Was the term “GEV” just a mistake?

Sunday, February 17th, 2019

Back in 1977, Steve Jackson Games came out with a sci-fi wargame named after the giant cybernetic tank central to its futuristic setting, the Ogre. Other units included infantry, artillery, and highly mobile hovercraft — known in the game as GEVs, or Ground Effect Vehicles.

Years later I learned that a ground effect vehicle is not a hovercraft, or air cushion vehicle, but a winged airplane, designed to use the wing-in-ground-effect — the reduction in drag experienced by an aircraft as it approaches a height approximately twice a wingspan’s length off the ground (or other level surface such as the sea).

Winchell Chung, who runs the Atomic Rockets website and goes by the handle of Nyrath, did the original art for the game, and I recently asked him, was the term “GEV” just a mistake? Or were they not meant to be air-cushion vehicles (ACVs) originally?

He wasn’t sure, but he made three points:

  1. The draft rules described units as armored hovercraft. Not aircraft. Fast moving ground units. They were called GEVs.
  2. I vaguely remember reading that GEM [for Ground Effect Machine] was a synonym for hovercraft, and I assumed GEV was a variant.
  3. I used a Popular Mechanics cover as inspiration.

Popular Mechanics Tiger Sharks of the Vietnam Swamps

He swapped out the propeller in the back with twin jet turbine engines and made the skirt look armor plated:

Winchell Chungs GEV 1 Winchell Chungs GEV 2 Winchell Chungs GEV 3

Then he sent a trial drawing to Steve Jackson, who added his comments in red:

Winchell Chungs GEV with Steve Jackson's Comments

The THOR system is composed of a thousand or more cheap satellites

Sunday, February 17th, 2019

If you drop something dense and aerodynamic from high enough up, it will hit the ground really, really hard — maybe hard enough to qualify as a kinetic bombardment weapon:

During the Vietnam War, the US used what it called “Lazy Dog” bombs. These were simply solid-steel pieces, less than 2 inches long, fitted with fins.

There was no explosive: They were simply dropped by the hundreds from planes flying above Vietnam.

Lazy Dog projectiles (aka “kinetic bombardment”) could reach speeds of up to 500 mph as they fell to the ground and could penetrate 9 inches of concrete after being dropped from as little as 3,000 feet.

If you drop a telephone pole-sized (20′×1′) tungsten cylinder from orbit, the 9-ton “rod from God” should hit at Mach 10, with the kinetic energy equivalent to 11.5 tons of TNT (or 7.2 tons of dynamite).

Robin Hanson recently mentioned such “rods from God,” and I just happened to be reading There Will Be War, which includes Jerry Pournelle’s “original” 1981 description of Project THOR, which describes something subtly different — a barrage of 20-pound projectiles made of tungsten, less than an inch in diameter and three or four feet long, traveling at Mach 23:

One of the most difficult security missions which the United States must accomplish is the protection of our interests around the globe. Incidents like the North Korean seizure of the USS Pueblo have demonstrated our weakness in not being able to respond quickly and authoritatively in remote locations. Our only solution to this problem so far has been the naval carrier task force. Carrier-based aircraft can project military force to protect our citizens and allies in remote regions of the world. Unfortunately, the high cost and vulnerability of nuclear carriers and their required aircraft and support fleets make them an unattractive solution.

[...]

To balance the force of gravity, a satellite two hundred miles above the surface must travel at a speed of seventeen thousand five hundred miles per hour. At this speed, the satellite travels around the Earth once every ninety minutes. With a hundred satellites in orbits near this altitude and traveling in random orbital inclinations, one of the satellites will pass over any given location on Earth every thirty minutes. With a thousand satellites, the timing between satellites overhead is less than ten minutes. The basic physics of orbital motion gives us our global coverage; it also gives us the weapon. The extremely high velocity of a satellite in orbit gives it a tremendous amount of kinetic energy. If a one pound object moving at orbital velocity ran into a stationary target, the energy released in the impact will be the equivalent of exploding almost ten pounds of TNT.

[...]

The THOR system is composed of a thousand or more cheap satellites, each made up of a bundle of projectiles, guidance and communications electronics, and a simple rocket engine.

[...]

The result is spectacular: a bundle of tens or hundreds of twenty pound projectiles streak down at four miles per second to strike targets with the explosive equivalent of two hundred pound bombs each.

[...]

Even if an enemy were to detonate one or more nuclear devices in space in an attempt to destroy THOR, there are a thousand or more widely scattered satellites he must destroy. Because the satellites are at different altitudes and have different orbital inclinations, any holes produced in the global coverage by a nuclear explosion are filled in after several hours by the orbital motions of the satellites.

[...]

The satellite can be cocooned in foam, which would be difficult to detect with radar anyway and could be shaped to make detection even more difficult (stealth satellites!).

[...]

