Adam Savage harnesses Spot to a dog-cart

Saturday, February 15th, 2020

Adam Savage wanted to use Spot, from Boston Dynamics, to take him on a trip, so he created what he called a robot rickshaw — but which I’d call a robot dog-cart:

A mix of neural networks and depth-aware video frame interpolation

Friday, February 14th, 2020

YouTuber Denis Shiryaev took the Lumière Brothers’ 1896 short clip “Arrival of a Train at La Ciotat” — digitized at 640-by-480 resolution, and 20 frames per second — ran it through some neural networks, and upscaled it to 4K resolution, at 60 fps:

As you can see, it’s not exactly impressive by today’s standards, so Denis used a mix of neural networks from Gigapixel AI and a technique called depth-aware video frame interpolation to not only upscale the resolution of the video, but also increase its frame rate to something that looks a lot smoother to the human eye.

Hydrogen is a bad car fuel, but maybe a decent boat fuel?

Thursday, February 13th, 2020

Hydrogen is a bad car fuel, Toyota has learned from the Mirai hydrogen experiment, but it may make a decent boat fuel, as it hopes to demonstrate with its Energy Observer, a former racing catamaran with some new additions:

The Energy Observer uses a pair of wind turbines and a vast array of solar photo-voltaic cells to both propel the vessel and provide power to its on-board hydrogen-creating electrolysis process. Sea water is essentially zapped into its component parts and the isolated hydrogen is captured to be expended inside the Toyota fuel cell generator. The process emits nothing but oxygen and water out the “tailpipe”.

Toyota Energy Observer

In optimum conditions, the boat is propelled entirely by wind and solar. A rack of lithium cells onboard keep the thing running when it’s cloudy or calm winds, and Toyota’s fuel cell system takes over to produce the boat’s propelling energy at night.

I’m thinking it might be a better airship fuel.

Seymour Cray had a hobby of digging tunnels under his house

Tuesday, February 11th, 2020

Seymour Cray, of Cray supercomputing fame, had a hobby of digging tunnels under his house, Whyvert mentioned, and he found it helpful:

“While I’m digging in the tunnel, the elves will often come to me with solutions to my problem.”

Can you draw a bicycle?

Thursday, February 6th, 2020

We overestimate our ability to explain how things work. Cognitive psychologist Rebecca Lawson at the University of Liverpool measured how well people understand how everyday objects work using the bicycle:

I have given the test to over 200 students and parents coming to Open Days at the University. Over 96% had learnt to cycle as children with a further 1.5% learning as adults and less than 3% never having learned. Also 52% of this group owned a bicycle. Sadly, the figures on actual cycling were low, with just 1% cycling most days, 4% cycling around once a week and 9% cycling about once a month. The vast majority either never cycle (52%) or rarely do so (33%). Nevertheless, even for these non-cyclists, bicycles are a common sight. Secondly, if Rozenblit and Keil are correct, people should greatly over-estimate their understanding of how bicycles work because bicycle parts are visible and they seem to be simple, mechanical devices.

Draw a Bicycle Figure 1

I first asked people to draw a bicycle and I then asked them to select which of four alternatives were correct for the frame, the pedals and the chain, see Figure 1. I used the multiple choice test to check that errors that people made were not just due to problems with drawing or in my judgement of the accuracy of their drawings, see Figure 2.

Draw a Bicycle Figure 2

I looked at three types of errors which would severely impair the functioning of a bicycle (see Figure 3 for examples of all three):

1. drawing the frame joining the front and back wheels (making steering impossible)

2. not placing the pedals between the wheels and inside the chain (the pedals were sometimes drawn attached to the front wheel, the back wheel or dangling off the cross-bar)

3. not putting the chain around the pedals and the back wheel (these errors were almost all because people drew the chain looping around both the front and the back wheel of the bicycle)

Draw a Bicycle Figure 3

It seems that many people have virtually no understanding of how bicycles work. This is despite bicycles being highly familiar and most people having learnt how to ride one. Most people know that turning the pedals drives one or both of the bicycle wheels forward, but they probably understand little more than this.


One last thing: unexpected sex effects. One finding that I was not looking for jumped out from the data. There were huge sex differences with females making many more errors than males.


Thus, at least for frame and chain errors, females make around twice as many errors as males. It could be argued that this is still a matter of experience. It is likely that boys cycle more than girls so many males who currently rarely cycle may have, over their lifetime, seen and used more bicycles than females. However the sex difference is even more extreme for those who claim to cycle around once a month, once a week or most days.


Not only do male non-cyclists make fewer errors than female non-cyclists, they also make fewer errors than female cyclists; whilst male cyclists make almost no errors.

