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wait, can't you just tilt a four-wheeled suitcase and have it become a two-wheeled suitcase? mine seems to work fine for this! but maybe i've been indoctrinated by sleek four-wheeled luggage advertising and no longer remember the comparative robustness of the two-wheel design.

also, strong relate to the feeling of having a flaw in one's approach to life—i feel this with at least eight dozen things that feel MUCH more difficult for me that they seem to be for the average person.

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The problem with tilting the four-wheeled suitcase is the casters! It's a bit hard to explain, but since the wheels rotate, the suitcase won't "maintain a track" without you constantly needing to rotate it, and the wheels are much more likely to get stuck on things. I think the casters are unavoidable in a 4-wheeled design, because you steer the 4-wheeled suitcase by "pushing" it rather than rotating it.

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My 4-wheel carryon is not optimal for 2-wheeled tilt operation for this reason, but it's still very good. And being able to put my heavy laptop bag on top of it in 4-wheel mode when walking to a faraway airport gate is a huge win. Personally, I love this hybrid design and will never get either a pure 4-wheel or pure 2-wheel/tilt bag.

Maybe the wider point is that nothing in life is single-objective, but everything is a multi-objective Pareto problem. And depending on the problem, where the sweet spot is on the efficient frontier can vary from the simple/robust side of the curve to the complex/fragile side.

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This post has a very Lindyman energy to it (not complaining or condescending! I find his stuff fun).

I think your point on Soylent can best explain this. Humans appear to often struggle with scaling things across thresholds of complexity. We are very good at understanding low-dimension systems, but have been cursed with the knowledge that higher-dimension ones can theoretically be more optimal. Increasing complexity introduces more variables which people either don’t realize exist, or are an unexpected source of fragility.

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This Lindyman? https://lindynewsletter.beehiiv.com/ I wasn't familiar, though I think I see what you mean. (Any particular recommendations? Hard to get a feel for the essence of Lindyman at a glance.)

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yep. he's active on Twitter @PaulSkallas. he's a culture commentator looking at things through the lens of the Lindy Effect.

I personally found his piece on Refinement Culture to be the best to get a flavor (https://lindynewsletter.beehiiv.com/p/refinement-culture)

Also good are his posts on Exercise (https://lindynewsletter.beehiiv.com/p/exercise-problem), and the late 90s/early 00s fixation on vulgarity as an accepted, even admired, trait (https://lindynewsletter.beehiiv.com/p/vulgar-wave)

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Not sure if this is a tongue in cheek joke, but you can tilt a 4 wheeled suitcase just like you can a two wheeled suitcase. If it wasn’t a joke, enjoy your newfound luggage experience!

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You can tilt a 4-wheeled suitcase but that gives you a much worse two-wheeled suitcase because the wheels can spin. This means it's harder to go in a straight direction and the wheels get stuck on things more. (I know this sounds insignificant, but I tell you in practice it's huge!)

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Clearly the next evolution in ever more complex-yet-fragile suitcase design is a button that locks the wheels. I can already imagine the mechanical complexity.

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For various reasons, over the last couple of weeks I’ve been using both two-wheeled and four-wheeled suitcases, and the four-wheeled ones behaved identically to the two-wheeled ones when tilted. The castors just consistently stayed pointed in the correct direction and I was able to go over rough surfaces equally well with both. So maybe you just need to get a better four-wheeled suitcase?

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Reality is more complicated. One example: "plump". When you are young your fat is on the hips, buttocks (subcutaneous). When you get older another type of fat (visceral) gets deposited in the belly around your organs. Visceral fat is connected to inflammation and other bad things. That is why you can afford to eat more when you are young (and more active probably) but have to be leaner when you get older. Not to mention the knees, the less weight they have to carry the happier they are.

Another thing: those "classic" NASA rockets were pointy, the ones I saw go up recently with tourists were differently shaped, more like penises. Was there a reason for this change - or is it a message ?

Also, Soylent (Green) is made of people ! But you knew that already I think. If not, watch the movie.

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Not to dispute any of your facts, but note that the statistics say you want to get plumper when older, not thinner! My guess is either that (a) despite everything, it's still worth it because the older you are, the more likely you might have an injury or illness that prevents you from eating or (b) the stats are confounded and the causality is off.

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Statistics: what is the baseline ? In a population that is on the verge of starvation being plump is better. Ever seen those images of girls being forced to drink a lot of fat, where one of their feet is clamped in a vise ? Those girls were worth a lot of money when married of.

