Tuesday Tech Links {2016.10.27}


Bendable Concrete

Regular Concrete is very strong and hard, and has incredible compressive strength.  We embed rebar into concrete in order to give it additional tensile and bending strength, but concrete just does not bend, not like metals do.  It’s also very brittle, so if concrete does bend, it almost immediately cracks and begins to shatter.  Add some tiny polymer fibers to the concrete mix, however, and you get a very strong, kinda bendy concrete.  I expect civil engineers all up and down the West Coast will be very interested in this.

Carbon Reveals Yet Another Solid Structure

I’m starting to wonder how many ways we can figure out to arrange carbon atoms in novel and useful configurations.  I mean, come on, a simple laser and we get electrically conductive sheets of diamond that glow!  Goodbye Gorilla Glass.

New Composite Alloy That Is Lightweight and Strong

Magnesium, despite it’s reputation as something firefighters hate dealing with, is an industrially useful metal.  It’s lighter than aluminum and a lot cheaper, but not quite strong enough to be a contender in aircraft and racecars.  Alloy it with nanoscale ceramic particles, and suddenly it’s giving aluminum a run for the money.  They key here seems to be the nanoscale size of the particles.  Microscale doesn’t work.

Metallic Surface Etching Allows for Strong Metal to Anything Bonding

Aside from welding, geting metals to form a strong bond is a trick, and getting metals to bond strongly to dissimilar metals (welding dissimilar metals rarely ends well), or other materials is also hard to do.  Etch the surface of the metal (probably with a laser) to form nanoscale structures, and non-welded strong bonds are possible.  Whether or not this could replace welding remains to be seen, but welding is used in a lot of constructions where it’s overkill, but it’s used because nothing else works.  Likewise, metal is often attached to non-metals with fasteners (screws, bolts, etc.) because a glue bonded surface won’t do it, but punching holes through things in order to use fasteners weakens the part, so more material is needed (thus increasing costs, weight, etc.).

I Have a Fascination With Anything Made From Spider Silk

It’s synthetic spider silk, but still, it’s spider silk, and hello, we can produce a synthetic spider silk in sufficient quantities that we can build a car seat!

Novel Concrete Block Design Allows For Faster Construction

I gotta admit, this is such a simple idea I’m honestly not certain why anyone still uses traditional concrete blocks (cinder blocks).  Or have similar ideas been tried in the past and found wanting (or killed by established players)?


Airlander 10 Hybrid Airship

I just really like airships, especially hybrid airships, and the Airlander recently did it’s maiden flight (even though it still has some issues).  Even if airships took off again as a mode of transport, they’ll probably never replace high speed jetliners, but I could certainly seem them as a niche option like cruise liners, for people who have the time, and want the experience of the journey.  Just imagine such an airship, with a windowed lounge on the dorsal surface, on a clear night…

The IKEA-fication of the world is nearly complete.

First off, it’s from the guy who designed the McLaren F1.  Second, it’s cheap.  But most importantly, it comes flat packed, probably with an Allen wrench included.

I Just Want One – Seriously, that’s it.

Using MicroTurbines Instead of Otto Cycle Engines to Power Hybrid Vehicles

So there is a reason cars come with piston engines and not turbines.  Turbines are annoyingly loud, do not produce a lot of torque, and are very finicky about maintenance.  There are ways to overcome the first two issues, but that last one has always been a bugbear.  People are just really bad about personal vehicle maintenance, and turbines, while very reliable and robust, demand that you do the regular maintenance if you wish them to remain reliable and robust.  Still, with tight machine tolerances, and very limited operating ranges, you can have a turbine that is much more forgiving.  Attach that turbine to the generator of a hybrid vehicle and you have, by definition, a tight operating range.  Better still, spinning a small generator is not a high torque operation, so no massive gearbox to turn high speed into torque.  It’s not a bad idea.

Primer on Asteroid Mining

Erect that Space Elevator and this gets a whole lot easier…

The Double Bubble Airliner

Wing and Tube has been the go-to design for airliners for decades, and while ideas like flying wings have been kicking around for a while, those are still a ways off.  Putting two tubes side by side is something we can do, today (pretty much).  The benefit is that large, twin aisle airliners are mostly empty space.  The passenger deck runs pretty much through the center of the fuselage, so you get lots of standing headroom, and a whole lot of empty cargo space below the passenger deck.  Usually airlines take on other cargo besides your luggage so that empty space is making some money, but while an airline can usually keep the seats full, filling the cargo hold is not as much of a sure thing.  A double hull gives you more seats to fill without adding a ton of extra empty space.  Plus you get other aerodynamic benefits (check out the brochure at the link).

