NaevaTheRat [she/her]

I used to run physics labs at uni so I’d hope I was as alright teacher still. Never made it as a real physicist though ;_;

Everything soft and slow like your brain yes.

It’s pretty hand wavy. The question: why is the speed of sound so slow? (which is essentially isomorphic to this one) is pretty hard to answer. I can’t do the the maths to derive it anymore haha.

There are similar things about light slowdown during refraction and stuff.

It’s just much easier to view certain bulk phenomena as waves in homogeneous material but it can be very unsatisfactory. Hence all the bullshit artists in this thread talking about speed limits, the standard model, and time dilation. For some reason “it just be that way ok?” feels more satisfying if the thing you’re asserting seems more fundamental, but it doesn’t really make stuff clearer.

So have to ask what a solid is to answer this question.

Sticks are quite complex, so lets consider a simpler solid: an elementally pure iron rod.

You can imagine said rod as if it were a fixed array of crystalline atomic cores surrounded by a jelly-like substance. In this ‘jellium’ model the atomic cores have a positive charge, they are the protons and neutrons, and the jelly has a negative charge. The jelly is the wavefunction that represents the electron structure in bulk. If that makes no sense, congrats on knowing your limits.

You’ve probably seen the more modern model of an atom where there’s a nucleus and around it is an electron fuzz with discrete energy levels. Or if you’ve studied at uni strange geometry representing a threshold in probability of finding the electron/s there on a given measurement (if not familiar under certain conditions reality kinda unfocuses it’s eyes and things that we often think of as points become volumes of possible effect). This is a good model of a single atom, but when we bring atoms together they change each other’s properties and the result is that these density functions (the weird electron cloud/shape things) start to blur together.

In our iron rod the electrons delocalize sufficiently we can kinda think of it as a weird jelly. A real stick is more complex, but can kinda be thought of as a stack of smaller jelly treats packed against each other.

When you push on the rod you’re mashing the jelly of your hand into the jelly of the rod, this causes a shockwave that begins to spread, it propagates like a ripple in a skipping rope or a bounce on a trampoline. But since it’s moving ‘amount of electron like properties here’. That makes some areas more negatively charged which drags the positively charged atom cores slowly after it. It moves much slower than the speed of light as we aren’t considering individual electrons which can move energy between them via photons, but the propagation of a disturbance in the collective arrangement of many that are tightly linked (we say coupled).

We can’t imagine a stick that is perfectly rigid because we would be proposing a kind of matter that does not exist, one which isn’t made of a lot of fuzzy electron jelly stuff but something else entirely. We can imagine matter where the jelly is very stiff, and consequently less energy goes into wobbling it all about and the squish moves forward very fast but that speed is still much slower than light because of this collective behaviour.

I don’t know why you are pretending to have physics knowledge when you very obviously do not have an education in it. What do you get out of pretending to be an expert on the internet? There’s no reward for it.

• Aceticon BcS Applied Bullshit

My mistake, that’s why sound travels at the speed of light.

It’s just not useful to talk about this at the level of the standard model. We are interested in the bulk behaviour of condensed matter, the fact of the matter is that you will not be able to tell that the other end of the stick has been touched until the pressure wave reaches the end. It doesn’t matter if individual force carriers are moving at the speed of light because they are not moving in a single straight line. You are interested in the net velocity.

Wikipedia isn’t a textbook. Don’t overcomplicate shit and mislead people because you’ve spent a few hours browsing particle physics articles stoned.

As it so happens the way the atoms push each other is electromagnetism, in other words sending photons (same thing light is made of) to each other but these photons are not at visible wavelengths so you don’t see them as light.

Wat? I strongly believe you are not correct. Which is to say, I think you are talking out of your arse entirely. If you push on a thing you peturb the electron structure of the material. These peturbations propagate as vibratory modes modeled as phonons.

While technically some of this energy is emitted as thermal radiation that is not primarily where it goes. And phonons themselves propagate at a slower rate than the speed of light, a significantly slower rate. Like a million times slower.

the OG Nazis were dumb as bricks lmao. Weird nerds with massive egos half of which believed in magic.

Western democracy turning to the fascism which our forebeears helped defeat wasn’t on my bingo card.

The most annoying thing is the commies 100 years ago being right about this lmao. I certainly had to revisit some of my assumptions when a lot of leftist theory predicted the declines we’ve been seeing.

mandatory minimum sentencing is a completely fucked up knee jerk reaction. The government does sweet FA to tackle Nazis because half of Parliament is sympathetic to them, then decide to earn some quick PR by interferring with the court system and lending legitimacy to an extremely blunt instrument primarily used to lock up indigenous kids.

edit: no actually fuck this. Anti hate speech laws were only really updated for this shit a year ago (tells ya something huh), there literally hasn’t been time to test if the courts are just throwing Nazis back out onto the street with a slap on the wrist. Gaol is basically never good and the idea of punishing someone disproportionately as a warning to others is completely unjust. MMS is largely used in Australia to fuck up children and Aboriginal Aussies, the police still have to actually charge people and since they’re sympathic to fascism laws get applied unjustly.

LGBT people face vilification like actual eugenics enforced by the state until last year for trans people in NSW, murder by cops until quite recently that was never investigate, expulsion from private schools (students recently protected I think, teachers not) but faith groups get immunity to existing hate speech laws. The government doing this is in favour of completely ludicrous and fashy anti protest laws, and directs an increasingly militarised police state to spend most of their effort fabricating evidence against climate protestors while intelligence agencies scream into the void about a rising tide of fascism.

Mins himself (large pusher for this from nsw) is an enthusiastic supporter of ethnic cleansing in occupied Palestine. This is not an anti fascist measure from any sort of coherent platform. It is a stupid kneejerk reaction that will do nothing to actually stop facist (remember, they are very good at dog whistles) from a government that has no interest in stemming the tide of fascism.

Bullshit totalitarian cruelty doesn’t start being good because it’s used against people you hate sometimes, that just legitimises bullshit totalitarian cruelty and provides cover. Fuck this law, fuck this government.

We do have to ask if Malthusians are really people…

I’d donate my body to a Tanner. Cows can’t make this choice in a we can understand at least.

Jokes like this make me uncomfortable :( there’s legit eco fash positions like this. Invasive species rhetoric is bad applied to all species imho, because killing children for some sort of inherited sin seems unreasonable to me.

“portable handheld”, look inside, gaming laptop without a keyboard.

K

I strongly suspect you have some wires crossed. There have been some attempts at simulating brains but I think a fruit fly is partially done and it’s making a fair few assumptions.

It’s pretty straightforward to completely replicate the behavior of e.g. a house fly in software

Could you provide an example of a complete housefly model?

orders of magnitude soz

physics causes brainrot and everything becomes OOM

Also interesting: If you were to take your nerves out and lay them end on end you would die.

Spices. Very much spices. If I was limited to like 5 good ones I’d make do but I have a drawer with like 50 spices in it I use regularly and it’s my happy place.