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Ray Bradbury once explained with a poem why he writes science fiction and why space travel is so important to him. It is perhaps my favorite poem. Text version: The fence we walked between the years We ached and almost touched that stuff; O, Thomas, will a Race one day stand really tall Short man, Large dream I love this poem deeply for how dumb his reason is. He’s very straightforward about why he dreams of space travel ‘Twould teach us, not to, never to, be dead Advancing space travel is a silly way of try to escape death, but when the mind really really wants something, it clings to the best plan it can find for achieving it. Even if that plan is very very dumb. I see a lot of honor in this poem because while many hope to escape death, few are willing to admit to themselves, much less talk openly about their dumb plan for it. Their friends and family would think they were foolish, naive and a bit suspect – only villains want to cheat death. But Bradbury was willing to dream openly anyway. His courage makes it easier for us to have courage too. I have a similar awed respect for the child who whispers quietly to herself when she’s alone ‘I wish mom wouldn’t hit me’. They both have the virtue of looking directly at a terrible darkness they are powerless in front of and whispering ‘I wish that weren’t there’. The poem is also tragic now that he’s dead. It reminds me of all those who have gone before me, longing futilely and silently, and now he has joined them. My mother and the many billions of other humans who preceeded me. And hoped by stretching tall that they might keep their land I, too, long to keep my soul.
Followup to: Words as Mental Paintbrush Handles, Guessing The Teacher’s Password Jessica Taylor recently wrote a description of Paul Christiano’s and MIRI’s differing driving intuitions for thinking about the AI alignment problem. Jacob Steinhardt observes that the “do cognitive reductions” intuition seems to be at the heart of MIRI’s thought and the “search for solutions and fundamental obstructions” intuition at the heart of Paul’s thought. As I read his comment, I noticed myself make an error I’ve made before: thinking I get the intuitions by mere virtue of not thinking they’re crazy. I call this The “I Already Get It” Slide, and I suspect this error happens to people all the time but passes unnoticed. This is unfortunate because the error prevents you from actually absorbing other’s intutions, and absorbing other’s intuitions is important for doing anything hard. Jessica describes Search For Solutions And Fundamental Obstructions like this: Almost all technical problems are either tractable to solve or are intractable/impossible for a good reason. […] If the previous intuition is true, we should Search For Solutions And Fundamental Obstructions. If there is either a solution or a fundamental obstruction to a problem, then an obvious way to make progress on the problem is to alternate between generating obvious solutions and finding good reasons why a class of solutions (or all solutions) won’t work. In the case of AI alignment, we should try getting a very good solution (e.g. one that allows the aligned AI to be competitive with unprincipled AI systems such as ones based on deep learning by exploiting the same techniques) until we have a fundamental obstruction to this. Such a fundamental obstruction would tell us which relaxations to the “full problem” we should consider, and be useful for convincing others that coordination is required to ensure that aligned AI can prevail even if it is not competitive with unaligned AI. As I thought about Paul’s Search For Solutions And Fundamental Obstructions intuition, a justification easily came to mind — a non-verbal feeling that it looked like other well-accepted problem solving strategies. This justification was easy, familiar and wrong. There is no way that “it looks like other accepted strategies” is actually the reason Paul thinks finding fundamental obstructions is central. And yet it was very easy for me to mentally slide from getting the conclusion and not immediately thinking it’s crazy, into thinking I also got the intuitive argument that generated it. If I had to guess at Paul’s actual intuitive reasons, I would guess something like this In Computer Science Theory, whenever there have been these kind of hard and confusing problems and people have tried to solve them, they’ve always turned out to either be possible or have some very revealing fundamental problem. For example, here are 4 clear examples. Furthermore, this makes intuitive sense because X. Also, this is also the case in these 3 other fields. And AI alignment looks a lot like these fields because it has Y and Z in common.