When does classical physics start to break down? Is there an

>>8865394
Ignore any signs of retardation that I probably displayed in the OP.

By macrophysics I mean something like the complement of Quantum Mechanics. Universal set - QM where QM is the collection of all formulas and ideas (feynman diagrams and shit related to that) that describe physics at that level.

The physical limit of computer processors is reached when they become so thin that electrons become able to tunnel outside of their intended paths.

So I would assume that is the limit of classical physics.

>>8865402
That's mostly why I'm asking this. It was the first time I noticed IRL that classical physics can't describe anything and that QM has a real effect on us.

So what's that point exactly? individual electrons / photons that are modeled individually instead of treating them as groups?

that's what quantum means to me at least, an unit, it would make sense if QM was just about the behavior of individual photons / electrons and other shit like (don't laugh please) quarks, leptons and whatever else is out there

>>8865394
You're using good enough terminology. In thermodynamics or statistical mechanics, there's a concept known as the quantum concentration. Its the number of cubes with a side length equal to the DeBroglie wavelength ( essentially the particle-wavelength ) that would occupy a unit volume. If the concentration of particles is near the quantum concentration, then that means that the particles are close enough together that their wavelike-nature is dominating their interactions. So, if (normal concentration)/(quantum concentration) ~ 1 , then you need to use quantum mechanics.

Or, way simpler to say, whenever the scale of what you're working with is near the wavelength of the particles. Alternatively, literally anything to do with energy transitions in any sort of molecule or atom is going to require quantum as well.

>>8865416
The word "quantum" itself is just in reference to having discrete units of things. And that's what quantum is.

You have discrete units of energy rather than as little or as much or however much you like. Electrons orbiting the nucleus can only have certain, set amounts of energy - little packets. And those little packets are called "quanta", and in the case of light, the basic packet of light-energy ( and all electromagnetic rays) is the photon.

>>8865418
That's just amazing. The visual image that what you said creates. I'm sure it's a really dumbed down version probably but it makes me really curious to see what it's really about, mathematically.

Is it really that simple? I'm talking about the ratio you've mentioned. normal / quantum ~ 1.

But don't very long wavelengths exist? For example, for radio at 3kHz the wavelength is 100km (had to google this). I mean, surely you can model anything at that scale with "normal" physics.

Does "wavelength" in your post imply something else, something more basic and low level?

>>8865425
I see.

Is it all some kind of multi-dimensional field where every point has a probability associated with it? A probability for position and other properties. Or is this explanation way too simple?

Does QM imply a lot of probability? a lot of calculus? I wonder what it's like, mathematically. I heard that the 1+2+3+...=-1/12 meme is actually very relevant in QM and describes some behavior regarding virtual particles.

>>8865394
I think when you can not apply Isaac Newton's laws of classical physics of subatomic observed phenomenon.

>>8865442
>I heard that the 1+2+3+...=-1/12 meme is actually very relevant in QM

It is used in QFT. But then again pretty much half of everything you do in QFT is various tricks to cancel out divergences.

>>8865402
That's a great way of understanding it

>>8865425
so... we're NOT living inside of a computer? are we sure about that? because it makes it sound like we're living inside of s computer

>>8865463
thank you for your responses so far! very informative


I thought about it, It has to be true in some mathematical context. Can you tell me what is the context in which a 1+2+3+... sum is treated as being equivalent to -1/12? is it the same context in which the result is obtained in mathematics? cesaro summing, riemann zeta, stuff like that? or is it only kind of similar? is it exactly the same mathematical context if you could call it that? or does it "just work"?

>>8865484
It is a Complex Analysis thing, an analytic continuation of the Riemann Zeta function.

>>8865484
https://www.youtube.com/watch?v=w-I6XTVZXww

not bait I promise

>>8865394
The point where classical physics broke down was called the Ultraviolet Catastrophe. From what i remember about it, classical physics did not account for black bodies being able to radiate energy and therefore would just infinitely absorb energy, so a new concept was investigated by Planck with his photons and such.

>>8865394
look up photoelectric effect and ultraviolet catastrophe.