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Ask HN: What scientific phenomenon do you wish someone would explain better?

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Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#751

Post by gigama »

__sy__ wrote: post #217
arkanciscan wrote: post #173

Quantum Computers. Not like I'm five, but like I'm a software engineer who has a pretty decent understanding of how a classical turing machine works. I can't tell you how many times I've heard someone say "qubits are like bits except they don't have to be just 1 or 0" without providing any coherent explanation of how that's useful. I've also heard that they can try every possible solution to a problem. What I don't u…

Since no one has listed it yet, please check out https://quantum.country/ It's by Andy Matuschak and Michael Nielsen, and it is excellent. Have fun!

upvoted

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#752

Post by klmadfejno »

mda wrote: post #342
klmadfejno wrote: post #269

Earlier quoted context omitted.

https://www.smbc-comics.com/comic/the-talk-3 The basic gist I get is that quantum computing, for a very specific set of problems, like optimization, let's you search the space more efficiently. With quantum mechanics you can associate computations with positive or negative probability amplitudes. With the right design, you cause multiple paths to incorrect answers to have opposite amplitudes, so that interference cau…

I found the comic not very good either. Kid suddenly blurts "Wait a minute, that means a qubit corresponds to a unit vector in 2 dimensional Hilbert space" Yeah.

Not quite what I meant. I think the comic is excellent. In case its not painfully obvious, the joke is equating lay people's poor understanding of quantum mechanics to a child's misunderstanding of sex. It's not trying to dumb down the concept of quantum computers at all, it's just trying to point out how incorrect how dumb pop science simplifications of it are. The 'qubits are bits with a range of value between 0 and 1 that use quantum magic to test all possibilities at once' is utter fiction.

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#753

Post by carapace »

bunya017 wrote: post #656

Asynchronous programming With the addition of async to django core, I felt its time to finally learn the concept. I first took interest in async early last year when I re-read a medium post on Japronto; an async python web framework that claims to be faster than Go and Node. Since then, I've been on the lookout for introductory posts about async but all I see is snippets from the docs with little or no modifications…

"async" is BS. You can't smear concurrency over your systems like Nutella.

Read "Communicating Sequential Processes" by Tony Hoare https://www.cs.cmu.edu/~crary/819-f09/Hoare78.pdf

There's also a book: http://www.usingcsp.com/

See also https://en.wikipedia.org/wiki/Process_calculus

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#754

Post by sideshowb »

marcosdumay wrote: post #737
sideshowb wrote: post #677

Earlier quoted context omitted.

So in this case the business did not create as much wealth as intended (it produced apples which turned out not to be needed as much they had originally planned). The default is a side effect of that outcome, not its cause.

Could you not see the $4 disappearing on the GP scenario?

I can see that the bank ended up with $4 less than it planned to, but I don't see that as money being destroyed. It happened because the original estimate of hypothetical dollars was wrong. (Also if the hypothetical dollars are "money" then you're double counting it: creating $10 in circulation has required creating $17 overall which strikes me as poor notation to say the least). (Also if all had gone according to plan, the extra $4 would have come from the pockets of people buying apples. That $4 is still in circulation, either in the same pockets or it got spent elsewhere).

Suppose I buy a painting. I believe it to be an original Van Gogh so I pay $10 million for it. I then find out it is fake, and worthless. Was $10 million (of money) destroyed? Of course not, I just mis-valued an asset. Suppose it then turns out to be real after all. Owing to the fascinating history of this painting it is now valued at $20 million. Was $10 million of money created (relative to the moment when I originally thought it was a Van Gogh)? No. Was $10 million of wealth created? Yes as the world now has one more thing worth $10 million in it.

Money != wealth, even in the materialist sense where wealth consists purely of goods and services. Money is a metric we use to keep track of wealth, and in general it's considered helpful if that relationship holds, so if we're trying to maintain that relation rigorously the central bank should print another $10 million (or create it by making loans) to reflect our knowledge and appreciation of the Van Gogh - if it doesn't then the existing fixed quantity of money in the system will now be representing a greater quantity of wealth, causing deflation.

