Symbolic Forest

This is an astronomy post, but it’s also not really an astronomy post; it’s more a post about me and the way I think.

When I was small, I was terrified by the size of the universe. I can remember, about seven or eight or so, really struggling with the concept that the universe might be infinite and might not be, and I can still remember the mental picture I tried to come up with of a universe where the stars just, at some point, stopped; and beyond there was just blackness.

It probably doesn’t work like that, but still in my head somewhere is the concept that it might do. Moreover, I have trouble with another, broader concept, which is that—assuming you can travel between both hemispheres—we can “see” all of the observable universe.

“See” is in quotes there because, well, you can’t see everything for practical reasons. Most things are too faint, firstly. At any given time half the sky is too close to the Sun, too: you can’t see Mercury right now for example. But in theory, barring things being too faint, barring you having to wait for the Earth to move a bit or having to travel from one side of the Equator to the other, the whole universe is up above some point on the planet’s surface at any given time.

This probably seems tediously self-evident if you think of the planet as a ball spinning through space. For some reason, though, the whole concept still catches me by surprise occasionally. I still think that things must be able to, I don’t know, hide around a corner or something like that. I think I must have picked up the idea from a book I had as a child about Halley’s Comet, which included diagrams of where you would be able to see the comet in the sky in 1986, and talked about how comets appeared and disappeared in the sky. That’s the general tone when talking about comets and asteroids and so on: they appear in the sky and they disappear again. So it took me a long time to realise that all of the comets and all of the asteroids are up there, in front of us, all along; we just can’t see them right now. Halley’s comet doesn’t just pop out from behind a tree every seventy-five years: it’s up there in the sky the whole time, just not visible.

Halley’s comet is maybe a bad example for this. Because it’s so famous, and because of the light-gathering power of modern telescopes, we can now track it through its entire orbit. According to Stellarium it’s currently at coordinates 8h26m/+1°46’, but as it’s only a few years from perigee it’s an incredibly-faint magnitude 25.5 so will appear as a just a fuzzy handful of pixels on any photo. Nevertheless, if you go outside tonight and look up at the constellation Hydra close to its tripoint with Monoceros and Canis Minor, up there it is. As are all the others. Everything in the sky that you’re likely to see in your lifetime is already up there in the sky, just invisible and unrecognised. And despite the fact that I know this, that I know on a rough, superficial level how the mechanics of cosmology work, it still feels a little strange to me. It still feels in my mind as if there should be some patch of the sky that we can’t see, that is hiding around some sort of galactic corner.

Whenever I see diagrams of the whole sky that say “this is the whole universe”—cosmic background radiation maps, for example—I’m slightly disturbed that in some sense the whole universe fits into one small image. “Surely it must be bigger?” my mind ends up thinking. The edges trick me: that’s not the edge of the universe, it’s just an artifact of plotting a spherical sky onto a flat piece of paper, just like any sort of atlas. The mental disconnect, though, leaves me feeling deeply uncomfortable.

Really, what I feel I should inspire me here is to take away that the night sky is far more mysterious and secretive than we know. It’s not just laid out flat in front of us as it appears to be: it’s full of unknown things and unanswered questions, even though all of them are genuinely sitting right there up above us somewhere. I don’t know if I’ll ever manage to change the way my head thinks about the night sky, but if I can, there is a whole universe of wonder concealed but fully within sight.

Keyword noise: astronomy, cosmology, comets, asteroids, Halley's Comet.

A few weeks ago, I read on Twitter—sadly I seem to have lost the reference—that the Welsh Hydref, used for either the month of October or autumn as a whole, originally had the literal meaning of “stag-cry”. From that, it turned into “stag-rutting season” and hence autumn. Geiriadur Prifysgol Cymru lists “stag-rutting”, but not “stag-cry”.

Moreover, November, mis Tachwedd, literally means “the month of slaughter”. Together, I think they make a beautifully evocative phrase. The stag-cry and the slaughter. Winter is setting in.