The foam would insulate the satellite against the heat and shock of nuclear explosions or laser beams.

[...]

The jet of metal particles produced when a shaped charge warhead detonates is traveling at about the same velocity as a THOR projectile when striking a target.

[...]

The jet of metal from the TOW warhead weighs only a fraction of an ounce; a THOR projectile weighs over twenty pounds!

[...]

If the projectile were composed of an outer shell with sand-sized particles inside, it could be designed to explode and disperse the particles just before impact. The metal particles would instantly vaporize, with the resulting shock wave flattening troops, aircraft, or other targets much like the fuel-air explosive bombs presently in service.

[...]

The advantages of the THOR weapon system are its low cost, global coverage, quick reaction time, and survivability.

[...]

To de-orbit the projectiles and bring them down at an angle of thirty degrees from vertical requires almost as much energy as was required to orbit the projectiles initially, and requires a large quantity of propellant for each THOR satellite.

[...]

The individual THOR satellites are most vulnerable while the de-orbit propulsion burn is taking place, when a rocket exhaust plume is a bright beacon marking the location of the satellite for possible destruction by enemy laser weapon satellites. Two solutions are a cold gas propulsion system (high weight of propellant required) or a very fast propulsion impulse which ends before the laser weapon could be brought to bear on the THOR satellite.

[...]

With the Global Positioning System navigation satellite network in operation, each satellite could passively receive its own location in space to a very high accuracy while doing nothing to reveal its own position.

[...]

Communication by laser beams, which are extremely narrow and almost impossible to intercept, may be possible if the position of each of the thousand or more THOR satellites can be calculated accurately enough to hit the desired satellite.

[...]

The projectile could be protected by an ablative nose tip which would vaporize and carry off the heat from atmospheric friction during the few seconds of atmospheric passage.

[...]

The high speed of the projectile through the atmosphere near the ground where the density of the air is highest would produce a luminous bow shock wave directly in front of the missile. Penetrating such a layer might be a problem, but high frequency radio waves, infrared light, visible light, or ultraviolet light might be effective for targeting. A visible light sensor might have a window covered with a filter which passes light of a wavelength which is not emitted by the ionized air in the shockwave.

The real point of the system, as he points out, is that it could quickly (and cheaply) hit any target, anywhere on earth — which seemed really, really useful, a few months later, when HMS Sheffield succumbed to a French-made Exocet missile in the Falklands. Of course, getting tungsten rods up into space is only economical once you have frequent launches of your newfangled space shuttle.

The great vice of the Greeks was extrapolation

Wednesday, February 13th, 2019

I recently read Ignition!, by John D. Clark, and I found it an odd mix of fun, opinionated bits and dry chemistry:

“Now it is clear that anyone working with rocket fuels is outstandingly mad. I don’t mean garden-variety crazy or a merely raving lunatic. I mean a record-shattering exponent of far-out insanity.”

“It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water — with which it reacts explosively. It can be kept in some of the ordinary structural metals — steel, copper, aluminium, etc. — because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.”

“If your propellants flow into the chamber and ignite immediately, you’re in business. But if they flow in, collect in a puddle, and then ignite, you have an explosion which generally demolishes the engine and its immediate surroundings. The accepted euphemism for this sequence of events is a ‘hard start.’”

“Their guess turned out to be right, but one is reminded of E. T. Bell’s remark that the great vice of the Greeks was not sodomy but extrapolation.”

“…a molecule with one reducing (fuel) end and one oxidizing end, separated by a pair of firmly crossed fingers, is an invitation to disaster.”

“I looked around and signaled to my own gang, and we started backing away gently, like so many cats with wet feet.”

“And there is one disconcerting thing about working with a computer — it’s likely to talk back to you. You make some tiny mistake in your FORTRAN language — putting a letter in the wrong column, say, or omitting a comma — and the 360 comes to a screeching halt and prints out rude remarks, like “ILLEGAL FORMAT,” or “UNKNOWN PROBLEM,” or, if the man who wrote the program was really feeling nasty that morning, “WHAT’S THE MATTER STUPID? CAN’T YOU READ?” Everyone who uses a computer frequently has had, from time to time, a mad desire to attack the precocious abacus with an axe.”

There is no trace to follow

Tuesday, February 5th, 2019

The Internet is full of commercial activity, not all of it legal. Dropgangs may be the future of darknet markets:

To prevent the problems of customer binding, and losing business when darknet markets go down, merchants have begun to leave the specialized and centralized platforms and instead ventured to use widely accessible technology to build their own communications and operational back-ends.

Instead of using websites on the darknet, merchants are now operating invite-only channels on widely available mobile messaging systems like Telegram. This allows the merchant to control the reach of their communication better and be less vulnerable to system take-downs. To further stabilize the connection between merchant and customer, repeat customers are given unique messaging contacts that are independent of shared channels and thus even less likely to be found and taken down. Channels are often operated by automated bots that allow customers to inquire about offers and initiate the purchase, often even allowing a fully bot-driven experience without human intervention on the merchant’s side.

