Most people aren’t shoplifters

Sunday, January 28th, 2018

TechCrunch looks inside Amazon’s surveillance-powered no-checkout convenience store, which should work just fine as long as all the customers are Amazon employees:

In addition to the cameras, there are weight sensors in the shelves, and the system is aware of every item’s exact weight — so no trying to grab two yogurts at once and palm the second, as I considered trying. You might be able to do it Indiana Jones style, with a suitable amount of sand in a sack, but that’s more effort than most shoplifters are willing to put out.

And, as Kumar noted to me, most people aren’t shoplifters, and the system is designed around most people. Building a system that assumes ill intent rather than merely detecting discrepancies is not always a good design choice.

Space is open for business

Sunday, January 21st, 2018

Space is open for business. Rocket Lab has announced, with its successful Electron rocket launch, from its own private launch pad in New Zealand, which reached orbit and successfully deployed multiple small satellites that will map the earth’s surface and track weather systems and shipping.

The Electron rocket is disposable:

It is made of lightweight carbon composite material and has 3D-printed engines to reduce costs and assembly times. It is 17m long, roughly a quarter of the size of rivals such as SpaceX’s Falcon 9 rocket, which can carry satellites the size of a van into orbit. Each Rocket Lab launch costs about $5m, compared to $62m for SpaceX, the company founded by billionaire Elon Musk.

Sunday’s launch was the second test flight by the Electron rocket following an earlier flight in May. On that occasion the rocket entered space but was unable to reach lower earth orbit due to a technical fault. It is planning a third test flight later this year.

Some satellite providers are willing to risk their products on test rockets due the lengthy backlog in launches that has built up as the industry expands. Rocket Lab deployed the three small satellites on behalf of Planet and Spire Global, US-based satellite providers that are deploying constellations of nanosatellites at a low earth orbit of about 500km.

Rocket Lab says its private launch pad on the picturesque Mahia peninsula on New Zealand’s North Island gives it a commercial advantage to many competitors, who use government-run facilities such as Cape Canaveral in the US. The company is licensed to conduct a launch every 72 hours from the remote location, which benefits from the lack of air and shipping travel in the vicinity.

I first heard about Rocket Lab just last year.

An alternative to “old fashioned” deuterium-tritium fusion

Thursday, January 18th, 2018

HB11 Energy proposes an alternative to “old fashioned” deuterium-tritium fusion, laser hydrogen-boron fusion:

A scientific paper accepted for publication describes the road map that has deemed the approach by one of the founders with his team as a viable approach based on the experimentally confirmed reaction gains one billion times higher than the classical values, placing it far ahead any DT fusion approaches.

Other advantages: Unlike deuterium-tritium fusion and fission techniques, the HB11 reaction is sufficiently clean with respect to production of any harmful byproducts or radiation. It also has the potential to create electricity directly without the need for a heat exchanger and steam turbine to generate electricity as required for coal or fission nuclear power stations. This will allow power stations to be built with a relatively small capital investment and footprint based on presently achieved extreme laser technology.

We expect to be able to provide energy for about one-quarter of the price of coal fired power, without any carbon emissions or radioactive by-products, which will be disruptive to the power industry. With the small size and footprint of a HB11 power station, the addressable market is expected to reach further than the power grid to applications such as ships, submarines, large factories or to remote locations such as isolated towns and mine sites.

The birth of the digital camera

Monday, January 8th, 2018

Former Kodak employee Steve Sasson tells the story of the birth of the digital camera:

I worked for Eastman Kodak Company for over 35 years. I began in July of 1973. I was a junior engineer. My supervisor said, ‘We’ve got a filler job for you. There’s a new type of imaging device called a charged couple device imager; we want someone look at one of these and see if we could do anything useful with it.’

Our conversation probably lasted about 30 seconds, it was nothing.

Most of the parts I used to build it, I stole from around the factory. Digital volt meters and chips, digital tape cassette, prototype box, it looks like an erector set with a blue box on top with a lens stuck on top. And I would output to a television set. We took our first full images in December of 1975.

I folded the camera up, and I walked down a hallway, and there was a young lab technician, her name was Joy. I asked her, ‘Could I take a snapshot of you?’ She said, ‘sure, whatever.’ The tape started to move, that’s how I know I made a picture. I popped it out of the tape player, put it into the playback system. It was quite a moment, because this crazy thing actually worked. Up popped the image. We could see her black hair and a white background, but her face was complete static, completely unrecognizable. Jim and I were overjoyed at what we saw, because we knew so many reasons why we wouldn’t see anything at all.

Joy had followed us in, she looked at the picture and she said, ‘Needs work.’

We filed for a patent, and the first patent for a digital camera was granted in 1978. U.S. Patent 5016107. We started to show it to people at Kodak. Then, it became more interesting.

I thought they’d spend all their time asking me how did I get this to work. They didn’t ask me any of the hows, they asked me, ‘Why? Why would anyone want to do this?’

Would you pay $70,000 for a lunar vacation?

Wednesday, January 3rd, 2018

Would you pay $70,000 for a lunar vacation? That’s what Andy Weir estimates it’ll cost — eventually, in the 2080s, when Artemis takes place. Here are his key points, edited down:

The cheapest way to get mass to LEO (at the time of this writing) is with a SpaceX Falcon 9 booster. They charge $61.2 million for the launch, and it can put 13,150kg of mass into LEO. So right now, that means it costs $4,653 per kilogram.

The commercial space industry, through competition and engineering advances, will settle down to the same fuel-to-overhead ratio as the modern airline industry.

For each flight, I noted the price of each class of ticket, then worked out the take — the total amount of money the airline gets if every seat on the plane is sold at its listed cost. The fuel consumed is based on the flight duration and the fuel consumption rate of the aircraft. The cost of that fuel is based on the market price of jet fuel on the day I looked up those tickets, which was $0.475/kg. (Actually, the price was 38 cents per liter, but I wanted price per kg and jet fuel has a density of 0.8kg/L). [...] So for the rest of this paper I’ll assume a commercial airline spends 16.5% of its take on fuel.