The gun is mounted on an unstable platform

Friday, January 31st, 2020

In Men, Machines, and Modern Times, Elting E. Morison looks at how we learn to live and work with innovation. He illustrates the three stages of users’ resistance to change — ignoring it, rational rebuttal, and name-calling — first with an example from naval history:

The governing fact in gunfire at sea is that the gun is mounted on an unstable platform, a rolling ship. This constant motion obviously complicates the problem of holding a steady aim. Before 1898 this problem was solved in the following elementary fashion. A gun pointer estimated the range of the target, ordinarily in the nineties about 16oo yards. He then raised the gun barrel to give the gun the elevation to carry the shell to the target at the estimated range. This elevating process was accomplished by turning a small wheel on the gun mount that operated the elevating gears. With the gun thus fixed for range, the gun pointer peered through open sights, not unlike those on a small rifle, and waited until the roll of the ship brought the sights on the target. He then pressed the firing button that discharged the gun. There were by 1898, on some naval guns, telescope sights, which naturally greatly enlarged the image of the target for the gun pointer. But these sights were rarely used by gun pointers. They were lashed securely to the gun barrel, and, recoiling with the barrel, jammed back against the unwary pointer’s eye. Therefore, when used at all, they were used only to take an initial sight for purposes of estimating the range before the gun was fired.

Notice now two things about the process. First of all, the rapidity of fire was controlled by the rolling period of the ship. Pointers had to wait for the one moment in the roll when the sights were brought on the target. Notice also this: there is in every pointer what is called a “firing interval” — that is, the time lag between his impulse to fire the gun and the translation of this impulse into the act of pressing the firing button. A pointer, because of this reaction time, could not wait to fire the gun until the exact moment when the roll of the ship brought the sights onto the target; he had to will to fire a little before, while the sights were off the target. Since the firing interval was an individual matter, varying obviously from man to man, each pointer had to estimate from long practice his own interval and compensate for it accordingly.

These things, together with others we need not here investigate, conspired to make gunfire at sea relatively uncertain and ineffective. The pointer, on a moving platform, estimating range and firing interval, shooting while his sight was off the target, became in a sense an individual artist.

In 1898, many of the uncertainties were removed from the process and the position of the gun pointer radically altered by the introduction of continuous-aim firing. The major change was that which enabled the gun pointer to keep his sight and gun barrel on the target throughout the roll of the ship. This was accomplished by altering the gear ratio in the elevating gear to permit a pointer to compensate for the roll of the vessel by rapidly elevating and depressing the gun. From this change another followed. With the possibility of maintaining the gun always on the target, the desirability of improved sights became immediately apparent. The advantages of the telescope sight as opposed to the open sight were for the first time fully realized. But the existing telescope sight, it will be recalled, moved with the recoil of the gun and jammed back against the eye of the gunner. To correct this, the sight was mounted on a sleeve that permitted the gun barrel to recoil through it without moving the telescope.

These two improvements in elevating gear and sighting eliminated the major uncertainties in gunfire at sea and greatly increased the possibilities of both accurate and rapid fire.

You must take my word for it, since the time allowed is small, that this changed naval gunnery from an art to a science, and that gunnery accuracy in the British and our Navy increased, as one student said, 3000% in six years. This does not mean much except to suggest a great increase in accuracy. The following comparative figures may mean a little more. In 1899 five ships of the North Atlantic Squadron fired five minutes each at a lightship hulk at the conventional range of 1600 yards. After twenty-five minutes of banging away, two hits had been made on the sails of the elderly vessel. Six years later one naval gunner made fifteen hits in one minute at a target 75 by 25 feet at the same range — 1600 yards; half of them hit in a bull’s eye 50 inches square.

Now with the instruments (the gun, elevating gear, and telescope), the method, and the results of continuous-aim firing in mind, let us turn to the subject of major interest: how was the idea, obviously so simple an idea, of continuous-aim firing developed, who introduced it into the United States Navy, and what was its reception?

The idea was the product of the fertile mind of the English officer Admiral Sir Percy Scott. He arrived at it in this way while, in 1898, he was the captain of H.M.S. Scylla. For the previous two or three years he had given much thought independently and almost alone in the British Navy to means of improving gunnery. One rough day, when the ship, at target practice, was pitching and rolling violently, he walked up and down the gun deck watching his gun crews. Because of the heavy weather, they were making very bad scores. Scott noticed, however, that one pointer was appreciably more accurate than the rest. He watched this man with care, and saw, after a time, that he was unconsciously working his elevating gear back and forth in a partially successful effort to compensate for the roll of the vessel. It flashed through Scott’s mind at that moment that here was the sovereign remedy for the problem of inaccurate fire. What one man could do partially and unconsciously perhaps all men could be trained to do consciously and completely.

Acting on this assumption, he did three things. First, in all the guns of the Scylla, he changed the gear ratio in the elevating gear, previously used only to set the gun in fixed position for range, so that a gunner could easily elevate and depress the gun to follow a target throughout the roll. Second, he rerigged his telescopes so that they would not be influenced by the recoil of the gun. Third, he rigged a small target at the mouth of the gun, which was moved up and down by a crank to simulate a moving target. By following this target as it moved and firing at it with a subcaliber rifle rigged in the breech of the gun, time pointer could practice every day. Thus equipped, the ship became a training ground for gunners. Where before the good pointer was an individual artist, pointers now became trained technicians, fairly uniform in their capacity to shoot. The effect was immediately felt. Within a year the Scylla established records that were remarkable.

