Ex Die in DIEM

by duncan mcnicholl

The Slope

There’s a hill, or at least a slope, and when we walk through our lives it’s the slope that we walk. For the most part we’re following along the side, like a contour canal or a railway, and we meander back and forth to stay at the same height but keep moving.

We can’t stay still, and if we climb too high then the air gets thin and we start to lose touch with what’s going on back down there on the path. But it isn’t climbing high that’s been my problem lately, I don’t think.

Sometimes when you’re hiking and you try to stay level you come across a patch of scree or loose earth, where the sheep have grazed to bare soil and what earth there was has blown or washed away. If you’re sure-footed, you can navigate these patches, slow down and step carefully and get through it without sliding down too much. But that kind of walking is tiring and requires concentration and focus of the sort that you can’t alway manage, especially when you’re trying to juggle all of the other things you have to do while you walk. We can hope that as we get used to the juggling, as we practice it on the firmer ground it will become easier and easier, taking less attention away from walking, away from keeping that all-important footing.

There’s an element of grace to juggling.

In a beautiful essay called On the Marionette Theatre, Kleist explains that grace is a fickle thing: we can often do things by feel quite confidently, until we try to think about what we’re doing, at which point it quickly collapses and requires hard work and wisdom to regain. That’s the way it is with juggling, I think: we get used to it, and happily manage it as we walk along, but when we drop a ball or lose our rhythm, it’s back to the beginning and suddenly we need all of our focus just to keep the balls in the air, and now there’s nothing left with which to navigate.

But that’s only if we drop the balls, if we lose our rhythm. And what could cause that kind of thing to happen? Well, slipping and falling.

Because the thing about scree is that you can lose your footing so easily, but when you do it’s not just you that slips and falls a little, the scree goes with you, grinding a miniature gravel avalanche down the slope and taking you with it. And then you pick up your juggling balls, and you start to climb, and you start to juggle. The climbing is easier when you keep the balls and your arms still and out in front holding your balance on the climb, but that’s a luxury you can’t always afford. Even when you can, the climb can be so difficult: two steps forward, one step back as the slope shifts and slides underneath you, and you have to keep trying to climb, no matter how tired you are, because if you try to just stand still and catch your breath then maybe the slope will slip anyway, and instead of staying where you are you’re falling again, and you can’t tell if you’ve dropped a juggling ball or not: did you have four? No, I think it was three. It’s always been three, right?

Except no-one else was keeping track: they’re you’re balls, not anyone else’s. It’s not that they don’t care, it’s just that they have to keep track of their balls, and the juggling, and the walking.

And so maybe you’ve fallen, and you didn’t always try to climb because you were just tuckered out from the slide, and now even when you can keep the juggling going and even when you’re climbing, you still can’t quite remember what the path looked like, what it felt like to be up there on the contour, and you know that you have to keep it up if you want to be there again, but you take two steps and you slide back and you take another two and there’s another slide and it all just feels a bit too much, a bit too hard.

But you can pause. You can take a breath and look around and see that we are all on the slope, that we are all still trying to climb, some of us juggling, some of us with our heads down and our hands out, some of us falling and sliding. The people up there on the path, some of them went too high and had to come back, some of them have managed to walk that path all along, but some of them were down here in the gravel, and they climbed back up, maybe with help, maybe without. Maybe they have advice. Maybe they know how to help.

Maybe they just know that we’re all on the slope.

The Slope was published on a

Intercontinental

So this is overdue, but I went to America.

Intercontinental was published on a

Prestressed

If you want to build a bridge of any significant size these days, you’re going to be using at least some prestressed concrete to do so. Concrete’s great stuff for big buildings, you see: strong, relatively light, and very very easy to work with. You can simply pour it into an appropriately shaped mould and produce whatever shape you want, ready to be slotted into place in your structure. You can even cast it in place, building temporary walls around the volume you want your edifice to occupy and then filling it up, letting it set and voilà: a big old chunk of building.

The problem with using straight-up concrete is that it’s frustratingly asymmetrical: it is great when you press in on it, but tends to crumble if you pull it apart. In slightly more scientific language, it is much stronger in compression than tension. That’s where the prestressed part comes in: if you want your concrete part to be strong when it has an adverse load on it, sometimes you have to make sure that there’s a load on it before you even finish making it.

There are a couple of ways of forming prestressed concrete, but the coolest is to make a mould and then stretch steel cables inside it, with the stretched ends poking through holes so that you can maintain the tension while the concrete hardens. Once you’re all set (pun completely intended), you break down the mould and cut the steel cables flush with the new concrete surface. Removing the tension on the cables makes them contract, putting a compressive load on the concrete. Remember, concrete does well under compression, so what we have now is a component that’s already filled with stresses, but importantly with stresses it can deal with comfortably.

When you subject prestressed concrete to tensile loads in the stressed directions, the overall load remains compressive, and so the concrete doesn’t fail in use. It’s a cool technological magic trick, and it means your bridge will be both beautiful and deeply functional, as long as no one removes the steel.

I don’t think concrete is the only thing that does better with one kind of load than another: I do too. If you need my help, I will always do my best to give it to you, but if I need my help, I often find that I don’t know what to do. I’m quite good at getting myself stuck in the mental equivalent of a tailspin, going round and round and round with no way to manoeuvre myself back onto an even keel, and despite my experiences I’m often at a loss for what to do.