A passenger spacecraft would weigh the same as a passenger aircraft capable of carrying the same number of people.

The commercial space industry will use hydrogen-oxygen fuel.

The thing that matters most about rocket fuel is a property called “specific impulse.” I don’t want to bore you with physics (I’m here to bore you with economics) so I’ll just say this: specific impulse is a measure of how efficient a rocket fuel is. The higher a fuel’s specific impulse, the less of it you need to get a ship moving a given velocity. And hydrogen-oxygen fuel has the best specific impulse known. Also, it creates water as its exhaust, so there are no pollutants. And finally, it’s cheap to produce.

Right now, there are engineering limitations to using hydrogen-oxygen fuel. The main one being that it burns very hot — hotter than any engine can handle. But again, I’m assuming all these challenges get researched and solved by a profit-hungry industry.

The final piece of the puzzle is the cost of hydrogen and oxygen. This was a little harder to find. I was able to find reliable data on the 2002 price of bulk hydrogen, so I adjusted the 2002 dollars into 2015 dollars and got $0.93/kg. As for oxygen, I used the publicly available data on what NASA pays for it — $0.16/kg in 2015 dollars. The reaction requires one part hydrogen and eight parts oxygen (by mass), so the total fuel cost is $0.245/kg.

Okay, we have a ship that weighs 165,500kg and we’re going to put 550 passengers on it. We’ll give them 100kg each for their bodies and luggage. That’s a total mass of 215,500kg.

The specific impulse of hydrogen-oxygen fuel is 389s (yes, the unit for measuring specific impulse is “seconds”. It makes no intuitive sense, just roll with it). To get to LEO you need to accelerate by 9,800m/s. LEO actually only requires 7,800m/s, but you lose around 2,000m/s during the ascent to air resistance and other inefficiencies.

Again, I’m skipping over the physics (Tsiolkovsky’s Rocket Equation, if you’re curious) but those numbers mean we’ll need 12.04kg of fuel for every 1kg we want to put into LEO. We want to put 215,000kg into LEO, so we need 2,594,620kg of fuel.

At our calculated fuel cost ($0.245/kg) that means the total fuel cost for the launch is $637,200.

Now I get to use my airline fuel overhead figure. Airlines have 16.5% fuel overhead ratio and we’re going to assume the space industry will as well. So $637,109 is 16.5% of our total ticket take. And that means our total take is $3,861,266.

Our ship carries 550 passengers, meaning each passenger will have to pay $7,020.48.

According to my research, it takes a total of 5,930m/s of delta-v to get from LEO to the surface of the Moon. More physics and math happens here, but it means that for every kilogram of cargo you want to put on the lunar surface, you have to put 4.73kg of mass into LEO. 1kg of actual cargo, and 3.73kg of fuel to get that cargo to the Moon.

So what’s it cost to put freight on the Moon? Well, it would cost 4.73 times what it would cost to put the cargo in LEO. So, while it costs $35.10 to put a kilogram into LEO, it would cost $166.02 to put it on the surface of the Moon.

You have to get your body to LEO ($7020), and then soft-landed on the moon. So you end up needing the same overhead – 4.73 times the LEO cost. $33,206.87.

So let’s say you want a two-week stay. That’s a total of 28 days of expenses at $800, so $22,400. Round that up to $25,000 because vacations always cost more than you expect. That plus the $45,000 travel costs totals $70,000.

So I ask again: Would you pay $70,000 for a lunar vacation?

We need to have some rules for making some rules

Tuesday, January 2nd, 2018

A group is its own worst enemy, Clay Shirky explained, almost 15 years ago:

Now, there’s a large body of literature saying “We built this software, a group came and used it, and they began to exhibit behaviors that surprised us enormously, so we’ve gone and documented these behaviors.” Over and over and over again this pattern comes up. (I hear Stewart [Brand, of the WELL] laughing.) The WELL is one of those places where this pattern came up over and over again.


The best explanation I have found for the ways in which this pattern establishes itself, the group is its own worst enemy, comes from a book by W.R. Bion called “Experiences in Groups,” written in the middle of the last century.

Bion was a psychologist who was doing group therapy with groups of neurotics. (Drawing parallels between that and the Internet is left as an exercise for the reader.) The thing that Bion discovered was that the neurotics in his care were, as a group, conspiring to defeat therapy.

There was no overt communication or coordination. But he could see that whenever he would try to do anything that was meant to have an effect, the group would somehow quash it. And he was driving himself crazy, in the colloquial sense of the term, trying to figure out whether or not he should be looking at the situation as: Are these individuals taking action on their own? Or is this a coordinated group?

He could never resolve the question, and so he decided that the unresolvability of the question was the answer. To the question: Do you view groups of people as aggregations of individuals or as a cohesive group, his answer was: “Hopelessly committed to both.”

He said that humans are fundamentally individual, and also fundamentally social. Every one of us has a kind of rational decision-making mind where we can assess what’s going on and make decisions and act on them. And we are all also able to enter viscerally into emotional bonds with other groups of people that transcend the intellectual aspects of the individual.

In fact, Bion was so convinced that this was the right answer that the image he put on the front cover of his book was a Necker cube, one of those cubes that you can look at and make resolve in one of two ways, but you can never see both views of the cube at the same time. So groups can be analyzed both as collections of individuals and having this kind of emotive group experience.

Now, it’s pretty easy to see how groups of people who have formal memberships, groups that have been labeled and named like “I am a member of such-and-such a guild in a massively multi-player online role-playing game,” it’s easy to see how you would have some kind of group cohesion there. But Bion’s thesis is that this effect is much, much deeper, and kicks in much, much sooner than many of us expect. So I want to illustrate this with a story, and to illustrate the illustration, I’ll use a story from your life. Because even if I don’t know you, I know what I’m about to describe has happened to you.

