The Sunbeam Radiant Control Toaster from 1949 is still smarter than any toaster sold today

December 6th, 2021

The Sunbeam Radiant Control Toaster from 1949 is still smarter than any toaster sold today:

With the Sunbeam, the heat radiating from the bread itself warms up a bimetal strip (one of the simplest kinds of thermostats) which, being made of two different kinds of metal that expand at different rates, ends up bending backwards to sever the connection and stop the flow of electricity when the toast is done. And here’s the most ingenious part: when the heating wire shrinks as it cools down, that is what triggers the mechanical chain reaction that lifts your bread back up.

They go for an average of $130 on eBay, with fully restored models fetching two to four times that at auction.

Toyota is poised to make affordability, not range, at the center of its EV play

December 5th, 2021

Toyota is poised to put affordability, not range, at the center of its EV play:

“‘Nothing happens until you sell a car’ is an expression we have internally,” he summed. “To have a positive impact on the environment, you must sell a high volume of cars…so it’s really important that the price point is such that we can make an actual business model out of it.”

To that point, Toyota expects that it will be selling millions of electric vehicles by the end of the decade. In September, the automaker announced plans to spend $13.5 billion on battery development through then, with aims of cutting the battery cost per vehicle by 50% versus the bZ4X.

[...]

“The bottom line is, over time we view EV range similar to horsepower,” Ericksen said, comparing it to how almost any customer really wanted 400 horsepower but, at an affordability standpoint, might settle for 120 hp. “People who are affluent and can afford a really expensive vehicle can afford a lot of horsepower.”

“Batteries are expensive, and the bigger you make the battery, the more expensive it is,” Ericksen said. “So the trick, I think long-term is not all about range, range, range; the trick is matching the range and the price point to what the consumer can afford.”

“And as people become more accustomed to operating an EV I think the anxiety over range is going to dissipate,” he continued, saying that many EV shoppers are going to understand they don’t need 300 or 400 miles—and certainly not in a second or third car.

Although we tend to agree that range is a red herring, especially for that second or third car, Toyota will face some headwinds if it dives into the “just enough” category. In a study released earlier this year, J.D. Power found that EVs with more than 200 miles of range had higher levels of satisfaction than those with less. And back in 2017, a comprehensive Autolist survey on minimum range found that only 14.6% of individuals saw 200 miles of range as enough, while the largest group, 38.9%, considered 300 miles of range to be enough. It emphasized, then, that a jump from 250 to 300 miles yielded an increase of 30% more people willing to buy an EV.

Range really is like horsepower.

Being asked to explain the experimenter’s reasoning produced considerably more learning

December 4th, 2021

Five-year-olds whose pretest performance showed that they had not mastered number conservation were presented four training sessions:

Some were just given feedback on their number conservation performance; others were given feedback and asked to explain their reasoning; yet others were given feedback and asked to explain the reasoning that led to the experimenter’s judgment. Being asked to explain the experimenter’s reasoning produced considerably more learning than either of the other two procedures.

Number conservation is kind of hard:

The Bulletproof Musician summarizes the results:

The kids who were asked to imagine what the expert’s perspective might be ultimately got 62 percent of the questions correct over the course of their four testing sessions. Whereas the group that provided their own reasoning for the answer only got 48 percent of the problems correct. And those who provided no rationale got 49 percent correct.

Praise curtails discussion and serves mainly to reinforce the teacher’s role as the authority who bestows rewards

December 3rd, 2021

Although error avoidance during learning appears to be the rule in American classrooms, Janet Metcalfe says, laboratory studies suggest that it may be a counterproductive strategy, at least for neurologically typical students:

Experimental investigations indicate that errorful learning followed by corrective feedback is beneficial to learning. Interestingly, the beneficial effects are particularly salient when individuals strongly believe that their error is correct: Errors committed with high confidence are corrected more readily than low-confidence errors. Corrective feedback, including analysis of the reasoning leading up to the mistake, is crucial. Aside from the direct benefit to learners, teachers gain valuable information from errors, and error tolerance encourages students’ active, exploratory, generative engagement. If the goal is optimal performance in high-stakes situations, it may be worthwhile to allow and even encourage students to commit and correct errors while they are in low-stakes learning situations rather than to assiduously avoid errors at all costs.

