elihu

...or to open the door of someone else's car if you're a passenger.

No, I think the idea is it backfeeds into everything connected by the same wire -- unless the grid shuts down entirely and there's no 60-cycle signal to synchronize to, in which case it shuts down for safety.

Maybe a useful mental model is a trampoline? The grid is like a jumping elephant or something (I don't know if they jump, we'll say they do for the sake of the analogy), and you could have people also jumping on the trampoline. If they're a bit late, the elephant launches them in the air, and if they're a bit early the elephant sucks the energy out of their jump, but that energy makes the elephant jump higher. And a fully distributed grid would be one where there is no elephant, just a million people jumping on a trampoline.

Wouldn't all three being plugged in be likely to trip the breaker, because it's just AC and the breaker can't really tell whether energy is flowing "forwards" or "backwards"?

Seems like the worst case scenario is when you mix solar panels with load on the same circuit.

800W at 110v is about 7 amps. Suppose you have a 7 amp solar inverter plugged in as the first thing on that circuit. Further down the line, you have 22 amps worth of load. The circuit breaker sees 15 amps, but the wiring between the panel and the load is carrying 22 amps, which would ordinarily trip the breaker but it doesn't because the solar setup is masking it.

I'm not an electrician. Perhaps wiring code has enough safety margin that being 800 watts over on some circuit isn't actually a serious safety concern, but I could understand why this might not be allowed.

The EU is on 230v, so maybe it's a bit more practical over there because you can add twice the solar capacity for the same amount of additional current you'd have in the US, so they aren't eating into the safety margin quite as much. Though it seems they also use thinner wire gauge generally, so maybe the difference is moot.

Having good technical tools won't fix a failing society, but they're still nice to have and they make state surveillance of its citizens just a little bit harder. I mean, where would we be without strong cryptography?

The way I look at it is that a manager can make decisions with wider scope, but the people under them exert greater control in day-to-day tasks over some narrower scope. In software development, for example, a manager might set goals for some project, but it's individual developers who are actually writing the code that usually have the most leeway to decide for themselves how best to solve some particular problem. (So long as it's within the bounds of what peer reviewers will accept.)

I think org charts would better fit how I think of the organizations they represent if they were drawn upside-down, like a tree.

It's the most common unit for describing the explosive yield of a nuclear weapon. So, it's a lot smaller than the bombs dropped on Japan in WWII, but a lot bigger than a Davy Crockett. That's a sort-of-useful frame of reference.

The only other things I can think of that would create a similar kind of blast are a volcanic eruption or something like that fertilizer explosion in Beirut in 2020 (~1100 tons TNT equivalent.)

The Super Turcano is a prop-driven aircraft that's often suggested for this role.

Or, alternatively, you switch to DC to get more current capacity over existing wires. (At a given voltage, a wire can generally carry more DC current because it doesn't have the same "skin effect" that AC has.) Even if the hardware at the substation is more expensive, it might be cheaper than upgrading the transmission lines.

I've been wondering for awhile about the economics of the AC vs DC grid thing. Historically, AC made a lot more sense because transformers are simple and relatively straightforward to make. But now we have amazing capabilities to handle enormous amounts of power with modern IGBTs and similar power-switching transistors. (A modern high-end EV motor controller, for instance, might be able to handle a megawatt of power. Not continuously, but still.) Is a DC-DC converter now more economically viable than an equivalent transformer? The former is more techincally complicated, but the latter is bulky and requires large quantities of expensive input materials like copper.

I really want the US to get on board with solar in general. Parking lot solar is a good thing generally, but I don't think it should be mandatory because it's an inefficient use of resources. We don't have any shortage of rural land.

Maybe a more flexible policy could be something like: for every parking spot, you must add 1 kw of solar somewhere on your property (whether that's the parking lot or building roof or whatever is up to you) or add 2 kw of solar somewhere within a 20 miles of the site or add 3kw of solar somewhere in the US.

A lot of companies might find that the last option is the cheapest, and if that's the case we should want and encourage them to do that instead.

It can be either AC or DC. Aluminum TIG welding uses AC, whereas you'd use electrode-negative DC for steel or copper. As I understand it, with aluminum you need the electrode-negative part of the waveform to transfer heat to the work piece, but you need the electrode-positive part of the waveform to clear out the crud that accumulates in the electrode-negative part. Often you set a lopsided duty cycle and use different frequencies depending on how deep you want the weld to penetrate.