Hydrogen Fuel Cell 4-Seater Aircraft

It’s a fuel cell aircraft that isn’t a gossamer gimmick.

Packing Batteries To Power Supersonic Airliners

I’m going to be honest here, the specifics of battery tech are not my thing, but the idea intrigues me,  We couldn’t do something like this with current energy densities, but if Workman is right, it’s not entirely out of reach.  Plus, it sticks with the tradition of keeping the fuel in the wings.

Using Hydrogels to Prevent Biofouling

This one is more about the hydrogels than it is transportation, but the application is ships.  The short of it is, barnacles are a drag, current coatings to prevent barnacles are toxic and leach into the ocean.  Hydrogel coatings could prevent barnacle attachment and be non-toxic.  Just gotta see if they can withstand the rigors of sailing the ocean blue.

Green Tech

Bubble Wrapped Sponge Can Boil Water With Sunlight

Another case of, how has no one ever noticed this before?  OK, to be fair, this isn’t that obvious, and they were careful in their selection of materials.  I wonder how long before this becomes a staple of middle school science classes?

Big Step Toward Solar Power Windows

Imagine if all the windows in a tall, glass skyscraper were transparent solar panels.  Now they can be.

Storing Energy In Molten Silicon

We all know one of the big issues with solar is night.  The obvious solution is make extra power during the day and store it.  One way being kicked around was using molten salts, but salts can be expensive, and extremely toxic.  Enter silicon.  Massively abundant, non toxic, and better heat capacity that most salts.

Nano-Structured Catalyst Turns CO2 Into Ethanol

Or, we could turn CO2 into ethanol, then use the ethanol at night.  To date, the process to capture CO2 into ethanol has been energy intensive enough to not be worth it.  But recently, a team took a well known catalyst that allows for the low power formation of ethanol from CO2 and stepped it up a notch with nanoscale structures formed from the catalyst.  The process still requires power, specifically a little bit of electrical current through the catalyst, but if scalable and economic, it could be a game changer.

Artificial Photosynthesis

Or we could use solar to produce hydrogen with artificial photosynthesis cells, then push the hydrogen through fuel cells at night.

Genetically Modified Photosynthesis

Or we could skip the artificial part and just use photosynthesis directly to produce hydrogen with GMO algae.

BioTech and BioMimicry

Absorbing Oil Without Absorbing Water

Cleaning up an oil slick on open water usually involves soaking up a ton of water with the oil, that must then be separated from the oil, tested and cleaned, and then discharged.  But if can just avoid soaking up the water…  Taking a cue from a hydrophobic plant leaf, now we can do just that.

Beer – It’s Almost As Widely Useful As Carbon

Beer waste water can be recycled to make batteries by turning into into carbon electrodes.  So down a pint, you are making batteries.  Also, I am not surprised in the least that this comes from the Boulder campus.

Also, Spent Coffee Grounds Are Surprisingly Useful

Coffee grounds can be turned into water filtration foam, and lots of other useful things beside garden compost.

Causing Salt To Bloom Out Of Soil

Don’t we have a soil scientist lurking hereabouts?  This reminds me in a way of using plants to extract heavy metals from soils, since plants often draw the metals up in through their roots.

If It Works For Beavers…

I can wait to see fuzzy rubber surfers on the Oregon coast!

Cicadas Aren’t Just Summer Noise Machines

Aside from making it hard to talk to another human during the summer, it seems those wings have other uses.  Not only are the nanostructures on the wing surface antibacterial, they are also antireflective in a way that might be very useful for solar cell efficiency.  Still annoying loud bugs.

Electronic and Other Tech

Desktop WaterJet Cutter

We got desktop 3D Printers, CNC mills, laser cutters, and now water jet cutters.  When can I get a desktop vapor dep so I can build IC chips at home?

Acoustic Holograms

Not sure how useful this is right now, but the video at the link is cool to watch.