At this point I should like to stop a minute to notice several things directly related to, and involved in, the process of innovation. To begin with, the personality of the innovator. I wish there were time to say a good deal about Admiral Sir Percy Scott. He was a wonderful man. Three small bits of evidence must here suffice, however. First, he had a certain mechanical ingenuity. Second, his personal life was shot through with frustration and bitterness. There was a divorce and a quarrel with that ambitious officer Lord Charles Beresford, the sounds of which, Scott liked to recall, penetrated to the last outposts of empire. Finally, he possessed, like Swift, a savage indignation directed ordinarily at the inelastic intelligence of all constituted authority, especially the British Admiralty.

There are other points worth mention here. Notice first that Scott was not responsible for the invention of the basic instruments that made the reform in gunnery possible. This reform rested upon the gun itself, which as a rifle had been in existence on ships for at least forty years; the elevating gear, which had been, in the form Scott found it, a part of the rifled gun from the beginning; and the telescope sight, which had been on shipboard at least eight years. Scott’s contribution was to bring these three elements appropriately modified into a combination that made continuous-aim firing possible for the first time. Notice also that he was allowed to bring these elements into combination by accident, by watching the unconscious action of a gun pointer endeavoring through the operation of his elevating gear to correct partially for the roll of his vessel. Scott, as we have seen, had been interested in gunnery; he had thought about ways to increase accuracy by practice and improvement of existing machinery; but able as he was, he had not been able to produce on his own initiative and by his own thinking the essential idea and modify instruments to fit his purpose. Notice here, finally, the intricate interaction of chance, the intellectual climate, and Scott’s mind. Fortune (in this case, the unaware gun pointer) indeed favors the prepared mind but even fortune and the prepared mind need a favorable environment before they can conspire to produce sudden change. No intelligence can proceed very far above the threshold of existing data or the binding combinations of existing data.

In 1900 Percy Scott went out to the China Station as commanding officer of H.M.S. Terrible. In that ship he continued his training methods and his spectacular successes in naval gunnery. On the China Station he met up with an American junior officer, William S. Sims. Sims had little of the mechanical ingenuity of Percy Scott, but the two were drawn together by temperamental similarities that are worth noticing here. Sims had the same intolerance for what is called spit and polish and the same contempt for bureaucratic inertia as his British brother officer. He had for some years been concerned, as had Scott, with what he took to be the inefficiency of his own Navy. Just before he met Scott, for example, he had shipped out to China in the brand new pride of the fleet, the battleship Kentucky. After careful investigation and reflections he had informed his superiors in Washington that she was “not a battleship at all — but a crime against the white race.” The spirit with which he pushed forward his efforts to reform the naval service can best be stated in his own words to a brother officer: “I am perfectly willing that those holding views differing from mine should continue to live, but with every fibre of my being I loathe indirection and shiftiness, and where it occurs in high place, and is used to save face at the expense of the vital interests of our great service (in which silly people place such a child-like trust), I want that man’s blood and I will have it no matter what it costs me personally.”

From Scott in 1900 Sims learned all there was to know about continuous-aim firing. He modified, with the Englishman’s active assistance, the gear on his own ship and tried out the new system. After a few months training, his experimental batteries began making remarkable records at target practice. Sure of the usefulness of his gunnery methods, Sims then turned to the task of educating the Navy at large. In thirteen great official reports he documented the case for continuous-aim firing, supporting his arguments at every turn with a mass of factual data. Over a period of two years, he reiterated three principal points: first, he continually cited the records established by Scott’s ships, the Scylla and the Terrible, and supported these with the accumulating data from his own tests on an American ship; second, he described the mechanisms used and the training procedures instituted by Scott and himself to obtain these records; third, he explained that our own mechanisms were not generally adequate without modification to meet the demands placed on then by continuous-aim firing. Our elevating gear, useful to raise or lower a gun slowly to fix it in position for the proper range, did not always work easily and rapidly enough to enable a gunner to follow a target with his gun throughout the roll of the ship. Sims also explained that such few telescope sights as there were on board our ships were useless. Their cross wires were so thick or coarse they obscured the target, and the sights had been attached to the gun in such a way that the recoil system of the gun plunged the eyepiece against the eye of the gun pointer.

This was the substance not only of the first but of all the succeeding reports written on the subject of gunnery from the China Station. It will be interesting to see what response these met with in Washington. The response falls roughly into three easily identifiable stages. First stage: At first, there was no response. Sims had directed his comments to the Bureau of Ordnance and the Bureau of Navigation; in both bureaus there was dead silence. The thing — claims and records of continuous-aim firing — was not credible. The reports were simply filed away and forgotten. Some indeed, it was later discovered to Sims’s delight, were half-eaten-away by cockroaches.

