Moderndescartes
moderndescartes.com · Personal blog · on HN since 2014
Moderndescartes is an engineer's blog on machine learning, Go AI, Google's readability process, energy storage, and engineering practice.
What HN saysHN commenters link it for the Monte Carlo tree search deep dive, the readability essay, and the factobattery idea for energy storage.
28HN people shared it
7linked it in comments
88stories submitted
1.1Kstory points
4 months agolast shared
2014people per year2026
Most-shared posts
- 1The Factobattery5 people · 7 points · first shared 2023 · discussion on HN
- 2Readability: Google's temple to engineering excellence (2023)4 people · 10 points · first shared 2023 · 2 comments on HN
- 3From GnuGo to AlphaGo Zero – A Roadmap for Solving Difficult Problems4 people · 8 points · first shared 2025 · discussion on HN
- 4What's in a Codebase?3 people · 5 points · first shared 2026 · discussion on HN
- 5My Path to Machine Learning3 people · 4 points · first shared 2017 · discussion on HN
- 6Who Pays You? and Why?3 people · 3 points · first shared 2024 · discussion on HN
- 7Learn perfect pitch in 15 years2 people · 176 points · first shared 2024 · 147 comments on HN
- 8A Deep Dive into Monte Carlo Tree Search2 people · 150 points · first shared 2018 · 6 comments on HN
- 9How (Not?) to Use Python’s List Comprehensions2 people · 136 points · first shared 2016 · 73 comments on HN
- 10Data-Oriented Programming in Python2 people · 105 points · first shared 2020 · 32 comments on HN
- 11The Chemistry of Refrigerants2 people · 9 points · first shared 2022 · discussion on HN
- 12Taste2 people · 8 points · first shared 2025 · 1 comments on HN
- 13Better ways to name your utils module2 people · 2 points · first shared 2023 · 1 comments on HN
- 14For Want of a Join2 people · 2 points · first shared 2022 · discussion on HN
- 15Carbon Neutral Concrete – The Numbers2 people · 1 points · first shared 2021 · 1 comments on HN
What HN people wrote when they linked it
cgreerrun · 2023-02-15
> I came up with a nifty implementation in Python that outperforms the naive impl by 30x, allowing a pure python MCTS/NN interop implementation. See https://www.moderndescartes.com/essays/deep_dive_mcts/
Great post!
Chasing pointers in the MCTS tree is definitely a slow approach. Although typically there are < 900 "considerations" per move for alphazero. I've found getting value/policy predictions from a neural network (or GBDT[1]) for the node expansions during those considerations is at least an order of magnitude slower than the MCTS tree-hopping logic.
[1] https://github.com/cgreer/alpha-zero-boosted
tczMUFlmoNk · 2025-12-05
You may wish to search for "readability at Google". Here is one article:
https://www.moderndescartes.com/essays/readability/
(I have not read this article closely, but it is about the right concept, so I provide it as a starting point since "readability" writ large can be an ambiguous term.)
brilee · 2025-09-18
Taste is the field behind the goalposts, and we as humans are constantly expanding that field by "having taste" and developing taste as a community.
https://www.moderndescartes.com/essays/taste/
aitchnyu · 2024-12-17
Could be a good candidate for factobattery. Overbuild the system, run them at full speed at peak solar generation, then underclock them at night.
https://www.moderndescartes.com/essays/factobattery/
schiffern · 2024-09-01
Even pumped hydro is pretty small for seasonal storage.
Probably the only economical approach will be some sort of factobattery[1], which can be thought of as a flow battery which operates "once through" to avoid round-trip losses. Instead of outputting electricity, the beneficiated material itself is the economic output.
This eliminates the entire chemistry-to-electricity side of the process, which may require dissimilar equipment under some approaches.
[1] https://www.moderndescartes.com/essays/factobattery/
codethief · 2024-06-29
For non-Googlers like me, here's some background about "readability":
https://www.moderndescartes.com/essays/readability/
PaulHoule · 2024-01-10
This report, which is often quoted,
https://www.eia.gov/analysis/studies/powerplants/capitalcost/
gives a crazy low cost for a solar + battery plant that assumes storage for an hour and a half which is certainly too little. When I split out their generation and storage numbers and put in the assumption that 12 hours of storage gets you through the night the price is getting in the same range as gas turbine power plants.
There's the seasonal problem too, the answer to that is some combination of building more solar capacity or adding huge amounts of storage. I'd estimate that the daily insolation varies by a factor of 2 or so in NY
https://www.solarenergylocal.com/states/new-york/new-york/
so you could build maybe twice the solar capacity and have enough generation in the winter. Judged that way the system cost is creeping in the direction of what nuclear energy costs, though you've got a lot of "free" electricity in the summer although that could be "free as in puppy". Hypothetically you could do something like desalinate seawater and pump it uphill into reservoirs but operating any kind of industrial factory intermittently is going to be murder for capital and operating costs. There is this idea
https://www.moderndescartes.com/essays/factobattery/
where you could smooth out diurnal variation in a "hydrogen economy" factory by overbuilding electrolyzers, but to take advantage of "free" summer electricity you might have to lay off all your workers half the…