If you go to 100% electrode positive you tend to heat the metal rather poorly, but can turn the end of your tungsten electrode into a molten blob -- which is usually not desirable.

It may be a boon to EV makers everywhere including in China, but I don't think it's a boon to China generally as they buy a lot of their oil from the Gulf states. Thus they're more directly affected by the Hormuz shutdown than the US (which is a net oil exporter and is mostly only affected indirectly by price increases).

Like the Ukraine war, maybe one good thing thing we can say about this terrible situation is that it may encourage a lot of countries to move to renewables (or nuclear) sooner than they otherwise would and cut back on fossil fuels.

The energy crises of the 1970s caused people to start caring a lot more about fuel economy. Now we have the technology for people not to need to buy gas to propel their vehicle at all, and many of them once they switch they're never switching back.

That's true enough at the level of individual households. If the whole neighborhood switches to EVs, the power grid in general might not be built to handle it.

(Personally I don't expect this will be that big a deal, since switching to EVs is something that happens one household at a time over many years. So, it shouldn't come as a sudden shock, and its something the utilities can make long term plans about. It just means power utilities need to be on the ball about not putting off infrastructure upgrades, and it means somewhat higher electricity prices for residential customers.)

Sure, that's basically just intonation (JI). You pick what key you want to play in and a scale, and then you build an instrument around that scale.

(Though something that happens in just intonation is that you often find out you need more notes than you might have originally thought, because JI makes distinctions between notes that are treated as the same in 12-TET. For instance, you might have 10/9 or 9/8 as your major second, or your minor seventh might be 9/5, 16/9, 7/4, or 12/7 depending on context.)

I don't think any just intonation guitar has been mass produced, but you can definitely build one or modify an existing guitar if you have the right tools and are willing to do a bunch of math and learn how to install frets.

This page is about a JI keyboard I built a while back, but there's also a few pictures of a couple old Harmony guitars I adapted to JI: https://jsnow.bootlegether.net/jik/keyboard.html

Here's a so-so performance of myself playing a Bach piece on a newer and vastly improved version of that just intonation keyboard: https://www.youtube.com/watch?v=rqbWnDhip0A

In 12-EDO the song has 11 distinct pitch classes. (Bach used the tritone, but not the minor second.) In my straightforward JI interpretation, I use 15 pitch classes. (I would have used 16, but my keyboard simply doesn't have a key for that note.)

> the irony it comes from the same people who blame Israel for not letting supplies into Gaza during war.

Israel did in fact do that. In fact there were several months of Israel not allowing any food or supplies whatsoever into Gaza. That was about a year ago. (It's possible Israel may have been supplying rival groups unfriendly to Hamas with food/supplies/weapons in secret, but all regular humanitarian aid was shut off.)

Whether or not one would accept deaths of civilians to get rid of Khamenei, I don't think anyone should accept a school full of children being blown up for no obvious reason. If there was somehow a reason why Khameni could not have killed without attacking that school, then those reasons should be plainly spelled out and evidence presented. As things stand with the limited information we have now, it just looks like a war crime with no strategic upside.

Also worth mentioning Baldassare Forestiere, who spent about 40 years digging an extensive network of tunnels in Fresno, CA.

https://en.wikipedia.org/wiki/Forestiere_Underground_Gardens

Maybe Claude is just a fan of Tengen Toppa Gurren Lagann? (Or influenced by the fandom thereof.)

If the fundamental is 100hz, then the 1st harmonic is the fundamental (100hz), the 2nd harmonic is 200hz, the 3rd harmonic is 300hz, and so on.

Sometimes the harmonics aren't exact. On a piano, if the fundamental is 100hz then the 2nd harmonic might be, say, 200.1hz or something. Some inharmonic instruments like gongs aren't anywhere close to the "ideal" harmonic series.

A minor terminology quibble: the video refers to the Nth harmonic as if it's the fundamental frequency times N+1, but it's usually fairly standard to refer to the frequency that's N times the fundamental as the Nth Harmonic. So, the fundamental is the 1st harmonic.

For overtones, there's less of an established standard, but usually the 1st overtone is twice the fundamental, the 2nd overtone is 3x, and so on. (I tend to avoid talking in terms of overtones because of the ambiguity.)

The other side of this is that if you want your open source project to be useful to people, relevant, included by default in Linux distributions, highly regarded by the community, and so on then it's expected that you treat your users well.