Study Shows That Complaints Against Police Plummet With Body Cameras

I’m going to resist saying “DUH!”, but in all seriousness, this right here should be all we need to get every honest police officer on board with the idea in general, even if the specifics of implementation, usage, and storage still need to be hammered out.

Full Color e-Paper

My phone is going to get even thinner, isn’t it.  Especially when I can put a layer of diamond on top of it.

Creating A Quantum Bridge To Network Quantum Computers

I doubt I’ll ever have cause to write code for a quantum computer in my lifetime, but the technology side of this does seem to keep marching right along.

Image by UCL Mathematical and Physical Sciences Tuesday Tech Links {2016.10.27}

Staff Writer

A Navy Turbine Tech who learned to spin wrenches on old cars, Oscar has since been trained as an Engineer & Software Developer & now writes tools for other engineers. When not in his shop or at work, he can be found spending time with his family, gardening, hiking, kayaking, gaming, or whatever strikes his fancy & fits in the budget. ...more →

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75 thoughts on “Tuesday Tech Links {2016.10.27}

  1. Random notes:

    The C02 to ethanol is also noteworthy because it directly produces ethanol, not methanol with byproducts. C02 in water, run across the catalyst, produces very pure ethanol — very little further processing needed. The most likely potential use? Storing excess power from solar. It’s not the most efficient battery, but it’s closed loop and cheap.

    Bendable Concrete: There’s another group who might be very interested in bendable concrete: Architects.


      • I’m really trying not to. Giant curved cylindrical buildings, thrust menacingly against the sky. Odd curves and weird angles, designed to frustrate people trying to put up shelving or use corner desks.

        Cursing tilers and carpet layers. Carpenters thrilled at all the custom work…

        (Yes, I’ve lived in a house with a curved wall. Why do you ask?)


      • I would suspect they would still use rebar, since it lends a lot of tensile & bending strength. The biggest advantage is the fact that if the concrete can flex that much, it won’t crack & shatter under bending loads, which doesn’t always immediately compromise the strength of the concrete structure, but it does risk allowing water penetration & exposing the rebar to water & corrosion, which will cause expansion from the rust or from freezing, further cracking the concrete, etc.


    • The questions about the ethanol catalyst will be mostly about how quickly the catalyst gets fouled, how easy can it be cleaned, how long does it last, how much is needed to produce a given volume of ethanol per time, and how cheaply can the catalyst be produced.

      None of these are difficult questions, they just weren’t questions the initial study looked at too hard.


      • I suspect they’ll get looked at pretty hard, because one-step C02 to ethanol without having to filter out impurities is pretty sweet.

        Useful enough to throw engineering effort because it’s got solid, already understood, uses that would be thrilled to find a simpler, more reliable method. Cheaper’s just bonus. :)


        • Agreed. I don’t think this will be a one note story, it’s a big enough game changer that there is a lot of excitement brewing over it. Either this method will get refined to industrial scale, or it’ll give birth to something even better.


          • Nanoscale engineering is just now starting to mature, to the point where individual labs can start playing with it (or custom ordering pieces) — you don’t need massive upfront investments to start poking at it in a lab.

            Where, you know, grad students at mid-range colleges (not just the heavily endowed ones) might actually get a chance to do work with it.

            Which means a lot more eyeballs playing with a lot more ideas, so I expect the actually applied uses to jump significantly over the next few decades, in a lot more fields.

            In short, it’s becoming another reliable tool in the engineer’s toolbox.


    • An interesting thing to me is that the traditional way of producing ethanol – with yeast and fermentable sugars – produces about as much CO2 as ethanol by weight, plus some heat. If most of that CO2 can also become ethanol, it seems that could be very efficient- the biofuel factory / distillery already has all the infrastructure and shipping logistics for sending out ethanol.

      I don’t know if the heat part of the fermentation is too little, or if it could usefully supply some of the electricity for the catalyst…


      • There’s already a number of processes to turn C02 into ethanol, but they require high temperatures to run, often expensive catalysts, and I think all of them turn C02 into methanol that then requires further processing to turn into ethanol.

        This one uses a cheap catalyst (nitrogen on nanoscale engineered copper and some voltage) and runs at room temperature, and has a pretty high (60-ish percent, I think) efficiency.

        It’s pretty good for turning power into ethanol, which can then be burned later for fuel, while being entirely C02 neutral.


