reason, I got a signal, but once again it failed to connect. I know my thirty day data allowance is due to run out (in fact, I’m pretty sure it expired yesterday), but I couldn’t even access the website to buy more data. Fed up, I decided to resort to Twentieth Century technology instead, and spent quite a while looking through the Aberdare Leader microfilm archives.
I thought I’d find a piece in there from late February or early March 1982, when Dad resigned from the local council. I found a brief item from the Western Mail, but although I scoured the news pages right from the January snowfall to the Easter school photos, I drew a blank. Maybe I’ll try again in another twenty years or so, when the ongoing process of digitisation and online cataloguing reaches the 1980s.
Martin came in, so we decided to repair to the Prince for a glass of Coke and to warm ourselves by the fire. While we were there, the BBC News Channel showed a picture of a large solar flare. It might have been CGI, or it might have been actual data gathered from a space probe somewhere in the cosmic gloom. (The sound was off, so we had no way of knowing.) But it reminded me of something which Billy, another of Aberdare’s legion of technophobes, keeps bringing up when he’s had a few pints.
Nigel Calder wrote a book a good few years ago called The Manic Sun. I haven’t read it, but Billy has, so he’s given me (and anyone else who’ll listen) the gist of it. In a nutshell, Mr Calder’s book predicts massive solar flare activity which will play havoc with the Earth’s weather and telecommunications systems. I picked up something similar last week on a couple of websites. Apparently some scientists think that the Sun’s magnetic field is due to flip over any time now.
We’re certainly going through a period of extreme weather at the moment – the first wave of aid has just reached the more remote areas of the Philippines, where Typhoon Haiyan made its devastating landfall just under a fortnight ago. There was also a huge volcanic eruption in Indonesia soon afterwards. In the words of Private Eye magazine – are they possibly related? I think we should be told…
Anyway, I gave up trying to top up the MyFi while I was listening to the evening news. I listened to I’m Sorry I Haven’t a Clue and then came to the pub to use their wifi. I’ve checked my emails, checked Facebook, and (most importantly) I haven’t missed a day of NaBloPoMo. It was a close-run thing. I might not bother topping up this fortnight after all, and come here to use the wifi instead. It’s a lot warmer than my house, for one thing.
However, there might be even more unanticipated consequences of all this solar activity. John Finnemore was the fourth member of the Clue panel in their opening shows recorded at Weston-super-Mare. Hitherto, Mr Finnemore’s radio outings (as writer and/or performer) have epitomized the sort of unfunny ‘new comedy’ which I outlined in No Laughing Matter.
Tonight, things were very different. First, he made me laugh out loud several times, especially during his first attempt at Mornington Crescent, where he really threw himself into the nonsensical spirit of the game. Even better, he proved himself to be the new champion of Pick Up Song, finishing within much less than a gnat’s crotchet of the original record.
Has the manic sun re-engineered Mr Finnemore’s cerebral cortex and somehow made him capable of great comedy moments? Or has it just fried my brain? Watch this space…