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Cake day: June 9th, 2023

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  • 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.



  • TauZero@mander.xyztoScience Memes@mander.xyzIrresistible
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    4 months ago

    For an object heavier than the Earth, 1g radius will be greater than the radius of Earth. For 56 Earth masses that’s sqrt(56) times bigger = 48000km.

    A 56 Earth mass black hole will take 5.5e55 years to evaporate according to this calculator. A 100kg black hole (more close to what Richard used to be) is much smaller than the nucleus of an atom and will evaporate in 0.05 nanoseconds.

    Curiously there was a paper recently that calculated that even if there was a small black hole in the center of the Sun, it would take millions of years for it to grow, because the aperture is so small not much can fit through, and the infalling gas heats up so much as to repel the rest, creating an internal hot bubble.


  • TauZero@mander.xyztoMildly Infuriating@lemmy.worldTethered Bottle Caps
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    4 months ago

    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 was apprehensive about EVs but the first time I rode in one I immediately fell in love with it. I get carsick easily, and the super-smooth ride without the chug-chug-chug of an internal combustion engine made the experience surprisingly much more pleasant for me. I do not use a car, but if I had to buy one, I don’t think I could ever stomach an ICE again knowing that this alternative is available.


  • One example: on May 30, 2020 in Minneapolis, during the protests after George Floyd killing, some police were driving around the streets in an unmarked van, shooting at pedestrians at random without stopping. They later claimed they were shooting rubber bullets to “encourage” people to obey the curfew order. Of course, if you are the one being shot at in a drive by from a mystery van, you have no time to determine what kind of bullets are being fired… One pedestrian shot back! There is a video of it.

    The guy was immediately arrested, miraculously without being shot to death in the process, and put on trial, but acquitted due to justifiable self-defense. The police did not drive around shooting randomly any more after that though. I see the guy even won a $1.5M lawsuit against the police now!




  • 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.




  • Oh! They don’t mean that black holes must come in perfect pairs! The headline makes it sound like it’s about wormholes across vast distances. No! What they’ve found is a stable “orbit” solution for the two-body problem. Normally when you place two bodies anywhere in an empty universe, they will gravitate towards each other until they collide. But in a universe with dark energy, there is some perfect distance between them, where the accelerating expansion perfectly counterbalances the accelerating attraction. They’ve used general relativity math to actually calculate such an arrangement.

    The “stable” orbit in this case is the same kind of stable as a pencil balanced on its sharp tip - if it tilts even slightly one way it will fall out of control. Although they tantalize the idea that they might be able to make it truly stable against small perturbations once they finish their spinning black hole solution.

    I would like to have known some specific numbers examples! Like if you have as much dark energy as our universe, and two 10-solar-masses stellar black holes, how far apart would that be? Is it like 1Ly or 1MLy? How far for two 10-million-solar masses supermassive black holes? The formulas they created should give the exact answer but I am not skilled enough to substitute the correct numbers for the letters.


  • I think it’s precisely because there is no governing body for English and all the rules are colloquial, developed through usage, that people do get grumpy! They are the only ones who can create and enforce the rules! Each English speaker feels personally responsible and compelled to correct use they perceive is in violation of the rules the way they want them to be. If they don’t do it right then and there, no one else can.


  • That’s why Google is pushing hard their Web Environment Integrity. It’s DRM for the browser! They want the TPM chip in your computer to attest that the code running processing the video stream is authentic. Then you can’t slice out the ads because you do not have physical access to the inside of TPM. With HDCP encryption on the HDMI video output, you gonna need to point a literal video camera at the physical screen to DVR the video and slice out the ads later.

    They’ve been working hard for decades to lock down the video pipeline with TPM and HDCP and now WEI. They said “don’t worry about it” and we let them. They are really close to snapping the trap shut!

    Now please excuse me, my tongue is falling off with all the acronyms…



  • Echoes of the Eye expansion to Outer Wilds. I managed to avoid all the spoilers, watched some playthroughs but thankfully didn’t study them too closely. Importantly, the streamers never looked “up” during the parts of the gameplay that I’ve seen, so to me it appeared just like another normal environment (well, normal at least by Outer Wilds standards). I already loved the original game, and decided I must play this for myself.

    So when I entered through that doorway for the first time I was genuinely stunned. “You fuckers, you really did it this time. You actually went ahead and did it!” I mean…

    spoiler

    Space habitats have always been a staple of science fiction novels, and they have appeared a couple times in video games already, like in Mass Effect and Halo, but there they were only used as background - the actual playable area was limited. Never before this had anyone successfully implemented a life-size Bishop Ring with the full “You see that mountain? You can walk there!” boastfulness. And sometimes that mountain is on the ceiling. And when the water breaks, oh boy…




  • If the black hole specifically disappeared, it would have no effect on us. The solar system would not even be launched on a 100 million year trajectory out of the galaxy, as galactic rotation is dependent on the masses of stellar and interstellar matter in the disk and dark matter in the halo. The supermassive galactic black holes, despite being supermassive, still only make up a tiny percentage of total galactic mass.

    If you want to wow your friends, tell them about false vacuum decay. We could have bubbles of true vacuum expanding out in space from multiple directions towards us at lightspeed, and no way of knowing about them, stopping them, or outrunning them. Any point in space could nucleate a new true vacuum bubble at any time, just like a given uranium atom could decay now or in 5 billion years or never. Even spookier, by principle of quantum immortality, the Earth could have been engulfed by vacuum bubbles many times before, and we are just the one tiny sliver of probability space where by luck alone we survived long enough to talk about it here and now.

    Thankfully false vacuum is just an idea and there is currently no evidence that it is real.