    • What “wastewater” are we talking about? My homebrewing doesn’t yield the sort of wastewater that seems likely to produce good ethanol.

      There’s cleaning water, which has a variety of cleaning and sanitizing components (soap, bleach, sanitizing acid). This has to be discarded: it will kill plants or animals, and it isn’t a re-usable cleaning solution with crud left over from beermaking in it. In particular, I keep the stuff away from my dogs (well, “dog,” singular, for now, although I suspect we’ll be getting a second one again soon enough) because the rhizomes in hops are very dangerous for dogs to consume.

      Then there’s rinse water, which will have residual amounts of this stuff in it but mainly will be basically tap water. I recirculate ice water in my wort chilling device, which gets a bit of salt in it before the chill but otherwise is tap water again. Other brewers use different means of chilling boiled wort down to a proper temperature for pitching yeast that may not use so much water. But this “waste” product is impure but probably just less-than-potable tap water. I use it to water my potted plants in the back yard.

      I periodically take out trivially-small samples of the fermenting liquid to measure the specific gravity during fermentation. Obviously, the sugary water which I turn into mash, then wort, then beer, is not “waste” in any meaningful sense of the word. Creating this (delicious, ethanol-rich) product is the object of the exercise.

      Finally, there’s the trub, which is mostly expended yeast, which is an unappealing-looking goo, more solid than liquid, that settles at the bottom of the fermentation vessels. A craft brewery, unlike a homebrewer of my caliber, will have a small laboratory or other similar space where the expended yeasts are revived from a portion of trub, for use in the next batch.

      So I suppose if the remainder of the trub that wasn’t recaptured were rinsed out of the fermentation vessels with potable water, before more water with soap was used to scrub and sanitize the vessel, that could yield a solution of liquid which would be rich in depleted organic material and some revivable yeasts. Is that the kind of wastewater that they’re talking about using to create high-grade ethanol for battery/quasi-battery use?


      • For future reference, we generally use “Linkage” to put an isolated link for something interesting up quickly. It takes the form of an excerpt from the Linked article, a link to the article with attribution to the source, and in almost all cases no additional editorial commentary. There’s a different technical setup for a post marked “Linkage” to make it appear in a different place on the front page.

        Compendiums like this show a substantially higher level of intellectual input by the author, so we treat them like standalone articles. You’ll notice the popular Morning Edition and Linky Friday posts that often posts show up amongst the other regular articles on the front page.


  2. I too, wonder about those concrete blocks. My suspicion is that the manufacture of concrete blocks is a very low-margin business, which means a very low rate of innovation. Making the new blocks probably requires a whole new manufacturing process, as well as new shipping methods, because they aren’t square.


    • The story says that they don’t use a binder. That would seem to disqualify them from a variety of applications due to water ingress issues — leakage if they’re below grade, damage from freeze-thaw cycles, etc. In the areas where they’re being used, those aren’t problems. And the need to avoid mixing cement may make up for shipping the irregular shapes.


      • They don’t need a binder (I read that as mortar between the blocks), but that doesn’t mean one can’t be applied. The interlocking design would make for a much stronger wall that straight blocks do.


    • Blocks are made with a forming machine fitted with multi-part molds (I think). One should be able to take the same machine and swap out the old molds with new ones without having to build a whole new machine.

      I wouldn’t be surprised if it was a low margin business, especially for blocks sold to contractors & construction companies, who buy in large volume. Blocks sold to big box stores probably have slightly better profits, but don’t move a lot of volume.


  3. Great set o links.

    I’m a little more bearish on the bendable concrete though. They seem to be really pushing the roadway & roadbed, which makes me think it’s better at plastic deformation under periodic rated load, (which is great for roads) but not so much that you’re able to do a whole lot more with it along the z axis.


  4. This reminds me in a way of using plants to extract heavy metals from soils, since plants often draw the metals up in through their roots.

    When they dismantled the former Rocky Flats plutonium processing plant in Colorado, some of the plutonium was left in the ground because it didn’t migrate with the ground water (and no one knew how to actually separate it anyway). Unfortunately, one of the native plants mistakes plutonium for some other trace element it uses and moves it to the surface. Another emerging problem is burrowing rodents, who are bringing plutonium-contaminated soil up out of their tunnels.


  5. RE: Body Cameras

    One thing I’d like to see is the number of *upheld* complaints.