“ But I also bet that not only will Paul have a more detailed argument, but also he will use a different ontology in a way that makes the argument meaningfully different. The argument is not yet compelling to me. Now, perhaps his arguments sound weak or just boring to you. How could a useful intuition be consistent with weak sounding arguments? To answer, put yourself in Paul’s shoes, and ask yourself what could explain weak or boring sounding arguments? Maybe you have a strong but difficult to articulate intution – maybe a mental picture of how different parts of the research process move against each other. Or maybe you can articulate your intuition, but when you do people quickly offer counterarguments that are — sigh — totally off topic. They nod along as if understanding, but then go right back to what they were doing before. You can probably imagine your conclusion being wrong, but not your insight being irrelevant. If Paul is at least as sensible as you are and his arguments sound weak or boring, you probably haven’t grokked his real internal reasons. Your intuitive mental picture of how parts of the research process moves is shaped differently than his. Maybe you’re even using different piece. If so, then it is not surprising that you come to different conclusions. You don’t even have the machinery to come to his conclusion. Maybe instead you think that getting his intuitive reasons from him doesn’t matter. After all, now that I know what Search For Solutions And Fundamental Obstructions means, I can just check that it should be a central strategy myself. But without an intuitive model of why it should be a central strategy, to check I would probably have to do computer science theory for at least a few months. Without my own intuitive model pulled from Paul’s intuitive model, there’s little to distinguish Search For Solutions And Fundamental Obstructions from a near-infinite variety of nearby strategies like “search for solutions and obstructions on complexity problems” or “search directly for fundamental obstructions”. Intuitive models let us cut down our uncertainty in great swaths by concentrating our probability on simple hypotheses. With my own intuitive model, checking often just requires seeing a few well chosen examples, or even just thinking back on past problems. All this is to say that Paul almost certainly has a valuable intuitive reason for his position. If I don’t catch my slide from understanding the conclusion to thinking I understand the argument, I’ll never notice that there’s something more to absorb. There’s a world of difference between understanding what Search For Solutions And Fundamental Obstructions means, and understanding the intuition that generates it. A difference, in other words, between understanding the conclusion and understanding the argument for it. If you mistake the conclusion for the argument, you will never get the argument. This reasoning doesn’t just apply to Paul and his intuitions, it applies to anyone who you think is about as reasonable as you. If they avoid errors about as well as you, then it would be silly to think that their intutions don’t point to real insight about the world. This also applies nicely to MIRI’s intuition that doing Cognitive Reductions is the main thing that can push AI alignment research ahead. Jessica describes Do Cognitive Reductions like this: Cognitive Reductions are great. When we feel confused about something, there is often a way out of this confusion, by figuring out which algorithm would have generated that confusion. Often, this works even when the original problem seemed “messy” or “subjective”; something that looks messy can have simple principles behind it that haven’t been discovered yet. Again, it is tempting to gloss over the fact that cognitive reductions are useful but not central, since we do already agree to some extent. But consider: if I were in their position, what kind of intuitions would actually lead me to think that Cognitive Reduction is so central? It couldn’t be just a stronger version of the belief that I already have, that would just make me think its somewhat more useful, rather than something to base my whole strategy around. Only a new argument could make sense of that. If I go argue with MIRI without noticing that there’s an argument I’m missing, we’ll just go around in circles. I suspect that The “I Already Get It” Slide happens all the time and passes unnoticed. That people mistake a person’s conclusions with their intuitive reasons and don’t end up absorbing their real arguments, even when they have insight. That would explain why peoples opinions converge so slowly.