I spent a while sitting outside on clear nights over the past week, hoping to see the Geminid meteor shower. Nothing much, sadly, came of it. On Saturday, though, I did see a handful of meteors in the night sky. I’ve always looked for summer meteors before, flashing across the sky in a razor-thin line; but these were relatively slow-moving, fat things. I say “slow-moving”: they still crossed my field of view in little more than an instant. Their light was a much broader line, though, tapering at start and finish. If nothing else, it gave me good inspiration for the story I posted yesterday. Hopefully I’ll have better luck when the Geminids come around again next year. This year, though, is now nearly at an end. The stag-cry and the slaughter, and winter is upon us again.

Keyword noise: Cymraeg, seasons, autumn, yr Hydref, meteor shower, meteors, Geminids, astronomy.

The other day I mentioned losing the Office Party and gaining various remote seasonal events instead. For example: someone thought it would be a nice idea to all have a seasonal crafting session together. Everyone who volunteered an interest was sent a small-but-festive cross-stitch kit, and then we spent a lunchtime getting together on a video call to sit and stitch for an hour, whilst the organiser explained how to get started and the rest of us found various ways to make mistakes.

Full marks if you can spot everything I’ve got wrong so far. This represents quite a bit more than one hour’s work, because I’ve spent a while working on it since. You never know, I might even get it finished before Christmas.

Keyword noise: Yuletide, Christmas, crafting, sewing, cross-stitch, colleagues.

As it is such a lovely, sunny, bright and winter day, we went out for a walk, for a picnic on Troopers Hill. The lumpy, bumpy and steep slope overlooking the Avon, crowned with a rough and slightly wonky chimney. It was busyish, not crowded, but full of groups of families, walking dogs, eating picnics and flying kites. We sat and ate our food, tried to look at the view without squinting, and watched buzzards hovering and circling over the woods.

The chimney was probably built in the late 18th century for copper smelting. Various copper and brass works lined the Avon and Frome in the 18th century; it was Bristol’s major industry, powering the city’s corner of the transatlantic slave trade. The chimney on Troopers Hill fumed to turn copper and zinc ore into brass kettles and other ware, for sale in West Africa in exchange for people, to be shipped as slaves to the Caribbean for the enrichment of Bristolian merchants. Quite a dark history for a local landmark. The brass works did not survive the end of the slave trade, as they no longer had a guaranteed profitable market for most of their products; by the mid-19th century, the copper smelters had closed. Troopers Hill was still covered by other heavy industries, though: coal mining, clay mining, stone quarrying, and a tar distillery. As the industries declined through the twentieth century, though, it slowly turned into a slightly wild and unruly green space. The chimney, though, was left looking over everything.

The council have repaired the base of the chimney, where the flues would originally have entered it, and built a little passageway into it. Inside, you can see the light at the end of the tunnel.

Keyword noise: Bristol, Troopers Hill, history, local history, archaeology, industrial archaeology, photography.

So, we’re coming to the end of a strange and challenging year. And I know it’s been a strange and challenging year, because at the office we’re in the middle of our end-of-year staff reviews and the phrase “this has been a strange and challenging year for all of us” features prominantly when summing up what’s been going on.

One aspect of this strange and challenging December, though, is something I’m actually quite enjoying. The death of the Office Christmas Party, where you and all your colleagues squeeze in to a cramped and busy restaurant for some mediocre food and the chance to pull a cracker. They do vary, of course: some are better than others. The year we went to allegedly the biggest all-you-can-eat buffet restaurant in Europe was a particular low point: at any time of the year, eating there involves so much queuing and slowly shuffling around under neon signs holding a plate that by the end of the evening you feel like an extra in a cyberpunk remake of Oliver! Wherever you end up, though, the food is never great, the music is always awful, and there are far too many people around who are very, very drunk. This was even the case a few years back when due to a double-booking mix-up we ended up having to have our Christmas Party in early November, way before anybody had even had a mince pie.