    Here’s a report from a few years ago where body cameras caused complaints to fall from 81 to 51, year-on-year. Upheld complaints also fell, from 24 to 19.

    …which means that the percentage of upheld complaints increased by nearly nine percent.

    So with body cameras, maybe there will be less complaints overall, but if one is filed it’s more likely to be upheld. Small surprise that so many officers are opposed to the idea! Dealing with complaints is just part of the job (and they pay you the same whether you’re cooling your heels in court or out on the street getting screamed at) so a reduction in the overall number doesn’t matter to them, but if you say “wearing this body camera means an extra one-in-ten chance that any complaint against you gets upheld”, whoops my body camera fell on the ground and I ran over it a couple times on accident.


      • It makes sense. People are less likely to file frivolous complaints (complaints they KNOW are baseless, as opposed to complaints they think are sound but are bunk to rational observers) if they know there’s footage of the incident.

        Therefore, people persisting in pursuing complaints — knowing the footage exists — are more likely have what they think are valid complaints. They think the tape will back them.

        Conversely, knowing there’s footage — they’re less likely to make stuff up to try to stir things up (revenge, angry, whatever motive) because they know there’s film of it.


    • I think that analysis is flawed. It’s entirely possible that that flawed analysis is in fact behind opposition to body cameras, but it’s still flawed.

      Number of complaints per cop fell
      Number of upheld complaints per cop fell, but not by as much

      So, setting out at the beginning of one’s shift with a body cam reduces both the chance of having a complaint filed, and the chance of having a complaint upheld.

      The only scenario where not wearing the body cam is advantageous is after a complaint has been filed, you travel back in time and forget to wear the body cam for that day only.

      (This is similar to some of the unclear stats about the various effects of bike helmets – they definitely reduce risk of head injury given that you’ve been in a crash, but it’s also possible that they increase the risk of getting in a crash in the first place, possibly by enough that the risk of injury to all parts of the body offsets the utility of wearing them. So the ideal situation is to not wear a helmet, except on the one day you get in a crash)


      • “So, setting out at the beginning of one’s shift with a body cam reduces both the chance of having a complaint filed, and the chance of having a complaint upheld.”

        No cameras: 24 upheld / 81 complaints = 29.63% upheld
        With cameras: 19 upheld / 51 complaints = 37.25% upheld

        So complaints filed with cameras were more likely to be upheld.


        • The problem here is that at this point, anyone is taking the officers opinion into account.

          Imagine we are talking about new welfare* reporting requirements. Using the new requirements, the welfare fraud division is able to reduce not only the number of investigations by 50%, but they can also reduce the number of baseless investigations, such that their resources are more effectively used to uncover actual cases of fraud more consistently. How much attention should be paid to welfare recipients or agencies that complain about the extra paperwork?

          I get the officers position, but A) there is the bigger picture in that investigating and dealing with citizen complaints costs departments, and thus communities, money, so a large reduction in those is a win. Likewise, more upheld complaints mean more evidence against bad officers who should be removed from the force, hopefully before they do something really bad and cost the community millions. And B) If officers are doing the job right, they should trust that the camera will exonerate them (remember my comment about honest officers); or, alternatively, the department has policies in place that are not based in anything approaching the reality of police work, in which case the union will have better ammunition to get those policies adjusted.

          So it starts coming down to, officers either haven’t thought it through, or they are officers who shouldn’t be carrying a badge & gun.

          *Or replace welfare with the SEC, whatever irks your priors.


          • I’m not saying that the officers’ opinions ought to be taken into account. I’m explaining why “you should totally wear body cameras!” is not as easy a sell for cops as one might think.


                • Perhaps, but I lean heavily toward the idea that public employees, while performing their duties have no right to privacy (aside from going to the bathroom). There may be times when those duties require privacy, such as closed door meetings to discuss sensitive subjects, or hearings dealing with children and abuse, etc., but in general, while at work and not on break, the right to privacy doesn’t exist with regard to those duties.


                  • Oscar,
                    When you spy on a person, you spy on them in the bathroom too.
                    Right to privacy should not be misconstrued to mean “don’t film” — it really means “unless you’ve got a damn good reason, don’t look”


                  • Oh, I agree.

                    The problem, of course, is that cops have been saying for years “if you’ve nothing to hide, you’ve nothing to fear” and there are *SOOOOOOOOOOOOOOO* many things wrong with that.