[...]

It might seem intuitive that if one does not want errors on the test that counts, then one should avoid errors at all stages of learning. In this view, committing errors should make those errors more salient and entrench them into both the memory and the operating procedures of the person who makes them. Exercising the errors should make the errors themselves stronger, thus increasing their probability of recurrence. Such a view, which is consistent with a number of the oldest and most well established theories of learning and memory (Bandura 1986, Barnes & Underwood 1959, Skinner 1953), suggests that errors are bad and should be avoided at all costs.

[...]

However, Stevenson & Stigler (1994; see also Stigler & Hiebert 2009) and their colleagues conducted a landmark study in which they were able to videotape lessons in grade 8 mathematics classrooms in a variety of countries, including the United States, Taiwan, China, and Japan. Of most interest, given that Japan is by far outstripping the United States in math scores, is the striking difference in the teaching methods used in those two countries. Although there may be many other reasons for the differences in math scores, one highly salient difference is whether or not teachers engage with students’ errors. Videotapes show that, in the United States, set procedures for doing particular kinds of problems are explicitly taught. These correct procedures are rehearsed and emphasized; errors are avoided or ignored. The students are not passive in American classrooms. A teacher may ask for student participation in repeating, for example, a procedure for borrowing when subtracting. When asking a question such as, “Can you subtract 9 from 5?” to prompt students to answer, “No, you have to borrow to make the 5 a 15,” the teacher may fail to even acknowledge the deviant child who says, “Yes. It’s negative 4.” If the response does not fit with the procedure being exercised, it is not reinforced. Errors (as well as deviant correct answers) are neither punished nor discussed but are disregarded. Praise is given, but only for the “correct” answer.

As Stevenson & Stigler (1994) pointed out, praise curtails discussion and serves mainly to reinforce the teacher’s role as the authority who bestows rewards. It does not empower students to think, criticize, reconsider, evaluate, and explore their own thought processes. By way of contrast, in Japan praise is rarely given. There, the norm is extended discussion of errors, including the reasons for them and the ways in which they may seem plausible but nevertheless lead to the incorrect answer, as well as discussion of the route and reasons to the correct answer. Such in-depth discussion of the thought processes underlying both actual and potential errors encourages exploratory approaches by students.

Instead of beginning with teacher-directed classwork and explication, Japanese students first try to solve problems on their own, a process that is likely to be filled with false starts. Only after these (usually failed) attempts by students does teacher-directed discussion — interactively involving students and targeting students’ initial efforts and core mathematical principles — occur. It is expected that students will struggle and make errors, insofar as they rarely have available a fluent procedure that allows them to solve the problems. Nor are students expected to find the process of learning easy. But the time spent struggling on their own to work out a solution is considered a crucial part of the learning process, as is the discussion with the class when it reconvenes to share the methods, to describe the difficulties and pitfalls as well as the insights, and to provide feedback on the principles at stake as well as the solutions.

As Stevenson & Stigler (1994, p. 193) note, “Perhaps because of the strong influence of behavioristic teaching, which says conditions should be arranged so that the learner avoids errors and makes only a reinforceable response, American teachers place little emphasis on the constructive use of errors as a teaching technique. Learning about what is wrong may hasten understanding of why the correct procedures are appropriate, but errors may also be interpreted as failure. And Americans, reluctant to have such interpretations made of their children’s performance, strive to avoid situations where this might happen.”

The Japanese active learning approach well reflects the fundamental ideas of a learning-from-errors approach. Engaging with errors is difficult, but difficulty can be desirable for learning (Bjork 2012). In comparison with approaches that stress error avoidance, making training more challenging by allowing false starts and errors followed by feedback, discussion, and correction may ultimately lead to better and more flexible transfer of skills to later critical situations.