This year, though, no cramming into a crowded restaurant! Hurrah! Instead, we’re having a Remote Christmas Meal—order from wherever you like and expense it—and various other events spread through the month organised by different departments and teams. I’ve ended up booked into about four pub quizzes because quite a few teams have gone for that as a default option,^*, but there’s plenty of variety and choice, and, more importantly, it’s all optional. There are enough different Christmas activities going on that I can dip into a mince pie eating session one day, a pub quiz the next and help judge a tree-decorating competition the day after. Because it’s all optional, none of it seems at all forced.

I know a lot of you don’t really feel like remote socialising is real socialising at all; find it more stressful than the pre-2020 in-person kind of socialising. For someone like me, though, it’s a comfort to know I can just switch Zoom off and I’m back in my own room again. Even in-person, though, I’d always have much preferred this idea of a slate of smaller Christmas events that you don’t have to go to if you don’t want to, than the traditional standard Everyone Goes Out office party. Now if you’ll excuse me, I’m going to eat a mince pie and tomorrow watch someone try to disguise their cat as a reindeer. Cheers!

* In fact I’ve already won one of them at the time of writing.

Keyword noise: Yuletide, Christmas, colleagues, work, parties, Christmas parties, socialising, anxiety.

After a few weekends without touching it, I did a bit more work on the papercraft pinhole camera (previously discussed here, here and here) today. I’m sure The Children have completely forgotten that it was supposed to be for them originally.

Today was the moment that some of the key engineering parts of it dropped into place. Firstly, the film take-up spool was glued into its position.

The main stem of the spool had to be threaded through a triangular hole in a small piece of card with small flaps on the inside of the hole, and these flaps had to be glued to the spool without sticking anything to the main body of the camera, so that the spool is free to rotate. My biggest worry was not pushing that piece of card far enough up the spool, because the spool has to be wide enough to hold a roll of film. It’s one of those things we will only find out about when we try to put a film into it and wind it on, I suspect.

You can see, also, that I’ve tried to fix my earlier mistake building half the camera upside-down, by hacking at the body with a scalpel and extending the frame mask downwards a little bit. I might touch up the edge of that with a black marker.

Next, the shutter mechanism, made by laminating six pieces of card together, trapping a sliding shutter piece in the middle. The sliding piece—itself laminated from two thicknesses of card—is the rectangular piece in this picture.

When the whole mechanism is built up it’s a fairly chunky-feeling assembly, complete with a functional bayonet-mount on the back just like an SLR.

The main “pinhole”, which is a metal sheet, is then stuck in place in front of the shutter assembly with double-sided tape, and various semi-cosmetic rings of cardboard are stuck on in front of it, partly to make it look like a real camera lens and partly to hood the pinhole from glare. I’m quite pleased just how well the shutter itself seems to work, but not really confident in my cardboard-rolling ability for the next step.

Keyword noise: photography, pinhole cameras, analogue, camera, film, film photography, papercraft.

If you have a day to spare at the tail end of autumn, and the weather is all damp and misty, what better to do than go for a walk in the woods? In this case, a Forestry England wood just outside Failand, Ashton Hill Plantation. At its centre is a stand of sequoias, looking suitably mysterious in the mist. For a moment you can start to imagine you’re in some sort of supernatural horror-mystery filmed in Washington State.

However, brief glimpses of the rolling landscape outside the woods, showing off the traditional English fear of outsiders, soon remind you where you are.

Near the edge of the wood is a fairy tree, naturally beloved by The Child Who Likes Fairies, decorated with several tiny doors and various garlands and trimmings round its base. Further up, I noticed at adult head height, something that seemed much deeper, speaking directly to the fairies themselves, not there to entertain children.

A corn dolly pinned to the tree with a baby’s teething toy. Some sort of offering; some sort of old ritual; maybe some sort of prayer.

Keyword noise: North Somerset, Failand, paganism, religion, autumn, The Children, countryside, England, folk custom, giant redwoods, green space, photography, rural, Somerset, woods, sequoias.

Yesterday afternoon, sitting at my desk as dusk was falling, the skies were clear and I could clearly see the moon and Mars rising in the sky. As soon as I logged off from work, I scampered downstairs and went outside, and saw Jupiter and Saturn just visible above the rooftops at the back of the house. “Let’s get the telescope!” I said to The Child Who Likes Animals Space. “Before they set!”