                    In the short term, it might be fun to say it back just to get them to wear the damn cameras.

                    In doing so, however, we’d be conceding the issue of whether people who have nothing to hide have nothing to fear and we’d end up regretting that in short time…

                    But, immediately, there would be the benefit of seeing the sauce for the goose being sauce for the gander.


                    • Except I’m not saying that. It isn’t about nothing to hide, nothing to fear; it’s about public employees interacting with the public can not be hidden at all, without the consent of the members of the public they are currently interacting with.


        • Exactly – they were less likely to be filed at all, and more likely to be upheld when filed at all, but by less than the reduction in filing rate, so the odds of having a complaint filed and upheld is still lower with the camera.

          Applying that as an argument against body cameras, from the cop’s perspective, only makes sense if you figure cops enjoy the process of a complaint investigation enough that it is on net preferable to have a complaint filed and dismissed, compared to not having a complaint filed at all. “Gee it’s a shame about these body cameras, I haven’t been hauled in front of a citizen complaint tribunal and lost sleep waiting for the result in ages.”

          I have to imagine that’s not the case – having a complaint filed and ultimately dismissed has got to be a stressful and frustrating experience even if ultimately not as bad as having one filed and upheld.

          Odds of a complaint being filed and dismissed based on some interaction I have at work today:
          No camera: (81 complaints filed – 24 upheld) / (100 officers * 200 shifts) = 0.29%
          Camera: (51 complaints filed – 19 upheld) / (100 officers * 200 shifts) = 0.16%

          Odds of a complaint being filed and upheld based on some interaction I have at work today:
          No camera: (24 complaints upheld) / (100 officers * 200 shifts) = 0.12%
          Camera: (19 complaints upheld) / (100 officers * 200 shifts) = 0.10%


          • Which makes sense – the cameras could easily deter two things
            – police brutality by a little bit
            – false complaints of police brutality by a lot

            By analogy: imagine you work in a job with a significant hazard from fire. A new safety device is available that reduces burns leading to injury by 80%, and fatal burns by only 40% (because it’s more effective against medium intensity flames than against extremely high intensity flames).

            If you adopt the device you’re much less likely to be burned leading to injury and significantly less likely to burn to death.

            Do you reject the device because it increases the odds that the remaining burn incidents will be fatal?

            Like I say above – just because it would be poor risk management to reject the safety device, doesn’t mean some folks won’t use that flawed logic and reject it.


          • “Applying that as an argument against body cameras, from the cop’s perspective, only makes sense if you figure cops enjoy the process of a complaint investigation enough that it is on net preferable to have a complaint filed and dismissed, compared to not having a complaint filed at all.”

            “enjoy”, no, but it’s part of the job, and probably one of the easier parts, and they get paid for doing it.

            So introducing body cameras:
            *Reduces but doesn’t eliminate complaints
            *Increases the likelihood that a filed complaint will be upheld.

            While these are not at all reasons to not have cameras, they’re reasons why you shouldn’t necessarily expect enthusiastic and voluntary compliance from officers.


        • That’s a very strange math (in anyone is still reading)

          If I’m a cop, I worry about upheld complaints per cop

          If 100 cops have 81 complaints (very sleazy cops, don’t you think) without cameras, each cop has an 81% chance of getting a complaint, and a 29.63% chance of it being upheald

          So each cop without cameras faces a 24.00% chance of facing an upheld complaint.

          With cameras, there’s only a 51% chance of receiving a complaint, and even though the complaints themselves have a higher chance of being upheld, each cop is facing only an 18.00% chance of facing an upheld complaint.

          Cameras are a win for cops too

          (It’s a similar math than that that says that, even though whites have a higher chance of being shot in a police encounter than blacks, blacks have so many more encounters, that the end result is that more blacks than white die in police encounters)

          (Please don’t tell me that treating the chance of a complaint, and the chance of it being upheld are not random, independent events in the life of a sleazy cop. Maybe some opposition might be rooted in the fact that the events are not random at all)


          • You’re not actually addressing the fact that a filed complaint has a higher chance of being upheld. You’re still looking at overall rate. And from a non-officer viewpoint an improvement in the overall rate is desirable, but you’re still telling an officer “if an event occurs there’s a higher risk that it’ll have serious consequences”.