So I think what I’m trying to say is that the best preparation for surprises that I’m ill-equipped to deal with is to prestress my mind. If I can find people who will rely on me at least some of the time, and seek out opportunities to help them, I think that that will help me stay anchored and steady when the rough winds come.

Prestressed was published on a

Angular Momentum

As part of the permanent collection at the Glasgow Science Centre, there is a circular platform which is mounted on ball bearings to allow it to turn easily. Attached to this platform is a bicycle wheel mounted by its hub, allowing it to be spun up to a nice high speed and then tipped from side to side. The whole setup is there to help people to understand the conservation of angular momentum: when the wheel is spinning and you try to tip it, the entire platform on which you are standing rotates in such a way angular momentum of the wheel, the platform and you is conserved.

You might have been given the chance to play with a similar setup at a science museum or science festival, or perhaps you’ve seen its close cousin, a freely revolving office chair and some weights, where the occupant of the chair holds the weights out to their sides while someone spins them, and can hugely increase the rate of spin by pulling the weights in towards themselves. It’s a lovely demonstration, but doesn’t have an immediately obvious use.

Esoteric uses abound, however: modern ships use something good called a gyrocompass which operates along similar lines, maintaining its orientation as the ship turns around it and so providing a reference for navigational purposes. The International Space Station and a variety of space telescopes use reaction wheels or control moment gyroscopes to efficiently change (or maintain) direction in space, allowing long exposure photography or uninterrupted communications to occur. The ISS is really using the gyros to ensure that the most robust part of the station faces in the direction of its orbit to increase its chances of survival in the chaos of low earth orbit, but the principal is the same.

It’s not just angular momentum that we store in wheels, though: we can use them to store energy too. Sometimes this is on a very short timescale, like a flywheel on a reciprocating engine absorbing the excess energy from a piston stroke and returning it to the crankshaft when the piston is idle, and sometimes it is over a longer period, such as when it is used to provide very high currents in fusion reactors, or as grid energy storage for load-balancing electricity grids.

On of the coolest uses of a flywheel for energy storage, however, was the KERS used in formula one starting in the 2009 season. It sucks up kinetic energy under braking, and adds it back to the driveshaft under acceleration, giving a power boost without using any extra fuel. The rules don’t say that KERS have to be flywheel based, and in fact all of the teams now use electrical systems instead which is sad from a mechanical engineering standpoint. The reason for the move away from flywheels is essentially that in a crash, nobody really wants a deliberately heavy chunk of metal spinning at sixty thousand rpm to come flying out of the car and tear its way through walls, the track and the crowd.

And now we’re getting to the point I wanted to make, I think. Sometimes it feels like there’s a part of our brain – or maybe heart – that acts like a flywheel. We spin ourselves up and up, even sometimes without realising what we’re doing, but adding more and more speed with stress and worry and anxiety, or fear and anger and confusion, and the flywheel just gets faster and faster and faster.

And with this flywheel spinning away, we end up trapped, in a way: all of that angular momentum means that we can’t turn or alter our path, even when we know that it’s the best thing to do, even if we think that the only way to dispel the momentum is to take a break, or break into a new heading, change our point of view in search of some clarity. And if that happens, you can end up on a collision course, unable to turn away as you barrel into events and interactions that would leave you battered and worn under the best of circumstances. Except these aren’t the best of circumstances.

If you come off the rails and crash with that great flywheel humming away inside of you, full of restless energy and everything you’ve been absorbing and not dealing with, all of that momentum that has nowhere else to go, and the whole thing might just drag its way out, tearing you up as it crashes through you, and spinning off to cause chaos while all you can do is watch.

And that’s why it’s so important to make sure that your flywheel isn’t carrying too much load, and to be aware of it, and keep it in check while you still can.

Angular Momentum was published on a

Cleopatra

I’ve read the script, and the costume fits
So I’ll play my part

Cleopatra was published on a

Understanding

It’s a big world, and it’s full of people. 510,072,000 square kilometres, and seven point four billion persons, respectively and roughly. But that’s never what we mean when we say that it’s a big world, or a small world, or a strange world. We’re always talking from our personal experience of the world, and that experience is different for each and every one of us.

There are shared experiences, of course: working together, or learning together, or spending holidays together. In many ways, a family is a group of people with shared experiences, who have spent time together and who know how the rest of the group think and what each has been through. That fluid definition explains how someone might feel like they have a sister even though their mother had only boys, or how a family unit can change and grow over time, absorbing and incorporating beloved additions. As Large puts it in Garden State,

Maybe that’s all a family really is: a group of people who miss the same imaginary place.

But from the time you leave for school, even your family don’t know you completely: the only person who has taken your journey is you, and you’re the one person who gets every little part. Of course, it’s often the case that there’s someone out there who will understand an individual piece: my school friends might be unsurprised to find me listening to Avril Lavigne on the bus home, and my colleagues from when I lived in Cambridge know why my Cards Against Humanity deck includes a card just marked “Karen Lonsdale”.

And if you’re very lucky, there might be someone with whom you share everything: not just the experiences of the present and the hopes of the future, but slowly and surely all the nooks and crannies of your past: the events, the books, the films, the music and the conversations. This sharing of the whole of yourself is one of the most profound experiences you can have, and upon realising that you can even share the profundity. And so the feeling grows.

Love is always about understanding, even if sometimes it’s just about having faith that understanding will come with time.

Understanding was published on a