The use of messaging platforms provides a much better user experience to the customers, who can now reach their suppliers with mobile applications they are used to already. It also means that a larger part of the communication isn’t routed through the Tor or I2P networks anymore but each side — merchant and customer — employ their own protection technology, often using widely spread VPNs.

The other major change is the use of “dead drops” instead of the postal system which has proven vulnerable to tracking and interception. Now, goods are hidden in publicly accessible places like parks and the location is given to the customer on purchase. The customer then goes to the location and picks up the goods. This means that delivery becomes asynchronous for the merchant, he can hide a lot of product in different locations for future, not yet known, purchases. For the client the time to delivery is significantly shorter than waiting for a letter or parcel shipped by traditional means — he has the product in his hands in a matter of hours instead of days. Furthermore this method does not require for the customer to give any personally identifiable information to the merchant, which in turn doesn’t have to safeguard it anymore. Less data means less risk for everyone.

The use of dead drops also significantly reduces the risk of the merchant to be discovered by tracking within the postal system. He does not have to visit any easily to surveil post office or letter box, instead the whole public space becomes his hiding territory.

Cryptocurrencies are still the main means of payment, but due to the higher customer-binding, and vetting process by the merchant, escrows are seldom employed. Usually only multi-party transactions between customer and merchant are established, and often not even that.

Marketing and initial vetting of both merchant and customer now happens in darknet forums and chat channels that themselves aren’t involved in any deal anymore. In these places merchants and customers take part in the discussion of best procedures, methods and prices. The market connects and develops best practices by sharing experience. Furthermore these places also serve as record of reputation, though in a still very primitive way.

Other than allowing much more secure and efficient business for both sides of the transaction, this has also led to changes in the organizational structure of merchants:

Instead of the flat hierarchies witnessed with darknet markets, merchants today employ hierarchical structures again. These consist of procurement layer, sales layer, and distribution layer. The people constituting each layer usually do not know the identity of the higher layers nor are ever in personal contact with them. All interaction is digital — messaging systems and cryptocurrencies again, product moves only through dead drops.

The procurement layer purchases product wholesale and smuggles it into the region. It is then sold for cryptocurrency to select people that operate the sales layer. After that transaction the risks of both procurement and sales layer are isolated.

The sales layer divides the product into smaller units and gives the location of those dead drops to the distribution layer. The distribution layer then divides the product again and places typical sales quantities into new dead drops. The location of these dead drops is communicated to the sales layer which then sells these locations to the customers through messaging systems.

To prevent theft by the distribution layer, the sales layer randomly tests dead drops by tasking different members of the distribution layer with picking up product from a dead drop and hiding it somewhere else, after verification of the contents. Usually each unit of product is tagged with a piece of paper containing a unique secret word which is used to prove to the sales layer that a dead drop was found. Members of the distribution layer have to post security — in the form of cryptocurrency — to the sales layer, and they lose part of that security with every dead drop that fails the testing, and with every dead drop they failed to test. So far, no reports of using violence to ensure performance of members of these structures has become known.

This concept of using messaging, cryptocurrency and dead drops even within the merchant structure allows for the members within each layer being completely isolated from each other, and not knowing anything about higher layers at all. There is no trace to follow if a distribution layer member is captured while servicing a dead drop. He will often not even be distinguishable from a regular customer. This makes these structures extremely secure against infiltration, takeover and capture. They are inherently resilient.

Furthermore the members of the sales layer often employ advanced physical tradecraft to prevent surveillance by the procurement layer when they pick up product. This makes it very hard to dismantle such a structure from the top.

If members of such a structure are captured they usually have no critical information to share, no information about persons, places, times of meeting. No interaction that would make this information necessary ever takes place.

It is because of the use of dead drops and hierarchical structures that we call this kind of organization a Dropgang.

The result of this evolution is a highly decentralized, specialized and resilient method of running black market commerce. Less information is acquired, shipments are faster, isolation between participants is high, and multiple independent sales channels are established.

Widespread use would provide an entire new category for the Darwin Awards

Thursday, January 31st, 2019

The Four Thieves Vinegar Collective is a volunteer network of anarchists and hackers developing DIY medicines:

Four Thieves claims to have successfully synthesized five different kinds of pharmaceuticals, all of which were made using MicroLab. The device attempts to mimic an expensive machine usually only found in chemistry laboratories for a fraction of the price using readily available off-the-shelf parts. In the case of the MicroLab, the reaction chambers consist of a small mason jar mounted inside a larger mason jar with a 3D-printed lid whose printing instructions are available online. A few small plastic hoses and a thermistor to measure temperature are then attached through the lid to circulate fluids through the contraption to induce the chemical reactions necessary to manufacture various medicines. The whole process is automated using a small computer that costs about $30.