Second stage: It is never pleasant for any man’s best work to be left unnoticed by superiors, and it was an unpleasantness that Sims suffered extremely ill. In his later reports, beside the accumulating data he used to clinch his argument, he changed his tone. He used deliberately shocking language because, as he said, “They were furious at my first papers and stowed them away. I therefore made up my mind I would give these later papers such a form that they would be dangerous documents to leave neglected in the files.” To another friend he added, “I want scalps or nothing and if I can’t have ‘em I won’t play.”

Besides altering his tone, he took another step to be sure his views would receive attention. He sent copies of his reports to other officers in the fleet. Aware as a result that Sims’s gunnery claims were being circulated and talked about, the men in Washington were then stirred to action. They responded, notably through the Chief of the Bureau of Ordnance, who had general charge of the equipment used in gunnery practice, as follows: (1) our equipment was in general as good as the British; (2) since our equipment was as good, the trouble must be with the men, but the gun pointer and the training of gun pointers were the responsibility of the officers on the ships; and most significant (3) continuous-aim firing was impossible. Experiments had revealed that five men at work on the elevating gear of a six-inch gun could not produce the power necessary to compensate for a roll of five degrees in ten seconds. These experiments and calculations demonstrated beyond peradventure or doubt that Scott’s system of gunfire was not possible.

This was the second stage — the attempt to meet Sims’s claims by logical, rational rebuttal. Only one difficulty is discoverable in these arguments; they were wrong at important points. To begin with, while there was little difference between the standard British equipment and the standard American equipment, the instruments on Scott’s two ships, the Scylla and the Terrible, were far better than the standard equipment on our ships. Second, all the men could not be trained in continuous-aim firing until equipment was improved throughout the fleet. Third, the experiments with the elevating gear had been ingeniously contrived at the Washington Navy Yard — on solid ground. It had, therefore, been possible to dispense in the Bureau of Ordnance calculation with Newton’s first law of motion, which naturally operated at sea to assist the gunner in elevating or depressing a gun mounted on a moving ship. Another difficulty was of course that continuous-aim firing was in use on Scott’s and some of our own ships at the time the Chief of the Bureau of Ordnance was writing that it was a mathematical impossibility. In every way I find this second stage, the apparent resort to reason, the most entertaining and instructive in our investigation of the responses to innovation.

Third stage: The rational period in the counterpoint between Sims and the Washington men was soon passed. It was followed by the third stage, that of name-calling — the argumentum ad hominem. Sims, of course, by the high temperature he was running and by his calculated over-statement, invited this. He was told in official endorsements on his reports that there were others quite as sincere and loyal as he and far less difficult; he was dismissed as a crackbrained egotist; he was called a deliberate falsifier of evidence.

The rising opposition and the character of the opposition were not calculated to discourage further efforts by Sims. It convinced him that he was being attacked by shifty, dishonest men who were the victims, as he said, of insufferable conceit and ignorance. He made up his mind, therefore, that he was prepared to go to any extent to obtain the “scalps” and the “blood” he was after. Accordingly, he, a lieutenant, took the extraordinary step of writing the President of the United States, Theodore Roosevelt, to inform him of the remarkable records of Scott’s ships, of the inadequacy of our own gunnery routines and records, and of the refusal of the Navy Department to act. Roosevelt, who always liked to respond to such appeals when he conveniently could, brought Sims back from China late in 1902 and installed him as Inspector of Target Practice, a post the naval officer held throughout the remaining six years of the Administration. And when he left, after many spirited encounters we cannot here investigate, he was universally acclaimed as “the man who taught us how to shoot.”

All the rigidity and strength the pickup needs comes from everything you’re looking at

Monday, January 27th, 2020

Lean-design guru Sandy Munro suggests that the Tesla Cybertruck may only need $30 million in capital expenditures to tool up for production of 50,000 units per year:

Tesla’s secret sauce is the fact it appears the truck’s exoskeleton also act as its body panels. So, all the rigidity and strength the pickup needs comes from everything you’re looking at, and it just needs welding and assembly. The fact there’s no painting involved, just plain stainless steel, is also a tremendous cost-saver, per Munro.

The control tones had to be within the range of normal human speech

Sunday, January 26th, 2020

Those beeps you hear in recordings of astronauts in space have a name — Quindar Tones:

First, let’s be specific about those beeps: there’s actually two different beeps that happen, one a sine wave tone at a frequency of 2.525 KHz that lasts for 250 milliseconds, and one that’s a sine wave tone at 2.475 KHz, for the same duration.

That first and slightly higher tone is called the intro tone and the lower one is the outro. As their names suggest, one is for the start of something, and one for the end.

What that something is related to how the CapCom — that means “capsule communicator” which was what they called the ground control team member (usually an astronaut) who was in charge of talking directly to the astronauts on the spacecraft. Having one person designated to communicate with the astronauts helps reduce any possible confusion and cross-talk.

