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Joined 2 years ago
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Cake day: June 9th, 2023

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  • PostUp = ip route add 100.64.0.0/10 dev tailscale0
    

    Looks like you need to stick this line in the tailscale service file, since it’s the only time that the existence of the tailscale0 device is guaranteed. If you don’t want to modify the service file inside the package, could you write your own systemd service file and include the tailscale service as a prerequisite?

    Also make sure that when you start the VPN first and then tailscale, you don’t get a double tunnel situation where tailscale goes out through the VPN (unless that’s what you wanted).




  • I like this cosmology calculator: https://www.astro.ucla.edu/~wright/CosmoCalc.html Enter redshift z=1100 (which is the observed redshift of the CMB) and hit the “general” button, which calculates the distances using the currently-accepted general model and Hubble parameter/dark matter/dark energy values. This gives the “comoving radial distance” of 45.5 Gly (giga light years). That means that if right now, at this very instant, you put down a meter stick in front of you, and the buddy next to you put down a meter stick, and the buddy next to them, and so on through the next galaxy, and every galaxy, all the way to the place where the CMB in that direction originally came from (the place is still there and there is probably a galaxy there now though there wasn’t one back then), there will be 45 billion light years worth of meter sticks.

    The other values of note are the light travel time of 13.72 Gyr (travel time is how distances are usually reported in news articles, as opposed to scientific articles that only report the redshift z), and the age of the universe at the time the light was emitted: 0.37 My = 370000 years, which is the age when recombination happened. The total age of the universe (13.721 Gyr) is the sum of these two.

    The value you probably want is the “angular size distance” in the calculator, which is the meter-stick method done in the moment when the light was emitted rather than at the moment right now. In this case the distance is 0.0413 Gly. Only 41 million light years, really close by! There was a lot of stuff packed together, but it has stretched out since. The relationship between the two distances is:

    comoving distance = angular-size distance * (z + 1)
    

    So redshift of 1100 means the spacing has been made 1101x times wider.

    Of course if the universe were literally stationary then your question wouldn’t make sense because the universe would never cool down and CMB would not happen. If the universe expansion had stopped at the moment the CMB happened, then the distance to the CMB you want is the 13.72 Gly travel time distance, but it wouldn’t be our CMB anymore, it would be some other last scattering surface much farther out away.


  • Yeah, I concede that small caps are more likely to be carried away by rainwater than whole bottles :D. What I meant was that for every loose cap on the ground there is a bottle lying around somewhere, and also there are bottles with caps on. No one is tossing their cap into the bushes and then taking the bottle to the recycling center.


  • I pick up street litter, and having picked up thousands of pounds, I have never felt that loose caps are a problem, let alone one that requires such a solution. The number of littered bottles, with or without a cap, is greater than the number of loose caps, and the amount of plastic in every bottle dwarfs the plastic in a cap. Fixing the cap to the bottle will do nothing to improve the recycling rate of plastic if entire bottles are already tossed anyway.

    I consider the idea of cap tethers as adversarial memetic warfare thrust upon us for some unknown ulterior purpose, possibly to make us hate the very idea of environmental consciousness. Same as paper straws. I like plastic bag bans though.

    As far as picking litter is concerned, I personally prefer finding bottles without a cap. At least those are empty, all liquid having evaporated after the bottle has spent several months in the bushes. The capped bottles are often half-full and are just nasty. (Who even pays for a bottle of drink and not drinks half of it anyway?)


  • It is important to remember that, unless accompanied by convincing evidence for selective advantage, any single inheritable trait is more likely to have arisen from genetic drift, not from natural selection! There is, in my opinion, too much focus on conversation about superficial phenotypic traits like “shape of the nose” this and “angle of the eye” that, all the arguments about how one is better than another. Could the asiatic epicanthic fold give advantage against icy winds? Maaaybe… But it doesn’t even have to. What about the asiatic dry earwax gene? You’d struggle to even come up with a story of how dry earwax or wet earwax is actually better under certain conditions, or you could just say “it’s a single nucleotide polymorphism that could have spread by genetic drift” and be done.

    Very few human traits have definitely been naturally selected for: light skin in non-sunny climates for better vitamin D production, sickle cell gene for malaria resistance, lactase persistence for animal milk consumption. Even there, the estimated selective advantage is actually much smaller than you’d expect: lactose tolerance confers only something like 1% advantage! There are many more possible neutral mutations than advantageous ones, and each one has a chance to be fixed in the entire population by genetic drift, meaning that any widespread human trait that is less clearly advantageous than lactose tolerance is more likely to be neutral than advantageous at all.

    Even mildly disadvantageous mutations can be fixed by genetic drift, especially in humans since we have had many bottlenecks and founder effects. There was an area in Appalachia populated by blue-skinned people due to founder effect. No one is going to try to argue how having blue skin was actually advantageous for them to blend into their environment! There is an area in Dominican Republic with a very high rate of children born intersex, again due to a founder effect mutation. They are not considered exceptional and live normal lives as their culture has adapted to treat them as routine, as a kind of third gender. But they are not some kind of new level of human evolution, an adaptation for an intersectional era!

    The only mutations that definitely cannot spread by genetic drift are those that definitely kill you.




  • I’d love to use ISO sizes, but even if I know that I need a 40-622 wheel, there is no way to search for it on the storefront if every single seller made gross mistakes in labeling their product! I have to ignore the specs shown entirely and make educated guesses based on title alone. For example “WHEEL AL 700 FRONT ALEX AP18 QR Silver UCP” in the picture is almost certainly a 700C wheel and NOT an 18-inch wheel. The “18” in the title probably stands for 18mm rim width, which means that this wheel will fit my bike and tire, but is a bit more narrow than ideal 23mm. The sellers must be copying the title verbatim from the manufacturer, and then haphazardly filling out the specifications without knowing or understanding the actual numbers. The ISO size is not mentioned at all.


  • Given a radiative forcing coefficient of ln(new ppm/old ppm)/ln(2)*3.7 W/m**2 I have previously calculated that for every 1kWh of electricity generated from natural gas, an additional 2.2 kWh of heat is dumped into the atmosphere due to greenhouse effect in every year thereafter (for at least 1000 years that the resulting carbon dioxide remains in the air). So while the initial numbers are similar, you have to remember that the heat you generate is a one-time release (that dissipates into space as infrared radiation), but the greenhouse effect remains around in perpetuity, accumulating from year to year. If you are consuming 1kW of fossil electricity on average, after 100 years you are still only generating 1.67kW of heat (1kW from your devices and .67kW from 60% efficient power plant), but you also get an extra 220kW of heat from accumulated greenhouse gas.

    I have wondered this question myself, and it does appear that the heat from the fossil/nuclear power itself is negligible over long term compared to the greenhouse effect. At least until you reach a Kardashev type I civilization level and have so many nuclear/fusion reactors that they noticeably raise the global temperature and necessitate special radiators.