When you get older you get plumper, automatically, you do not need to want it, it just happens. Your hip bone breaks because it becomes brittler - especially in females - and you lose the cartilage etc. When you are leaner you are often more flexible and able to "fall properly". I am not sold (yet).

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This is the statistics: https://www.thelancet.com/journals/landia/article/PIIS2213-8587(18)30288-2/fulltext

The baseline is (I think) never-smokers in the UK.

Anyway, I'm not fully sold myself! They basically just look at correlations between BMI and risk, while trying to "control" for various other things. So this is *much* less trustworthy than an RCT that actually had people change their weight and see if that impacted longevity. (But such an RCT would be hard to do...)

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As an elderly woman who recently had to upsize her jeans from 14 to 16, I would love statistics that bigger is better at my age (although there probably is a tipping point). When I grew up the saying was "fat people are happy people", maybe there is some truth in that ? But, again, only up to a certain BMI - the 600 pounders in the TLC programs do not seem happy, they punish themselves with food until it kills them.

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Yeah, I guess this figure is the one to look at: https://dynomight.net/img/luggage/BMI.svg (The "hazard ratio" (HR) is the relative odds of dying, so lower is better.)

The optimal weight doesn't increase *too* much as you get older... For someone <50 years old, the optimal BMI is ~22. That increases between 50 and 80 to ~27.

Judging from this figure (https://www.thelancet.com/cms/attachment/dbeefe1f-7719-4427-991b-5e7c617c779c/gr1.jpg) the average in rich English speaking countries for adults is currently 28 or so. And of course, most people are less than 80 years old. So most people would probably be better off losing weight, not gaining!

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According to the Stanford Longevity Center has the oldest age-group (over 75) healthier MBI's than the average American. However this is misleading: BMI does not consider the difference between muscle mass and fat mass. "New studies echo the importance of lean mass analysis in older adults. (...) Higher muscle mass was correlated with lower mortality, suggesting that medical professionals should focus special energy on assessment of lean body mass, favoring more detailed measures over BMI." So not just losing weight, but making sure to lose fat and keep as much muscle as possible.

When it comes to accidents in and around the house, which are killers, we should take into account that fatter people often walk between sticks or with a walker, etc. They probably do not do things leaner people feel called to do. Didn't they recently save an elderly woman who was on a hiking trip in rather hot weather and got lost ?

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(Humungously colossal comment, sorry! Please do feel free to delete if it's too long!)

Some of your examples are really quite confusing to me!

Cars: Tarmac roads go almost everywhere that almost everybody in the West needs to go to. A run-of-the-mill hatchback or saloon is cheaper to manufacture, cheaper to buy, cheaper to insure, cheaper (here in the UK at least) to tax, *much* cheaper to run, easier to drive, easier to find spare parts for, considerably better for the planet, and mechanically simpler than a big off-road-capable 4-wheel-drive. It looks to me like what you give as an example of the simpler, more ruggesd solution is, for most people, more complicated, more expensive, and more hassle, and your example of the "fancy" solution is in most cases simpler and cheaper for most people?

Sponges: The Roman soldiers presumably got their sponges from the army - yes, they were sponges off the state.. - who presumably had easy access to lots of sponges but lots of difficulty manufacturing and distributing suitable cups. If the Roman army found it easy to manufacture and distribute shatter-proof cups (eg. if they could have made them from plastic) presumably they'd have issued those to their soldiers instead; similarly, modern military-issue plasic cups certainly feel (to the end-user, at least) like the cheapest, no-frills, most efficient possible option. In both cases, then, it feels like maybe each option was the cheapest, more rugged solution for its respective civilisation, rather than one being universally simpler across all civliisations?

(Side-note: to the Romans, "vinegar" had a secondary meaning of "cheap wine", and "cheap wine" had a secondary meaning of "water with juuust enough ethanol in it to stop us all getting cholera". When we translate Roman vinegar as just "vinegar" that's usually a context-dependent translation rather than becasue we know for certain they meant modern-type vinegar and not either cheap wine or ethanol-water. Not super-relevant to the discussion but I hope interesting!)