You are at a party, and you get bored. You say “This isn’t doing it for me anymore. I’d rather be someplace else. I’d rather be home asleep. The people I wanted to talk to aren’t here.” Whatever. The party fails to meet some threshold of interest. And then a really remarkable thing happens: You don’t leave. You make a decision “I don’t like this.” If you were in a bookstore and you said “I’m done,” you’d walk out. If you were in a coffee shop and said “This is boring,” you’d walk out.

You’re sitting at a party, you decide “I don’t like this; I don’t want to be here.” And then you don’t leave. That kind of social stickiness is what Bion is talking about.

And then, another really remarkable thing happens. Twenty minutes later, one person stands up and gets their coat, and what happens? Suddenly everyone is getting their coats on, all at the same time. Which means that everyone had decided that the party was not for them, and no one had done anything about it, until finally this triggering event let the air out of the group, and everyone kind of felt okay about leaving.

This effect is so steady it’s sometimes called the paradox of groups. It’s obvious that there are no groups without members. But what’s less obvious is that there are no members without a group. Because what would you be a member of?

So there’s this very complicated moment of a group coming together, where enough individuals, for whatever reason, sort of agree that something worthwhile is happening, and the decision they make at that moment is: This is good and must be protected. And at that moment, even if it’s subconscious, you start getting group effects. And the effects that we’ve seen come up over and over and over again in online communities.

Now, Bion decided that what he was watching with the neurotics was the group defending itself against his attempts to make the group do what they said they were supposed to do. The group was convened to get better, this group of people was in therapy to get better. But they were defeating that. And he said, there are some very specific patterns that they’re entering into to defeat the ostensible purpose of the group meeting together. And he detailed three patterns.

The first is sex talk, what he called, in his mid-century prose, “A group met for pairing off.” And what that means is, the group conceives of its purpose as the hosting of flirtatious or salacious talk or emotions passing between pairs of members.

You go on IRC and you scan the channel list, and you say “Oh, I know what that group is about, because I see the channel label.” And you go into the group, you will also almost invariably find that it’s about sex talk as well. Not necessarily overt. But that is always in scope in human conversations, according to Bion. That is one basic pattern that groups can always devolve into, away from the sophisticated purpose and towards one of these basic purposes.

The second basic pattern that Bion detailed: The identification and vilification of external enemies. This is a very common pattern. Anyone who was around the Open Source movement in the mid-Nineties could see this all the time. If you cared about Linux on the desktop, there was a big list of jobs to do. But you could always instead get a conversation going about Microsoft and Bill Gates. And people would start bleeding from their ears, they would get so mad.

If you want to make it better, there’s a list of things to do. It’s Open Source, right? Just fix it. “No, no, Microsoft and Bill Gates grrrrr …”, the froth would start coming out. The external enemy — nothing causes a group to galvanize like an external enemy.

So even if someone isn’t really your enemy, identifying them as an enemy can cause a pleasant sense of group cohesion. And groups often gravitate towards members who are the most paranoid and make them leaders, because those are the people who are best at identifying external enemies.

The third pattern Bion identified: Religious veneration. The nomination and worship of a religious icon or a set of religious tenets. The religious pattern is, essentially, we have nominated something that’s beyond critique. You can see this pattern on the Internet any day you like. Go onto a Tolkein newsgroup or discussion forum, and try saying “You know, The Two Towers is a little dull. I mean loooong. We didn’t need that much description about the forest, because it’s pretty much the same forest all the way.”

Try having that discussion. On the door of the group it will say: “This is for discussing the works of Tolkein.” Go in and try and have that discussion.

Now, in some places people say “Yes, but it needed to, because it had to convey the sense of lassitude,” or whatever. But in most places you’ll simply be flamed to high heaven, because you’re interfering with the religious text.

So these are human patterns that have shown up on the Internet, not because of the software, but because it’s being used by humans. Bion has identified this possibility of groups sandbagging their sophisticated goals with these basic urges. And what he finally came to, in analyzing this tension, is that group structure is necessary. Robert’s Rules of Order are necessary. Constitutions are necessary. Norms, rituals, laws, the whole list of ways that we say, out of the universe of possible behaviors, we’re going to draw a relatively small circle around the acceptable ones.

He said the group structure is necessary to defend the group from itself. Group structure exists to keep a group on target, on track, on message, on charter, whatever. To keep a group focused on its own sophisticated goals and to keep a group from sliding into these basic patterns. Group structure defends the group from the action of its own members.

In the Seventies — this is a pattern that’s shown up on the network over and over again — in the Seventies, a BBS called Communitree launched, one of the very early dial-up BBSes. This was launched when people didn’t own computers, institutions owned computers.

Communitree was founded on the principles of open access and free dialogue. “Communitree” — the name just says “California in the Seventies.” And the notion was, effectively, throw off structure and new and beautiful patterns will arise.

And, indeed, as anyone who has put discussion software into groups that were previously disconnected has seen, that does happen. Incredible things happen. The early days of Echo, the early days of usenet, the early days of Lucasfilms Habitat, over and over again, you see all this incredible upwelling of people who suddenly are connected in ways they weren’t before.

And then, as time sets in, difficulties emerge. In this case, one of the difficulties was occasioned by the fact that one of the institutions that got hold of some modems was a high school. And who, in 1978, was hanging out in the room with the computer and the modems in it, but the boys of that high school. And the boys weren’t terribly interested in sophisticated adult conversation. They were interested in fart jokes. They were interested in salacious talk. They were interested in running amok and posting four-letter words and nyah-nyah-nyah, all over the bulletin board.

And the adults who had set up Communitree were horrified, and overrun by these students. The place that was founded on open access had too much open access, too much openness. They couldn’t defend themselves against their own users. The place that was founded on free speech had too much freedom. They had no way of saying “No, that’s not the kind of free speech we meant.”

But that was a requirement. In order to defend themselves against being overrun, that was something that they needed to have that they didn’t have, and as a result, they simply shut the site down.

