31,603 karma · joined June 21, 2011
If there is anything i can help you with, feel free to poke me.
FWIW-By supports pyomo they mean I can install their python package and hand a pyomo model to their solver API. I don’t want that. I want to use pyomo’s solver API which is how I interact with all other solvers
In the end I just don’t see who they are selling to. If their advantage is a single call solver for different model kinds, which is what they spend the most time talking about, that could be done with a small python package, and would already exist if it was a big issue
As a manager, the people I hired were almost always smarter than me or better than me at various things. That's why i hired them.
I did my best to make sure they were empowered to solve the problems the org needed solving.
Why would I not want their opinions or viewpoints, especially if they differed from my own?
Heck, why would i try to enforce my opinion or viewpoint in the first place?
Not realizing this makes the boss here a crappy manager. Yes, lots of crappy managers exist (for many reasons - one commonly overlooked one being that technicaly knowledge/etc is often shared and discussed much more than manager or organizational knowledge. So it doesn't proliferate as easily and quickly. There are many other reasons, some simpler, some more complex)
Truthfully, I resolved many many more arguments between people (within my own org or between orgs) than between me and someone else.
At the same time, the person arguing with their boss doesn't realize (until much later) their job is not to be technically right. Technically right/good is one of many aspects that are often getting traded off against each other. One thing they seem to not have discussed at all is "is this worth arguing about?". Does this choice really matter? What was the worst thing that happens if they don't do it the way they were arguing about. How likely is that really to happen, and if it does, can you tell early enough to do something about it? etc.
Reading this story feels like someone dragging out an argument continuously that simply didn't need to be argued about at all because it didn't matter enough.
The takeaway isn't that you should avoid arguing with your boss (as others say, you should run away from bosses you can't disagree with). The takeaway is that you should stop and think about whether this is really an argument that needs to be had, instead of arguing about everything because it's not perfect.
For free, mind you, this is not part of a paid offering on my part.
These are easy for the case of non-demand rates (IE the rate just changes at x hour to x price), and can be solved by HIGHS/et al in a second or two. You can actually prove there is at least one optimal solution that only changes inverter programming at a rate change point.
They are actually quite complex when the rate has a demand charge (IE you are charged not just for x price per kwh, but also some amount * max demand usage of any single hour in a month).
The max demand charge is usually 80% of the bill.
The complexity is because recharging the batteries (particularly without solar) is the same as any other load from a demand perspective. So they have to be trickled (or charged from solar), etc. On top of that, lots of inverters have a limited amount of TOU slots you can use (for example, sol-ark inverters only support 6 periods). Which constrains it painfully. Gurobi can solve it in about 30 seconds. HIGHS takes around 15 minutes to solve it for 2 years of hourly history data.
Remember, NEOS is both free, and pyomo already supports it natively without me changing anything - i can use both neos and local without any issue.
Why would i move to something with a different API that i have to pay for?
Often, the difference on "harder" problems is 10x or more.
I have problems that gurobi solves in 30 seconds that take 15 minutes or more for ~every non-commercial solver (or-tools, HIGHS, ipopt, etc).
But right now, this wouldn't even be interesting to me to use even if they actually were fronting commercial solvers, because they can't actually run it any faster and having this ".solve" API does nothing - pyomo already does that for me in practice.
Because it is a rooted tree, only DFS intervals are required to determine ancestry.
You can detect whether a new blocking loop is going to be formed through online dominator maintenance/online cycle detection, etc, during optimization, rather than use a heuristic, if you wanted to.
Not sure it's practically faster, but that's at least the graph-theoretic answer.
In practice, outside of the suggested heuristic, I have to imagine you'd normally throw branch and bound at this, using some lazy-cut for the blocking loops (IE you can keep any of these edges but not all of them) and let it go to town.
The paper (at least, this paper) doesn't compare that to what they did, and i'd be shocked if someone hasn't tried this before, so not sure it's useful.
I'll also say you can get existing AI models to tell you the above, but you have to push them a bit most of the time step by step. Just handing them the whole overall problem, as described, and saying "what are the graph theoretical problems related to this" it sort of gets lost.
Probably because the LLM isn't doing a good job of predicting graph-theoretic words when the language is not graph theoretic, but if you translate it into a graph theoretic language piece by piece, and ask it about that, the prediction becomes better :)
I have a rivian, and my wife has a car with carplay. I've had rivians for years now. I don't miss carplay when i drive my Rivian.
In truth, I used carplay for 3 main things - navigation that didn't suck, listening to music on the apps i wanted to, and reading text messages out loud.
Rivian has made those things not suck. So i don't miss carplay.
On my wife's car, those things suck, badly, without carplay.
I'm sure there are people out there who heavily depend on carplay for other things, and thus, it really does matter if they have carplay or not.
and maybe a day will come when the features carplay could provide me are as shitty on the Rivian as they are on my wife's car, and i'll start demanding it again.
But at least right now, that's not true, and so I think Rivian's choice is fine.