More in science
[Note that this article is a transcript of the video embedded above.] I love the periodic table of the elements. I love it because it reveals the deeper order of what seems like an otherwise wildly disparate collection of atoms with different physical forms, chemical properties, and nuclear stabilities. I love it because, even before we actually found the elements that fit into each box, we knew that something did and could even predict some things about those elements before they were ever discovered. And finally, I love it because it’s a bit messy. Not everything lines up perfectly, and in some ways, it’s still a work in progress. In many ways, human-created standards follow that same form, and I want to try and convince you that they deserve the same affection. Let me present the periodic table of standard North American electrical connections. Isn’t it beautiful? I’m fascinated by stuff like this: a diversity of needs and purposes put into a relatively nice, neat order. But why do we need so many? And where do any of these actually get used? Well, I’ve spent the past month reading just about everything I could find on electrical plugs and receptacles to figure those questions out, and I even have a few of them here so I can show you what I learned. I’m Grady, and this is Practical Engineering. Electricity is something we really don’t want to be proprietary. It’s one thing if your charger doesn’t work on your buddy’s cell phone. It’s another thing entirely when you have to rewire your house because you bought a different brand of toaster. The National Electrical Manufacturers Association, or NEMA, was founded in 1926 as a coalition of companies making electrical equipment. Their members realized that life would be better with some standards, so that any company making an electrical device could be reasonably confident that the people who might want to buy that device would be able to use it, and more importantly, use it safely. This didn’t happen overnight. It took a diverse group of manufacturers, engineers, and testing labs to form a consensus around the system we use today. And it’s far from a perfect system. My friends Mehdi and Alec have covered receptacle-related topics on their channels, including the merits and disadvantages of the NEMA designs. But it works pretty well. Well enough that the NEMA connector standards have been adopted not just in the US, but all of North America, Central America, parts of South America, Japan, Taiwan, the Philippines, and beyond. Here’s that table again. You probably noticed that every type of plug and receptacle has its own special number. They seem a bit arcane at first glance, but it’s actually a handy naming scheme that’s pretty straightforward to understand. The first number is the configuration that defines the combination of voltage rating, wire count, and grounding style. These numbers are a bit arbitrary, but they kind of represent a certain class of receptacles and plugs. For example, NEMA 1 receptacles are rated for 125 volts and have just 2 poles (a hot and neutral) with no ground. The NEMA 1-15 was the classic North American outlet until the 1960s, and you still see these in older buildings. Lots of devices made today can still use them, especially low-voltage equipment like chargers, and, critically, those without external metal parts. If an energized wire inside the device comes loose and contacts the case, there’s still an insulating barrier protecting someone from being shocked. The reason NEMA 1 receptacles are mostly a thing of the past is what could happen when equipment didn’t have that protection. If a device with a metal enclosure or exposed metal parts had an energized wire come loose, that metal would be energized too. But, critically, it might not create a short circuit. With nowhere for current to flow, the device could just sit there, indefinitely dangerous, until someone happened to touch it, allowing current to flow through them to a lower potential. The ground wire we see in nearly all plugs and receptacles today fixes that specific hazard. Bonding exposed conductive elements and connecting them to ground makes sure that if they somehow become energized, current will flow, a short circuit will form, and protective devices like breakers will activate. Today we use the NEMA 5 standard for the vast majority of receptacles and plugs. Even if you’ve never heard of NEMA or seen the other plugs on the periodic table, you’re almost certainly familiar with this design. They have a 125 volt rating to handle the standard 120 volt service for most electrical devices with a little buffer. They have an energized pole, called the hot; a neutral pole to provide a return path, and a separate ground return that is bonded to the neutral line in the main electrical panel. The ground pin on most outlets is round instead of flat, and that’s the reason why nearly all electrical outlets kind of look like they’re screaming. Or at least they do to me. One thing about NEMA 5, and actually most of the NEMA configurations, is that the outlets have polarity. On the NEMA 5-15, the neutral slot is a bit wider than the hot, making it so the plug can only go in one way. In function, polarity often doesn’t matter for AC circuits. Current travels in both directions, so the equipment inside the device can’t really tell the difference. And some devices, like switch-mode power supplies, don’t care which direction they’re plugged in. Both blades are the same size. For safety, though, a lot of devices do. You really don’t want heating elements, motor coils, and circuit boards energized and waiting for a ground. It’s less hazardous to put the switch on the hot wire so that nothing beyond the cord is energized until it’s turned on. Enforcing polarity at the plug prevents “switched neutrals” along with other issues like electrical noise. The NEMA 5-15 plug and outlet were designed to be backward compatible with the older 1-15 standard. 