Food: I feel like we do know enough about nutrition to be able to optimise nutrients *better than the average Westerner optimises when left to their own devices*, and the food industry is incredibly dependent on vast global supply chains and unpredictable weather patterns, and very reliant on just-in-time production. By contrast, if civilisation made a concerted effort to manufacture something like Soylent, it would be easy to feed everybody in the world a meal that's statistically more nutritious than the one they're likely to otherwise get and we'd be much less at the mercy of global trade, the weather, etc. It appears to me that the solution (no pun intended) you present as fancy is actually simpler, cheaper and more reliable, and the one you present as simpler and more reliable is actually just the pointy-end of a vast, brittle system?

(The reason we all, self included, want food rather than Soylent is because we're just not optimising for simplicity, reliability or efficiency here (at least not globally) and we'd get - to quote a very wise man - tired of eating the same goddamn goop every day...)

Suitcases: For most people, your suitcase only ever makes four journeys under its own steam: from your house to your car boot, from your car boot to the baggage check-in desk, from the baggage carousel to the nearest taxi, and from the taxi to your hotel room. All these journeys are 95% perfectly smooth and level and 5% covered by lifts or access ramps. (Personally I agree with you; I need the flexibility to go hors-piste with my suitcase and I resent that part of my limited baggage allowance by both weight and volume, which could be gainfully spent on another four bowties or a lovely cummerbund, is instead taken up with a mechanism that I don't want or need - but I do recognise that 4-wheelers are a better solution for the average suitcase consumer's use-case)

(Re. using a four-wheeler like a two-wheeler: never tried (I mean, why on Earth would I ever have a four-wheeled suitcase...) but it's quite surprising to me that it doesn't work. In vehicle kinematics the trail angle allows casters - "castors"? - to track in a straight line; its part of how eg. motorcycles remain stable at high speeds, and why operating a shopping trolley isn't like participating in a demolition derby...)

General point: I feel like almost all the points of confusion disappear if we recognise that simplicity/reliability vs. fanciness is just one design axis in a multiaxial space, that any given design's position on other axes can be as, if not more, important, and that altering a design's position along one of those other axes can as a secondary effect make it more or less simple/fancy than we'd otherwise prefer?

Bonus example: My own personal example of simplicity/ruggedness counterintuitively losing out is my vacuum cleaner. When I needed to buy a vacuum cleaner I just bought the same vacuum cleaner as they had on the last ship I'd sailed on (I hear on Roman triremes they used sponges rather than vacuum cleaners...) which is an industrial model and which has turned out to more reliable and more capable (eg. able to vacuum up liquids, having a much more powerful suction, being able to run in reverse to function as a blower, etc. etc.), and made of much tougher plastic (near-identical metal models are also available) than a domestic model whilst also being actually cheaper to buy. If one can live with the downside of it's being twice the weight* and sounding like an aeroplane taking off, it does seem a good example of simplicity/ruggedness actually being optimal but occupying a much smaller market share?

*Luckily it has four wheels rather than two....

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Thanks, you make some great points. I was thinking about some of this in terms of the two "dynamics" at the end. e.g. an ultra-rugged Hilux is great over rough terrain but for most Westerners this doesn't matter because everything is paved. ("The world became less chaotic") And for drinking, I think the "fancy" solution (cups) just became very good and very robust. So I totally agree that the tradeoffs change over time.

For using a four-wheeler like a two-wheeler, it's hard to explain, but I tell you, it's much worse! If it wasn't, why not put casters on 2-wheeled suitcases.

(Today I learned that US and UK English spell caster/castor differently.)

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Thanks for engaging (I always feel like I'm too wordy and tedious!)

I think the Hilux works better on rough terrain because it is, in some sense, more fancy (bigger engine, four-wheel-drive system, multiple differentials, low-range gearbox, turbocharged, DPF'd engine, etc. etc.). I would be forced to admit that a WWII-era Willys Jeep would be both simpler and more rugged than a WWII-era Jaguar, though - so perhaps your insight about the maturation of the technology is the critical factor, here?

For the cups, I think earthenware cups have always been the simpler solution for domestic purposes and that hasn't changed over time - we use them, the Romans used them, etc.; it's just the armed forces' unique use-case where the optimum changed from sponge to tin to plastic.

For the four-wheeler I believe you, aye - I am just confused by it! It's kinda the opposite of what I learned (or, ait appears, what I mis-learned..) about vehicle kinematics (which did actually cover castors!) Personally I wouldn't put castors on two wheelers anyway because they take up more space and weigh more than simple spindles - but I admit the extra weight and volume likely aren't a consideration for most consumers and it's probably the handling issue you describe.