Now you could ask whether or not the founders’ inability to defend themselves from this onslaught, from being overrun, was a technical or a social problem. Did the software not allow the problem to be solved? Or was it the social configuration of the group that founded it, where they simply couldn’t stomach the idea of adding censorship to protect their system. But in a way, it doesn’t matter, because technical and social issues are deeply intertwined. There’s no way to completely separate them.

What matters is, a group designed this and then was unable, in the context they’d set up, partly a technical and partly a social context, to save it from this attack from within. And attack from within is what matters. Communitree wasn’t shut down by people trying to crash or syn-flood the server. It was shut down by people logging in and posting, which is what the system was designed to allow. The technological pattern of normal use and attack were identical at the machine level, so there was no way to specify technologically what should and shouldn’t happen. Some of the users wanted the system to continue to exist and to provide a forum for discussion. And other of the users, the high school boys, either didn’t care or were actively inimical. And the system provided no way for the former group to defend itself from the latter.

Now, this story has been written many times. It’s actually frustrating to see how many times it’s been written. You’d hope that at some point that someone would write it down, and they often do, but what then doesn’t happen is other people don’t read it.

The most charitable description of this repeated pattern is “learning from experience.” But learning from experience is the worst possible way to learn something. Learning from experience is one up from remembering. That’s not great. The best way to learn something is when someone else figures it out and tells you: “Don’t go in that swamp. There are alligators in there.”

Learning from experience about the alligators is lousy, compared to learning from reading, say. There hasn’t been, unfortunately, in this arena, a lot of learning from reading. And so, lessons from Lucasfilms’ Habitat, written in 1990, reads a lot like Rose Stone’s description of Communitree from 1978.

This pattern has happened over and over and over again. Someone built the system, they assumed certain user behaviors. The users came on and exhibited different behaviors. And the people running the system discovered to their horror that the technological and social issues could not in fact be decoupled.

There’s a great document called “LambdaMOO Takes a New Direction,” which is about the wizards of LambdaMOO, Pavel Curtis’s Xerox PARC experiment in building a MUD world. And one day the wizards of LambdaMOO announced “We’ve gotten this system up and running, and all these interesting social effects are happening. Henceforth we wizards will only be involved in technological issues. We’re not going to get involved in any of that social stuff.”

And then, I think about 18 months later — I don’t remember the exact gap of time — they come back. The wizards come back, extremely cranky. And they say: “What we have learned from you whining users is that we can’t do what we said we would do. We cannot separate the technological aspects from the social aspects of running a virtual world.

“So we’re back, and we’re taking wizardly fiat back, and we’re going to do things to run the system. We are effectively setting ourselves up as a government, because this place needs a government, because without us, the place was falling apart.”

People who work on social software are closer in spirit to economists and political scientists than they are to people making compilers. They both look like programming, but when you’re dealing with groups of people as one of your run-time phenomena, that is an incredibly different practice. In the political realm, we would call these kinds of crises a constitutional crisis. It’s what happens when the tension between the individual and the group, and the rights and responsibilities of individuals and groups, gets so serious that something has to be done.

And the worst crisis is the first crisis, because it’s not just “We need to have some rules.” It’s also “We need to have some rules for making some rules.” And this is what we see over and over again in large and long-lived social software systems. Constitutions are a necessary component of large, long-lived, heterogeneous groups.

Geoff Cohen has a great observation about this. He said “The likelihood that any unmoderated group will eventually get into a flame-war about whether or not to have a moderator approaches one as time increases.” As a group commits to its existence as a group, and begins to think that the group is good or important, the chance that they will begin to call for additional structure, in order to defend themselves from themselves, gets very, very high.

(Hat tip to Morlock Publishing. I told him I was reminded of Robert Conquest’s Three Laws of Politics, and Elam Bend noted that my post comes up first if you Google that term.)

Yeah, we’ll throw off the yoke

Tuesday, January 2nd, 2018

Tyler Cowen interviews Andy Weir (The Martian, Artemis) on the economics of space travel, and it veers off into some less technical topics:

Cowen: Now let me ask you some questions about governance in space. I’ve read some of your favorite works are by Robert Heinlein, The Moon Is a Harsh Mistress; Red Mars of course by Kim Stanley Robinson; Asimov’s Caves of Steel. And it’s a consistent theme in these stories. In fact, the stories you love, they involve an element of rebellion.

Weir: They do.

Cowen: If we had a colony on the Moon, how long do you think it would be before that colony would seek independence from Earth rule?

Weir: Well, first off, it wouldn’t be Earth rule. It would be ruled by some specific country. Right?

Cowen: Sure, or company.

Weir: Or… Country. You can’t really seek independence from a company.

Cowen: Well, it could be like the East India Company, right? The Kenya Space Corporation, they have some features of East India.

Weir: Right. They’re much nicer than the East India Company was.

Weir: Yeah, well, the Kenya Space Corporation in my book is just… They have a very simple business model. They build Artemis and then rent out lots. They don’t try to control its economy or its people or anything. They’re literally just landlords, and absentee landlords at that. But you can’t declare independence from a company because, by definition, the company owns all the assets. If you say, “I’m independent from the company,” what you’re doing is resigning. Right?

Cowen: Well, you’re stealing, in a way. But it happens, right?

Weir: Yeah. But if you’re talking about some sort of revolution or something like that, well I guess the first step is you’d have to be pretty sure that you are self-sufficient and independent. You have to be, like, Earth-independent. Which, in the case of Artemis, it’s not.

Cowen: But you have some allies. So what’s now the United States declares independence from what was then Britain, and the French help us. Other people who are upset at Britain help the American colonies to become independent.

So as long as you have some outside allies, wouldn’t you expect, within say 50 years’ time, a lunar colony, a Mars colony would try to seek independence so those rents could be captured by domestic interests?