Considerable research now indicates that engagement with errors fosters the secondary benefits of deep discussion of thought processes and exploratory active learning and that the view that the commission of errors hurts learning of the correct response is incorrect. Indeed, many tightly controlled experimental investigations have now shown that in comparison with error-free study, the generation of errors, as long as it is followed by corrective feedback, results in better memory for the correct response.

[...]

Early studies by Izawa (1967, 1970) showed that multiple unsuccessful retrieval attempts led to better memory for the correct feedback than did a procedure producing fewer incorrect responses. Kane & Anderson (1978) showed similar results: Attempting the generation of the last word of the sentence, even if what was generated was wrong, led to enhanced correct performance compared to reading the sentence correctly from the outset. Slamecka & Fevreiski (1983) asked people to remember near antonyms, such as trivial-vital or oscillate-settle. Even failed attempts (followed by feedback containing the correct answer) improved later recall of the correct answers over simply reading the correct answer. Kornell et al. (2015) have conducted a recent investigation of the same issue and have reached similar conclusions.

[...]

It appears that to be beneficial, the guess needs to be somewhat informed rather than a shot in the dark.
[...]

Interestingly, in the related-pair case in which a large beneficial effect of committing errors was found, the participants were metacognitively unaware of the benefit. Even immediately after they had experienced the task and had evidenced a benefit of 20 percent (i.e., roughly the difference between a C-minus and an A, if it had been a course grade), participants thought that the error-free condition had resulted in better recall (Huelser & Metcalfe 2012). This lack of awareness of the benefits of error generation may contribute to the aversion to errors in the American teaching style evinced in Stigler’s work.

These people worship “the science” but have, shall we say, a selective understanding of it

November 30th, 2021

When the time came to lock down, Freddie deBoer locked down:

When they switched from saying it was selfish to wear a mask to saying it was selfish to not wear a mask I started wearing a mask. I maintain “social distance” even though it’s always been a vague concept of dubious value. I got both vaccine shots as soon as I could and will soon get a booster, even though I’m vaccinated, have had Covid, and I’m 40 years old and healthy. I have no problem showing the app at bars and restaurants to get in. I don’t think ivermectin is an effective treatment against Covid-19; I am very encouraged by the new Pfizer therapeutic. I tell adults to get vaccinated all the time, although I confess that I think the vaccination of young children is mostly a matter of security theater. I am compliant, I guess you might say, which is flattering or unflattering depending on what side of whatever wearying culture divide you’re standing on.

And also the effort against Covid is a colossal social exercise in forcing all of us to submit to the whims of unaccountable authorities who have been proven wrong on elementary questions but who we are still told work only in the spirit of total rationality and science, and our submission to them is enforced by a self-appointed cadre of ordinary people no more informed than the rest of us and whose attitudes are dictated by the rawest and most unjustifiable fears, passions, and desire for control.

There is a new variant, apparently. I know because our newsmedia breathlessly and relentlessly reports on bad Covid news. Unfortunately, they simply refuse to report on good Covid news, at least with anything like equal scale; I invite you to investigate the archives of even the most sober of news sources and compare how they cover cases going up compared to cases going down. Meanwhile, the public health authorities react to every twist of the narrative as an excuse for more fear and greater restrictions, insisting that “an abundance of caution” is always the way to proceed. (No word on whether a correct amount of caution would be a good idea.) Meanwhile the virus does discriminate, despite what you’ve heard over and over again, and in fact it discriminates against very particular and easily-identifiable subpopulations, and most people are not among them, and so every turn of this thing that does not result in mass death and disruption for the larger populace makes that populace feel lied to by the endlessly-panicky media and the abundantly cautious public health officials. We are approaching two years of Covid-19 as a crisis and yet no one in a position of authority has seemed to put it together that the public is exquisitely sensitive to those who cry wolf. Maybe Omicron really is “the big one,” but they’ve said that about every last development in this endless story, so how would we ever know?