To date, Four Thieves has used the device to produce homemade Naloxone, a drug used to prevent opiate overdoses better known as Narcan; Daraprim, a drug that treats infections in people with HIV; Cabotegravir, a preventative HIV medicine that may only need to be taken four times per year; and mifepristone and misoprostol, two chemicals needed for pharmaceutical abortions.

[...]

As for the DEA, none of the pharmaceuticals produced by the collective are controlled substance, so their possession is only subject to local laws about prescription medicines. If a person has a disease and prescription for the drug to treat that disease, they shouldn’t run into any legal issues if they were to manufacture their own medicine. Four Thieves is effectively just liberating information on how to manufacture certain medicines at home and developing the open source tools to make it happen. If someone decides to make drugs using the collective’s guides then that’s their own business, but Four Thieves doesn’t pretend that the information it releases is for “educational purposes only.”

[...]

The catalyst for Four Thieves Vinegar Collective was a trip Laufer took to El Salvador in 2008 when he was still in graduate school. While visiting a rural medical clinic as part of an envoy documenting human rights violations in the country, he learned that it had run out of birth control three months prior. When the clinic contacted the central hospital in San Salvador, it was informed the other hospital had also run out of birth control. Laufer told me he was stunned that the hospitals were unable to source birth control, a relatively simple drug to manufacture that’s been around for over half-a-century. He figured if drug dealers in the country were able to use underground labs to manufacture illicit drugs, a similar approach could be taken to life-saving medicines.

This doesn’t seem wise:

Eric Von Hippel, an economist at MIT that researches “open innovation,” is enthusiastic about the promise of DIY drug production, but only under certain conditions. He cited a pilot program in the Netherlands that is exploring the independent production of medicines that are tailor made for individual patients as a good example of safe, DIY drug production. These drugs are made in the hospital by trained experts. Von Hippel believes it can be dangerous when patients undertake drug production on their own.
“If one does not do chemical reactions under just-right conditions, one can easily create dangerous by-products along with the drug one is trying to produce,” von Hippel told me in an email. “Careful control of reactor conditions is unlikely in DIY chemical reactors such as the MicroLab design offered for free by the Four Thieves Vinegar Collective.”

His colleague, Harold DeMonaco, a visiting scientist at MIT, agreed. DeMonaco suggested that a more rational solution to the problems addressed would be for patients to work with compounding pharmacies. Compounding pharmacies prepare personalized medicine for their customers and DeMonaco said they are able to synthesize the same drugs Four Thieves is producing at low costs, but with “appropriate safeguards.”

“Unless the system is idiot proof and includes validation of the final product, the user is exposed to a laundry list of rather nasty stuff,” DeMonaco told me in an email. “Widespread use [of Four Thieves’ devices] would provide an entire new category for the Darwin Awards.”

We were looking for the Future Book in the wrong place

Sunday, January 13th, 2019

The interactive book of the future hasn’t caught on, but technology has changed books nonetheless:

Physical books today look like physical books of last century. And digital books of today look, feel, and function almost identically to digital books of 10 years ago, when the Kindle launched. The biggest change is that many of Amazon’s competitors have gone belly up or shrunken to irrelevancy. The digital reading and digital book startup ecosystem that briefly emerged in the early 2010s has shriveled to a nubbin.

Amazon won. Trounced, really. As of the end of 2017, about 45 percent (up from 37 percent in 2015) of all print sales and 83 percent of all ebook sales happen through Amazon channels. There are few alternatives with meaningful mind- or market share, especially among digital books.

Yet here’s the surprise: We were looking for the Future Book in the wrong place. It’s not the form, necessarily, that needed to evolve — I think we can agree that, in an age of infinite distraction, one of the strongest assets of a “book” as a book is its singular, sustained, distraction-free, blissfully immutable voice. Instead, technology changed everything that enables a book, fomenting a quiet revolution. Funding, printing, fulfillment, community-building — everything leading up to and supporting a book has shifted meaningfully, even if the containers haven’t.

[...]

Our Future Book is composed of email, tweets, YouTube videos, mailing lists, crowdfunding campaigns, PDF to .mobi converters, Amazon warehouses, and a surge of hyper-affordable offset printers in places like Hong Kong.

Wood-based supermaterial is stronger and tougher than steel

Saturday, January 5th, 2019

A new wood-based supermaterial is stronger and tougher than steel:

In their natural form, wood cells are kept rigid due to polymers known as lignin and hemicellulose, interspersed with nanofibres of cellulose. Wood also contains systems of narrow tubes known as lumina, which run along its growth direction. To transform this structure into a more useful material, Hu’s team first treat samples of wood with a salt solution, which removes most of the lignin and hemicellulose, making the cell walls porous and less rigid. Afterwards, the researchers hot-press the wood at 100 °C, causing the cell walls and the lumina to collapse. This reduces the wood to just 20% of its original thickness.