Since the CapCom would be in the busy, noisy Mission Control room, they’d want to choose when to open their microphones to talk to the spacecraft, so NASA used a push-to-talk (PTT) system.

It’s like how a CB works, if you’re as miserably old as I am and remember that — you hold down a button while you talk, and let up when you’re done.

This is normally not a big deal to implement, but the space program had very unique requirements. In the setup that NASA developed, which used tracking stations all over the world to keep in near-constant communication with the spacecraft, the audio from CapCom to be sent into space was transmitted to the various stations across the globe via dedicated telephone lines.

These lines were just for voice audio — if NASA wanted to send control signals like transmit on and off, they’d need to run a whole parallel set of wires, which would be expensive. So, they came up with a solution: use the same lines for control signals as well!

Because the lines were optimized for human voice audio, the control tones had to be within the range of normal human speech, which is why the tones are audible.

The bird’s fingers are important for steering

Sunday, January 19th, 2020

Birds change the shape of their wings far more than planes do, and David Lentink, a professor of mechanical engineering at Stanford University, and his team explored this while creating their PigeonBot:

The researchers used common pigeon cadavers to try to figure out the mechanics of how birds control the motion of their feathers during flight. Scientists had thought the feathers might be controlled by individual muscles. But they learned that some aspects of bird wing motion are simpler than they expected.

Lentink says that several doctoral students realized that simply by moving the birds’ “wrist” and “finger,” the feathers would fall into place. When the bird’s wrist and finger moves, “all the feathers move, too, and they do this automatically,” he said. “And that’s really cool.”

The findings are some of the first evidence that the bird’s fingers are important for steering. The team replicated the bird’s wing on the PigeonBot using 40 pigeon feathers, springs and rubber bands connected to a wrist and finger structure. When the wrist and finger move, all the feathers move, too.

The researchers used a wind tunnel to see how the feather-and-rubber band design worked under turbulent conditions. “Most aerospace engineers would say this is not going to work well, but it turned out to be incredibly robust,” Lentink says.

They also pinpointed something interesting about how the feathers work together that helps most birds fly in turbulent conditions. At certain moments during flight, such as when a bird is extending its wings, tiny hooks on the feathers lock together like Velcro.

“These tiny, microscopic micro-structures that are between feathers lock them together as soon as they separate too far apart, and a gap is about to form. And it’s really spectacular,” Lentink adds. “It requires an enormous force to separate them.”

These tiny hooks are so small that they’re hard to see even through a microscope. Then, when a bird tucks its wing back in, the feathers unlock automatically, like directional Velcro. Separating the locked feathers makes an audible sound for most birds. The team published this finding in a separate paper in the journal Science.

It’s worth noting that the PigeonBot doesn’t incorporate something you might associate with birds’ wings – flapping. The designers were focused on incorporating the more subtle wrist-and-finger motions of the wings, so the bot appears to be gliding through the air while it’s in flight.

I guess Dune‘s ornithopters might not be so fanciful after all, and we might see a better human-power ornithopter, too.

Technology will, by itself, degrade

Sunday, January 12th, 2020

I didn’t recognize Jonathan Blow by name — he’s the “indie” game designer behind Braid, which I haven’t played, but which I have mentioned — but he recently gave a speech about a topic that interests me, Preventing the Collapse of Civilization:

He presents the key point fifteen minutes in:

This is why technology degrades. It takes a lot of energy to communicate from generation to generation, there are losses.

Nikita Prokopov summarizes it this way:

The software crisis is systemic and generational. Say, the first generation works on thing X. After X is done and becomes popular, time passes and the next generation of programmers comes and works on Y, based on X. They do not need to know, exactly, how X is built, why it was built that way, or how to write an alternative X from scratch. They are not lesser people or lazier, they just have no real need to write X2 since X already exists and allows them to solve more pressing tasks.

The biggest a-ha moment of the talk was that if you are working on Y and Y is based on X, that does not imply automatically that you would know X also. Even if the people who build X are still around, knowledge does not spread automatically and, without actual necessity, it will go away with the people who originally possessed it.

This is counter-intuitive: most people would think that if we’ve built, for example, a space ship or a complex airplane in the past, we could build it again at any time. But no, if we weren’t building a particular plane uninterruptedly, then after just 50 years it is already easier to develop a new one from scratch rather than trying to revive old processes and documentation. Knowledge does not automatically transfer to the next generation.

In programming, we are developing abstractions at an alarming rate. When enough of those are stacked, it becomes impossible to figure out or control what’s going on down the stack. This is where my contribution begins: I believe I have found some pretty vivid examples of how the ladder of abstractions has started to fall and nobody can do anything about it now because we all are used to work only at the very tip of it.

I still think a good general education would teach how to rebuild civilization. (I haven’t read my copy of How to Invent Everything: A Survival Guide for the Stranded Time Traveler yet, but it looks promising.)

