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Joined 2 years ago
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Cake day: November 19th, 2023

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  • When wind speed doubles, the energy it carries increases eightfold,

    Edit: I’m wrong, see edit below!

    Huh? Kinetic energy increase is square, not cubic.

    KE=1/2 m v^2

    So every doubling of speed should increase the available kinetic energy by 4 times, not 8. 3 times the speed is 9 times the energy. Granted there are probably some efficiency gains in excess of this at the low end, but as a rule that’s just wrong.

    Edit: Cool, I learned something new! I neglected to consider it in terms of power, just thought about kinetic energy.

    So something like: KE = 1/2 m v^2

    = 1/2 ( rho V) v^2

    = 1/2 ( rho A d) (d/t)^2

    = 1/2 rho A d^3 1/t^2

    Where P = KE/t

    Thus:

    P = 1/2 rho A (d/t)^3

    = 1/2 rho A v^3

    Lots of other aspects I’m sure I have wrong, but I see how the cubic came to be.





  • WFloyd@lemmy.worldtoSelfhosted@lemmy.worldA noob question about VPSs and bandwidth
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    11 months ago

    will all my Jellyfin traffic go through the VPS

    Yes

    and count as bandwidth used?

    Yes, twice (download from home to the server, and upload from the server to the client)

    I do the same thing - I have a 3TB limit, but usually only use 300GB, sharing Jellyfin to a dozen or so users.

    Edit: I’m sure there are plenty of good VPS providers out there, I personally have been using NerdRack for a few years now (got a VPS on special and the rate is locked as long as I keep it). Looks like they’ll do $11/year right now for a KVM VPS that’s sufficient.


  • Huh? This is from July 2023. There have been many of these proposed before, and possibly a few since. Looks like you need a license to distribute files these days anyway.

    I spent a few years designing 3D printed guns for fun, none of them were effective or well known, and I never manufactured any myself. I did that that as a teenager, before there were laws, and it’s what got me into engineering before I pursued a degree. This was pretty early on in hobbyist 3D printing, it was all super experimental. Ultimately, 3D printing is just one method of manufacturing - there are many out there, and honestly the barrier of entry is low regardless of what method you choose. If someone has the skills to run a 3D printer, they can buy the hardware store components to make a gun regardless.

    The better bet for legislation would be to more comprehensively ban unlicensed manufacturing, whatever the method, and more strictly regulate which parts may be bought unlicensed (barrels, trigger assembly, magazine, etc). On a personal note, I think it’s too deeply engrained in American culture to shift anyway, but I hope we keep trying to change the world for the better l (stricter background checks, more stringent home safety requirements, etc.)



  • Ostensibly, that’s because the app wants Bluetooth and/or WiFi access so it can connect to the printer. Because you can use WiFi and Bluetooth to determine location (based on large crowd sourced databases of these data points that have been geolocated), the OS has to ask for location permission as well, even if you just need to see WiFi and Bluetooth.

    That being said, once they have this permission, I have 0 doubt they log the actual location as well…

    Mozilla used to run a free service for this, and collected that data in the background using mobile Firefox. A replacement is https://beacondb.net/, which is still building enough location data to become useful. Services like this aren’t nefarious, they’re actually really important in getting a quick GPS lock on mobile. Phone hardware actually have pretty poor GPS receivers, but if you can determine an approximate location prior, you get much better results, especially once supplemented with inertial measurements and snapping to mapped roads.