The vast majority of HN in the US is almost certainly within the top 1% of earners in the US (the cutoff is ~660k for households, ~450k for individuals), and the rest is probably within the top 10% (the cutoff is ~260k for households, ~150k for individuals). So overall it's a fairly privileged place, even if it likes to often pretend it's not.
In my life i've been both very poor and very rich. I'm now happy, and that matters a lot more than either.
I also happen to think it's fairly naive to believe that making lots of money makes it trivial to leave a place.
It's like believing having loved someone for 20 years makes it easier to get divorced.
Timing wise, I happened to leave after my old grants expired and before my new grants would be in my account. I was a VP of engineering when i left. Google pays VP's quite well.
If there's a reason you want more exact numbers, poke me over email.
Sometimes not.
I left with more than 4 million in RSU's left.
Pretty much any Googler who leaves will be leaving lots of money on the table.
This is because they are usually 3/4 year grants, so it's pretty much impossible to leave without lots of unvested RSU.
There are some 1 year grants, but those are much more uncommon (~1%)
At this point, airlines make most of their actual profit from credit cards.
I forget who said it, but "airlines are banks that happen to fly planes" is true, at least profit wise.
Permethrin is not well absorbed through skin anyway (0.5-1%). But easily absorbed by breathing it.
The first study is talking about constant occupational exposure. By people not wearing basic PPE, over the course of many many years. It's like taking a shower in permethrin every day for 30 minutes. You can pretty much substitute lots of every day things that get absorbed by skin for "permethrin" here and it would cause some very serious symptoms.
The second study used 34mg/kg of permethrin. That is an insane amount, and one that you could not even likely get without intentional ingestion of concentrated powder form.
If you weight 150lbs, that is 2300mg. So a huge horse sized pill of permethrin, every day, will cause issues.
Shocking.
2300mg a day of most substances will cause issues.
Hell, 2300mg a day of most things will cause serious issues faster than permethrin
2300mg of vitamin b3 would destroy your liver very quickly (weeks/months).
2300mg of vitamin b6 would cause permanent nerve damage very quickly (weeks/months)
etc
The reason we don't classify all pesticides as equally dangerous is because they are not all equally dangerous.
Lumping them all together and painting them with a single brush is as unhelpful here as it is when it is done in any other context.
Permethrin is just a synthetic version of pyrethrin, which is extracted from chrysanthemums.
It is probably one of the least harmful substances you will ever be around.
Lyme disease is easily a much greater threat to people than exposure to permethrin and derivatives while hiking.
The exposure to wood dust and other small particles from disturbing the wood chips is probably a greater threat than the permethrin.
It reminds me very heavily of being on woodworking forums as ever more mass automation happened, and the infinite arguments around whether using power tools/CNC/etc was still "real woodworking".
Lots of previously "hand-crafted" industries have dealt with mass automation. Software is not the first or the last. Hand-wringing by practitioners will change nothing, as it did not for any other industry. The vast majority of customers only care about the results, not the means. While there are some in the high end commission world who care about the art form, this is very rare and not sustainable for the majority.
History says folks would be better off learning how folks survived and adapted in those industries, rather than trying to argue about how worthless or crappy the change is.
Hobby wise, sure, whatever, but as a business what happens is very clear
In any case, it’s highly doubtful being different from ELF is offering real value to anyone at this point, it’s just nobody wants to spend time, money, etc to migrate when incremental change to their own formats gets most of what they want.
Though it is probably accurate to say apple probably has it the worst here. Mach-O tooling is almost certainly the least available out of ELF, COFF, and Mach-O.
DEET is a toluene derivative which is why it is super effective at melting plastics and doesn’t evaporate quickly
It was actually discovered by massive brute force chemical search for repellants
This is also straightforward enough and enough evidence exists that it would be hard to drag it out.
The overall point remains the same: the toxicity, both short and long term, of MMA, is comparable to lots of everyday substances that are both commonly eaten and inhaled.
It just isn't that toxic as far as chemicals go. That doesn't mean it would be like great for you but calling it "highly toxic" is tremendously overblown and doesnt serve anyone well to claim.
Let's save the highly toxic claim for things that actually deserve it. We don't have to sensationalize everything. I maintain my view that the explosion would likely be much much worse than the odds of significant respiratory damage from MMA.
Also note the sensationalization also causes placebo effect. People miles away started claiming "their lungs hurt" when
1. There was no leak
2. Even if their was and it was a conspiracy or whatever, your lungs have ~no pain receptors and your chest/pleura/etc would generally not hurt from MMA overexposure. Your throat would and your skin would, depending on concentration. But nobody complained about skin irritation when the is basically no way to end up with one without the other.
Etc.
Sensationalization of this hurt people so far more than the actual issue!
Additionally it is almost certainly not in vapor form at 100 degrees. In sunlight it will also polymerize to a solid pretty quickly.
As such you'd practically have to drink it inside to hit the ld50.
The explosion would be much worse than a release of liquid or vapor based MMA during the day, and here it almost certainly solidified at this point
It also has a fairly small explosive concentration range (2-12%).
