Tech Tuesday 04/30/19

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Oscar Gordon

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.

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22 Responses

  1. TT6: anytime we are talking about airships I remember the – very brief – period when airships really did look like they might rule the skies, and my favorites to read about were the Akron-class and their sparrow aircraft (https://www.airships.net/us-navy-rigid-airships/uss-akron-macon/) they could launch and recover. It was shortlived of course, only a few years before both were destroyed in accidents.Report

  2. Avatar Chip Daniels says:

    Did someone mention Airships?

    I submit my proposal for replacing California’s HSR with the much more realistic and plausible California Daylight series of airship, docking at a neo-gothic tower near you.

    View this post on Instagram A post shared by Chip Daniels (@wchip_aia) on Mar 31, 2019 at 10:57am PDT

    //www.instagram.com/embed.jsReport

    • Avatar Aaron David in reply to Chip Daniels says:

      Actually, that is a hell of a lot better idea than HSR. Not only do you have the ability to shift routes around pretty quickly to account for need, but with them avoiding traditional transit gateways you can get a better feel for how people will actually use transit when needed. Granted, they will be slower that flight, but no slower than HSR with nimbyism.Report

    • Let me put my systems hat on for a minute. This is not a critique of your drawing, which I love, but of the general concept.

      Assume we want a passenger capacity of 150 people or more. That puts us up into the Hindenburg class vehicles: 250 meters long and 45 meters in diameter. For service here in Denver, say, you would definitely want cover for passengers getting on and off. Postulate a hanger arrangement near Denver’s Union Station, where the airship eases in out of the wind and precipitation, some passengers get off, some more get on, and the airship leaves from the other end of the hanger. Leave some space all around and estimate the hanger at 300 meters by 75 meters by 60-70 meters tall (of a size with the Tustin hangers in Orange County, which are impressive). That’s about the same width and twice the length of the current terminal area that serves as the hub for the entire light/commuter rail system. With modern thrust vectoring, you need about the same size area outside each end of the hanger where the airship can “land” and “take off”.

      There’s a reason airship facilities wound up being way out in the country.Report

      • I’ve been in Hanger One at Lakehurst multiple times, and it is basically the dimensions you are talking about here 966 feet (294 m) long, 350 feet (110 m) wide and 224 feet (68 m) high. And Lakehurst certainly qualifies as out in the country, which is why it’s used for exercises and NAVAIR experimentation so much.Report

      • Avatar Oscar Gordon in reply to Michael Cain says:

        The only reason you need a hanger is wind, not passenger comfort. If all you want to do is keep passengers out of the rain, a covered walkway is fine.

        Mooring to a tower, while having a certain practicality, just becomes nearly impossible on a windy day.Report

      • Avatar Chip Daniels in reply to Michael Cain says:

        Thanks for the comments!

        Plate 5 in the continuing series shows the general arrangement of the triple expansion steam engine that lifts the entire Concourse Gallery from ground level to the 70th floor Loading Platform.

        The structure resists the lateral force of wind by use of flying buttresses which spread out from the upper level to several streets across at ground level.Report

  3. Avatar Oscar Gordon says:

    I truly believe there is a lot more utility to be mined from the whole idea of airships, but no one wants to spend the money to find out what there is. Too many stale notions of their limitations from decades ago.Report

    • Avatar Aaron David in reply to Oscar Gordon says:

      The Hindenburg looms large indeed.Report

    • Avatar bookdragon in reply to Oscar Gordon says:

      Yes! And looking at the one in your post, I wonder if there’s any way a filter could be incorporated in the air breathing cycle without too much loss. That would let it clean pollutants from the air while it was doing whatever its primary task might be. Seems like that could be a selling point to get investment, esp from China.Report

    • Avatar George Turner in reply to Oscar Gordon says:

      Aerogels are lighter than air, and incredibly strong and stiff for their weight.

      To heck with airships. Let’s build giant floating cities out of aerogel!

