Tried to sign off with "best" and wrote "beset" instead, which seems appropriate
Beset,
Madeleine
Remote
Madeleine Bonsma-Fisher, PhD
@mbonsma@mastodon.social
mastodon 4.8.0-nightly.2026-10-06University of Toronto postdoc (bikes + data), biophysics PhD, mom. I post about bikes and safe streets, local politics, and sometimes science. She/her.
#DataScience #BikeTooter #OttBike #BikeTO #ActiveTravel #Transportation #UrbanPlanning #CargoBike #eBike #biking #maps #science #Python #cats #fedi22
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Joined April 25, 2022
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Cruising around in my SUV (Snack Utility Vehicle)
Winter cyclists, it is time for us to accept that other people exist
Curious about cargo bikes or biking with kids? Seasoned pro interested in meeting bike friends? Come to our cargo bike meetup on April 18 @ Withrow Park!
#BikeTO #CarryShitOlympics
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TL;DR: an unassembled jigsaw puzzle takes up an area that is the square root of 3 times the area of the assembled puzzle, or about 1.7 times the assembled area. This is *independent of the number of pieces*.
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These rates are an order of magnitude higher than injury rates for driving in Canada, by comparison (0.3 injuries or fatalities per million km in 2023).
But I would argue that per distance is not the right comparison for cars vs. bikes, and something more like rate per trip would be better.
Canadians drive something like 15,000 km per year on average. Bike commuters' average trip is 20 minutes, so even if you biked to work every weekday, you would still be under 4000 km biked for the year.
Pedal Poll 2026 is 9 days away! This year's count is VERY exciting: this will be a completely new dataset gathering information on micromobility modes while maintaining comparability with five previous years of bike counts.
Sign up for a counting shift in your community! https://velocanadabikes.org/pedalpoll/
Your periodic reminder that MANY people can't drive, including all children.
Even among the license-eligible age group, many people don't drive. In Canada there were about 26.5 million licensed drivers in 2018, or about 85% of the population over 15. That leaves almost 1 in 7 teens and adults without driving as an option to get around.
This is your periodic reminder that car dependency is ableist and exclusive.
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The results were the most incredible agreement between theory and data I've ever seen in over a decade of being a physicist. I think I gasped when I saw this plot. Without any fitting, our simple theory *very accurately* predicted the unassembled area of all these puzzles.
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@Andres4NY@social.ridetrans.it yes, definitely. Other research (with different methods) has found the opposite, and I don't feel like there's a good explanation for why it should be lower for e-bikes.
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This work was a pandemic collaboration between me and the brilliant Kent Bonsma-Fisher, with assistance from our toddler and cat. The result, in his words, was "the cleanest dataset I have ever collected." Today our results are public on #arXiv!
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So there you have it: you'll need a puzzle table just under twice as big as your assembled puzzle in order to not resort to the box lid or that random side table. Grab a puzzle and impress your relatives this holiday season with your predictive powers!
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@ryanprior@mastodon.social @rasterweb@mastodon.social This is actually in Toronto (I think in Montreal they don't have to specify that the bagels are Montreal-style?) Yes - they're more dense and a bit sweet. Once you get hooked, you can't stop!
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We derived a theory with a "spherical cow in a vacuum" approach: we approximated each puzzle piece area as a circle, then calculated the area of the circles packed together. Our prediction: the unassembled area is sqrt(3) times the assembled area. Then we took data.
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@haraldkliems@fosstodon.org This paper does include that actually!
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We built 9 puzzles across a variety of total sizes and with piece numbers ranging from 9 to 2000. We laid out all the pieces flat, trying to be realistic by not paying much attention to how they were arranged and not spending time trying to get them closer together.
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We were surprised that the unassembled area didn't depend on the number of puzzle pieces. The intuition is this: if you have a small number of large pieces, the gaps between pieces are big, but this is multiplied by a small total number of pieces, and vice versa for small pieces.
@Pepijn@mastodon.online definitely lots more to be done! This journal has a 1000 word limit, so it's meant to be very brief single-result papers. They talk about trip purpose in the "future research" section!
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@michaelgemar@cosocial.ca our convenient Kettlemans location closed and this is a location we can get to semi-regularly. They're just as good IMO! I also go to Bagels on Fire on Queen or Bagel Time, both good.
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@hanscees@ieji.de pretty accurate!
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@platkus@mastodon.social this is a weird hill to die on, the parameters are very clear both in the paper and later in this thread
https://mastodon.social/@mbonsma/111564845145935604
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@TomSwirly@toot.community @stillmoms@mastodon.social you are very welcome to develop a more comprehensive theory of puzzle packing area!
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@claralistensprechen3rd it is, that's exactly the point! But the *unassembled* puzzle takes up more space, and we wanted to know how much more!
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@BerndGoldschmidt@mastodon.social it might break down for some very irregular piece shapes, but it seems like not really! That's the beauty of the simplification, anything "not square" about the pieces is a small variation that seems to not matter.
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@kbob@chaos.social very cool, thanks for the contrasting data point!
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@platkus@mastodon.social my dude, laying out all the pieces flat is ALSO in the very first post in this thread! You're replying to the third post! https://mastodon.social/@mbonsma/111564828670828672
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@Kencf618033@social.linux.pizza we are working on the 3D version now! The big question is what physical analogy to use. I think popped corn is a great example - they're not exactly spheres, but assuming spherical packing would probably give you a very good estimate of the volume. But what would "assembled" popcorn be? 🤔
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@TomSwirly@toot.community two things: first, we did not specifically select for "normal" puzzles and the theory still works, aka most puzzles have pieces that are kind of vaguely square even with nubs and holes. One of the puzzles was a very large linear children's floor puzzle. Second, I'm not convinced it *would* break down even if the pieces had a wider distribution of shapes, because they might still pack according to circles with the average area, on average. More data needed!
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@Chancerubbage@mastodon.social @gruber@mastodon.social I would argue that you don't need an extra full puzzle area for assembly - at least in my experience, some pieces hang out inside the partially assembled puzzle during the process. You definitely need *some* area to work, but as soon as you start assembling, the total area starts to go down.
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@snoda@mstdn.ca I used 15 and over because I was trying to estimate the fraction of people who could get a license who don't have one. I agree, younger kids also need independence and car dependency hurts them too.
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@DrivingUsMad@urbanists.social wow, that's really high!
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@tobypinder@mastodon.social such a good point - we view license suspension as a cruel punishment only because the other options are terrible, and it means people are allowed to drive who really really shouldn't.
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@RoyBrander@urbanists.social good catch!
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@platkus@mastodon.social we and you are making different assumptions about what constitutes the area of a puzzle. Our question was "how much area does it take to lay out all the pieces in a single layer", while of course in the box they don't need to be in a single layer. In the extreme case, you could stack every piece on top of the others and say the area of an unassembled puzzle is 1 piece. That's fine! Just not what we were trying to figure out.
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@ellie@ellieayla.net heck yes!
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@ansible42@social.ridetrans.it the motor stops boosting at 25, yes. I've definitely gone faster than the limit on my e-bikes if going downhill, for instance.
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@liilliil@mastodon.online this one is an Urban Arrow, a brand from the Netherlands but sold in bike shops elsewhere!
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@liilliil@mastodon.online the bike or the bagels? 😅
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@raynerlucas@mastodon.social love it