The compressed substance contains densely-packed wood cells aligned along the growth direction, which results in a strongly-aligned system of cellulose nanofibres. These fibres have hydrogen and oxide groups in their molecular structures, giving rise to strong hydrogen-bond interactions between them. The density of the new material is about three times higher than that of untreated wood.

Once they had perfected the conversion process, Hu’s team set about testing the properties of their new substance. In most structural materials there is a trade-off between tensile strength (resistance to breaking while being stretched) and toughness (how much energy a material can absorb without shattering) — but the researchers saw improvements in both properties in their new material. Its tensile strength is 11.5 times higher than that of natural wood, making it much stronger than common plastics such as nylon and polystyrene. However, the toughness of the new material is also boosted — it is 8.3 times higher than natural wood, making it tougher than most metal alloys.

(Hat tip to Hans Schantz.)

Aluminum normally casts a silvery white light when it burns

Sunday, December 30th, 2018

The green-blue glow that filled the New York City sky was not caused by a transformer explosion, Consolidated Edison clarified:

The extraordinary event had in fact been traced to a voltage monitoring gizmo known as a coupling capacitor potential device — or CCPD if you happen to operate a power grid — that failed to function properly at a Queens substation on Thursday night.

That led to an arc flash in which electricity delivered via a 138,000-volt transmission line jumped from one point to another, ionizing the very air through which it leapt. The energy was too great to be constrained to a straight trajectory, and it began to arc with its own power. The arc grew higher and higher, as did the heat it generated.

“Temperatures can reach as high as 35,000 degrees Fahrenheit,” notes a General Electric fact sheet. “This is hotter than the surface of the sun.”

The fact sheet adds, “Arc Flash temperatures can… liquefy or vaporize metal parts in the vicinity.”

Some of the substation equipment is aluminum, which normally casts a silvery white light when it burns. But at extremely high temperatures such as this bit of sun in Queens, the light generated by the vaporized aluminum was the almost-Tiffany blue that New York City residents saw rise into the sky and spread through the low-lying cloud cover.

Make a radio using simple supplies

Tuesday, December 18th, 2018

I’m a bit shocked that I hadn’t stumbled across How to Invent Everything: A Survival Guide for the Stranded Time Traveler until just now, while reading about how building a radio transmitter is easier than building a clock:

Historically, humans were able to navigate with two instruments: a sextant and a clock. A sextant is used to measure the altitude of the celestial north pole so you can determine your latitude. The clock is needed to measure the difference between local noon and Greenwich Mean Time so you can get your longitude. Yes, that’s really how it works — here are the details if you are interested.

But how would you build these on your own? The sextant is pretty simple — it’s just a tool for measuring angles. The clock on the other hand, that’s not so easy. I don’t think I could build an accurate clock from scratch even if I knew exactly how it works (it’s not that difficult conceptually).

If the clock is so difficult to make, then don’t make it — that is the idea from Ryan North, and it’s brilliant. Instead he suggests that it would be easier to make a radio and use that for navigation. If you can build a radio transmitter, you won’t need a clock. The key part of using a clock for navigation is to know the difference between local noon (when the Sun is at its highest point) and noon in Greenwich (or any other reference location). If you have a radio, you can just broadcast the time from Greenwich and compare that to your local time. Boom. You just found out where you are. You didn’t even need to wind up a pocket watch.

Now you are thinking — but isn’t a radio even more complicated than a clock? Nope. The clock needs precision and accuracy in the building process. If you understand physics, you can make a crude radio, no problem. That’s exactly what I’m going to do. I’m going to make a radio using just the simplest supplies I can find.

Of course there are some prerequisites. If you are stuck in the past, you are going to need to “invent” some other things first. Here’s what you need (none of these are terribly difficult).

  • Copper wire. I guess it doesn’t have to be copper, but you will need some metal wire. This shouldn’t be too difficult once you get a good forge going.
  • A battery. If you have two different types of metals and an acid, you can make a battery. It’s that easy. In fact, you can even make a battery from several pennies—here’s how.
  • A ferromagnetic material like iron.
  • A radio receiver. I know this seems like cheating, but it’s not that difficult to build. Here is how you can make one. There are other ways to do this that might be easier, but the bottom line is it’s possible to make one.

That’s pretty much all you need. Even a stranded time traveler could eventually figure out these things.

A diode for magnetic fields opens up a lot of new possibilities

Wednesday, November 28th, 2018

Dr. Jordi Prat-Camps of the University of Sussex has demonstrated that the coupling between two magnetic elements can be made asymmetrical:

Working with colleagues from the Austrian Academy of Sciences and University of Innsbruck, Dr. Prat-Camps’ research rips up the physics rule book by showing it is possible to make one magnet connect to another without the connection happening in the opposite direction.