It doesn’t collect data on how hard body parts are hitting the ground or other players

Friday, December 27th, 2019

Amazon-analyzed big data may not be enough to predict injuries in the NFL :

The Amazon Web Services partnership will try to close the gap with league-level data from the NFL’s Next Gen Stats, which capture location data, speed, and acceleration for every player on the field hundreds of times a minute through microchips in their pads. It also includes video footage of games, information on playing surface and environmental factors, and anonymized player injury data, according to the NFL. It doesn’t collect data on how hard body parts are hitting the ground or other players, which is one limitation, Binney says. But it can see, with granular detail, how and at what speed a player ran a play, changed direction, or made a tackle. The goal is to find out if any common elements of football are more likely than others to lead to any injury.

This stat caught my eye:

Currently, the injury count per game is holding steady at an average of six or seven.


It’d be hard to imagine a more powerful asset for criminals

Thursday, December 26th, 2019

Wes Siler’s friend Joe had his MacBook and iPad stolen from the back of a locked car over Thanksgiving:

So far, so normal, right? Well, the thieves only broke the small window immediately adjacent to where his devices were hidden and only took the backpack containing them. Police told him it was likely they’d used a Bluetooth scanner to target his car and even located exactly where his devices were before breaking into it.

When he texted me about what happened, I turned to Google to see what a Bluetooth scanner was and immediately found dozens of smartphone apps. The first one I downloaded didn’t just show me the signal strengths it detected, it also listed the specific types of devices and even displayed pictures of them—you know, for easy identification. Using signal strength as a distance meter, I found the phone my fiancée misplaced before she went to work. Another app displayed a live list of the devices commuters had in their cars while driving past my house. These apps are free and take no technical know-how or experience whatsoever to use. While they aren’t designed specifically to aid thieves (developers need tools like these when designing Bluetooth accessories), it’d be hard to imagine a more powerful asset for criminals.

A Tesla valve allows a fluid to flow preferentially in one direction, without moving parts

Wednesday, December 18th, 2019

In 1920, Nikola Tesla was awarded U.S. Patent 1,329,559 for his valvular conduit, or Tesla valve, which allows a fluid to flow preferentially in one direction, without moving parts:

That’s a goofy sounding scheme

Wednesday, December 18th, 2019

Jerry Pournelle closes There Will Be War Volume II with a discussion of the strategic dilemma facing the United States, where any defensive measure reduces the stability of Mutual Assured Destruction:

Civil Defense structures were originally planned as part of the Interstate Highway System. There were to be fallout and partial blast shelters under most of the approach ramps. This would have been easy to do as part of the construction, and a few model shelters were actually built as a demonstration.


The Triad is composed of manned bombers, submarine launched ballistic missiles (SLBM), and land-based intercontinental ballistic missiles (ICBM). Prior to the ICBM leg we had Snark, an air-breathing pilotless aircraft capable of flying intercontinental distances—an early “cruise missile.”

Each leg, then, depends on a different mechanism for survival. The manned bomber is very soft; it can be killed on the ground by nukes landing a long way off. It depends for early survival on warning: unlike the other two legs of the Triad, the manned bombers can be launched at an early stage of alert and still be recalled.


(I helped work on updates to the B-52 as my first aerospace job.)


One USAF colonel recently described a B-52 as “a mass of parts flying in loose formation.”


Even if the bombers can penetrate, they’re not useful for fighting a nuclear war. You can’t send the bombers to attack Soviet missile bases; there’d be nothing to hit but empty holes by the time a subsonic bomber got to the target.


Cruise missiles can be an excellent supplement to the strategic force, but they are certainly not a potential leg of the Triad. They are vulnerable to everything that kills airplanes (on the ground or in the air) without the recall advantages of manned aircraft.

The second leg of the Triad is the submarine. Its survival depends entirely on concealment. If you can locate a submarine to within a few miles, it can be killed by an ICBM carrying an H-bomb.


Note, by the way, that all the subs in harbor — up to a third of them, sometimes more — are dead the day the war starts.


Unfortunately, the submarine’s concealment isn’t what it used to be. Subs can be located in at least two ways. First, by tracking them from their bases; every submariner can tell you stories about playing tag with the Russkis when they leave Holy Loch.

Worse, though, the oceans aren’t nearly so opaque as we thought. Not long ago we took a look at some radar pictures made from a satellite. “Look at that,” one of the engineers said. “You can see stuff down in the ocean! Deep in the ocean.” And sure enough, using “synthetic aperture” radars, the oceans have become somewhat transparent down to about fifty meters. While the subs can go deeper than that, they can’t launch from deeper than that.


Incidentally, as I write this, a Soviet naval surveillance satellite is about to fall. It carried a 100 kilowatt nuclear power plant. The United States has yet to put a ten kilowatt satellite into orbit.


Submarines have to launch their missiles from unpredictable places (by definition; imagine what the KGB would pay to find out where our subs would launch from), and this drastically limits their accuracy.


