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Cake day: June 15th, 2023

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  • Transonic speeds, I think I have heard you might have a seconds warning or so, but also I think sometimes you don’t because the shell is travelling at nearly the speed of sound, it depends on charges, firing arc and other things of course.

    I suppose it also depends how close you are to the gun firing the shell. As in, you might hear the primary report from the gun when the shell leaves the barrel in a straight line across the ground to your ears, but the shell itself is traveling in a ballistic arc and may only reach supersonic speeds in the terminal phase when it is coming down on you. So you wouldn’t hear the shell arrive, but you’d be aware it is coming.

    I hope I never have to be on the receiving end to find out for sure.


  • The shadow fleet exists because it isn’t easy to know who is who.

    I see an easy fix. Most of the time these Shadowfleet tankers are turning off their AIS beacons to hide their movements. Step one is for Starlink operators to collect lists of active Starlink connections that exist without a cosponsoring realtime AIS signature. You’ve now got a list which contains nearly all of the shadowfleet vessels with Starlink (and some bad data from a handful of legit ships that were having communication difficulties or maintenance occurring during Starlink use). This would be fantastic targeting data for Ukraine!

    If Starlink wanted a denial effect, they could simply bake in a pseudo AIS signal (not the traditional VHF transmission) derived from Starlink posiioning data into the Starlink product so that as soon as Starlink is used, it itself is broadcasting your position into AIS through a proxy server.





  • I remember swtich grass being a thing but looking into it it seems like they have not really solved the problems of breakdown.

    There’s two ways main bases to make ethanol at scale:

    • sugar
    • cellulose

    The sugar path is what we’re doing everywhere with corn and elsewhere with sugar cane/beet waste. The switch grass is a cellulose path, but switch grass isn’t the only feedstock that can be used. Its talked about the most because switch grass is really easy to grow.

    Industrial cellulose ethanol is still only a tiny industry with only 3 commercial scale plants in operation today in the world (2 in Brazil, 1 in China). It has promise to be more, but its been small for decades.

    The biggest push for cellulose approach is for making Sustainable Aviation Fuel (SAF).

    source




  • That just isn’t true.

    If you want a well researched and referenced argument. Here is a good one.

    It takes far more people to build, maintain, and service airplanes and the infrastructure to support them than to do the same for trains, and even when traveling a train requires fewer personnel per passenger-kilometer.

    If you’re moving the goalposts to include all the infrastructure of air travel, then you must also include the infrastructure costs of long haul rail travel. Building out new rail travel for hundreds of miles of long haul service (which is what I think OP is looking at, and what I specifically replied to) is monstrously expensive.

    Airplanes and cars are massively subsidized

    Can you point me at examples unsubsidized financially self sustaining (profitable) long haul rail anywhere in the world?

    and their uncovered externalities are much more costly to society too.

    We’ve to enough moving parts in this conversation. Lets table this one to include actual costs paid and ticket prices please.


  • Even the hassle of flying is worth the time and money saved.

    You’ve touched on the answer here. The answer is duration of travel. The same labor that is required to move one trainload of passengers on a long haul route can move many many times that number of passengers on an aircraft simply because the aircraft spends less time traveling. So the cost of the tickets must rise to cover the costs and eek out some profit.



  • “The last people you should be getting advice from about electric cars is electric car enthusiasts.”

    And then, Alex the electric car enthusiast himself, goes on to say later:

    “I don’t know why the world isn’t getting excited about this! You can literally have a gas station at home using the exact same technology that operates a clothes dryer!”

    I love you Alex! Never Change!

    First, he’s right in his first statement. Those of us that really are enthusiasts will go far beyond what is needed, and may lose sight of what someone that isn’t an enthusiast actually cares about.

    Second, a suggestion for Alex, if you are on the Fediverse: You very briefly touched on the NEMA 6-20, but I think it needs more attention.

    To me that outlet (which goes on a 240v at 20A circuit) is the sweet spot for home EV charging with regards to speed and low cost. Why? It uses the same common cheap 12/2 household wire that many of your existing household circuits use. With copper prices always on the rise, larger gauge wire starts getting exponentially expensive. The magic is really the 240v. You don’t get double the charging speed of 120v, you get nearly quadruple! And for the same wire! One other change I’d recommend is getting hardwired EVSE (car charger) because it can let you charge faster on the same wire as a plug in charger (because of electrical safety codes). If you have an electrician at your house running a circuit anyway, having them wire up a hardwired charger at the same time is not a high price increase.

    I know this is a Tesla specific charge, but the value here is showing all the various current ratings and how that scales with charging speed. Check out our 240v 20A hardwired charger performance (in the green square):

    15 MPH of charging from cheap 12/2 wire (regular yellow romex)!

    One extra note here, if you already have a dedicated 120v (15A or 20A) circuit to your garage with a regular outlet on it, you can simply change the breaker in the box to a 240v breaker and change the outlet receptacle in the garage with zero modification to the wire in the wall) and get the benefits of 240v speed charging!


  • First, I think we both don’t like the Pi5. So we are in agreement on that. If you want we can stop right there on the same page.

    I’m not sure why you’re referring to the Pi4

    My first post in this thread was talking about Pi low power and small physical size. I was talking about all Raspberry Pis in general. I never put forth the Pi5. You did when you raised the 5V5A requirement. That exists only on the Pi5. You’ll also see in that first post of mine is where I disavowed any recommendation of Pi5.

    You then went on in your next post about Raspberry Pis needing active cooling and heat sinks. Again, that is only the Pi5, which again, I said I don’t support.

    So if you’re wondering why I keep talking about Pi4 and below is because those are the ones I like. In this thread you keep posting facts about Pi5 (without pointing out that those only apply to Pi5), and so that’s why I keep referring to Pi4 (and below).

    You say you don’t use or recommend the Pi5 and yet you’re seemingly arguing that its power supply requirements aren’t a big deal and that improvements should absolutely not be made to it.

    I’m arguing power supply requirements shouldn’t be made to Pi4 (or below). I don’t use Pi5.





  • Low power draw but ridiculous power supply requirements of 5V5A (depending on the model) with a USB-C connector which isnt a thing outside of this specific application meaning they’re going to be expensive and hard to source.

    That’s only for the Pi 5 (the highest end unit), and I’ll agree that at that level its hard to justify a Pi over a larger computer. Even for the Pi 5 its not that hard to find those Power Supplies. Most laptops today use power supplies that meet or exceed those specs. You’re right that those are more expensive than Pi 4 and below Power Supplies.

    They should have just done a barrel plug or put an effing voltage regulator on board like Arduinos.

    Again, no defense of Pi 5 from me. However, for everything below Pi 5, HARD PASS on a voltage regulator. I don’t want that heat in the tiny Pi case. At the lower power requirements of Pi4 and below USB power is fine.