“Before what set?” said The Child, but I was already rushing off to get his telescope and set it up in the back garden.

By the time I’d hoicked it out of its box, Jupiter had already gone down below the roofline, but Saturn was still there. Sadly, I could only see it when I was stood up. The telescope, sitting on a camping table, was too low down to spot it. I briefly considered setting the smaller camping table on top of the larger camping table and making some sort of rickety makeshift telescope-tower, but it would probably have ended in some sort of injury to one or both of us. So, like we’d done before, we looked at the moon, we looked at Mars, and we looked at random bright stars. “Point it at that blue thing!” he shouted. “That’s a very hot star!” This time, at least, he was a lot calmer and could stand still looking through the eyepiece without having to break off every couple of seconds to run back and forth with excitement. I experimented with holding my phone camera in front of the eyepiece. Worst. Astrophotography. Ever.

After The Children decided they’d rather go inside and watch TV I left the telescope set up; and after they’d gone to bed, the skies were still clear. Time for some telescope practice for me, I decided. Using an app on my phone to show me roughly where things were, I tried focusing on key visible stars then swinging the telescope sideways to find a nearby Messier object. The results? Not very successful, other than a possible sighting of M29, the Cooling Tower Cluster.

Getting a rough fix and vaguely hoping to spot the thing clearly wasn’t working. So, I fetched my laptop, and fired up Stellarium in Night Mode. I picked a target—the Triangulum Galaxy—and went looking for it.

Although the skies were clear, the seeing wasn’t great. Even a newbie like me could tell that the seeing wasn’t good. Vega normally stands out to me like a sore thumb, but last night it didn’t really appear any brighter or more significant than the stars of the Northern Cross to its south, which normally are noticably fainter. Nevertheless, I could see Hamal and Sheratan, the brightest stars in Aries, and could spot the telescope nicely onto Hamal and swing it between the two. Zooming in on Hamal in Stellarium, and flicking my head back and forth from the telescope eyepiece to the dim red screen of the computer, I could slowly navigate my way upwards from star to star until I reached Mothallah, which I hadn’t managed to see with the naked eye.

From there, I could similarly hop south towards the spot where the Triangulum Galaxy should be, navigating from star to star and matching the scene in the sky to the screen of the computer. But when I reached it: nothing. Just a blank patch of sky. I found Mothallah again, then worked my way across by a different route. Still nothing. The Triangulum Galaxy has been stolen!

Let’s try the Andromeda Galaxy instead, I thought, given that it’s one of the brightest galaxies in the sky. I found Mirach by eye, spotted the telescope on to it, and walked over to where the galaxy should be. Another blank patch of sky, with a faint hazy blob in the middle of it. Hurrah! A faint hazy blob!

I’m almost glad I hadn’t found it the other day when The Child Who Likes Animals had asked me to find it, because I suspect if I had he’d have been awfully disappointed. I was a bit puzzled, though, because in theory the Andromeda Galaxy is of naked-eye magnitude. I should have seen much more than a fuzzy blob, surely?

A quick note about how astronomical “apparent magnitude”, or brightness to you and me, works. It’s a relative scale based loosely on the subjective scales used by ancient astronomers, and as it’s relative it’s written down as a number without units. The higher the number, the fainter the thing is; and a difference of five in the apparent magnitude number means “a hundred times brighter”. If you have a calculator to hand you can work out that a drop in magnitude of 1 therefore means “2.5119 times brighter”.^* The star Vega, mentioned earlier, has magnitude 0, so a few things in the sky have negative magnitudes: Sirius is -1.47, Jupiter varies from -1.66 to -2.94, and Venus from -2.98 to -4.92, almost 100 times as bright as Vega.

On a good night, with a clear dark sky, the human eye should in theory be able to see things as faint as magnitude 6 or so. Last night was clearly nowhere near that: I could see Sheratan at 2.655 and Albeiro (in the Northern Cross of Cygnus) at 3, but couldn’t see Mothallah at 3.42. Through the telescope, though, I was happily stepping my way across the sky using stars of 8 to 8.4, roughly speaking, stars around 140 times less bright than the faintest I could see without it.