Meanwhile we live among a Praetorian guard of busybodies who want everyone to know that the rest of us aren’t taking Covid seriously enough. These are people who are existentially similar to the “Karen,” 2020’s favorite archetype, except that they’re used to calling other people Karens. But they are precisely that figure of clueless white deference to authority that self-nominates as the world’s hall monitor. And while they want you to mask up and vaccinate and obey other rules, what’s much more important to them than regulating your behavior is that they let you know that you don’t feel the right way about Covid. You aren’t taking it seriously enough! You aren’t frightened enough! Who told you that you ever get to go back to normal? It’s not enough that you follow the rules and perform these weird rituals that we’re all compelled to. You are damned if you want things to return to normal. To want that is the gravest sin. To prefer the before times is a mark of terrible unseriousness. Covid is not, to these people, a simple public health emergency but some sort of divine test of our character, and what is weighed in that test is not our actions or their outcomes, but our neuroses, our noble anxiety, our sacred attachment to feeling bad and wanting to go on feeling bad.

These people worship “the science” but have, shall we say, a selective understanding of it. We’ve known for a long time that it’s very hard to catch Covid outdoors, and that children face very little risk, and again most adults are vaccinated. And yet if you took your kid trick or treating a month ago there’s a Greek chorus that wants you to know that it was terribly selfish and irresponsible, and some such thing as the science says so, irrespective of what the iterative, provisional, and antagonistic rhetorical processes of epidemiology might have to say. We have created an entirely new epistemology of public health science in the past couple of years, one that is somehow not a branch of medicine or biology but of public relations. Its vectors are not pathogens but perceptions. It tracks not the spread of disease but the spread of blame.

What people of this school demand is not sound public health policy or compliance with common-sense Covid regulations, much less an end to the epidemic. (That would end the fun.) What they want is for the world to stop. They want Covid to matter so much that we all look around and realize that something is fundamentally out of order and thus grind human life to a halt, in much the same way that they said “this is NOT normal!” when Trump was elected, as if that were true, as if the world would care if it was. And thudding around in the background is the palpable sense that they are attached to this condition that they say frightens and disturbs them, that they need it, as they imagine that finally something has come along so extreme and so wrong that it will arrest the world’s progress, stopping the ride so they can get out and cluck their tongue at the ridiculousness and injustice of it all.

Sodium won’t boil at any of the temperatures it should be exposed to

November 29th, 2021

TerraPower, a US-based nuclear power company backed by Bill Gates, has selected Kemmerer, Wyoming — population roughly 2,500, and home to the soon-to-be-closed coal-fired Naughton Power Plant — as the site for its first reactor:

The TerraPower project will see it replaced by a 345 megawatt reactor that would pioneer a number of technologies that haven’t been commercially deployed before.

These include a reactor design that needs minimal refueling, cooling by liquid sodium, and a molten-salt heat-storage system that will provide the plant with the flexibility needed to better integrate with renewable energy.

[…]

The reactor design is being developed jointly with GE Hitachi Nuclear Energy. A company called Bechtel will help with the construction, which will require a workforce equivalent to roughly 80 percent of Kemmerer’s population.

[…]

To begin with, the plant will not use water to transfer heat out of the reactor; instead, it will use liquid sodium. This has a major advantage in that sodium won’t boil at any of the temperatures it should be exposed to in the reactor. This means that none of the hardware that holds the coolant will be exposed to high pressures, which simplifies matters considerably. Sodium will, however, readily react with air and explosively react with water, which raises a distinct set of concerns.

Globally, only about 25 major reactors have been built using sodium coolant. Many were only built for research purposes, and only a handful remain operational. The last one in the US was built in 1965, and the last operational one was shuttered in 1994. So, it’s fair to say that the companies don’t have much hands-on experience to draw on.

Sodium-cooled designs, in contrast to water cooling, don’t slow the neutrons produced by fission reactions down; they’re often referred to as “fast reactors” for that reason. Fast neutrons have the ability to transform isotopes that don’t make useful fuel, allowing them to produce more fuel during operation.