1-15 plugs work just fine in the modern 5-15 outlets, and there are quite a few interesting compatibility cases like that in the NEMA standards. For example, the “15” in 5-15 refers to the current rating. Nearly every household device and appliance that runs on 120 volts is designed so that it never draws more than 15 amps, and actually, if the device is meant to run for more than 3 hours continuously, like a space heater, it can only draw 80% of that (which is 12 amps if you’re keeping score at home). That limit is obviously fine for most household appliances. But, especially in commercial spaces, it’s not quite enough power for certain devices like kitchen mixers, treadmills, copy machines, and power tools. Of course, we could just change the codes to require 20-amp circuits everywhere, but that has huge implications: larger circuit breakers, heavier-gauge wiring, and more expensive receptacles. And in many cases, it’s just not necessary. So instead, NEMA created a different receptacle and plug for 120-volt, 20-amp circuits, the 5-20. I have a bunch of these in the studio. You can see they have that T shape on the neutral slot. And 20-amp devices have the neutral blade rotated 90 degrees on the plug. But here’s the backward compatibility: regular 15-amp plugs fit into the 5-20 receptacle as well. NEMA 5 has 30 and 50 amp receptacles too, although they aren’t used very often these days because of a quirk about the historic availability of voltage. Today, split phase electrical service is basically standard for residential power. You get two 120-volt hot lines which can be used individually for smaller circuits or combined to get 240-volts for circuits that need more oomph. In the early 20th century, 240-volt service wasn’t always available, so you have these very-high-current 120-volt receptacles that could power heavy commercial cleaning equipment like floor burnishers and blowers, kitchen equipment like warming cabinets and steam tables, and large shop tools like table saws and compressors. Also, not all portable generators run at 240-volts, so older models used the larger NEMA 5 receptacles as well. These are still available and installed in places where, for whatever reason, a higher-voltage circuit is hard to come by. But in most cases, the more power-hungry devices are going to run on 240-volts. That brings us to NEMA 2. Like NEMA 1, these are ungrounded receptacles, but instead of a hot and neutral, they have two hots. Each is 180 degrees out of phase with its neighbor, so you get 240-volts across them, handled with a little cushion by the 250-volt rating. There were 20 and 30 amp receptacles, but, also like NEMA 1, these are mostly obsolete now that a ground is required by code. They’ve been replaced with NEMA 6, which has 15, 20, 30, and 50-amp receptacles and plugs. Of course, with double the voltage, you also get double the power compared to the NEMA 5 equivalents at the same current rating. The 6-15 is common for window or wall-mounted air conditioners. The 6-20 is used for heavier-duty air conditioners plus commercial kitchen equipment and shop tools. The 6-30 is used with large heaters, kilns, and heavy power tools. The 6-50 is kind of the standard welder outlet, plus it’s pretty common these days for level 2 EV chargers, capable of delivering nearly 10 kilowatts of continuous power through the receptacle. Like NEMA 5, the NEMA 6 has some backward compatibility, allowing 6-15 plugs to fit into 6-20 receptacles. This is kind of clever, but it doesn’t work all the way up the different current ratings. Of course a 50-amp outlet could easily handle a 15-amp device. And it would certainly be possible to design a series of outlets where each successive jump in current rating allowed those smaller devices to plug in. But there are two main reasons why they don’t: One is practicality. The blades on plugs aren’t all the same thickness. Designing a single receptacle slot that can safely grip both a thin, 15-amp blade and a massive 50-amp one would make manufacturing more difficult and increase the chances of developing loose connections inside the receptacle over time. Two is safety: circuit breakers are sized to protect everything downstream, including the plug and the appliance cord. If a thin cord on a low-current device develops an internal short, the resistance of that thin wire itself will cap the fault current so that a larger breaker might take much longer to trip or not trip at all. That could allow the wire to reach high enough temperatures to start a fire. Of course you don’t want a high-current device plugged into a lower-current-rated circuit, but if you trace out the things that can go wrong, it turns out that you also don’t want lower-current devices plugged into a high-capacity circuit. So, the plugs and outlets are designed to prevent both cases, except for the 15 and 20 amp situation, where the current is close enough that a breaker should still work as intended. 