Oh, thank goodness! I second-guessed myself when I saw your spelling and feared I'd been misspelling "castor" for years!

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In order for the analogies to work, I guess you need to be willing to interpret "fancy" in different ways for the different cases. I was using it to mean different combinations of "complex" / "non-robust" / "optimized for ideal circumstances". I think 4-wheeled suitcases are (arguably) all of these things compared to 2-wheeled suitcases, but it's not clear which aspect is the most salient!

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I MAY HATE THE 4-WHEELER MORE THAN YOU. My wife insists on using one and it is fine on completely flat surfaces, which don't exist on earth, unfortunately. Left unattended, it stealthily drifts away, typically bumping into some stranger down the street. The wheels are too small and improperly positioned to climb curbs. The best thing they do is allow you to spin the bag in circles. But why would you do that more than twice?

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this is the real issue with four wheelers. if you need to stop on slope like a ramp you either need to hold it in place or sit it on its side. even more annoying on buses or trains.

the slightest resistance - even a thin carpet - makes the four wheel mode worse than two wheel and trying to use four wheels on uneven surfaces causes the wheels with inconsistent contact with the ground to skitter around in a way that can’t be good for them. as you said, you have to pick it up to go up steps or kerbs if you don’t want to scuff your case. they’re just not designed for that.

despite all this, i adore my four wheeler and would never go back. when it’s on polished stone it glides under its own momentum such that i can take my hand off it for a second if i need to. it’s lovely in a queue. you just nudge it forward a little at a time without the whole production of tilting it in a tight space. i can wheel it sideways down narrow aisles. it’s brilliant.

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Targeted optimizations increase the number of unacceptable tradeoffs in ways that limit future development.

Swivel casters improve mobility in hotels and airports (sort of), implicitly blocking any change that might sacrifice this - development stops. I mean, G-RO exists, but c'mon.

The shuttle program seeks to eliminate waste, so we can't do anything during development that has a quantifiable, high risk of failure since that would defeat the purpose.

Capital punishment could serve a community's desire for revenge or crime prevention, but reducing the moral hazard through life imprisonment has always felt like paying in torturous installments. Exoneration might let us make things right, but who really gets made whole? 'Better that ten guilty men go free than one have forty-five years of life sucked away, hour by hour'?

For most of these problems, I think we can do better (or I don't believe we know we can't), but we're waiting for the next philosopher or entrepreneur with just enough hubris to challenge 'good enough'. We may mock their half-steps or be awed by the next step forward, but until then, we're nothing if not adaptable - even to the presently unacceptable.

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Hybrid vehicles have some nice feature over Battery only Electric Vehicles (BEVs) - specifically, consumers are fine with a much smaller battery in a Hybrid; a smaller battery means lower purchase price and less wear and tear on roads.

Hybrid vehicles are more complicated than BEVs, so BEVs will probably be cheaper than Hybrids at some point in the future, and could be right now if they used a smaller battery pack. (See the Wuling Hongguang Mini EV)

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There's a much dumber solution that I happen to love: Put a generator on a trailer. Rent it to people going on road trips.

This allows for cheaper EVs with smaller batteries, which is better for just about everyone. It also alleviates range anxiety.

The generator does not have to be especially big - 30 HP would be plenty, especially for a small, light BEV.

It's dumb but it's brilliant. It allows you to decouple the problems from choosing either BEV or Hybrid (literally!!)

Why a generator and not just use the engine to power the trailer wheels? Having a trailer in a "pusher" configuration would severely alter the dynamics and would be prone to loss of control.

Bonus: If you are concerned about grid stability, you can use the generator as a generator at your home. 30 HP is well beyond the needs of most homes.

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Wow, can you check my math? I was quite skeptical, but it seems to work out...

- EVs consume something like 200 Wh / km

- So if traveling 100 km/h you'd consume 20 kWh / h

- Small (~30HP) motors are indeed rated to output something like 20 kW.

How!? How can that work out? Why do ICE cars need so much more powerful engines? Is the difference that the ICE engine must provide much more "burst power" for acceleration, while a generator just needs to provide "average power"?

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Besides actually wanting the higher power for bursty scenarios, there's also the fact that engine power for cars usually is quoted at something like 5000 rpm and (in my experience at least) *most* of the time even in those scenarios people don't tend to go above 3k, with 1 to 2k being a normal cruising range.