Suppose one morning the Soviets knock out our Minutemen installations (not too difficult, as we’ll see in a bit) and many of our subs. They still have quite a few birds left. The Red Army is marching into Germany. The hot line chatters, and the message is pretty simple: “You haven’t really been hurt. Most of your cities are in good shape. Cool it, or we launch the rest of our force.”

At that point it would be useful to have something capable of knocking out the rest of their strategic force.

To have that capability, you need land-based missiles. To be exact, you need MX. MX, and only MX, has both the accuracy and the Multiple Independently Targetable Re-entry Vehicles (MIRVS, and they’re different from multiple warheads; MIRVS can attack targets much farther apart) that might give some counterforce capability.


If you attack a target with an ICBM, your “single shot probability of kill” (PKSS) depends on three major factors: attacker’s yield, attacker’s accuracy, and hardness of target.


While there are classified refinements, all the numbers you really need have long since been published in the US Government Printing Office’s “The Effects of Nuclear Weapons”. They’ve even been put on a circular slide rule that the RAND Corporation used to sell for about a dollar in the 60’s.


The Minutemen Missile lies in a soil that’s officially hardened to 300 PSI. When we put in Minutemen—the last one was installed in the 60’s—it was no bad guess that the Soviets could throw a megaton with a CEP of about a nautical mile. This gave them a PKSS of about .09, and it would take more than 20 warheads to give better than .9 kill probability. That was obviously a stable situation.[...]Going to ten megatons puts the PKSS to about 35%, and it still takes more than five attackers to get a 90% chance of killing one Minuteman; still not a lot to worry about.

Changes in accuracy, on the other hand, are very significant. Cutting the CEP in half (well, to 2700 feet) gives one megaton the same kill probability as ten had for a mile. Cutting CEP to 1000 feet is more drastic yet: now the single shot kill probability of one megaton is above 90%.

If you can get your accuracy to 600 feet CEP, then a 500 kiloton weapon has above 99% kill probability. Now all you need is multiple warheads, and you’re able to knock out more birds than you launched. Clearly this is getting unstable.

In 1964 we figured the Soviets had 6000 foot CEP, and predicted that by 1975 they’d have 600 feet. By 1975 I’d given up my clearances, and I don’t know what they achieved.


Item: weather satellites; winds over target are predictable, so you can correct for them. Item: lots of polar-orbiting satellites; by studying them, you can map gravitational anomalies. Item: observation satellites; location errors just aren’t significant any more. Item: the Soviets have been buying gyros, precision lathes, etc., as well as computers. They already had the mathematicians.


Two: in the 60’s we studied lots and lots of mobile basing schemes: road mobile, rail mobile, off-road mobile, canal and barge mobile, ship mobile, etc. We even looked at artificial ponds, and things that crawled around on the bottom of Lake Michigan. There were a lot of people in favor of mobile systems — then. Now, though, there are satellites, and you know, it’s just damned hard to hide something seventy feet long and weighing 190,000 pounds. (Actually, by the time you add the launcher, it’s more like 200 feet and 500,000 pounds.)


Worse, you can’t harden a mobile system very much. Even a “small” ICBM rocket is a pretty big object. Twenty PSI would probably be more than we could achieve. The kill radius of a 50 megaton weapon against a 20 PSI target is very large: area bombardment becomes attractive.


And nearly every mobile basing scheme puts nukes out where they have to be protected from terrorists and saboteurs including well-meaning US citizens aroused in protest (and you just know there’ll be plenty of them).

Air-mobile and air-launched were long-term favorites, and I was much for them in the 60’s. The Pentagon’s most recent analysis says we just can’t afford them; it would cost in the order of $150 billion, possibly more.


In fact, every alternative you’ve ever heard of, and a few you haven’t, were analyzed in great detail back in 1964. I know, because I was editor of the final report. I even invented one scheme myself, Citadel, which would put some birds as well as a national command post under a granite mountain. The problem with that one is that the birds will survive, but if they attack the doors, how does it get out after the attack?


First try the obvious: harden your birds. In 1964 we called it “Superhard,” 5000 PSI basing. Now 5000 PSI isn’t easy to come by. There are severe engineering problems, and it isn’t cheap. Worse, “Superhard” didn’t buy all that much: at 500 foot CEP’s a megaton has a 95% chance of killing “superhard” targets. (A megaton weapon makes a crater 250 feet deep and over a thousand feet in diameter even in hard rock.) Thus putting MX in 5000 PSI silos separated by miles didn’t seem worth the cost.


Just about every honest analyst who takes the trouble to work through the numbers comes away muttering “That’s a goofy sounding scheme, but damned if it doesn’t look like it might work…”


Use the space environment and our lead in high technology to construct missile defenses. They won’t be perfect, but they won’t need to be: the enemy can’t know how good our defenses are. Thus he can’t be sure of the outcome of his strike.


Whether space research pays for itself fifteen times over, as space enthusiasts say, or only twice over, as its critics say, nearly everyone is agreed that it does pay for itself — which is more than you can say for most other parts of the budget.

If we fail to provide for the common defense, it does no good to promote the general welfare.