Weir: Possibly. Ultimately, I believe that all major events in history are economic. And, I mean, independence was really about who gets to collect taxes, right? So if the people who live in a city are content with the economic status that they have, they’re not going to rebel. People don’t… People, despite what you see, I would challenge you to show me any situation where people revolted over purely ideology without any economic reason.

Cowen: But think about the American colonies. So the British were taxing us maybe 5 percent of GDP —

Weir: And the American colonies preferred that those taxes went to the American colonial governments.

Cowen: Yes, absolutely. But it wasn’t that much money, in a sense. That to me is what’s surprising.

Weir: Well, at that time, taxes globally were not that much money.

Cowen: Yeah.

When you read these books by Heinlein, Asimov, Kim Stanley Robinson . . .

Weir: Yeah, they always end up being political thrillers and that’s not what I’m going for. I’m showing the frontier town and the kind of cooperative aspects of human nature. I’m not…

For some reason, every book about colonizing space ultimately seems to lead to a revolution. Because that’s exciting, right? It’s Star Wars.

You know, you’ve got a rebellion, so “yeah, we’ll throw off the yoke,” and it has historical parallels and it’s all awesome like that. But I don’t necessarily think that’s going to be the case. Partially because as long as we keep following the rules of the Outer Space Treaty, which I believe we will, there’s no such thing as sovereign territory outside of Earth. So Artemis is, functionally speaking, an offshore platform.

Cowen: On Earth, do you think we should experiment more with seasteading? Set up sea colonies?

Weir: Yeah.

Cowen: Underground colonies?

Weir: Absolutely.

Cowen: Have them be politically autonomous, if they want?

Weir: You would have to change maritime law to be able to do that. Right now, under maritime law, you can seastead. I mean, you can do it right now. You can go out into the international waters and build something. You have to flag to some country, though.

Cowen: Right. A cruise ship, yeah.

Weir: Yeah. Well, yeah, you could flag to like Suriname or something like that. You could fly a flag of convenience. But, one way or another, you are subject to the laws of the country that you’re flying the flag of, just as Artemis is subject to the laws of Kenya.

He who does not know foreign languages does not know anything about his own

Sunday, December 31st, 2017

Machines have developed the ability to understand, process, and even translate languages:

In recent years, much of the research in machine learning has focused on the algorithmic concept of deep neural networks, or DNNs, which learn essentially by inferring patterns — often patterns of remarkable complexity — from large amounts of data. For example, a DNN-based machine can be fed many thousands of snippets of recorded English utterances, each one paired with its text transcription, and from this discern the patterns of correlation between the speech recordings and the paired transcriptions. These inferred correlation patterns get precise enough that, eventually, the system can “understand” English speech. In fact, today’s DNNs are so good that, when given enough training examples and a powerful enough computer, they can listen to a person speaking and make fewer transcription errors than would any human.

What may be surprising to some is that computerized learning machines exhibit transfer learning. For example, let’s consider an experiment involving two machine-learning systems, which for the sake of simplicity we’ll refer to as machines A and B. Machine A uses a brand-new DNN, whereas machine B uses a DNN that has been trained previously to understand English. Now, suppose we train both A and B on identical sets of recorded Mandarin utterances, along with their transcriptions. What happens? Remarkably, machine B (the previously English-trained one) ends up with better Mandarin capabilities than machine A. In effect, the system’s prior training on English ends up transferring capabilities to the related task of understanding Mandarin.

But there is an even more astonishing outcome of this experiment. Machine B not only ends up better on Mandarin, but B’s ability to understand English is also improved! It seems that Willans and Goethe were onto something — learning a second language enables deeper learning about both languages, even for a machine.

The signal was designed to exploit the difference

Sunday, December 17th, 2017

How does a Taser work?

When you pull the trigger of a Taser gun, a blast of compressed nitrogen launches its two barbed darts at 55 meters per second, less than a fifth the speed of a bullet from a typical pistol. Each projectile, which weighs 1.6 grams, has a 9-millimeter-long tip to penetrate clothing and the insulating outer layer of skin. Two whisper-thin wires trail behind for up to 9 meters, forming an electrical connection to the gun.

Because the barbs get stuck in clothing and fail to reach the skin about 30 percent of the time, the gun is designed to generate a brief arcing pulse, which ionizes the intervening air to establish a conductive path for the electricity. The arcing phase has an open-circuit peak voltage of 50,000 volts; that is, the voltage is 50 kilovolts only until the arc appears or until the barbs make contact with conductive flesh, which in the worst conditions offers around 400 ohms of resistance.

The target’s body is never exposed to the 50 kV. The X26 — the model commonly used by police departments — delivers a peak voltage of 1200 V to the body. Once the barbs establish a circuit, the gun generates a series of 100-microsecond pulses at a rate of 19 per second. Each pulse carries 100 microcoulombs of charge, so the average current is 1.9 milliamperes. To force the muscles to contract without risking electrocution, the signal was designed to exploit the difference between heart muscle and skeletal muscle.

Skeletal muscle constitutes 40 percent of a typical person’s mass and is responsible for making your biceps flex, your fingers type, and your eyelids wink. It’s organized into bundles of single-cell fibers that stretch from tendons attached to your skeleton. When your brain orders a muscle to flex, an electrical impulse shoots down a motor nerve to its termination at the midpoint of a muscle fiber. There the electrical signal changes into a chemical one, and the nerve ending sprays a molecular transmitter, acetylcholine, onto the muscle. In the milliseconds before enzymes have a chance to chew it up, some of the acetylcholine binds with receptors, called gated-ion channels, on the surface of the muscle cell. When acetylcholine sticks to them, they open, allowing the sodium ions in the surrounding salty fluid to rush in.

The movement of those ions raises the cell’s internal voltage, opening nearby ion channels that are triggered by voltage instead of by acetylcholine. As a result, a wave of voltage rolls outward along the fiber toward both ends of the muscle, moving as fast as 5 meters per second. As the voltage pulse spreads, it kick-starts the molecular machinery that contracts the muscle fiber.