240 volts are useful to supply more power at the same current rating, but of course it comes at a cost. Higher voltage means more potential, literally, for arcs to occur. Equipment designed to handle the higher voltage needs better insulation and more careful design. Take a clothes dryer for example. You want the extra voltage for the power-hungry heating elements, but all the other stuff inside (like timers, controllers, and clocks) can easily run on 120 and those lower-voltage components are more affordable. That’s where NEMA 10 came in. You get three poles: two hots and a neutral. In that way, you get dual voltage: 240 between the hots and 120 between each hot and neutral. Of course, NEMA 10 receptacles also lack a ground connection, so they’re mostly obsolete. Plenty of houses still have them installed for clothes dryers and kitchen ranges, but since the 1990s, they’ve been supplanted with the NEMA 14 configuration. This is the most widely-used 240-volt standard in North America today. It’s versatile, providing both voltages. And there are a full range of current capacities, allowing you to design a circuit that’s well-suited for a device, from 15 all the way up to 60 amps. The 14-15 is pretty rare. I couldn’t even find someone making the receptacle. The 14-20 is also not that common. Some food service equipment uses this like certain coffee makers. The warmers rely on 240 volts while the fans and timers run on 120. Same with some jobsite heaters and specialized laboratory equipment. The 14-30 is the standard residential electric clothes dryer plug and is often used for EV chargers. Some server and mainframe equipment uses it as well. The 14-50 is the standard residential cooking range and oven plug. It’s also widely used for EV chargers and pretty common at RV campgrounds as well. The 14-60 is more of a commercial or industrial receptacle, used for large kitchen appliances and distribution of power at events like concerts. Single phase electrical service covers nearly all residential and lots of commercial buildings. But, the grid runs on three phases and it’s pretty common for larger commercial buildings and essentially all industrial facilities to have three-phase service. It’s particularly useful for devices that use large motors. And of course, if you have the service, you’re going to need receptacles and plugs for those devices, or at least the ones that aren’t hard-wired. NEMA 11 was the standard for up to 250V with receptacles and plugs ranging from 15 to 50 amps. Those have been replaced by the new NEMA 15, again because of grounding requirements. And this is going to almost always be relatively specialized industrial devices: woodshop and machining tools, laboratory testing equipment, grinders, pumps, dust collectors, heavy welders, plasma cutters, and so on. It’s not stuff most people see in everyday life, and in many cases, each receptacle is going to be custom-installed for a specific piece of equipment. And since hard-wiring equipment directly to the service panel is typically the default, that makes receptacles like these even more rare. You really only see them in places that need a high degree of modularity, allowing for rapid reconfiguration of workspaces like jobsites, certain manufacturing facilities, and short life-cycle equipment that needs to be easily swapped out. There are two main three-phase service classes used in most commercial and industrial buildings in the US. The most common is 208 volts phase to phase, which uses the NEMA 15 configuration. There’s also 480 volts phase to phase, but like I mentioned before, you can get a lower voltage between phase and neutral (in this case, 277 volts). So NEMA 7 has plugs and receptacles specifically for using just one phase from buildings wired with 480-volt, three-phase service. A lot of commercial and industrial lights use these receptacles, like warehouses, factories, and arenas, making them easy to swap out without hard-wiring. Commercial ventilation and air conditioning systems use them too. And just like the dual-voltage 240-volt plugs, there are also dual-voltage three-phase plugs, delivering equipment with all three hot phases plus a neutral so different components can run at different voltages. NEMA 18 has receptacles for 208-volt service, although they don’t have a ground, so they’re mostly obsolete. There are no straight-blade plugs that have replaced NEMA 18. Aligning and inserting a 5-blade plug would be tricky and take a lot of force. And I’ve kind of buried the lede here only talking about the straight-blade NEMA standards. The reality is that a large number of the NEMA receptacles and plugs have an equivalent locking version. These use curved blades that twist inside the receptacle so they can’t be easily pulled out. Actually the locking versions are more common than the straight-blade equivalents in many cases, especially when it comes to portable