In TerraPower’s case, its design surrounds a core of enriched fuel with lots of less-useful isotopes. The reactor will be powered by the enriched core as it converts additional material to useful fuel, which will take over as the first gets exhausted. This process can repeat through several layers of conversion, limiting the downtime needed for refueling. But again, it hasn’t seen commercial use before.

The reactor will have a number of features that should allow passive safety, causing its internal heat to remain limited even if cooling circulation fails.

Finally, TerraPower won’t directly convert the heat extracted from the reactor into power; instead, it will store it as molten salt. As a result, although the reactor will be rated as 345 MW, the plant will be able to generate as much as 500 MW during periods of high demand or scale down to lower production when demand is reduced. This will allow the plant to better follow daily cycles of demand. In addition, the heat storage will also allow the Kemmerer site to better integrate with the growing use of renewable power (Wyoming is a major producer of wind power).

It’s not a good idea to tell yourself what not to do

November 27th, 2021

You’ve probably heard that it’s not a good idea to tell yourself what not to do:

A recent study (Gorgulu, 2019) looked at what would happen when experienced tennis players were asked to serve, and not miss, under a bit of pressure.

[...]

Specifically, when their anxiety went up, participants hit more balls long and wide — the exact thing they were explicitly told not to do. Meanwhile, the number of balls hit into the middle of the service box — the 0-point area, where they neither gained nor lost points — was pretty much the same regardless of whether they were nervous or not.

In other words, under pressure, the athletes didn’t just become less accurate servers in general. They became less accurate in a very specific way — hitting more balls to the exact place on the court that they were trying to avoid.

Which is pretty weird, when you think about it — so why does this happen?

Well, there are a few possibilities, but the theory of “ironic error” essentially suggests that we have two mental processes in play — an “operating” process and a “monitoring” process. And that when we’re under pressure, given the limited cognitive resources available to us, monitoring our performance ends up taking resources away from the operating process, which makes us more likely to mess up in exactly the way we’re trying not to.

The choice group totally outperformed the no-choice group

November 26th, 2021

A team of researchers recruited twenty-four 10-year old girls to learn five classical ballet positions:

Each participant was shown pictures of each position and given a verbal explanation of what to do. Then, it was time to give it a try. And after their first practice attempt, half of the participants (the choice group) were told that if they wanted, they could ask to see a video demonstration of the positions before any subsequent practice attempt.

The other participants (the no-choice group) were told that they would be shown videos from time to time, but not given any choice as to when. Each of these participants were “yoked” to another participant in the choice group, such that whenever their counterpart requested a video, they would be shown a video too.

Everyone did 50 practice repetitions (5 sets of 10), and then they were done for the day.

Autonomy support enhances performance expectancies, positive affect, and motor learning

The choice group totally outperformed the no-choice group.

Americans do indeed spend more when Thanksgiving falls early

November 25th, 2021

Retailers don’t just put up decorations to steal Christmas sales from each other, Tim Harford notes. They are also boosting the total amount we impressionable customers spend:

In 2005, the economist Emek Basker…studied the US, where Thanksgiving now ranges between November 22 and 28, leaving as few as 26 or as many as 32 shopping days between Thanksgiving and Christmas. She found a clear pattern: Americans do indeed spend more when Thanksgiving falls early. The sums aren’t trivial: about $10 per person per day in today’s terms. Robert Urbatsch, a political scientist, used a similar approach to examine the jobs market and found that longer Christmas seasons lead to higher levels of employment.

Professor Basker estimated total holiday spending by comparing all spending in November and December vs all spending in September and October; the difference was about $300 per person in today’s money. Using a slightly different method, the author of Scroogenomics Joel Waldfogel has produced broadly similar estimates of the Christmas bump in sales.