By directly jolting the motor nerves with electricity, a Taser can stimulate the muscle and get the same effect.

The force with which a skeletal muscle contracts depends on the frequency at which its nerve fires. The amount of contraction elicited is proportional to the stimulation rate, up to about 70 pulses per second. At that point, called tetanus, contractions can be dangerously strong. (The same thing happens in the disease tetanus, whose primary symptom, caused by the presence of a neurotoxin, is prolonged contraction of skeletal fibers.) The Taser, with its 19 pulses per second, operates far enough from the tetanus region so that the muscles contract continuously but without causing any major damage.

Heart muscle has a somewhat different physical and electrical structure. Instead of one long cell forming a fiber that stretches from tendon to tendon, heart muscle is composed of interconnected fibers made up of many cells. The cell-to-cell connections have a low resistance, so if an electrical impulse causes one heart cell to contract, its neighbors will quickly follow suit. With the help of some specialized conduction tissue, this arrangement makes the four chambers of the heart beat in harmony and pump blood efficiently. A big jolt of current at the right frequency can turn the coordinated pump into a quivering mass of muscle. That’s just what electrocution does: the burst of electricity causes the heart’s electrical activity to become chaotic, and it stops pumping adequately — a situation known as ventricular fibrillation.

The Taser takes advantage of two natural protections against electrocution that arise from the difference between skeletal and cardiac muscle. The first — anatomy — is so obvious that it is typically overlooked. The skeletal muscles are on the outer shell of the body; the heart is nestled farther inside. In your upper body, the skeletal muscles are arranged in bands surrounding your rib cage. Because of skeletal muscle fibers’ natural inclination to conduct low-frequency electricity along their length, a larger current injected into such a muscle tends to follow the grain around the chest rather than the smaller current that penetrates toward the heart.

The second protection results from the different timing requirements of the nerves that trigger muscle contractions and the heart’s intrinsic electronics. To lock up skeletal muscle without causing ventricular fibrillation, an electronic waveform has to have a specific configuration of pulse length and current.

The key metric that electrophysiologists use to describe the relationship between the effect of pulse length and current is chronaxie, a concept similar to what we engineers call the system time constant. Electrophysiologists figure out a nerve’s chronaxie by first finding the minimal amount of current that triggers a nerve cell using a long pulse. In successive tests, the pulse is shortened. A briefer pulse of the same current is less likely to trigger the nerve, so to get the attached muscle to contract, you have to up the amperage. The chronaxie is defined as the minimum stimulus length to trigger a cell at twice the current determined from that first very long pulse. Shorten the pulse below the chronaxie and it will take more current to have any effect. So the Taser should be designed to deliver pulses of a length just short of the chronaxie of skeletal muscle nerves but far shorter than the chronaxie of heart muscle nerves.

And that’s the case. To see just how different skeletal and heart muscles are, let’s look at what it takes to seriously upset a heart’s rhythm. Basically, there are two ways: by using a relatively high average current, or by zapping it with a small number of extremely high-current pulses.

In terms of average current, the 1.9 mA mentioned earlier is about 1 percent of what’s needed to cause the heart of the typical male to fibrillate. So the Taser’s average current is far from the danger zone for healthy human hearts.

As far as single-pulse current goes, the Taser is again in the clear. The heart’s chronaxie is about 3 milliseconds — that’s 30 times as long as the chronaxie of skeletal muscle nerves and the pulse lengths of a Taser. The single-pulse current required to electrocute someone by directly pulsing the most sensitive part of the heartbeat using 3-ms pulses is about 3 A. Because a Taser’s 100-ms pulses are such a small fraction of the heart’s chronaxie, it would take significantly higher current — on the order of 90 A — to electrocute someone using a Taser.

When you factor in that the Taser barbs are likely to land in current-shunting skeletal muscle not near the heart, you wind up with a pretty large margin of safety.

The civilian version is apparently quite small — “close to a Glock 42,” according to one review.

An inelegant weapon for a more barbaric age

Friday, December 15th, 2017

A lightsaber would not be an elegant weapon, as any plasma torch able to cut through a blast door like butter would vaporize flesh explosively:

He thanks Matter Beam of Tough SF for running the numbers. His estimate of a light saber’s output was 35 MW, about the same as a nuclear submarine’s reactor.

I found some footage of a modern plasma torch cutting through meat:

Star Trek’s phasers have the same problem as Star Wars’ light sabers, by the way. Vaporizing a human wouldn’t be much more elegant.

Handle’s theory of consolidation

Tuesday, November 28th, 2017

Hayek claimed that local knowledge favors decentralization. Socialists hoped that cybernetics — what we’d now call “IT” — would overcome this problem. Handle thinks we’re just about there:

IT and increasingly capable and sophisticated management information systems, which themselves benefit from massive economies of scale, and the management techniques they enable, has invalidated this argument. If anything, big companies now seem to have a clear advantage with regards to acquiring and leveraging “local knowledge,” and combined with the other advantages of brand recognition, size and sophistication and capacity for, e.g., rent-seeking and bearing the burden of compliance overhead, that leaves “the little, genuinely-independent guy” with zero chance in the long run.

The Internet vision of the 1990s is turning out to be wrong, Arnold Kling adds.

Intellectual indoor plumbing and toxic ideas that spread like wildfire

Monday, November 27th, 2017

Glenn Reynolds has been reading James C. Scott’s Against the Grain, and he notes how fragile early civilizations were:

A bunch of people and their animals would crowd together in a city, and diseases that weren’t much of a threat when everybody was spread out hunting and gathering would suddenly spread like wildfire and depopulate the town almost overnight.

As Scott writes, an early city was more like a refugee resettlement camp than a modern urban area. He observes that “the pioneers who created this historically novel ecology could not possibly have known the disease vectors they were inadvertently unleashing.”

