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Joined 3 年前
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Cake day: 2023年6月18日

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  • If you don’t put any ohm at all, miss amp just gets pushed all the way through the tube really fast without doing anything. Like if the next part of the tube is an LED, all that amp coming through would make it glow way too bright and then explode or something.

    There’s a second thing you can do with two ohms. If you line up two ohms one after the other, then a little volt appears in the chamber in the middle between them. But miss middle volt is a smaller version of the big volt, and her size depends on how tight your ohms are relative to each other.


  • They did this to Houston, but they did an extremely half-assed job. It was one thin layer of additional asphalt covering over the whole intersection. But you can still see the pride crosswalk peeking out from underneath at the edges.

    I’m still very upset.

    Especially now that the sidewalks have been defaced with hate messages, which were then blacked out with spray paint. Is there a way to get the spray paint off the concrete and go back to chalk?


  • This is still a big deal result with a lot of physical significance if it holds up.

    Full Navier-Stokes are / were understood to model all of the important physics associated with continuous domain fluids. (Continuous domain here means we approximate the many, many particles of the fluid as a smooth, continuous substance).

    In particular, Navier-Stokes are supposed to fully model fluids with turbulence. Turbulence is an everyday phenomenon that you can reproduce for yourself in your kitchen sink, and yet it is extremely difficult to formulate a mathematical function for it. Turbulence appears to be random if you look at it, and yet if it is produced by NS, then it is not random. Solving even the numeric approximations of NS for turbulent flows is difficult because the flows exhibit severe variation in velocity over wide ranges of time and distance scales.

    Anyhow, if NS is a good physical theory it has to have a physically realistic solution to every physically-possible set of initial conditions and environmental forcing functions. In math terms this mainly means that all of the velocities, pressures, and forces have to be finite and smooth at all times. Step discontinuities don’t really occur in the real physical world (although they do approximately occur).

    This result would mean that NS is not the end all final theory for classical continuum fluids. The scenario constructed by OpenAI is claimed to be one that can (at least theoretically) be setup and run in the real world. But if we did that, the real world is certain to do something else besides the infinite flow velocity vortex that OpenAI claims NS predicts. What would really happen in that experiment? Who knows. We’re gonna need to find some new physics to find out.









  • There’re a bunch of legal shenanigans that happened this afternoon on this topic. I’ll try to summarize.

    1. Kavanaugh really did rule in favour of the democrat-leaning map. All by himself.
    2. The emergency application that Kavanaugh denied came to the supreme court on appeal to from the supreme court of Missouri.
    3. In a separate lawsuit in federal court, a federal district judge ruled in favour of the Republican map (forcing MO to change its behaviour with a court order). The main reasoning for this decision is the Purcell Principle. A rule that federal courts can’t meddle with election maps right before an election.
    4. #3 happened just minutes after the Kavanaugh decision was posted.
    5. Despite that, the #3 decision does not disobey the Kavanaugh decision because it was decided on a different rationale. Also the Kavanaugh decision didn’t come with an opinion.
    6. The #3 decision was immediately appealed to both the 8th circuit and to Justice Kavanaugh on the supreme court.
    7. Kavanaugh asked for a response on this new appeal by next Tuesday.
    8. Kavanaugh is handling all these emergency appeals because he is assigned to handle the circuit that includes Missouri.

    Bottom line: Despite the Kavanaugh ruling, the Republican-leaning map is still the current map right now.

    Why is this federal district judge probably wrong? In the Alabama and Texas cases, the Supreme Court pretty well established that the Purcell Principle restrains the federal court system, but not state legislatures or state governments. Other court precedent says that the supreme court of Missouri is the ultimate decider of the meaning of the Missouri constitution and the Missouri laws. Federal courts are supposed to defer to state supreme courts if they need to know what a state law means. Here we have a federal judge telling Missouri that their supreme court is wrong on the laws of Missouri, and he’s incorrectly applying Purcell to the state supreme court.



  • At one time I researched hiking the Pacific Crest Trail. It was recommended to plan for a 4000-5000 calorie / day diet. But most thru-hikers found it was physically impossible to carry enough food and they lost 30-40 pounds on average over the course of the hike.

    Appalachian trail is a little bit easier in terms of access to civilization.