Okay so a person I talk with counters literally any possible argument with what boils down to "well quantum mechanics...

okay so a person I talk with counters literally any possible argument with what boils down to "well quantum mechanics disproves causality so you're wrong" (no, none of those arguments started as anything related to quantum mechanics)

I very much doubt that's true but I don't understand quantum mechanics and looking it up in wikipedia has made me understand it is too complicated to learn by skimming a wikipedia article. please summarize this for me, how crazy is quantum mechanics?

It isn't true
The person you talk to is what is known as a pseudo-intellectual pretentious brainlet
It is the equivalent of saying something like
>yeah well reality isn't real, so your wrong!

Some things start a lot of debate and cause a lot of confusion. There are also a lot of interpretations which are different. A lot of people just don't like it--nature being inherently probabilistic gives people the wiggins. Moreso than other courses, when you first learn it, you kind of have to just roll with it. You learn to DO quantum mechanics first. All this to say that you don't have to like it and you don't have to understand it on a deep level. You just have to accept that it is powerful and here to stay.

Alternatively you could smash his head with a hammer and say "since there is no causality, I couldn't have possibly harmed you"

First of all, what is true on the quantum scale doesn't apply to the macro scale. Second, he's confusing causality with determinism.

Quantum mechanics does not disprove either causality or determinism.

Not only that completely false, the opposite is true. It's called microcausality and it appears in QFT.

>Classic causality
>Events lead to specific other events

>Quantum mechanics causality
>Events lead to well-defined distributions of possible outcomes, systems are in well-defined distributions of possible states

Yeah, no. Causality is perfectly intact.

do you understand you didn't actually answer the question? I'm reading your post for the third time and I'm still not sure it even says anything at all.

Talking to humans outside of your professional interest and sexual relations is a meme anyways. You're the brainlet.

What answer did you want? Hit the reply button and type it out.

Your friend is a retard.
Tell him that special relativity is built on an assumption of causality and that both theories play nice together.

QM is one of two leading ways of thinking in modern physics (the other being General Relativity). It deals with very small objects such as photons, electrons, protons, neutrinos, you name it. It turns out that very small objects do not behave in the same way as large "classical" objects that you experience in your everyday life.
The key to this understanding is the Heisenberg Uncertainty Principle (HUP) whoch states that the wavelike or particle-like properties of an object are determined by their position, momentum, energy and time. The first two are more intuitive, so let's focus on them,
The more precisely an object's momentum is known (another way of saying how "confined it's EIGENFUNCTIONS are to a certain range of values) the less precisely its position can be known, and vive versa: DxDp

Bell's Theorem disproves determinism

>determinism (which is refuted by QM on SMALL scales
elaborate on this

*meant to say enough position uncertainty to behave like a wave

Determinism is the idea that a single action can only produce a single result. It is a specific case of the more general causality which simply states that a result requires an action.
On small scales, where the effects of QM apply, one case can lead to several different results, thus refuting determinism but preserving causality.

how does one thing lead to several results I am having trouble imagining that

No it doesn't. Many-worlds is perfectly compatible with Bell's theorem, and yet deterministic.

Let's not argue here about how sensible many world is. Whether you buy it or not, it DOES mean that Bell's theorem does not disprove determinism.

There are some outcomes that we cannot predict with 100% certainty regardless of how much information we have. This is another reason people are resistant to QM. That sounds pretty crazy.

To understand it properly, you need to do a course in linear algebra and QM, but I'll give it a go.
The act of measuring a system in QM is equivalent to applying a mathematical object, called and OPERATOR, to an equation. In linear algebra, you study matrices which have things called EIGENFUNCTIONS. There can be several different eigenfunctions for a sinlg e matrix.
If we call the matrix M, an eigenfucntion V and and eigenvalue a, then we have:

MV = aM

So the application of the matrix to one of its eigenfunctions "turns" the eigenfunction into the integer number, called the eigenvalue.
Now, as I said before, a matrix can have several eigenfunctions, and there can be several eigenvalues associated with any given eigenfuntion, so there are many combinations you can get.
If you imagine yourself measuring a system, then you apply an operator, which serves the same purpose as the matrix above, to an object which serves the purpose of the eigenfunction (in QM also referred to as the WAVEFUNCTION), and you may get several different eigenvalues, which are the measurements you receive back.
So you want to find out and electron's energy around an atom, you apply the energy operator, and you "collapse" the wavefunction (a range of probabilities) into one single value, which henceforth is the energy the electron has.
So ultimately, one action (applying the operator, or measuring the object) can lead to several different results from wavefunction collapse.

>The act of measuring a system in QM is equivalent to applying a mathematical object, called and OPERATOR, to an equation.
Do you still live in the 1960s? Because that's about how dated this view of quantum mechanics is.

Bell's theorem virtually rules out all local hidden variable theories of QM

>Do you still live in the 1960s
No, but I was explaining it to someone who has no idea about QM. Nice attempt at belittling someone.

kek

>implying reality is real

>Talking to humans outside of your professional interest and sexual relations is a meme
wait wtf this is true. why am i now just realizing?

do quantum eraser experiments imply anything about causality?

>implying implications are real

This!