Von Neumann’s genius was apparent early

November 24th, 2021

Tom Chivers (How to Read Numbers) reviews Ananyo Bhattacharya’s The Man from the Future, which explores the genius of John von Neumann:

Von Neumann’s genius was apparent early. In 1915, at the age of 11, he had gone to the famous gymnasium school in his native Budapest; the “legendary” maths teacher, László Rátz, immediately realised that von Neumann was beyond his ability to teach, and sent him for extra tuition at the local university. There he was mentored by Gábor Szegö, later head of Stanford’s maths department, who was “moved to tears” by his brilliance.

At 17, still at high school, he partly rescued Cantor’s set theory, the basis of much mathematical theory, from a crippling paradox. A couple of years later, he helped reconcile Werner Heisenberg and Erwin Schrödinger’s rival models of quantum mechanics. In the early Thirties, he met the astronomer Subrahmanyan Chandrasekhar, and worked with him on general relativity and the behaviour of stellar clusters. Chandrasekhar would later tell an interviewer, “If I say, ‘He reminds me of von Neumann,’ that’s about the best compliment I can give anyone.”

Von Neumamm read some Alan Turing research which imagined a hypothetical computing machine, and saw how to build a working computer. The paper he produced building on Turing’s ideas is considered “the birth certificate of modern computers”, according to the computer scientist Wolfgang Coy. With his wife Kläri, and Ulam, he pioneered Monte Carlo simulations, vital now in climate modelling and a million other fields.

[…]

What created this genius? Bhattacharya does not speculate a great deal, but there are things worth considering. First, simple genetics: his family was high-achieving. His father was a doctor of law and an economic adviser to the Hungarian government; his uneducated maternal grandfather apparently could “add or multiply numbers into the millions” in his head instantly, a trick von Neumann emulated. The family was “puzzled” by their son’s inability to play the piano properly at the age of five, suggesting rather higher expectations than most. But it turned out to be because he “had taken to propping up books on his music stand so he could read while ‘practising’”.

He also grew up in a fertile environment. Around the turn of the 20th century, the Budapest Jewish community of which he was part produced an astonishing number of great thinkers. Near-contemporaries included Dennis Gabor, “who won the Nobel Prize in physics in 1971 for inventing the hologram”; Theodore von Kármán, after whom the “Kármán line” is named, denoting the boundary between the Earth’s atmosphere and space; and Eugene Wigner, Edward Teller, and Leo Szilard, three of the greatest minds behind the Manhattan Project. The atomic bomb has been described as a “Hungarian high school science fair project”.

You don’t begin with a manifesto and a top-heavy board of advisors

November 23rd, 2021

Pano Kanelos has left his post as president of St. John’s College in Annapolis (the Great Books school) to build the University of Austin, dedicated to the fearless pursuit of truth.

Arnold Kling wishes them luck, but he doesn’t think that this is how start-ups work:

You don’t begin with a manifesto and a top-heavy board of advisors. You begin with a few very energetic founders trying to put together a prototype. I say get some proof-of-concept work done, then go after endorsements. Yes, it’s hard to do “proof-of-concept” if your mental model is to be a better version of Harvard. But that means you should have a different mental model.

Students were being asked to get answers by multiple methods

November 22nd, 2021

Physics professor Chad Orzel’s child (“SteelyKid”) started school in 2013, which was close to the peak of the freakout over Common Core Math:

The inscrutability of the new standards for elementary school math was an endlessly recurring topic in late-night talk show monologues and frustrated Facebook rants from high-school classmates whose kids are a bit older than mine. Nobody seemed able to understand what was now deemed to be third-grade math, and everybody was pissed about it.

As is often the case with issues touching on STEM in schools, I found this a little puzzling. As SteelyKid started to get into the math curriculum, I thought it was great — not just the endless algorithmic chugging I dimly remembered from my own childhood, but something much closer to actual math. Students were being asked to get answers by multiple methods, check them against each other, and explain how they knew their final answers were right. These are all things I struggle to get college frosh to do in intro physics, and here it was built right into the elementary school math curriculum.

So, on reflection, I guess it’s pretty obvious why everybody else hated it…

It would not be like the movies with intense dogfights

November 21st, 2021

Physics would constrain space-to-space engagements. These five key concepts help explain how:

  1. Satellites move quickly.
  2. Satellites move predictably.
  3. Space is big.
  4. Timing is everything.
  5. Satellites maneuver slowly.