The Americans should have looked up

Friday, December 13th, 2019

In Ghost Fleet, the Chinese “Directorate” — the replacement for the Communist Party — uses a manned space station armed with lasers to take out satellites:

The chemical oxygen iodine laser, or COIL, design had originally been developed by the U.S. Air Force in the late 1970s. It had even been flown on a converted 747 jumbo jet15 so the laser’s ability to shoot down missiles in midair could be tested. But the Americans had ultimately decided that using chemicals in enclosed spaces to power lasers was too dangerous.


The Directorate saw it differently. Two modules away from the crew, a toxic mix of hydrogen peroxide and potassium hydroxide was being blended with gaseous chlorine and molecular iodine.


There was no turning back once the chemicals had been mixed and the excited oxygen began to transfer its energy to the weapon. They would have forty-five minutes to act and then the power would be spent.


For years, military planners had fretted about antisatellite threats from ground-launched missiles, because that was how both the Americans and the Soviets had intended to take down each other’s satellite networks during the Cold War.

More recently, the Directorate had fed this fear by developing its own antisatellite missiles and then alternating between missile tests and arms-control negotiations that went nowhere, keeping the focus on the weapons based below. The Americans should have looked up.


A quiet hum pervaded the module. No crash of cannon or screams of death. Only the steady purr of a pump signified that the station was now at war.

The first target was WGS-4,16 a U.S. Air Force wideband gapfiller satellite. Shaped like a box with two solar wings, the 3,400-kilogram satellite had entered space in 2012 on top of a Delta 4 rocket launched from Cape Canaveral.

Costing over three hundred million dollars, the satellite offered the U.S. military and its allies 4.875 GHz of instantaneous switchable bandwidth, allowing it to move massive amounts of data. Through it ran the communications for everything from U.S. Air Force satellites to U.S. Navy submarines. It was also a primary node for the U.S. Space Command. The Pentagon had planned to put up a whole constellation of these satellites to make the network less vulnerable to attack, but contractor cost overruns had kept the number down to just six.

The space station’s chemical-powered laser fired a burst of energy that, if it were visible light instead of infrared, would have been a hundred thousand times brighter than the sun. Five hundred and twenty kilometers away, the first burst hit the satellite with a power roughly equivalent to a welding torch’s. It melted a hole in WGS-4’s external atmospheric shielding and then burned into its electronic guts.

Chang watched as Huan clicked open a red pen and made a line on the wall next to him, much like a World War I ace decorating his biplane to mark a kill. The scripted moment had been ordered from below, a key scene for the documentary that would be made of the operation, a triumph that would be watched by billions.


Originally known as the X-37,17 USA-226 was the U.S. military’s unmanned space plane. About an eighth the size of the old space shuttle, the tiny plane was used by the American government in much the same way the shuttle had been, to carry out various chores and repair jobs in space. It could rendezvous with satellites and refuel them, replace failed solar arrays using a robotic arm, and perform many other satellite-upkeep tasks.

But the Tiangong’s crew, and the rest of the world’s militaries, knew the U.S. military also used USA-226 as a space-going spy plane. It repeatedly flew over the same spots at the same altitude, notably the height typically used by military surveillance satellites: Pakistan for several weeks at a time, then Yemen and Kenya, and, more recently, the Siberian border.

With its primary control communications link via the WGS-4 satellite now lost, the tiny American space plane shifted into autonomous mode, its computers searching in vain for other guidance signals. In this interim period, USA-226’s protocol was to cease acceleration and execute a standard orbit to avoid collisions. In effect, the robotic space plane stopped for its own safety, making it an easy target.

The taikonauts moved on down the list: the U.S. Geosynchronous Space Situational Awareness system was next. These were satellites that watched other satellites. The Americans’ communications were now down, but once these satellites were taken out, the United States would be blind in space even if it proved able to bring its networks back online.

After that was the mere five satellites that made up the U.S. military’s Mobile User Objective System, akin to a global cellular phone provider for the military. Five pulses took out the narrowband communications network that linked all the American military’s aerial and maritime platforms, ground vehicles, and dismounted soldiers.

Then came the U.S. Navy’s Ultra High Frequency Follow-On (UFO) system,19 which linked all of its ships.

It was almost anticlimactic, the onboard targeting system moving the taikonauts through the attack’s algorithm step by step, slowing down only when a cluster of satellites sharing a common altitude needed to be dispatched one by one.

The last to be “serviced,” as Huan dryly put it, was a charged-particle detector satellite. The joint NASA and Energy Department system had been launched a few years after the Fukushima nuclear plant disaster as a way to detect radiation emissions. A volley of laser fire from Tiangong-3 exploded its fuel source.


On the other side of the Earth, discarded booster rockets were coming to life after months of dormancy. The boosters turned kamikazes advanced on collision courses with nearby American government and commercial communications and imaging satellites. The American ground controllers helplessly watched the chaos overhead, unable to maneuver their precious assets out of the way.