            Please note that I am not arguing against body cameras.


            • Taking human nature into account I think if you stress “less complaints” and “less frivolous complaints”, you’ll get cop buy-in because what they’ll think is: “Complaints against me are frivolous, but Doug there is a fricking idiot. So I’ll be getting no complaints, ’cause they know I got tape, but Doug there? His idiocy is gonna be on tape and the Captain ain’t gonna cover for it”.

              And the best part is, Doug’s thinking the same thinking the same thing — only the other way around.

              Because we’re arguing over phrasing, but what we’re talking about here is “The number of frivolous complaints is dropping. The people with valid complaints continue to complain”.

              The folks who really want to argue with that are going to be cops who KNOW they’re generating valid complaints, and those are probably a small fraction of the cops who are actually generating valid complaints.


              • See Jaybird’s answer above, about “if you don’t do anything wrong then you won’t have any cause to worry about this”.

                Which, again, is not wrong, but it’s also not an argument that will get people on your side.

                I guess what I’m saying here is, there isn’t a way that you’re going to get cops to like this very much, so body-camera deployment plans that depend on the cops liking them probably won’t get very far.


      • switters:
        You may know this Kazzy, but in most browsers (I think), you can just hold the control button down when you click a link and it will open it in a newtab.

        Or middle click, if you can manage it with the mouse wheel everyone has now.

        I have a side button I assigned to middle click, just because trying to click with a scroll wheel is a good way to slightly scroll the wheel and click in the wrong place.

        …incidentally, speaking of misclicking, I think I just accidentally reported switters’ post.


      • Oh, I know… but I’m often on mobile which requires holding the ‘click’ and then selecting the “Open in New Tab” button.

        Or doing what you describe on my laptop which has a slightly wonky touchpad.

        Both of which I consider a “step”.

        Yea… I’m lazy.

        But on another blog, I actually participated in an extended debate about whether linky posts should open in new tabs or not. It was… surprisingly intense.


  6. I don’t understand ‘The Double Bubble Airliner’ thing.

    What is the difference between this and just making the airplane body wider, and why don’t they just make the airplane wider?


    • On my way to see Dr Strange, so this will be brief.

      Airliner hulls are pressure vessels. Circular cross sections are very efficient shapes for pressure vessels, especially ones that are also carrying flight loads. An elliptical cross section is doable, but involves additional structure (read: weight).

      Double bubble gives you additional width while still enjoying the efficiencies for a minimum of additional structure.


      • Nope, still not following.

        A circle is, indeed, the best design, but *neither* an elliptical cross section or a double hull actually has any full circles.

        The only difference I can see between the two shapes is that a double hull would bend inward at the center of the top and bottom.

        But from what *I* understand of engineering, I’m having trouble figuring out how that would make anything more sturdy unless those circles *completed*. If they don’t complete, they don’t get any bonus…a C isn’t more sturdy than a U.

        Which, I mean, I guess they could complete, at some points in the plane. Or curve inward to meet at a vertical support.

        But I don’t understand how that’s any different than the ‘additional structure’ need for an elliptical cross section. Which could also do the same thing.

        Meanwhile, talking about additional weight, a double hull would result in *more surface area*, which results in more weight! Unless you built a bridge across the top and bottom, but then that’s just an elliptical cross section with a weird curved support internally!

        I mean, maybe I’m imagining this wrong. Holding the fingers and thumbs together of my two hands, I can make an elliptical cross section. And then I can curve my fingers some more and make a double hull cross section. And I notice the double hull is not only smaller (I.e., takes more surface area for the same size), it can actually crumple in a way the elliptical can’t, at the intersection of the two hulls.

        In other words, I don’t understand any of what you’re talking about, and I’m not sure I *can* understand without some sort of diagram.


        • Per the brochure, any weight increase to accommodate the added structure of the double-bubble cross section is much more than made up by increased efficiencies from integrating/aligning the fuselage and engines. It’s a classic “systems” thing — making one part somewhat less efficient allows greater efficiencies in other parts of the system.


        • So this explanation would be a bit more involved, enough so that it might be worth doing as a standalone post. Then I will be able to bring in pictures more easily, & also I can expand upon point about systems tradeoffs.

          So show of hands, whose interested in something more indepth regarding the double bubble airliner?


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