The findings run contrary to long-established beliefs of magnetic coupling, which emerge from the four Maxwell equations dating back to the seminal works of Michael Faraday and James Clerk Maxwell in the 19th century.

Dr. Prat-Camps said: “We have created the first device that behaves like a diode for magnetic fields. Electric diodes are so crucial that none of the existing electronic technologies such as microchips, computers or mobile phones would be possible without them. If our result for magnetic fields would have one millionth of the same impact as the developments in electric diodes, it would be a hugely impactful success. The creation of such a diode opens up a lot of new possibilities for other scientists and technicians to explore. Thanks to our discovery we think it might be possible to improve and the performance of wireless power transfer technologies to improve the efficiency of recharging phones, laptops and even cars.”

[...]

After several unsuccessful attempts to break magnetic reciprocity, the team decided to try using an electrical conductor in movement. By solving Maxwell’s equations analytically, the researchers very quickly demonstrated that not only could reciprocity be broken down but that, the coupling could be made maximally asymmetric, whereby the coupling from A to B would be different from zero but from B to A it would be exactly zero. Having shown that total unidirectional coupling was possible theoretically, the team designed and built a proof-of-concept experiment which confirmed their findings.

If he mysteriously disappears, we’ll have to assume a secret cabal has taken him out for revealing the hidden truth.

Ion thrusters allow a plane with no moving parts

Wednesday, November 21st, 2018

Electrohydrodynamic thrust, or ion thrust, could power aircraft — silently:

Ionic thrusters are simple in design: They feature one thin copper electrode, known as an emitter, and one thicker tube of a metal-like aluminum called a collector. A lightweight frame supports the wires, which connect to an electrical power source, and keeps them apart—the gap between them is vital to creating ionic wind.

When voltage is applied to the wires, the resulting field gradient pulls electrons away from surrounding air molecules, ionizing them. The ionized air molecules are strongly repelled by the emitter and strongly attracted to the collector. As they move toward the collector, they push the other air molecules around them, creating thrust.

[...]

Steven Barrett, assistant professor of aeronautics and astronautics at MIT, has now shown that ionic thrusters may, in fact, be perfect for aerospace applications—especially, he says, for surveillance vehicles.

“I first had the idea as an undergrad,” Barrett says, “because it was interesting to me that hobbyists were making small lifters, which showed this worked on some level. And I found out that these hobbyists were all wondering if it could be efficient enough to power a larger craft.” He picked up the project again when he became a faculty member and had more creative freedom.

Why pursue ionic thrusters? For one thing, Barrett says, they have the potential to outperform current jet engines. In a series of experiments in which Barrett fed electricity to a simple ionocraft attached to a digital scale, which allowed him to measure the exact thrust produced each time the craft left the ground, the model produced 110 newtons of thrust per kilowatt, versus a jet engine’s 2 newtons. Ionic thrusters are silent and, because they give off no heat, completely invisible to infrared sensors.

The system was most efficient at a low velocity, but Barrett explains that this is actually a positive. “You want to produce the most thrust you can at the lowest velocity,” he says.

He recently demonstrated the idea:

But unlike its predecessors, which had tumbled to the ground, Version 2 sailed nearly 200 feet through the air at roughly 11 miles per hour (17 kilometers per hour). With no visible exhaust and no roaring jet or whirling propeller—no moving parts at all, in fact—the aircraft seemed silently animated by an ethereal source. “It was very exciting,” Barrett says. “Then it crashed into the wall, which wasn’t ideal.”

(Hat tip to Jonathan Jeckell.)

A fuel cell that runs on methane at practical temperatures

Monday, November 12th, 2018

Methane fuel cells usually require temperatures of 750 to 1,000 degrees Celsius to run, but a new fuel cell with a new catalyst can run at 500 degrees, cooler than an automobile engine:

That lower temperature could trigger cascading cost savings in the ancillary technology needed to operate a fuel cell, potentially pushing the new cell to commercial viability. The researchers feel confident that engineers can design electric power units around this fuel cell with reasonable effort, something that has eluded previous methane fuel cells.

“Our cell could make for a straightforward, robust overall system that uses cheap stainless steel to make interconnectors,” said Meilin Liu, who led the study and is a Regents’ Professor in Georgia Tech’s School of Material Science and Engineering. Interconnectors are parts that help bring together many fuel cells into a stack, or functional unit.

“Above 750 degrees Celsius, no metal would withstand the temperature without oxidation, so you’d have a lot of trouble getting materials, and they would be extremely expensive and fragile, and contaminate the cell,” Liu said.

“Lowering the temperature to 500 degrees Celsius is a sensation in our world. Very few people have even tried it,” said Ben deGlee, a graduate research assistant in Liu’s lab and one of the first authors of the study. “When you get that low, it makes the job of the engineer designing the stack and connected technologies much easier.”