Warfighting on Earth typically involves competitors fighting to dominate a physical location:

Opposing military forces fight to control the land, sea, and air over a certain part of Earth to expand influence over people or resources. Space warfare does not follow this paradigm; satellites in orbit do not occupy or dominate a single location over time. Instead, satellites provide capabilities, such as communications, navigation, and intelligence gathering, to Earth-based militaries. Therefore, to “control space” is not necessarily to physically conquer sectors of space but rather to reduce or eliminate adversary satellite capabilities while ensuring one retains the ability to freely operate their own space capabilities.

[...]

Objects orbiting Earth have a strict relationship between altitude and speed. Orbital mechanics dictate that objects at lower altitudes will always move more quickly than those at higher altitudes. Any attempt to add or reduce a satellite’s speed will always lead to a change in altitude. Compare this relationship between speed and altitude to an aircraft, which often changes speed without affecting its altitude, and vice versa.

And that speed is fast. Satellites in commonly used circular orbits move at speeds between 3 km/s and 8 km/s (6,700 mph and 18,000 mph), depending on their altitude. In contrast, an average bullet only travels about 0.75 km/s (1,700 mph).

[...]

Also, because a satellite’s speed is tied to its altitude, a satellite will return to approximately the same point in its orbit at regular intervals (known as its period), regardless of the orbit’s shape and absent a maneuver to change the orbit.

[...]

To deviate from their prescribed orbit, satellites must use an engine to maneuver. This contrasts with airplanes, which mostly use air to change direction; the vacuum of space offers no such option.

[...]

Getting two satellites to the same altitude and the same plane is straightforward (though time and delta-V consuming), but that does not mean they are yet in the same spot. The phasing — current location along the orbital trajectory — of the two satellites must also be the same. Since speed and altitude are connected, getting two satellites in the same spot is not intuitive. Therefore, it requires careful planning and perfect timing.

One way to get close to another satellite is to perform a flyby. A flyby occurs when one satellite nearly matches the other satellite’s position without matching its orbit. Because the satellites are in different orbits, they will appear to speed past each other. These maneuvers are useful for inspection missions where the goal is not to destroy the target but to image it. Flybys often require minimal delta-V for an attacking satellite to perform since it can use natural intersection points of the two orbits to come close to its target. A related operation, known as an intercept, involves intentionally trying to match positions with the target, leading to the destruction of both satellites.

For two satellites in the same orbit, a common maneuver known as a phasing maneuver is required for one satellite to catch the other satellite. A phasing maneuver involves changing the satellite’s position in its orbit plane, either moving it ahead or behind of where it would normally be, similar to a train increasing or decreasing its speed to arrive at a destination sooner or later. Unlike a train, which can speed up or slow down without changing tracks, a satellite that changes speed also changes its altitude. This leads to the satellite entering into a new orbit known as a transfer orbit, an orbit used temporarily to move a satellite from an original orbit to a new orbit.

Phasing Maneuvers

Ground-based ASATs are missiles that rely on a rocket to deliver a small warhead to impact with a satellite. Because the rocket has a large delta-V capacity, the warhead itself is placed in the correct intercept trajectory and requires little propellant to reach its target — this makes them more intuitive as they behave more like traditional missiles.

[...]

In contrast, an orbital ASAT is basically a satellite that purposefully destroys other satellites. This can be done either with an RPO intercept or with onboard weapons. Unlike the ground ASAT missile, which can be launched without warning and at a moment’s notice, an orbital ASAT may be launched months to years ahead of a potential conflict.

[...]

Some counterspace threats utilize the electromagnetic spectrum to inflict either temporary (reversible) or permanent (irreversible) harm. These threats are attractive because the attacks happen from a distance, which adds a measure of deniability and lessens the burden of getting physically close. Intentional jamming can also be quite difficult to distinguish from unintentional interference, making attribution more challenging.

