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Joined 5 months ago
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Cake day: June 5th, 2025

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  • Right - the water has inertia in a straight line (as does the bucket). When they both try to go straight the string prevents it, accelerating them in a new direction. At each moment you look at the circular path the water’s inertia wants to go in a straight line (tangent to the circle). So at each instant it is behaving exactly as if you had been running in a straight line and stopped.

    What I meant about the geometry and axial tilt - imagine that instead of a bucket you had a dinner plate with a bucket handle. So the water was all at the level of the top of the bucket rim on a plate. As soon as you stopped the plate would flip and the water would splash off. Likewise, if you had the string connected only to the bottom edges of the bucket rather than its handle, as soon as you stopped the bucket would flip due to the water’s strong inertial force against the side of the bucket. The setup doesn’t tilt the bucket in the right way to keep the water contained and impart the new acceleration upon it.


  • Think of the inertia of a bucket of water on a string that you are holding by the string.

    If you are standing still the water and bucket and string behave like you expect.

    Start running suddenly and the bucket will seem to swing back behind you. Your frame of reference is in motion. But when I watch you do this I see a bucket and water at rest. Their inertia resists the sudden acceleration.

    As you pull the string along in your run, the swinging will stop. And with no acceleration (you are in a constant running velocity) the bucket will hang straight down again. The bucket and water are in your moving frame of reference. Their inertia is clear.

    What if you stop?

    Just like when you started running the inertia of the bucket and water will cause them to continue moving, swinging up. Their inertia is linear, but show up as an arc due to the string you’re holding when you accelerate to a stop. The water stays in the bucket because it’s geometry tilts its axis, keeping the bottom pointing in the direction of the watet’s inertia.

    If you were carrying the water on a spoon in the same conditions the water would spill. Because it doesn’t tilt the right way to hold it in.

    If, at that moment of stopping, you started swinging your arm in a circle you could create a circling bucket from your question. Sometimes the bucket will be upside down, but with sufficient acceleration the water will stay in.

    It’s the inertia doing the trick. Aided by the geometry of the bucket.



  • Still excludes much of Russia to the Urals (which is in the 3.9M figure).

    But to be clear, I’m not arguing that there’s a view which will make the US map look good by comparison. There are quite a few reasons why the US situation sucks.

    Part of it is how the population is distributed. Here’s a view of population density that helps tell that story:

    Compared with Europe his country has A LOT of empty space. Large tracts of agricultural land and large tracts of marginal to desolate land.

    Add to that the construction and funding of the railroads here. It was all owned by private enterprises focused on freight. If the freight dried up on a route there was no incentive to invest in maintenance. Many railways started fading right around the same time that passenger demand was drying up due to the construction of the interstate highway system and then later due to deregulation of the airlines. Mail started moving by plane and by truck, so that guaranteed income stream dried up too. When the railroads were consolidating and eliminating passenger routes to save money the government formed Amtrak to try and save a few routes. Outside of the northeast it has generally been a curiosity, an experience, more than a competitive transportation option. And most Americans are fine with that. They prefer to roll around in a pickup truck on their own.















  • Ok, so it’s probably using NetworkManager. I would try disabling it in /etc/NetworkManager/NetworkManager.conf by adding a block like:

    [ipv6]
    addr-gen-mode=stable-privacy
    method=disabled
    

    Then sudo systemctl restart NetworkManager. Can’t say for sure if this will work. I dislike using NetworkManager on my servers so I can’t test if this works. But hopefully the before/after of ip addr is different.

    Although it looks like your ip addr output posted an hour or so ago doesn’t show any ipv6 addressing. Maybe the problem is solved now.


  • Different programs have different defaults.

    But in your situation which would be more helpful - prevent this one docker command from using ipv6 (likely more difficult), or preventing all commands from using your broken ipv6 config (likely easier)?

    I have no idea about the first. Maybe some people know this detail. But I’m sure that with a distro and version that you’re running, there are lots of people who could help with the second. Raspberry Pi 3B+ is the hardware. What software are you using?


  • Docker is a distraction in your problem description.

    It’s like if you asked why the top gear in your car isn’t working and gave the model of car and engine type and gearbox. But it’s really that you’re stuck in slow traffic. Focus on the road name and destination to find a faster route.

    For your problem, search for how to disable ipv6 for the Linux distribution and version that you have installed. You will find lots of guidance. Or share those details here for someone to help.

    Or, better might be to see if there is a way to get ipv6 tunneling working on your connection. It may be possible even if the ISP is unhelpful.