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the slurperrrule
  • OH YARN I don't have my glasses and I couldn't work out how someone was knitting with a yam

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    Someone got woken up on Sunday morning 🀣
  • I love it, I doubt I'll ever get another bike but if I do that's a great thing to know about.

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    If gravity is a particle... How come it can escape a black hole? πŸ€”
  • No idea if I can reply to a deleted comment but I read the root comment totally wrong and just restated everything they said. My bad.

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    If gravity is a particle... How come it can escape a black hole? πŸ€”
  • We can kinda try to treat gravity like any other force and apply the standard machinery to turn that into a quantum theory and expect it to work. It doesn't for a lot of maths reasons, but one sort of intuitive reason is that it's not a force.

    Gravity is literally spacetime itself, not something that lives in spacetime. This distinction means it's very possible that it works in a completely different way to the rest of the quantum world. There are viable theories for gravity that look nothing like our highly successful quantum field theory.

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    If gravity is a particle... How come it can escape a black hole? πŸ€”
  • If that was the case, we would already have a quantum theory of gravity. The fact that "gravitons" (here I mean the particles of a second quantisation of GR) can interact with themselves makes the theory almost completely useless.

    It's technically possible to write down such a theory, but the only way to get results out of it is to first perform an infinite number of experiments.

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    If gravity is a particle... How come it can escape a black hole? πŸ€”
  • Almost none of this applies in the case of something like loop quantum gravity, which I understand very little of but I don't believe it's possible to discuss it using the language of QFT like I have above.

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    If gravity is a particle... How come it can escape a black hole? πŸ€”
  • I briefly worked in this area of physics, it's complicated and depends on your definition of a particle and which quantum gravity model you're talking about.

    To simplify things you can just ask the same thing about non-quantum gravity. Why does gravity escape the black hole? The painfully mundane answer is that the black hole is gravity, it's not escaping itself. Gravitational waves can't be emitted from inside the black hole but that's because those are a form of radiation and not the structure of spacetime.

    This is specifically important because even quantum gravity (the kind with gravitons) still has this distinction. Particles belong to a field and are excitations of it, the gravitational field itself is not made of those particles. The force associated with that field is mediated by gravitons, but what that really means is complicated and honestly possibly just the result of a cool mathematical trick. It also comes with a bunch of crazy behaviour where you have particles that can break the laws of physics by just kinda doing it so quickly that nature blinks and misses it.

    The point is, the quantum gravitational field is enough for the black hole to do its job when objects come by, gravitons don't actually need to escape, though they are involved in complicated ways.

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    Noise Pollution ruins quality of life
  • Ah right fair enough, I'm just talking about the situation in Australia

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    Noise Pollution ruins quality of life
  • The safety isn't about lane filtering so much as just intersections, but yeah it's a rubbish argument and any biker making it should shut the fuck up if they don't wear hi-vis on every ride

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    Someone got woken up on Sunday morning 🀣
  • This is honestly an entirely valid complaint. There are way too many motorcyclists who replace their mufflers with aftermarket ones that are illegally loud, in some cases loud enough to cause hearing damage to pedestrians.

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    Rule
  • Hard agree, unsubscribed from real engineering the moment I realised they made ads without ever declaring it. It's literally just propaganda at this point

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    If you could time travel, what would you change ?
  • I think I finally met the love of my life, I don't think I'd want to risk changing anything

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    What are the best (free) math resources out there?
  • If you're looking for books, then it depends on what field you want to study. Generally just I'd search for recommended textbooks for that field and then I'd definitely buy it and wouldn't just download it from libgen.is

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    Thank you!
  • Coffee is just a bean soup

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    Ahh... hearing programmer audiobooks before sleep feels relaxing
  • Now I'm wondering, surely someone has already made a language that's designed to read like scripture?

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    How's your week been?
  • My gender doc is an asshole and I want a new one... Just trying to sort out a missing pathology form and he emails me back in all caps screaming at me, misunderstands the situation, doesn't help and treats me like I'm crazy. Well, I'm just doing what he told me to do last appointment "just email me I can sort it out in no time."

    Still don't have the damn form so I guess he can get pissed off again that I haven't done them, and its completely his own fault. I am so goddamn over medical professionals being shit.

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    For younger generations, what was it like growing up with the internet?
  • I'm basically as old as gen z gets, '97. At home we only had dialup well after broadband was the norm, it wasn't really worth using. Instead I learnt what the internet is and how it works at school in computer lab classes.

    I was probably 7 or 8 when I made my first web page on our school intranet, they really pushed for us to be tech literate. The coolest part about this is that I grew up so tech literate that I was fully qualified for a job as a developer despite having no formal training. I did one introductory programming class in uni for a free HD and that was basically it.

    Yeah, I absolutely understand the insanity of having the internet so available. We had it in my early days on school computers, but the real game changer has been smart phones. Being able to carry that information everywhere is the insane part to me.

    Parents were strict, but I got around it really easily. I just used the wifi details my dad used for my Xbox to connect my iPod touch. I grew up on YouTube and podcasts from iTunes.

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    Being Agile
  • The only thing that keeps me sane while working for capitalists is that I get paid to do a lot of nothing

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    TIL Gravity is not about mass pulling other mass. It's mass bending ~~time~~ spacetime that makes other mass get closer
  • Oh god the case for a photon is super hard to talk about in any meaningful way, photons "see" every point in their journey as happening at the same instant of time and at the same place, null geodesics are nuts.

    But yeah, the underlying mathematics that causes this can (kinda) just be pinned on the normalisation of the four velocity, which I think is what you're describing.

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    Seconds
  • Oh god, no fluid mechanics is way too difficult. I stuck to studying quantum effects of black holes, which is much easier.

    (This isn't a joke, it's literally true)

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  • I was in an antique store and I found the anime section

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    Bought a mandolin today and I can't put it down, I can't wait to write tons of pretty songs :3

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    From the Narrm invasion day rally, we had an enormous turnout

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    Go listen to Big Thief!

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