      Some airship proposals have tried to dispense with ground handling by using helicopters to transport passengers to and from the airship. Nowadays that would probably be tasked to drones. Perhaps the plans were dropped when they realized that refueling the airship would require guys with Jerry cans taking helicopter rides. However, a Hindenburg sized airship could mount enough solar cells to provide about 3,000 horsepower, which isn’t far from the actual Hindenburg’s 4,500 or so.

      Since both skin friction and solar collection area would scale together, bigger wouldn’t mean more speed (thrust to drag). But a larger ship could better afford the weight penalty of the solar panels, since payload follows the cube law and skin area follows a square law.Report

      • Avatar Oscar Gordon in reply to George Turner says:

        Well, lighter than air doesn’t necessarily translate to sufficiently buoyant, but you might have something there. I’d have to go do some reading, but I wonder how gas permeable aerogels are? Like pack the bag with aerogel, then fill with helium or hydrogen.Report

        • Avatar George Turner in reply to Oscar Gordon says:

          That was my thought as well. And I don’t think a structure would have to be solid aerogel, but a conventional impermeable bag of helium inside an stiff aerogel skin and frame.

          However, years after I’d had those thoughts, some successful new airship designs put an emphasis on flexibility, with a flexible composite rod running from bow to stern, kind of like a big fishing pole. Their insight was that most prior Zeppelins were destroyed because they snapped in half during bad weather, because their thin and stiff girder shell construction made them extremely brittle regarding wind gusts that place the airframe under bending or shearing loads.

          So in that regard, an aerogel Zeppelin or floating city should be designed to include lots of structural flexibility.Report

  4. Avatar dragonfrog says:

    TT2: The fact that tree cover has *an* effect in reducing daytime temperatures is a bit of a “duh” result perhaps. But how much tree cover has how strong of an effect, not so much.

    I could not have told anyone specifically that the tipping point where it becomes really effective is 40% canopy coverage, or that the temperature reduction you can expect once you reach that point are around 4 to 5 degrees C.

    TT3 Strikes me as a perfect example of how computer science and social sciences can neatly mesh their blind spots to produce garbage results. Not that this result is *necessarily* garbage – it’s just that nothing in the short article reassures me it isn’t.

    Take
    “The study authors say that a PTSD diagnosis is most often determined by clinical interview or a self-report assessment, both inherently prone to biases.”
    plus
    “The researchers first recorded standard, hours-long diagnostic interviews, called Clinician-Administered PTSD Scale, or CAPS, of 53 Iraq and Afghanistan veterans with military service–related PTSD, as well as those of 78 veterans without the disease. The recordings were then fed into voice software from SRI International—the institute that also invented Apple’s Siri—to yield a total of 40,526 speech-based features captured in short spurts of talk, which the team’s AI program sifted through for patterns.”

    So, where’s the bit where they correct their input samples for clinician bias?

    “Predictive policing” is a nefarious example of that – you want to eliminate racism in police decisions (or, cynically, eliminate newspaper coverage of racism in police decisions), so you feed your racially-biased data on parolee re-arrest and conviction to a neural network, then use its predictions to make your next round of parole decisions. Now you’ve laundered your systemic racism through the infallibility of the computer, Wizard of Oz style.Report

  5. Avatar Kolohe says:

    TT6 – this also seems to be the type of thing that enables persistent aerial surveillance (in a permissive environment)Report

  6. Avatar George Turner says:

    Here’s an interesting big of tech news.

    Gizmodo: Color Changing LED’s

    Using Europium, researchers created a single LED that can be any color, which will mean one LED per pixel, not three.Report

  7. Avatar J_A says:

    TT8

    Completely off track, but one of my favorite TV shows, The Orville, first caught my attention because the name of the spacecraft made me smile (officially named after Orville Wright – it’s sister ship, the Wilbur, has been mentioned, too).

    I hope I see the Oscar proudly going where no one has gone beforeReport

  8. Avatar Oscar Gordon says:

    Here’s a very small bit of tech that Hanley put me on to. Small, but with profound impacts.Report

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