[...]

While there has never been a battle in space, we can still gauge what a war in space might look like. It would not be like the movies with intense dogfights. Instead space-based threats would be un-crewed and require slow and deliberate planning to get into position. Compared with the timing and flexibility limitations of on-orbit weapons, ground-based threats afford substantially shorter engagement execution timelines and the prospect of more numerous shots. The more we can internalize these insights, the better we can understand the stakes of a geopolitical fight in space.

Some of the best engineers would rather quit than be micromanaged

November 20th, 2021

The Pragmatic Engineer (Gergely Orosz) looks at how Big Tech runs tech projects and ends with the following ideas as food for thought:

  • Iterative changes always work better than ‘big bang’ ones. A European tech company struggling with shipping very slowly hired a new VP of Engineering. This person decided to move the whole organization to a NoEstimates method in the first few months of their tenure. They organized a major event, hired a rock band, and unveiled the new way of working. The following weeks and months were chaos, and the organization reverted to doing what it did beforehand.
  • It’s more work to teach someone to fish, than it is to catch a fish for them. My approach to project management has been to coach and mentor members of my team to become project leads themselves. It was a lot more work upfront, but resulted in the team delivering more, people growing faster, getting promoted faster, and those people becoming engineering leaders faster than their peers. This approach was one of my best decisions in an empowered environment.
  • Directing, mentoring and coaching all have their uses. Directing – telling people exactly how to do something – is micromanaging when they can do it themselves. However, it’s a supportive activity when they can’t. Choose your approaches depending on whether you direct, mentor or coach and give space to people or teams, based on their capabilities as well. Over time, you should be doing little to no directing. But you might need to start with this.
  • The fewer people you need to make decisions, the faster you can make them. If an engineer only needs to talk to an engineer to decide, that decision will be faster than if the engineer needs to talk to their project manager, who talks to another project manager, who talks to an engineer, who talks to… you get it.
  • Optimizing for reporting is optimizing for a low-trust environment. Reporting at the executive levels is important. However, if you roll out project management methodologies that add heavy processes for the sake of reporting, then you’ll get more process, lower trust, and people gaming whatever reports you’re trying to produce.
  • Consultants will be biased to deliver easy-to-measure results because this is the simplest way to prove their value. If the easy-to-measure result is a good goal, this makes consultants a good investment. Just make sure it is a worthwhile goal, and directionally correct.
  • Learning from direct competitors is underrated. Understanding what a faster-moving competitor is doing – and experimenting with something similar – is a very smart one. Having a coffee with a peer at a competitor can be a great professional, and networking investment, not to mention one that may inspire you.
  • Some of the best engineers would rather quit than be micromanaged, especially when the job market is hot, and it’s so easy to switch jobs. A relevant quote from a response to my survey: “Recently, C-level executives have started to mandate the ways of working for all teams (everyone needs to follow the same methodology). It resulted in a lot of engineers leaving.”

Passenger car drivers are seven times more likely to be killed in a crash with an SUV

November 19th, 2021

The problem with electric trucks is that they’re big and even heavier than their gas-powered counterparts:

Between 2000 and 2019, the average weight of vehicles involved in a fatal crash increased by 11%.

[...]

Their increasingly flat fronts and tall hoods create front blind zones two to three times larger than a sedan’s; one experiment sat 18 children in front of an SUV, and all were fully hidden from the driver by the massive hood. This exacerbates the risk of “frontover collisions,” in which a vehicle moving forward slowly hits a person the driver can’t see. Most frontover collision victims are between one and two-years-old, and the vast majority of frontover fatalities since the 1990s have involved an SUV, van or light truck. A recent study in the Economics of Transportation estimates that if between 2000 and 2019 all light trucks were replaced with cars, more than 8,000 pedestrians would still be alive today.

]…]

A study from the University at Buffalo concluded that passenger car drivers are seven times more likely to be killed in a crash with an SUV, partially due to the ability of the SUV to roll over the smaller car (a phenomenon unfortunately named “bumper mismatch”).