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You only need the peak output to impress your date as you merge onto the highway. Yes, burst and average are a very good way to put it.

This is how they made cars that got 50 mpg in the 1980's. Put a low output 3 cylinder engine in it, and make it very light.

And this is why high power EVs can still be efficient: you don't have to have all that jiggling mass and pumping loss and waste heat (and radiators to reject that waste heat) that ICE engines have, just add a bit more motor. You have some more inertia, and a bit more electromagnetic and mechanical resistance, but it's so much better than an ICE.

Automotive companies have made variable displacement engines with cylinder deactivation - which strikes me as being another example of your thesis in this post.

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It's not just peak output vs. average (though that certainly is a significant factor)

Some other relevant factors:

1) How you arrive at the average matters. Your 100kph EV is essentially in a state of equilibrium; a car that was constantly accelerating and decelerating (but still averaging 100kph) would need to produce considerably more power than the equilibriummobile!

2) ICEs are most efficient only within a very limited rev range. A generator can run constantly at its most efficient speed no matter how fast or slowly you wish to drive, whereas (disregarding the gearbox to keep it simple) an ICE that's connected to your wheels kinda has to run at whatever revolutions you happen to need for the speed you want to drive at any given moment.

3) Consumers want their car to be able to do stuff like travel at motorway speeds, up a hill, full of passengers, with their lucky anvil in the boot - and they want it to do this stuff comfortably and serenely and without shrieking and vibrating like it's perpetually on the verge of exploding. Such a design will essentially need "excess" power to ensure that it can accomplish basic duties without being too stressed.

4) The peak power output of an ICE engine is, in some sense, kinda arbitrary. The designers set a "redline" past which the rev limiter engages, they program in a fuel map that decides how much petrol to inject per cycle for any given conditions, they program a forced-induction system to deliver a given pressure, etc. etc. These limits are chosen to satisfy many criteria, but one critical criterion is, "if we let the engine exceed these limits, wlll it damage itself?" Since the engine has to be capable of more-than-usual performance anyway (because of factors such as (3) above) and since consumers by-and-large want the performance, it doesn't make much design sense to arbitrarily limit an engine to eg. 40bhp when the exact same design could produce 100bhp without damaging itself.

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I was ready to be up in arms about inflatable sleeping pads for cold weather camping, but you refused to blindly insist on your original thesis (rude! What will I complain about now?).

I still want to defend inflatable pads, though. The biggest difference to me is that they take up so much less room. Space is at an incredible premium when camping. As you noted, they also tend to insulate better, feel more comfortable, etc. If it’s really cold, what’s actually recommended is that you use both! The foam pad protects the inflatable from sharp rocks, and you need the stacked insulation anyway. I’ve also been rescued by my inflatable’s extra height when 35f (1 or 2c) water got into my tent overnight and soaked everything but me.

So yeah, I’d add inflatable pads to the “fancy, delicate solution is actually much better than the rough and rugged one” column.

One of the key differences between some of the examples where our intuitions seem to side with the rough and rugged examples vs the fancy and delicate are where the preferences being specialized into by the latter are primarily aesthetic. There could be a bit of a maslow’s hierarchy of needs thing going on here, where distance from the brute realities of a problem enables us to satisfy lower-priority preferences, which we genuinely care about, but abandon when confronted with harsh realities on the ground. Most of the examples in this post, however, have no aesthetic component whatsoever, in which cases I would expect the differences to be either more straightforward trade offs, or to favor the more developed solution.

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The simplicity/generality/convenience tradeoff space is fun. I thought about multitools when reading: a friend used to say the Leatherman was the wrong tool for every job. I've gone back and forth on having a separate knife and multi-bit screw driver, but then occasionally you do need some pliers and so on, and multiple items require some kind of further solution to keep together.

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There was an intermediate solution for a while in the 1970s and 1980s. People used to use a bungie and a schlepper to haul their suitcases around. The schlepper was a collapsible aluminum frame with two wheels and a little ledge to hold the suitcase. It was like a miniature handtruck with a long handle so you pull it along when walking. The bungie was an elastic cord to hold the suitcase to the schlepper.

They were polarizing. Some people thought they were absolutely great. Others thought they were a nightmare. They were all over the place for a while, but now people just buy a wheeled suitcase.

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