The Triangulum galaxy, though, is officially^** of magnitude 5.72. Andromeda is considerably brighter still, around the same magnitude as Mothallah. So what was going on?

A galaxy isn’t a point of light, like nearly all stars are. Nearly every star in the sky, other than a handful of stars like Betelgeuse when seen through very high magnifications, appears to be just a single point of light to the viewer here on Earth. A galaxy, by comparison, covers a broad chunk of the sky. That small fuzzy blob I could make out in Andromeda was really just the very brightest core of the galaxy; and the rest of that 3.4 magnitude of light is spread out over an area wide enough to fill my entire eyepiece. Through the telescope, it just becomes a vaguely paler area of sky.

Hopefully at some point we will get the telescope out on a night with rather better viewing conditions, and be able to see all of these things properly. Until then, it seems strangely unintuitive to be able to see hundreds of dimmer stars but not a theoretically many-times-brighter galaxy. That, though, is just how the physics works.

* Apparently, the formal definition “five means a factor of 100” was set down by a Victorian astronomer with what I think is a great name, N R Pogson. The relationship 1:2.5119 is therefore known as Pogson’s Ratio.

** I say “officially”. I mean “according to what I’ve just read on Wikipedia”, of course.

Keyword noise: astronomy, The Children, Saturn, Triangulum Galaxy, Andromeda Galaxy, Messier objects, magnitude, The Moon.

This is one of an occasional series of articles recounting the stories around my dad’s death from cancer in 2019, and what happened afterwards. More specifically, this post follows on directly from this one about his funeral service.

Personally speaking, I don’t have much experience of funeral services. At my dad’s I was steeling myself up to have to say thank you, afterwards, to all the people who had come along who I didn’t know at all. I remember as a child, being taken to church: the priest standing at the door as everyone filed out, shaking their hand and thanking them for coming. Somehow I had assumed we’d probably have to do the same thing, thank everyone for coming and for feeling suitably sad. Indeed, the undertakers asked if we wanted to stand outside the church and speak to the other mourners. The Mother, though, wasn’t ready for anything like that. She wanted us to get going as quickly as we could.

“As quickly as we could” is a bit of a misnomer for a funeral, of course. The Rector at The Mother’s church had already told us she liked to lead processions from the church to the cemetery on foot. At, it turned out, a fairly glacial pace, one step at a time. The cortege followed, and I tried to carefully drive at a matching pace without accidentally rear-ending the hearse. We crept through the village lanes linking the church and the cemetery, waiting at junctions for passing traffic, watching old men stop and remove their hats as we passed. The whole journey was well under half a mile, but it felt like an age.

Naturally, the rest of the extended family had all reached the cemetery well before us, and had all half-blocked the lane outside the cemetery with their cars to some distance either side of the cemetery gates. Not exactly knowing what to do, and with the limousine carrying my father’s frail sisters right behind us, I blindly followed the hearse through the cemetery gates and up the path. We just fitted through: but of course we did, you have to be able to get a hearse into a cemetery after all. We sailed slowly up the single path that runs up the middle of the field. The village cemetery is nearly full, with only a few spaces left available to people who lived within the bounds of the parish,^* so my dad’s grave was tucked away down at one corner at the far end, a mound of wet clay marking it out. Hand-dug by a professional artisan gravedigger, because the parish council has put a ban on mini-diggers. My mind naturally wondered if this would be a selling-point in Bishopston or St Werburghs.

We gathered around the muddy hole, its edged protected with fake turf. When all of us were in place, everyone decanted from their cars, the pallbearers carefully carried the wicker coffin over and solemnly lowered it into place. The Rector said her piece, and we scattered soil; then, one by one, flowers from a bunch of white roses. The undertaker had suggested this idea, “but don’t buy them from us,” she’d said. “Go to a supermarket before the funeral and pick some up, it’ll be a third of the price we charge.” So we had dutifully stopped off at Morrisons on the way there, for a bunch of white roses to be thrown into the grave. I took them round the mourners, offering them out to my various aunts and uncles and cousins in rough order of consanguinity downwards. Behind the hedge at the edge of the cemetery, a horse started neighing. The Child Who Likes Animals was trying to get away and look for bugs and minibeasts in the undergrowth.