Then I ran across this observation on Twitter: “The Internet is rewiring brains and social relations. Could it be producing a civilizational nervous breakdown?” And I saw another article noting that depression in teens skyrocketed between 2010 and 2015, as smartphones took over. It made me wonder if we’re in the same boat as the neolithic cities, only for what you might call viruses of the mind: Toxic ideas that spread like wildfire.


Likewise, in recent years we’ve gone from an era when ideas spread comparatively slowly, to one in which social media in particular allow them to spread like wildfire. Sometimes that’s good, when they’re good ideas. But most ideas are probably bad; certainly 90% of ideas aren’t in the top 10%. Maybe we don’t know the mental disease vectors that we’re inadvertently unleashing.

It took three things to help control the spread of disease in cities: sanitation, acclimation and better nutrition.


We don’t know much about the spread of ideas, or what would constitute the equivalent of intellectual indoor plumbing. (Censorship isn’t enough, as it often just promotes the spread of bad ideas that people in power like). Over time we’ll learn more. Maybe we’ll come up with something like the germ theory of disease for ideas.

And perhaps people will acclimate. Twitter is still new, and amplifies crazy opinions. People may learn to spend less time on social media or to avoid them altogether. (In Neal Stephenson’s The Diamond Age, the elites of the future consume their news on paper, and send each other handwritten notes; electronic communication is for the plebes.) But that will take time.

Where we can do something right away is with the equivalent of nutrition. Traditional training in critical thinking — the sort of thing the humanities used to revolve around, before they became focused on “social justice” — seems like it would be a useful protective. A skepticism regarding groupthink, ad hominem arguments and virtue signaling would likely offer considerable protection against the sort of mass hysteria we seem increasingly vulnerable to. Likewise, a social consensus on important ideas — the kinds of things we used to teach in civics classes — would help.

The Diamond Age is definitely one of those novels that stuck with me. (Dune is another.)

Arnold Kling points out that this ties in nicely with the recent talk between Jordan Peterson and Jonathan Haidt, where they discuss how the sense of disgust evolved to protect people not just from disease:

We tend to feel an instinctive disgust toward groups with customs and manners that differ from our own. If you can overcome this instinct to feel disgust when you are around foreigners, then you can benefit from their ideas and culture. But you increase somewhat your risk of contracting disease. Peterson describes Adolf Hitler as operating on the theory that having Jews or Gypsies in a population was like having rats in a factory. He was so concerned about the disease that might be spread by such creatures that he wanted them eradicated.

The problem is energy density

Friday, November 17th, 2017

Long-haul trucking is an odd choice for Tesla. The problem is energy density:

Batteries take up far more space and weight for a given output of energy than gasoline and diesel. That issue is becoming irrelevant in lighter vehicles like cars and smaller vans because they don’t require much power. But it looms large when it comes to the heavy-duty longer-distance trucks that consume about half of road freight fuel, and are expected to see the biggest demand growth.

Energy Density

Take a look, for instance at Daimler AG’s Urban eTruck, the first fully electric heavy-duty vehicle to go into production earlier this year. The 2.5-metric-ton battery alone on this beast weighs as much as a Chevrolet Suburban, one of the largest SUVs on the road. Furthermore — as the name indicates — it’s only intended for deliveries within cities, with a maximum range of 200 kilometers. That’s not going to do much damage to long-distance routes: A typical semi-trailer can carry enough fuel to travel at least five times that distance.The specifications emerging for the Tesla Semi suggest it may be able to improve on that, with a range of about 800 kilometers when carrying a 36-ton maximum load. There’s no word yet about the weight of the Semi’s battery, but it would have to be colossal to achieve those sorts of specs. That’s probably not the best route to energy efficiency, given that about 25 percent to 30 percent of the time trucks are driven empty. A significant slice of the Semi’s energy will be spent hauling around its massive power plant.

That explains why the numerous competitors to the Semi already out there are mainly focused on shorter-range urban logistics networks. It’s going to require technological breakthroughs — such as the development of commercial lithium-air cells, which could have gasoline-style energy densities — for batteries to really eat into the oil consumed by long-haul trucking and aviation.

Elon Musk is not a robot sent from the future to save humanity

Wednesday, November 15th, 2017

Over the course of nine months of reporting, Neil Strauss determined that Elon Musk is not a robot sent from the future to save humanity, but he may be the most successful and important entrepreneur in the world:

It’s an easy case to make: He’s probably the only person who has started four billion-dollar companies — PayPal, Tesla, SpaceX and Solar City. But at his core, Musk is not a businessman or entrepreneur. He’s an engineer, inventor and, as he puts it, “technologist.”

Most of Strauss’s piece is about Musk’s broken relationships — with ex-wives, with his recent ex-girlfriend, and with his “ruthless” estranged father.

Musk tries to do useful things:

Think of the other names that one associates with innovation this century: They’re people who built operating systems, devices, websites or social-media platforms. Even when it didn’t start out that way, the ideology in most cases soon became: How can I make my company the center of my users’ world? Consequently, social-media sites like Facebook and Twitter use a number of tricks to activate the addictive reward centers of a user’s brain.

If Musk’s employees suggested doing something like this, he’d probably look at them like they were crazy. This type of thinking doesn’t compute. “It’s really inconsistent to not be the way you want the world to be,” he says flatly, “and then through some means of trickery, operate according to one moral code while the rest of the world operates according to a different one. This is obviously not something that works. If everyone’s trying to trick everyone all the time, it’s a lot of noise and confusion. It’s better just to be straightforward and try to do useful things.”

He discusses building a permanent moon base, and further funding SpaceX by creating passenger rockets capable of traveling to any city in the world in less than an hour, a form of transport he calls “Earth-to-Earth.” I ask if there’s anything that he believes works that surprises people.

“I think being precise about the truth works. Truthful and precise. I try to tell people, ‘You don’t have to read between the lines with me. I’m saying the lines!’”

He enjoys the usual pop-culture geek favorites: The Onion, Rick and Morty, South Park, The Simpsons, and The Hitchhiker’s Guide to the Galaxy.