(the inhibitors it gets mixed with are about the same autoignition temperature, but have higher flashpoints).
In any case:
1. The pinhole issue can be resolved pretty easily by making a big hole instead of a small one :)
2. MMA is normally stored at ~0psi. The increasing pressure here is from runaway polymerization boiling the liquid (the runaway comes from the polymerization being strongly exothermic). These tanks are not built to handle very much pressure, usually a few psi max. I doubt whatever the tank pressure is currently qualifies as the kind of high pressure you are talking about.
3. There is apparently a significant crack now that is relieving most of the pressure. Which is preventing it from bursting. Assuming the crack didn't exist before this all occurred (so far the prevailing theory is it did not, but who knows how it will turn out), it almost certainly started as a pinhole that propagated, so if it was going to ignite the way you said, it would have happened already. My guess - even if what you say is 100% correct, the pressure is never high enough to cause issues, even with pinholes.
I would bet a lot of money the number here is also >1.
I would not be surprised to learn that is why the pipes/valves/etc are "gummed up" (to use the term from the article) - people who touch the valves/etc probably have mma on their hands/gloves, and then because those are outdoors, it eventually hardens.
Or something similar.
Which, of course, is pretty spark resistant to begin with.
Even if this wasn't true, this is not a hard problem, you can use non-sparking tools, proper coolant, lots of things to avoid sparks.
Or you know, we could require that highly flammable materials subject to thermal runaway have "drill here in case of emergency" patch of non-sparking material or something.
The cost of ATEX/Class 1 Div 1 compliance would not really go up if you required this.
So, there are two issues:
1. The grid is now pretty unreliable. Georgia Power overall is a great company to work with (compared to say PG&E), but power quality has dropped out the past few years in some areas.
I've had plenty of equipment destroyed due to grid spikes and other weirdness that just didn't occur a few years ago. To give a concrete example: About 3 weeks ago, there were 4 days where literally every arc fault breaker in the house would trip randomly. Why? Because the incoming waveform became super noisy[1], and arc fault breakers are tricky beasts :).
They do notice and fix these things eventually, but the practical time to resolution is days, not hours.
2. We live in an area where the power lines are above ground and trees are aging out. They were planted over 150 years ago, and for a lot of these trees, the lifespan is 125-150 years. So we don't just get taken out by storms, but just nature :)
Georgia power puts new lines underground exclusively, and has moved a lot underground even around us, but our street is the last on the line of service that is both above ground and quite long. As a result, literally any issue/disconnect over about a 2 mile length with tons and tons of old trees, takes us out. This is also partially the reason our power quality sucks so much - any issue is more likely to affect us more than others.
Again - when it comes to outages they are quite fast at repair, having dismantled and removed insanely huge trees, and then repaired the line, almost always within 24 hours.
But it's still annoying. Combined with #1, it's just easier to be semi-off grid (IE monitor grid and swap over when grid is gone or sucking) with a generator or equivalent. Note that because we all own historic homes built in the early 1900's, our electricity usage is is significantly higher than normal just due to lack of insulation, etc. Retrofits only help so much for various practical reasons.
In a newly built home, the generator cost would probably be closer to 15-20k. Battery cost would be similarly half. Nothing to sneeze at, of course, but still.
[1]. I have a very high end fluke power analyzer (a fluke 1775) that i've had for years to debug power quality issues. These are power quality analyzers meant to be used to test service issues like this. I actually bought it when i got tired of having PG&E lie to me in California.
It's definitely the case for me (and friends of mine), that between reasonably priced batteries, inverters,etc, doing good battery backup for the house (and peak demand shaving/etc, i use a lot of power and take advantage of time of use tariffs) is now less than half the price of a generator.
Most of my friends spent 35-45k on a generator.
I will have spent <20k on batteries + inverters. It would actually be even less, but i have 600amps of split phase for the house, and 150 amps of 480v 3 phase for the shop, so i need two different kinds of inverters.
It is all literally being installed right now.
I would actually go completely off grid, but i live in a historic area and have slate roofs so can't really do solar easily ;)
As for what changed - 12 months ago this setup would have been almost double the price, just because of the availability (or lack thereof) of the right kinds of products necessary to achieve it. I know because i priced it :)
Availability here isn't in terms of stock, but literally in terms of "variety and choice of product".
For example - the availability of UL certified low cost 48v batteries in various sizes has skyrocketed in the past year. Lots of states require UL certification, assuming you are doing this in a permitted/etc way) Additionally, a lot more outdoor batteries are now available (my setup is outdoors but mostly protected).
The availability of choices in higher kVA but still residential grade inverters has also skyrocketed, etc.
As for why the price was doubled - before i would have needed 2x the number of inverters, and you really couldn't get a good 480v inverter except with high volt batteries that are wildly less available and wildly more expensive. On top of that, the batteries you could use that were UL certified and outdoor rated or could easily be done in outdoor enclosures was much lower than it is now.