I took out my phone, trying to be relatively discreet, and took a photo of the coffin lying in the grave with soil and roses scattered on top. The last one. Soft rain had started, and the relatives were all heading to their cars, ready to head off to the waiting buffet over on the other side of the village. The bespoke artisan gravediggers were, I assumed, hiding somewhere round the corner ready to start their hand-shovelling as soon as was tactful, as soon as we were all out of sight. Loading the family back into the car, I gingerly reversed back down the path and out to the lane, dead slow lest there be any elderly relatives directly behind me. It wouldn’t really do to drive over somebody at a funeral.

* If you already own a plot but want to open it up to add another body, then the village council charges you about fifteen times more if the new body comes from outside the parish. Can’t be doing with outsiders moving in for eternity, I assume.

Keyword noise: death, funerals, The Children, The Father, religion, cemetery, burial.

The other day I mentioned The Children have just turned seven. As The Child Who Likes Animals has spent quite a lot of time in recent months liking space instead, watching Brian Cox’s The Planets innumerable times, memorising lists of dwarf planets, Kuiper Belt objects, centaurs and so on, and learning the difference between a red dwarf, a white dwarf and a brown dwarf. We decided, therefore, that it might be a nice idea for The Mother to get him a telescope, as a suitably grandmothery sort of present. Not trusting The Mother to judge what might be suitable, I reached out to a few astronomers I know for recommendations, and found something that both fell into The Mother’s budget and had a reasonable chance of imaging the rings of Saturn. The number of times I’ve looked down a telescope myself before can be counted on the fingers of one hand; but if I was age seven, was given a telescope, and found that it couldn’t show the rings of Saturn I’d be terribly disappointed.

Of course, I messed up to a certain extent. I’m sure I achieved my objectives, but there’s no way really that The Child Who Likes Animals would be able to actually point the telescope at something himself. So, this is going to be the sort of present that one of his mums sets up in the garden on dark nights; find out what he wants to point it at; try to point it; and then he looks down the eyepiece. Naturally, it becomes a family event, with The Child Who Likes Fairies also wanting to get involved.

As I said, I’ve hardly ever been near a telescope before, despite having books and books on astronomy when I was that age myself. So, on the few nights we’ve had so far when the cloud has at least been broken rather than blanketing, it has gone something like this: I set up the telescope outside. A child asks to point it at something, in a brief pause for breath whilst running around with crazed excitement. If it is an easy thing—the moon, say—I contort myself to the right angle to try to see through the finder, point the telescope and roughly nudge it about until we can see what we’re looking for, all the time with said thing bouncing up and down in the eyepiece as children bounce up and down on the decking. A child then steps up, instinctively grabs the telescope and knocks it out of alignment, and we go back to square one.

Eventually everyone has seen what we’re looking at, and one of them will name something else. I try to work out how to find it, with my laptop and a copy of Stellarium. I fail to find it, and end up sawing the telescope back and forth across the sky desperately trying to find the thing they have asked for. I try again with the finder, drape myself over the telescope and twist it around until the red finder dot is in just the right place; then look through the eyepiece and see nothing but haze. I look up at the sky again, and my target patch of sky, clear a few moments before, is suddenly covered in thick cloud. This cycle repeats a few times, until we either look at the moon again instead, or The Children get bored and go back into the house.

So far, we’ve successfully looked at the moon, Mars, and some random patches of sky that have lots of stars in but nothing I can actually put a name to. Oh well. I’m sure at some point we will get the hang of it, even if I end up becoming the main telescope user myself. It certainly has shown me just how non-empty an empty-looking patch of sky actually is, even living in a hazy, foggy, light-polluted city like this one. I’ll let you know if I manage to find anything less easy to spot. Or, indeed, if we do ever see the rings of Saturn.

Keyword noise: The Children, astronomy, failure, beginners.