The new cell also eliminates the need for a major ancillary device called a steam reformer, which is normally needed to convert methane and water into hydrogen fuel.

[...]

Hydrogen is the best fuel for powering fuel cells, but its cost is exorbitant. The researchers figured out how to convert methane to hydrogen in the fuel cell itself via the new catalyst, which is made with cerium, nickel and ruthenium and has the chemical formula Ce0.9Ni0.05Ru0.05O2, abbreviated CNR.

When methane and water molecules come into contact with the catalyst and heat, nickel chemically cleaves the methane molecule. Ruthenium does the same with water. The resulting parts come back together as that very desirable hydrogen (H2) and carbon monoxide (CO), which the researchers surprisingly put to good use.

“CO causes performance problems in most fuel cells, but here, we’re using it as a fuel,” Chen said.

A proposal for an archive revisiter

Thursday, November 8th, 2018

In his long list of statistical notes, Gwern includes a proposal for an archive revisiter:

One reason to take notes/clippings and leave comments in stimulating discussions is to later benefit by having references & citations at hand, and gradually build up an idea from disparate threads and make new connections between them. For this purpose, I make extensive excerpts from web pages & documents I read into my Evernote clippings (functioning as a commonplace book), and I comment constantly on Reddit, LessWrong, HN, etc. While expensive in time & effort, I often go back, months or years later, and search for a particular thing and expand & integrate it into another writing or expand it out to an entire essay of its own. (I also value highly not being in the situation where I believe something but I do not know why I believe it other than the conviction I read it somewhere, once.)

This sort of personal information management using simple personal information managers like Evernote works well enough when I have a clear memory of what the citation/factoid was, perhaps because it was so memorable, or when the citations or comments are in a nice cluster (perhaps because there was a key phrase in them or I kept going back & expanding a comment), but it loses out on key benefits to this procedure: serendipity and perspective.

As time passes, one may realize the importance of an odd tidbit or have utterly forgotten something or events considerably changed its meaning; in this case, you would benefit from revisiting & rereading that old bit & experiencing an aha! moment, but you don’t realize it. So one thing you could do is reread all your old clippings & comments, appraising them for reuse.

But how often? And it’s a pain to do so. And how do you keep track of which you’ve already read? One thing I do for my emails is semi-annually I (try to) read through my previous 6 months of email to see what might need to be followed up on10 or mined for inclusion in an article. (For example, an ignored request for data, or a discussion of darknet markets with a journalist I could excerpt into one of my DNM articles so I can point future journalists at that instead.) This is already difficult, and it would be even harder to expand. I have read through my LessWrong comment history… once. Years ago. It would be more difficult now. (And it would be impossible to read through my Reddit comments as the interface only goes back ~1000 comments.)

Simply re-reading periodically in big blocks may work but is suboptimal: there is no interface easily set up to reread them in small chunks over time, no constraints which avoid far too many reads, nor is there any way to remove individual items which you are certain need never be reviewed again. Reviewing is useful but can be an indefinite timesink. (My sent emails are not too hard to review in 6-month chunks, but my IRC logs are bad – 7,182,361 words in one channel alone – and my >38k Evernote clippings are worse; any lifestreaming will exacerbate the problem by orders of magnitude.) This is probably one reason that people who keep journals or diaries don’t reread Nor can it be crowdsourced or done by simply ranking comments by public upvotes (in the case of Reddit/LW/HN comments), because the most popular comments are ones you likely remember well & have already used up, and the oddities & serendipities you are hoping for are likely unrecognizable to outsiders.

This suggests some sort of reviewing framework where one systematically reviews old items (sent emails, comments, IRC logs by oneself), putting in a constant amount of time regularly and using some sort of ever expanding interval between re-reads as an item becomes exhausted & ever more likely to not be helpful. Similar to the logarithmically-bounded number of backups required for indefinite survival of data (Sandberg & Armstrong 2012), Deconstructing Deathism – Answering Objections to Immortality, Mike Perry 2013 (note: this is an entirely different kind of problem than those considered in Freeman Dyson’s immortal intelligences in Infinite in All Directions, which are more fundamental), discusses something like what I have in mind in terms of an immortal agent trying to review its memories & maintain a sense of continuity, pointing out that if time is allocated correctly, it will not consume 100% of the agent’s time but can be set to consume some bounded fraction.

[...]

So you could imagine some sort of software along the lines of spaced repetition systems like Anki, Mnemosyne, or Supermemo which you spend, say, 10 minutes a day at, simply rereading a selection of old emails you sent, lines from IRC with n lines of surrounding context, Reddit & LW comments etc; with an appropriate backoff & time-curve, you would reread each item maybe 3 times in your lifetime (eg first after a delay of a month, then a year or two, then decades). Each item could come with a rating function where the user rates it as an important or odd-seeming or incomplete item and to be exposed again in a few years, or as totally irrelevant and not to be shown again – as for many bits of idle chit-chat, mundane emails, or intemperate comments is not an instant too soon! (More positively, anything already incorporated into an essay or otherwise reused likely doesn’t need to be resurfaced.)

