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Cake day: June 26th, 2023

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  • vithigar@lemmy.catoScience Memes@mander.xyzOxygen
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    11 days ago

    The short version is that life needs something that’s at least a little unstable in order to extract chemical energy from things.

    The post is correct when viewed in a particular light, on a technicality, if you squint. By that same technicality iron rusting is also burning very slowly. They’re ignoring the rapidity which is implied by “burning”. But yes, oxygen is unstable, oxygen helps burn things, and oxygen is toxic if you get too much at once. Though you’d need to be breathing pure oxygen pressurized to about 1.4 atmospheres, or regular air pressurized to about 7 atmospheres, for that last one to happen. It’s a legitimate concern for deep SCUBA divers.

    But why does life need instability? Chemical instability is, in basic terms, just stored chemical energy, and that energy wants to be released. The more reactive something is the easier it is to get energy from reactions involving it. There’s a balancing act here where more reactive means easier energy, but also more dangerous. Oxygen is in a kind of sweet spot where it’s stable enough that it’s not generally going to explode or catch fire on its own, but can be coaxed into doing those things in controlled ways with other chemicals to extract energy when needed.






  • Yes, if you consider just a human-mass equivalent portion of the Sun then it’s not doing much, but that’s not really a useful comparison. We’re talking about total net entropy here, not entropy per unit mass.

    But yes, if it makes you feel any better, I’ll concede that if you had octillions of people our total metabolic energy output would, in fact, be significantly higher than that of the Sun.



  • For those of you who’ve never experienced the joy of PowerBuilder, this could often happen in their IDE due to debug mode actually altering the state of some variables.

    More specifically, if you watched a variable or property then it would be initialised to a default value by the debugger if it didn’t already exist, so any errors that were happening due to null values/references would just magically stop.

    Another fun one that made debugging difficult, “local” scoping is shared between multiple instances of the same event. So if you had, say, a mouse move event that fired ten times as the cursor transited a row and in that event you set something like integer li_current_x = xpos the most recent assignment would quash the value of li_current_x in every instance of that event that was currently executing.





  • In the moment at the table, arguably RoC, but that’s still not necessarily going to convey well to anyone who wasn’t there.

    Also, assuming OP’s previous submission is the “player shenanigans” which prompted this then it’s my opinion that it wasn’t cool at the table, either.


  • A pretty large proportion of “player shenanigans” stories amount to “we ignored the rules and allowed something ridiculous to happen”. This is fine if that’s what your group wants to do, but can’t really be expected to be relatable to the community at large.

    It’s similar to the stories about level 5 groups who miraculously defeat an ancient red dragon or whatever. It invariably only happens because of some utterly absurd homebrew/ruling, or the GM just played the dragon as an idiot.


  • vithigar@lemmy.catoMemes@lemmy.mlAmd fan
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    2 months ago

    There is analogous functionality for most of it, though it’s generally not quite as good across the board.

    FSR is AMD’s answer to DLSS, but the quality isn’t quite as good. However the implementation is hardware agnostic so everyone can use it, which is pretty nice. Even Nvidia’s users with older GPUs like a 1080 who are locked out of using DLSS can still use FSR in supported games. If you have an AMD card then you also get the option in the driver settings of enabling it globally for every game, whether it has support built in or not.

    Ray tracing is present and works just fine, though their performance is about a generation behind. It’s perfectly usable if you keep your expectations in line with that though. Especially in well optimized games like DOOM Eternal or light ray tracing like in Guardians of the Galaxy. Fully path traced lighting like in Cyberpunk 2077 is completely off the table though.

    Obviously AMD has hardware video encoders. People like to point out that the visual quality of then is lower than Nvidia’s but I always found them perfectly serviceable. AMD’s background recording stuff is also built directly into their driver suite, no need to install anything extra.

    While they do have their own GPU-powered microphone noise removal, a la RTX Voice, AMD does lack the full set of tools found in Nvidia Broadcast, e.g. video background removal and whatnot. There is also no equivalent to RTX HDR.

    Finally, if you’ve an interest in locally running any LLM or diffusion models they’re more of a pain to get working well on AMD as the majority of implementations are CUDA based.


  • vithigar@lemmy.catoScience Memes@mander.xyz8 Minutes
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    2 months ago

    Would it? What does “stationary” mean when discussing relative velocities? The mirror being stationary and the person firing the photon moving at a constant velocity is literally an indistinguishable scenario from a stationary person firing the photon at a moving mirror.

    If I am moving relative to a mirror when I fire the photon, then the mirror is moving relative to me, and will be in a different relative position by the time the “event” of my firing that photon reaches it.

    Also, the photon isn’t moving infinitely fast in my (the firer’s) reference frame. It’s moving infinitely fast in it’s own reference frame.


  • vithigar@lemmy.catoScience Memes@mander.xyz8 Minutes
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    2 months ago

    The observable effect is the same either way. If light is infinitely fast and causality propagates at c then it’s still going to take (distance to the mirror / c) for the fact that you turned on the light to reach the mirror, and that same amount of time for the fact that the light reflected to propagate back to you.


  • vithigar@lemmy.catoScience Memes@mander.xyz8 Minutes
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    2 months ago

    Kind of. The concept of simultaneity breaks down at distances where the speed of light matters. If we base it on what we currently observe and call “now” on the Sun the eight minute old state we currently observe then what does “now” on earth look like from the point of view of the Sun at that same moment? You can’t reconcile a single “now” for observers in both locations.

    An alternative take which is also consistent with observable physics is that the speed of light is infinite but it’s causality itself that propagates at c.

    Thinking in those terms also makes a number of relativistic effects more intuitive. You need infinite energy to reach the speed of light simply because it’s infinitely fast. Time dilates when moving because you’re encountering approaching causality earlier than you otherwise would have. Time “stops” for anything traveling at the speed of light because at infinite speed it just experiences literally everything in its line of travel at once and the concept of “after” becomes meaningless, encountering all future oncoming causality in a single instant.

    This was a bit of a tangent but it’s something that has fascinated me for a long time.