Not every project aspires to such things, but if you do then the path to success requires at a minimum not treating users as a burden.

Some users might be particularly rude or entitled, in which case you can politely decline their feature requests and move on.

Basically, it's never rude for a user to file a bug report or request a feature. It's never rude for the maintainer to decline to implement a feature if they haven't budgeted time (or other relevant resources) to do it, it doesn't align with the fundamental goals or architecture of the project, or they simply don't know how to do it.

It would be rude for a user to demand of maintainers more than they're willing to give, and it would be rude of a maintainer not to be at least somewhat mindful that spending at least a little bit of effort to respond to reasonable requests, fix known bugs, and keep documentation accurate and up-to-date can prevent a lot of random strangers from wasting a lot of time on something that isn't useful to them. No one has any contractual obligation to provide anything, but I think everyone should treat other people's time and attention as a scarce and valuable commodity, not to be wasted.

Didn't realize she played Lwaxana Troi. Knowing that now I wonder, am I going to hear the ship's computer as Lwaxana?

That could be one reason they want to do it. Maybe by using data from Palantir or harvested from Elon's work with DOGE, along with twitter user data and whatever else they can get, they want their AI to be the all-seeing eye of Sauron. (Which isn't too far from what the whole ad-tech industry is about in the first place.) Or they want to make sexually explicit deepfakes of everyone Elon doesn't like. Or they want to flood the internet with AI generated right-wing propaganda.

The main reason is that generating energy in space is very cheap and easy due to how ridiculously effective solar panels are.

Someone mentioned in the comments on a similar article that sun synchronous orbits are a thing. This was a new one to me. Apparently there's a trick that takes advantage of the Earth not being a perfect sphere to cause an orbit to precess at the right rate that it matches the Earth's orbit around the sun. So, you can put a satellite into a low-Earth orbit that has continuous sunlight.

https://en.wikipedia.org/wiki/Sun-synchronous_orbit

Is this worth all the cost and complexity of lobbing a bunch of data centers into orbit? I have no idea. If electricity costs are what's dominating the datacenter costs that AI companies are currently paying, then I'm willing to at least concede that it might be plausible.

If I were being asked to invest in this scheme, I would want to hear a convincing argument why just deploying more solar panels and batteries on Earth to get cheap power isn't a better solution. But since it's not my money, then if Elon is convinced that this is a great idea then he's welcome to prove that he (or more importantly, the people who work for him) have actually got this figured out.

Huh, I didn't know that that was possible without burning fuel. Kind of wild that it only works because the Earth has an equatorial bulge and isn't an exact sphere.

Communication is a well-understood problem, and SpaceX already has Starlink. They might need pretty high bandwidth, but that's not necessarily much of a problem in space. Latency could be a problem, except that AI training isn't the sort of problem where you care about latency.

I'd be curious where exactly they plan to put these datacenters... In low Earth orbit they would eventually reenter, which makes them a pollution source and you'd have no solar power half the time.

Parking them at the Earth-Sun L1 point would be better for solar power, but it would be more expensive to get stuff there.

That's not a new problem that no one has dealt with before. The ISS for instance has its External Active Thermal Control System (EACTS).

It's not so much a matter of whether it's an unsolvable problem but more like, how expensive is it to solve this problem, what are its limitations, and does the project still makes economic sense once you factor all that in?

Honestly, there's not a lot else I can think of if your goal is find some practical and profitable way to take advantage of relatively cheap access to near-Earth space. Communication is a big one, but Starlink is already doing that.

One of the things space has going for it is abundant cheap energy in the form of solar power. What can you do with megawatts of power in space though? What would you do with it? People have thought about beaming it back to Earth, but you'd take a big efficiency hit.

AI training needs lots of power, and it's not latency sensitive. That makes it a good candidate for space-based compute.

I'm willing to believe it's the best low-hanging fruit at the moment. You don't need any major technological advances to build a proof-of-concept. Whether it's possible for this to work well enough that it's actually cheaper than an equivalent terrestrial datacenter now or in the near future is something I can't answer.

Do they need to be maintained? If one compute node breaks, you just turn it off and don't worry about it. You just assume you'll have some amount of unrecoverable errors and build that into the cost/benefit analysis. As long as failures are in line with projections, it's baked in as a cost of doing business.

The idea itself may be sound, though that's unrelated to the question of whether Elon Musk can be relied on to be honest with investors about what their real failure projections and cost estimates are and whether it actually makes financial sense to do this now or in the near future.