generators, jobsite equipment, and events where things are always moving around. If your vacuum cleaner unplugs itself because you’ve gone too far into the hallway, that’s usually not a big deal, but if a three-phase 600 volt plasma cutter does the same thing, you can get serious damage from arcing. That’s why the locking standards extend beyond the voltage ratings of the straight-blade ones up to three-phase 600-volt circuits. They even have receptacles for 400-hertz power used in aerospace, submarine, and military systems. Of course, sometimes the standards make themselves. When it comes to RVs and travel trailers, (from what I can gather) the industry had already developed a 120-volt, 30-amp receptacle before NEMA formalized its catalogue of standards. Instead of forcing an entire industry to retool, NEMA just adopted what everyone was already using, calling it the TT-30. TT for travel trailer and 30 for the current capacity. In function, it’s not any different than the NEMA 5-30 receptacle and plug, but you’ll almost never see one of those, because the TT-30 is far more common. It’s a face only an outlet enthusiast could love. I haven’t really talked about the smaller versions of the locking connectors used where space is an issue. And there are even more specialized standards like ship-to-shore power, aircraft, and military uses. Of course, when you look beyond NEMA, there are way more standards out there. But I feel like this is enough to get you excited about the weird, wide world of electrical receptacle standardization. There are all kinds of practical considerations that make it much more complicated than just a 2D chart with voltage on one side and current on the other. Just like the periodic table of the elements, the NEMA connection standards are a bit messy. And that’s what I love about them.
The course of history is affected by many things, including the political and social situations of large groups of people, […]
Rethinking the electric field Have you ever wondered what an electric field actually is? The electric field is the foundation of most technologies that we rely on every day. From power grids and electronic devices to radio communication and the … Continue reading →
We are less than one month away from the end of the federal fiscal year, and traditionally there are internal deadlines for agencies to allocate their final spending by around September 9. Right now, the NSF is on track to issue about 4000 fewer (!!) awards in FY26 than it did annually back in FY21-FY24, and 2000 fewer than it did in the incredibly tumultuous FY25 (with its government shutdowns and mass cutbacks in agency personnel). This is dire, if like me you are a supporter of the agency and its vital role in the US research ecosystem. Perhaps even more distressing, the NSF is on track to underspend its FY26 budget appropriation (congressionally approved, presidentially signed) by between $1.25-1.5B, or 15-18%. This is essentially unprecedented - in the past, the NSF has always spent ~ 99% of its appropriation in a given fiscal year. Some large portion of this is from the mid-FY clawbacks that were reported in Science and Nature, supposedly squirreled away to support an as-yet unannounced OSTP "grand challenges" program. While technically the funds don't go away at the end of September, this kind of underspending raises the possibility of a pocket rescission. OMB and the executive branch have been pushing for massive cuts to the agency; Congress has disagreed. It sure looks like all the "see, don't worry, Congress didn't allow big cuts to the NSF" palliative statements don't hold up very well to scrutiny, if the majority party is content to just give up Article I power to the executive branch. In this period of complete flood-the-zone craziness, the mainstream news media seemingly doesn't have the bandwidth or interest to report on this; they seem to have judged that it's too obscure, it doesn't play in Peoria, the public doesn't really care. This kind of disruption will have ripple effects that last for many years and affect US scientific and economic competitiveness, and it's happening without much notice. This week's news about an agreement between NIH and DOD to funnel NIH funds for infectious disease to DOD (or, in the official statement, to work together on projects of mutual interest), is at least getting some public attention. Agencies agreeing to pass around at minimum hundreds of millions of dollars outside congressional oversight or what the appropriations acts say is another example of an Article I crisis, when the majority party basically hands over what are supposed to be congressional powers to executive branch. (An additional sciencey blog post coming soon!)
I am working on a new book called You Would Choose Now: Measuring America’s Progress Toward Fairness and Tolerance. It’s a data-driven exploration of progress (or not) in public opinion and civil rights. I posted the first two chapters as an Early Access edition on LeanPub (a platform for posting work in progress like this): https://leanpub.com/ywcn If you would like to check it out, the “Free Sample” has just the first chapter. If you sign up with an email address,... Read More Read More The post New Book! appeared first on Probably Overthinking It.
