Snow load is not mentioned when using horizontal panels. In higher latitudes, solar is relatively uncommon because of the sunlight deficit in winter. Panels that are deployed are usually placed at an incline equal to the latitude (or even vertically) to capitalize on free snow shedding and to regularize/maximize year-round minimum output (i.e. bring up winter by bringing down summer). Mounting solar panels flat is sensible from the standpoint of this technology (no solar output needed in the winter, that's what the storage is for!) but may be breaking a lot of ground (and panels) with horizontal panels in snow country.
Readit Newsalhirzel commented on Building ultra cheap energy storage for solar PV austinvernon.substack.com... · Posted by u/theptip
One potential virtuous cycle here is that accessibility trees used by tools like screen readers are also a nice potential way for a model to consume information about what's on screen and how it can be interacted with. So it creates an additional incentive for improving the accessibility of new and existing software, because doing that lights up integration with future models.
This cycle starts with an integration for model developers. I wonder if anyone is working on a generic ARIA hookup, as well as whatever standards are necessary for desktop/smartphone integration?
alhirzel commented on Ch.at – A lightweight LLM chat service accessible through HTTP, SSH, DNS and API ch.at/... · Posted by u/ownlife
What are the economics of this?
alhirzel commented on Algorithms for making interesting organic simulations bleuje.com/physarum-expla... · Posted by u/todsacerdoti
Reminds me of Electric Sheep
alhirzel commented on When Abandoned Mines Collapse practical.engineering/blo... · Posted by u/impish9208
That was fascinating. And contained some interesting stories relating to the function profit = f(lives_lost)
Especially the part where improved safety tooling (bolts) were used to increase efficiency rather than safety: regulatory dysfunction at its finest. Interestingly, in other regulated areas (such as toxic emissions into the environmental), there are clear echelons regarding what is required such as BPT vs BAT (best practicable vs achievable technology). For the coal mining case, if BAT had been the requirement (and the regulating body had enough teeth to enforce it), Chris's work might have been easier to fund.
alhirzel commented on When Abandoned Mines Collapse practical.engineering/blo... · Posted by u/impish9208
A great companion piece on a government bureaucrat who solved the problem on how to optimally support the roofs in longwall mines: https://www.washingtonpost.com/opinions/interactive/2024/mic...
That article touched on so many facets of a person's career: the pursuit of meaning, grit, familial context... It should be required reading for all young engineers.
alhirzel commented on Ask HN: What is the actual cost basis of the stock market? · Posted by u/whatever1
They either pay dividends or investors hope they will pay dividends one day (even META and GOOGL do now!) Or the company can get bought out.
Those are all very concrete reasons for valuations
GOOG currently pays ~0.47% APY. The GOOG stock price could reflect some certainty of these dividend payments, but there is not much stock price independent risk basis to choose GOOG over e.g. US treasury bonds at ~4.32% or Swiss bonds at ~0.77% APY.
As well, micro-fluctuations in APY driven by stock price values create inconsistent hopes: a dividend investor that will "never" sell should hope that stock prices do not exceed inflation so that APY is stable or goes up, while most people hope that stock prices inflate with the economy or go up so that appreciation can be realized at sale.
Then there are the people who bought at IPO, at which the closest thing to a true valuation exists: it is at the IPO cost basis that a true value is established. IPO is also where the company performance becomes coupled to the stock price as the general public invests money into the company in the sale, and employees with stock options become incentivized to exercise any available control over the stock price, including increasing company performance.
I think there is a continuum between dividend investors and stock price speculators, and there is also some kind of monotonically devolving continuum from a rational value basis into chaotic market forces. In one corner of this N-dimensional continuum, I can definitely agree with you.
alhirzel commented on Ask HN: What is the actual cost basis of the stock market? · Posted by u/whatever1
It's all a tower of cards based on what people think the cards are worth. Unless stocks pay dividend, valuation is afloat on the expectations of shareholders.
alhirzel commented on Designing space hardware is hard [video] youtube.com/watch?v=kXa0v... · Posted by u/surprisetalk
Designing for space is definitely an art full of pitfalls. Guides like [1] exist that cover basics, but experience is king.
One of my favorite pitfalls in aero is connector mating lifetimes. Any time there is a connector (like a good old-fashioned DB-9), there are metals in the contacts that will have a pressure-based interface (pin inserting into hole). High-ductility metals (copper, gold, etc. that are typically used for connectors) like to become brittle after getting bent around a bit. Unfortunately, when the individual conductors become more brittle, their stiffness goes down, and this results in the connector performing poorly on vibes. This is because the resonant properties of the individual pins within a connector are tuned to not have micro-disconnects during the vibration of launch - they are sufficiently stiff to withstand the forces. This tuning is a function of the number of times it has been connected and disconnected because of the embrittlement, so each connector has a "mating lifetime" on the order of 10 mates/demates before you have to scrap it. This means your flight electrical connectors are really, really important. I remember being a young naive engineer and being shocked and appalled by the waste.
[1]: https://ntrs.nasa.gov/api/citations/19900004959/downloads/19...