He used maths*, Alan was British.
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Alan Turing using math to repair his bike
21–30 of 69 posts
Re: Alan Turing using math to repair his bike
#22Kind of reminded me of the traditional wisdom that you should select chains and sprocket to avoid patterned wear. I don't know if there is an effect (especially with bikes and their low torque),but I always think about it when changing my chain. I suppose this only applies to single sprocket bike.
Isn't this only relevant for fixed gear bikes, where you can skid the rear wheel to brake, and you want maximize the number of possible "skid patches", or orientations of the rear wheel while the pedals are in a fixed position?
"I suppose this only applies to single sprocket bike."
Re: Alan Turing using math to repair his bike
#23From occasionally repairing modern bicycles the way the chain is falling off "regularly" doesn't click with me: If one spoke is bent so much (more like a serious wheel wobble) that - at some point - it touches a "damaged" chain link; this is quite a spectacular failure.
I have to assume back then those bicycles were built quite differently that something like that could happen in such a predicatble fashion. Or along the way some information was lost and something different added in that anectode.
Curious to see other versions I have quickly traced back the ancetode to a Nature article "Are mathematician logical" (1987) by Ian Stewart[0]; the version/wording unfortunately here is quite the same.
[0]https://doi.org/10.1038/325386a0 (via paywall --> sci-hub)
Re: Alan Turing using math to repair his bike
#24Earlier quoted context omitted.
Isn't this only relevant for fixed gear bikes, where you can skid the rear wheel to brake, and you want maximize the number of possible "skid patches", or orientations of the rear wheel while the pedals are in a fixed position?
"I suppose this only applies to single sprocket bike."
It applies to any bike. Ideally the number of links in the chain would be coprime to the number of teeth on every sprocket. The easiest way to achieve this is to make the number of links in the chain prime.
It'll still work just fine if you ignore this idea, but it might wear out more quickly. If you're a hobbyist just trying to make something work, you can safely ignore it and do whatever is most convenient. If you're a bicycle engineer trying to make things reliable and long-lasting, then there's no downside to making the number of links prime if you can arrange it.
I don't know whether bike companies actually do choose prime-numbered chains, maybe they have other constraints that are more important.
Re: Alan Turing using math to repair his bike
#25Earlier quoted context omitted.
I wonder which part of this (admittedly odd fashion statement) seemed surprising to you? Gas masks were of course ubiquitous during the war, so this was probably only about as eccentric as wearing an N95 mask would seem now. And the alarm clock seems like a fairly practical if whimsical hack in an age when chronometers would have been mechanical, and therefore quite expensive.
I didn't know about the gas masks being ubiquitous during the war; that makes that part a little less surprising. History can be sad.
I bought one at a swap meet in Amsterdam a few years ago. They were piled up high and cheap. It made a fun gift for a friend back home, but we got really odd looks on the train when wearing it :).
Re: Alan Turing using math to repair his bike
#26This anecdote is memorably presented as an application of modular arithmetic (along with the behavior of Enigma machine rotors) in Neal Stephenson’s Cryptonomicon . See the discussion in this review of the book: https://www.ams.org/notices/199911/rev-kasman.pdf
I have a love/hate relationship with his writing – he adores going off on tangents, and action often gets put on pause while he savors them (REAMDE has several long paragraphs of a character pulling themselves onto a boat, admiring the hull, praising the usefulness of the tires lashed to it, etc).
But it also introduces me to so many lovely things in the process. That moment in Cryptonomicon was quite cool.
Re: Alan Turing using math to repair his bike
#27> And in Turing’s case, it was further complicated by the fact that he always wore a gas mask as he rode, to prevent triggering his allergies. But the alarm clock he was known to wear around his waist might have helped. What? Is that for real? Edit: It is! > He loved to ride his bicycle through the countryside. To time himself, he would simply tie an alarm clock around his waist. During the war, according to I.J. Goo…
For years before Covid, I would wear a N95 mask while doing yard work, construction, biking, and even night walks. I got some stares. For awhile, I felt some of my neighbors thought I was trying to conceal my identity; but it was just for allergies. The last thing I wore it for was germs.
I've tried wearing an N95 for allergies, but my eyes still itch like mad so it's only moderately helpful.
Re: Alan Turing using math to repair his bike
#28[deleted]
Re: Alan Turing using math to repair his bike
#29> And in Turing’s case, it was further complicated by the fact that he always wore a gas mask as he rode, to prevent triggering his allergies. But the alarm clock he was known to wear around his waist might have helped. What? Is that for real? Edit: It is! > He loved to ride his bicycle through the countryside. To time himself, he would simply tie an alarm clock around his waist. During the war, according to I.J. Goo…
I wonder which part of this (admittedly odd fashion statement) seemed surprising to you? Gas masks were of course ubiquitous during the war, so this was probably only about as eccentric as wearing an N95 mask would seem now. And the alarm clock seems like a fairly practical if whimsical hack in an age when chronometers would have been mechanical, and therefore quite expensive.
I feel like the average person absolutely was not wearing a gas mask at all times. Having myself used an N95 in my neverending war on pollen I totally understand though.
Re: Alan Turing using math to repair his bike
#30Earlier quoted context omitted.
For years before Covid, I would wear a N95 mask while doing yard work, construction, biking, and even night walks. I got some stares. For awhile, I felt some of my neighbors thought I was trying to conceal my identity; but it was just for allergies. The last thing I wore it for was germs.
I've tried wearing an N95 for allergies, but my eyes still itch like mad so it's only moderately helpful.
I thought about commenting you could wear goggles, but that's just reinventing the gas mask. Turing was a genius!