Pykrete and Habakkuk

Wednesday, November 1st, 2017

When commenter Sam J. mentioned building ships out of concrete, I went searching for an old post on Pykrete, only to find that I hadn’t ever posted anything on Project Habakkuk:

Project Habakkuk or Habbakuk (spelling varies; see below) was a plan by the British during the Second World War to construct an aircraft carrier out of pykrete (a mixture of wood pulp and ice) for use against German U-boats in the mid-Atlantic, which were beyond the flight range of land-based planes at that time. The idea came from Geoffrey Pyke, who worked for Combined Operations Headquarters. After promising scale tests and the creation of a prototype on a lake in Alberta, Canada, the project was shelved due to rising costs, added requirements, and the availability of longer-range aircraft and escort carriers which closed the Mid-Atlantic gap the project was intended to address.


Pyke conceived the idea of Habbakuk while he was in the United States organising the production of M29 Weasels for Project Plough, a scheme to assemble an elite unit for winter operations in Norway, Romania and the Italian Alps. He had been considering the problem of how to protect seaborne landings and Atlantic convoys out of reach of aircraft cover. The problem was that steel and aluminium were in short supply, and were required for other purposes. Pyke realized that the answer was ice, which could be manufactured for only 1 percent of the energy needed to make an equivalent mass of steel. He proposed that an iceberg, natural or artificial, be levelled to provide a runway and hollowed out to shelter aircraft.


The project’s code name seems to have been consistently (mis)spelled Habbakuk in official documents at the time. This may in fact have been Pyke’s own error, as at least one early document apparently written by him (though unsigned) spells it that way. (However, post-war publications by people concerned with the project, such as Perutz and Goodeve, all restore the proper spelling, with one “b” and three “k”s.) The name is a reference to the project’s ambitious goal: “… be utterly amazed, for I am going to do something in your days that you would not believe, even if you were told.” (Habakkuk 1:5, NIV)


In early 1942 Pyke and Bernal called in Max Perutz to determine whether an icefloe large enough to withstand Atlantic conditions could be built up fast enough. Perutz pointed out that natural icebergs have too small a surface above water for an airstrip, and are prone to suddenly rolling over. The project would have been abandoned if it had not been for the invention of pykrete, a mixture of water and woodpulp that when frozen was stronger than plain ice, was slower-melting and would not sink. Developed by his government group and named after Pyke, It has been suggested that Pyke was inspired by Inuit sleds reinforced with moss. This is probably apocryphal, as the material was originally described in a paper by Mark and Hohenstein in Brooklyn.

Pykrete could be machined like wood and cast into shapes like metal, and when immersed in water formed an insulating shell of wet wood pulp on its surface that protected its interior from further melting. However, Perutz found a problem: ice flows slowly, in what is known as plastic flow, and his tests showed that a pykrete ship would slowly sag unless it was cooled to –16°C (3°F). To accomplish this the ship’s surface would have to be protected by insulation, and it would need a refrigeration plant and a complicated system of ducts.

Perutz proceeded to conduct experiments on the viability of pykrete and its optimum composition in a secret location underneath Smithfield Meat Market in the City of London. The research took place in a refrigerated meat locker behind a protective screen of frozen animal carcasses.

The decision was made to build a large-scale model at Jasper National Park in Canada to examine insulation and refrigeration techniques, and to see how pykrete would stand up to artillery and explosives. Large ice blocks were constructed at Lake Louise, Alberta, and a small prototype was constructed at Patricia Lake, Alberta, measuring only 60 by 30 feet (18 metres by 9 metres), weighing 1,000 tons and kept frozen by a one-horsepower motor. The work was done by conscientious objectors who did alternative service of various kinds instead of military service. They were never told what they were building. Bernal informed COHQ that the Canadians were building a 1,000-ton model, and that it was expected to take eight men fourteen days to build it. The Chief of Combined Operations (CCO) responded that Churchill had invited the Chiefs of Staff Committee to arrange for an order to be placed for one complete ship at once, with the highest priority, and that further ships were to be ordered immediately if it appeared that the scheme was certain of success.

The Canadians were confident about constructing a vessel for 1944. The necessary materials were available to them in the form of 300,000 tons of wood pulp, 25,000 tons of fibreboard insulation, 35,000 tons of timber and 10,000 tons of steel. The cost was estimated at £700,000.

Meanwhile Perutz had determined via his experiments at Smithfield Market that the optimum structural properties were given by a mixture of 14 per cent wood pulp and 86 per cent water. He wrote to Pyke in early April 1943 and pointed out that if certain tests were not completed in May, there would be no chance of delivering a completed ship in 1944.

By May the problem of cold flow had become serious and it was obvious that more steel reinforcement would be needed, as well as a more effective insulating skin around the vessel’s hull. This caused the cost estimate to increase to £2.5 million. In addition, the Canadians had decided that it was impractical to attempt the project “this coming season”. Bernal and Pyke were forced to conclude that no Habbakuk vessel would be ready in 1944.

Pyke was excluded from the planning for Habbakuk in an effort to secure American participation, a decision that Bernal supported. Pyke’s earlier disagreements with American personnel on Project Plough, which had caused his removal from that project, were the main factor in this decision.

Naval architects and engineers continued to work on Habbakuk with Bernal and Perutz during the summer of 1943. The requirements for the vessel became more demanding: it had to have a range of 7,000 miles (11,000 km) and be able to withstand the largest waves recorded, and the Admiralty wanted it to be torpedo-proof, which meant that the hull had to be at least 40 ft (12 m) thick. The Fleet Air Arm decided that heavy bombers should be able to take off from it, which meant that the deck had to be 2,000 ft (610 m) long. Steering also raised problems; it was initially projected that the ship would be steered by varying the speed of the motors on either side, but the Royal Navy decided that a rudder was essential. However, the problem of mounting and controlling a rudder over 100 ft (30 m) high was never solved.