09 Nov 2018
Reading a Metafilter post on “The End of Big Ag” (spoiler alert: probably not the end of Big Ag) got me curious about the feasibility of cities growing their own food, and exactly how much land it takes to keep a person fed. So I did a little napkin math.
tl;dr: It’s theoretically possible, I suppose, for a city to grow its own food, but it would be a huge challenge. Current cities can’t do it.
Dent corn has the highest calorie yield per acre of any row crop, at least of those commonly farmed today. (Potatoes are close, and the highest-performing root crop. I think the highest-yielding perennials are bananas/plantains, but not sure.) The average yield for field corn is 171 bushels/acre (although that’s always going up, and probably with effort it could go higher—but we’ll stick with typical US farming practices), at 56 pounds per bushel of edible corn, and ~1500 nutritional calories per pound, that’s about 14 million calories per acre under cultivation. An active person needs about 1 million calories per year (though at 2k calories/day it’s actually only 730k, but we’ll assume city-dwellers walk more than us lazy suburban schlubs).
So just as a low bound, absolute minimum, you’d need 1 acre under intensive row-crop-style cultivation for each 15 people, and that assumes zero waste during food preparation and service, etc. (Also, hope people figure out how to make hominy, or pellagra is going to be the cool new look next season.)
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14 Aug 2018
I have met the Bullshit Web, and it is me.
It’s not that I intended to create a bloated webpage, and I don’t
think anyone ever leads with that intention. But it’s terribly easy
to do. In fact, all you need to do is follow all the “current best
practices”, and what you’ll end up with is bullshit – potentially
orders of magnitude more of it than actual content.
I didn’t think too hard about this when I migrated by ancient blog
from its crusty Perl-based foundations onto a ‘modern’ static site
generator, with an inoffensive pre-built template I tweaked slightly.
But looking at its load times in Chrome, it’s amazing how a few small
decisions – “oh hey, let’s use a nice web font!” – can add hundreds
of kilobytes and full seconds onto an initial page load.
Hopefully we’re on the cusp of a return to web minimalism, as the
performance curve of end-user devices (particularly mobile devices)
starts to flatten out; it simply won’t be possible to continue to cram
quite so much shit into each page, and assume that faster connections
and rendering engines will make it acceptable.
But that will require a shift in thinking among everyone who creates
content for the web, where the performance cost of each “nice-to-have”
feature is weighed, and nothing is tossed in just for the heck of it,
or because that’s what “everyone else is doing”.
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12 Nov 2017
The last few months have been particularly busy for me, and as a result I haven’t been keeping tabs on basically anything outside of my day job. It was therefore interesting to read Gwern Branwen’s recently-updated article on “time lock” encryption, which has always been a topic of interest to me due to its wide range of applications.
Reliable time-lock encryption has been a goal since the early days of widespread strong cryptography, and is often discussed in the context of key escrow schemes like Shamir’s Secret Sharing Scheme (SSSS).
But in many ways, time-lock encryption has more practical applications to the average user than an escrow system like SSSS. (Although in part this is because SSSS has never, to my knowledge anyway, been implemented in an easy-to-use fashion. It has remained the province of very high-end applications, like signing the DNSSEC root zone key.) There are lots of applications where people don’t use cryptography because of the risk of data loss – making your data as vulnerable to complete and catastrophic loss as the key (which is sort of inherent in any good cryptographic scheme) is often not desirable. Similarly, there are probably places in which people are using data encryption and taking on the risk of data loss unknowingly, whether personally or on behalf of others. E.g. the person who encrypts their personal computer and memorizes the key, and then gets run over by a bus. Hopefully their family didn’t need or want anything on...
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