Ask Lemmy
A Fediverse community for open-ended, thought provoking questions
Rules: (interactive)
1) Be nice and; have fun
Doxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them
2) All posts must end with a '?'
This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?
3) No spam
Please do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.
4) NSFW is okay, within reason
Just remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either [email protected] or [email protected].
NSFW comments should be restricted to posts tagged [NSFW].
5) This is not a support community.
It is not a place for 'how do I?', type questions.
If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email [email protected]. For other questions check our partnered communities list, or use the search function.
6) No US Politics.
Please don't post about current US Politics. If you need to do this, try [email protected] or [email protected]
Reminder: The terms of service apply here too.
Partnered Communities:
Logo design credit goes to: tubbadu
view the rest of the comments
Reading a book that explains a book I don't understand and failing to understand either at the end.
Sounds like at least one of the books in question is shit
Or the subject matter is advanced.
I've read a lot of material on quantum physics and it's still mostly word salad to me.
A lot of people who present quantum mechanics to a laymen audience seem to intentionally present it to be as confusing as possible because they like the "mystery" behind it. Yet, it is also easy to present it in a trivially simple and boring way that is easy to understand.
Here, I will tell you a simple framework that is just 3 rules and if you keep them in mind then literally everything in quantum mechanics makes sense and follows quite simply.
If you keep those three principles in mind, then everything in quantum mechanics follows directly, every "paradox" is resolved, there is no confusion about anything.
For example, why is it that people say quantum mechanics is fundamentally random? Well, because if the universe is deterministic, then all outcomes have either a 0% or 100% probability, and all other probabilities are simply due to ignorance (what is called "epistemic"). Notice how 0% and 100% have no negative or imaginary terms. They thus could not give rise to quantum effects.
These quantum effects are interference effects. You see, if probabilities are only between 0% and 100% then they can only be cumulative. However, if they can be negative, then the probabilities of events can cancel each other out and you get no outcome at all. This is called destructive interference and is unique to quantum mechanics. Interference effects like this could not be observed in a deterministic universe because, in reality, no event could have a negative chance of occurring (because, again, in a deterministic universe, the only possible probabilities are 0% or 100%).
If we look at the double-slit experiment, people then ask why does the interference pattern seem to go away when you measure which path the photon took. Well, if you keep this in mind, it's simple. There's two reasons actually and it depends upon perspective.
If you are the person conducting the experiment, when you measure the photon, it's impossible to measure half a photon. It's either there or it's not, so 0% or 100%. You thus force it into a definite state, which again, these are deterministic probabilities (no negative or imaginary terms), and thus it loses its ability to interfere with itself.
Now, let's say you have an outside observer who doesn't see your measurement results. For him, it's still probabilistic since he has no idea which path it took. Yet, the whole point of a measuring device is to become statistically correlated with what you are measuring. So if we go to rule #3, the measuring device should be entangled with the particle, and so we cannot apply the quantum probabilities to the particle itself, but only to both the particle and measuring device taken together.
Hence, for the outside observer's perspective, only the particle and measuring device collectively could exhibit quantum interference. Yet, only the particle passes through the two slits on its own, without the measuring device. Thus, they too would predict it would not interfere with itself.
Just keep these three rules in mind and you basically "get" quantum mechanics. All the other fluff you hear is people attempting to make it sound more mystical than it actually is, such as by interpreting the probability distribution as a literal physical entity, or even going more bonkers and calling it a grand multiverse, and then debating over the nature of this entity they entirely made up.
It's literally just statistics with some slightly different rules.
That's a helpful perspective. I appreciate it.
I still have a lot of work on the underlying math because I didn't put in near the effort I should have in any of my actual classes, but I do genuinely want to get over the hump.
Right, I was expecting the earlier one to be a work of fiction
I'll agree with that. Convoluted nonsense for the sake of being convoluted is very rarely good writing. There's some stuff with more complexity and longer developing story-lines, but the minute to minute reading should still flow even if you don't see how the big picture is going to develop.
No no philosophy :(
You're not dumb if you fail to understand a book of philosophy. Very few are as straightforward as Das Kapital for example.