Sasha

joined 9 months ago
[โ€“] Sasha@lemmy.blahaj.zone 3 points 8 hours ago

Left pocket: Mask Grocery bag Earplugs Lip balm Stickers Keys

Right: Phone

It has changed an enormous amount, this article discusses it

[โ€“] Sasha@lemmy.blahaj.zone 3 points 3 days ago

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.

[โ€“] Sasha@lemmy.blahaj.zone 18 points 3 days ago* (last edited 3 days ago) (2 children)

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.

[โ€“] Sasha@lemmy.blahaj.zone 3 points 4 days ago

Ah right fair enough, I'm just talking about the situation in Australia

[โ€“] Sasha@lemmy.blahaj.zone 19 points 4 days ago (6 children)

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

[โ€“] Sasha@lemmy.blahaj.zone 4 points 1 week ago

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

[โ€“] Sasha@lemmy.blahaj.zone 8 points 2 weeks ago

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.

[โ€“] Sasha@lemmy.blahaj.zone 6 points 2 weeks ago

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.

[โ€“] Sasha@lemmy.blahaj.zone 5 points 2 weeks ago

Only a few really dry textbooks I'm afraid, it's a subject that's extremely difficult to explain in lay terms as the mathematics is so complicated.

That said if you're feeling masochistic, Schultz's first course in GR is the most approachable that I know.

[โ€“] Sasha@lemmy.blahaj.zone 4 points 2 weeks ago

It's just meant as a physical analogue to demonstrate some features (namely how the shape of the sheet/gravity affects things that travel on/through it) in a way that people can understand easily.

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