This wouldn’t be the same as a spaced repetition system which is designed to recall an item as many times as necessary, at the brink of forgetting, to ensure you memorize it; in this case, the forgetting curve & memorization are irrelevant and indeed, the priority here is to try to eliminate as many irrelevant or useless items as possible from showing up again so that the review doesn’t waste time.

More specifically, you could imagine an interface somewhat like Mutt which reads in a list of email files (my local POP email archives downloaded from Gmail with getmail4, filename IDs), chunks of IRC dialogue (a grep of my IRC logs producing lines written by me +- 10 lines for context, hashes for ID), LW/Reddit comments downloaded by either scraping or API via the BigQuery copy up to 2015, and stores IDs, review dates, and scores in a database. One would use it much like a SRS system, reading individual items for 10 or 20 minutes, and rating them, say, upvote (this could be useful someday, show me this ahead of schedule in the future) / downvote (push this far off into the future) / delete (never show again). Items would appear on an expanding schedule.

[...]

As far as I know, some to-do/self-help systems have something like a periodic review of past stuff, and as I mentioned, spaced repetition systems do something somewhat similar to this idea of exponential revisits, but there’s nothing like this at the moment.

The fall of Big Data and the rise of the Blockchain economy

Tuesday, October 30th, 2018

George Gilder’s Life After Google predicts the fall of Big Data and the rise of the Blockchain economy:

Famously, Google gives most of its content away for free, or (in comments Gilder credits to Tim Cook) if it’s free, you’re not the customer; you’re the product. That’s the least of it. Spanish has two words for “free”–gratis and libre. In our context it means gratis.

Let’s count the ways gratis benefits Google:

  • They are completely immune from any antitrust prosecution and most other regulatory oversight.
  • They can roll out buggy, beta software to consumers and improve it over time.
  • They don’t have to take responsibility for security. Unlike a bank, Google is at no risk if somehow your data gets corrupted or stolen.
  • They provide no customer support.
  • Your data doesn’t belong to you. Instead it belongs to Google, which can monetize it with the help of AI.
  • You get locked into a Google world, where everything you own is now at their mercy. (I’m in that situation.) Your data is precisely not libre.

Note that Google didn’t even bother to show up at the recent Congressional hearings about “fake news.” They consider themselves above the law (or, perhaps more accurately, below the law). They can get away with this because it’s free.

There are some disadvantages.

  • It’s not really free, but instead of paying with money you pay with time. Attention is the basic currency of Google-world.
  • People hate ads. “[O]nly 0.06 percent of smartphone ads were clicked through. Since more than 50 percent of the clicks were by mistake, according to surveys, the intentional response rate was 0.03 percent.” This works only for spammers. Ad-blockers are becoming universal.
  • Google thinks it can circumvent that by using AI to generate ads that will interest the user. No matter–people still hate them.The result is the value of advertising is declining. Gilder does not believe that AI will ever solve this problem. (I agree with him.)
  • Most important–Google loses any information about how valuable its products are. Airlines, for example, respond sensitively to price signals when determining which routes to fly, what equipment to use, what service levels to provide, etc. Price is the best communication mechanism known for conveying economic information. You immediately know what is valuable to consumers, and what isn’t.Google loses all that information by going gratis.Is Gmail more valuable than Waze? Google has no idea. As a result it has no way of knowing where to invest its money and resources. It’s just blindly throwing money at a dartboard.

It’s just plain good science fiction and it satisfies

Friday, October 26th, 2018

I haven’t read The Da Vinci Code — or any other conspiracy thrillers, now that I think of it — but I have to assume that Hans G. Schantz‘s Hidden Truth series reads like Dan Brown’s bestselling novel — but with physics taking the place of theology.

Schantz can credibly weave physics into his story, because he is a trained physicist and “wrote the book” on The Art and Science of Ultra-Wideband Antennas, and the first book definitely made me want to know more about the pioneers of electromagnetic theory — many of whom did die young or inexplicably left the field.

But the real draw — or drawback — of the novel is that it is unambiguously conservative and especially anti-Progressive. This makes it a bit of a guilty pleasure, if you ascribe to Jordan Peterson’s point about art versus propaganda:

Neovictorian reviewed the second book, and I think he reviewed it well:

It’s fun, it’s well written, it’s just plain good science fiction and it satisfies. Also, it’s a practical guide to understanding, infiltrating and grandly screwing with college SJWs. After you’ve read it, buy a copy (of both volumes) for your friends and children at school! Buy copies for younger kids, too. These books show how young people should conduct themselves with honor and perseverance, and not through preaching, but through example.

I may have to read Neovictorian’s own Sanity next.