As I said in my other post I am not an economist by training. If the economists want to call this thing that got created/destroyed here "money" then I guess I should let them, but I would like to hear a good reason why it makes sense to do so, and I haven't heard one. Absent of a good reason I might as well call it haddock. Or, considering the OP was asking which things that could be explained better, we could acknowledge what any good programmer knows: part of a good explanation is choosing the right names for things.

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#755

Post by lisper »

madhadron wrote: post #730
lisper wrote: post #725

Earlier quoted context omitted.

A spinor is a vector. It's not a vector in 3-D space, but that's true of all quantum state vectors, not just spinors.

The way the OP was using vector implied a 3D Gibbs-Heaviside vector, not an element of an arbitrary vector space.

Hogwash. Here is the full context:

> Is it a magnitude or a vector?

Of those choices, vector is clearly the more correct one.

Here is what a constructive response would have looked like:

"Lisper is correct when he says it's a vector and not a "magnitude" (the more common term is "scalar"), but there is an important subtlety: it is not a vector in 3-D space. Instead it is something called a spinor (https://en.wikipedia.org/wiki/Spinor) which is a kind of vector, but behaves differently than vectors in 3-D space in some important ways. For example, if you rotate a spinor 360 degrees you do not get back the same spinor you started with. You have to rotate a spinor 720 degrees to get back to where you started.

And in fact if you really want to get into the weeds, in the mathematical formalism of QM these are actually things called "rays" in something called a "Hilbert space" but no one cares about that, not even physicists, which is why all physicists refer to these things as "state vectors" rather than "state rays" even though there are some formal differences between vectors and rays. But only people who want to publicly exhibit their superior knowledge (as opposed to engaging in effective pedagogy) would ever bring up such trivial details."

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#756

Post by 0xff00ffee »

izuchukwu wrote: post #729
0xff00ffee wrote: post #372

Earlier quoted context omitted.

Short answer: there isn't an easy answer. Yet. (Give QC another 50 years). Proof? Just look at all the replies you got: each one is dozens of pages of complex (imaginary) math, control theory, and statistics. The hardest part of QC is exactly what you described: how to extract the answer. There is no algorithm, per se. You build the system to solve the problem. This is why QC is not a general purpose strategy: a quan…

This feels like the high-level missing piece in my understanding of its use. Do you know any resources that expand on QC’s effective potential more from this point of view?

Sorry, I do not.

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#757

Post by carapace »

Waterluvian wrote: post #679
Balgair wrote: post #420

Earlier quoted context omitted.

Correct. Mold will grow where there is food for it to grow, like bread. It will divide and grow exponentially, up to a point. That fact of exponents where they seem slow at first and then really rocket away? That's why mold seems to just appear overnight.

So it might be a fair statement to say that when I eat fresh bread there's already a molecular amount of mold already on it?

There's a molecular amount of mold already on everything. Mold spores are ubiquitous.

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#758

Post by lisper »

madhadron wrote: post #731
lisper wrote: post #706

Earlier quoted context omitted.

Because the difference between a ray and a vector is so minor that the words are effectively interchangeable, and in actual practice the word "vector" is invariably used. No one ever talks about the "quantum state ray." It is always the "quantum state vector." Also, simply saying "no it isn't" with no further explanation in response to any comment just obnoxious. It's essentially saying, "You're wrong, and I know why…

> anyone who does it deserves to be smacked down hard I was trying to hint that there was something you were overlooking in your explanation. Probably not an effective tactic in this medium. But thanks to your fine example, I will in future make sure to lay out things in exquisite detail while belittling the person I am replying to.

No, I hadn't overlooked it. I was providing an answer appropriate to the audience and the context. And that answer was actually correct. Not only was your answer not constructive, it was also flat-out wrong.

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#759

Post by mistermann »

vmception wrote: post #694
mistermann wrote: post #489

Earlier quoted context omitted.

> But when nobody knows what they're actually getting because it doesn't exist in a legal framework , then it muddies the whole experience. Trust (knowing the chemist directly, indirectly, ...) in specific individuals > a largely unknown (but known to be imperfect) system, for many people anyways. Obviously this isn't practical for the not well connected, but it's all we got for now. But as for your question, I've se…

yes this is my current predilection, but I can also concede that there are limitations in getting the truth of the matter. even in this very thread there is someone that has been in the mental hospitals and seen problems "with their own two eyes", but is unwilling to name names as part of a code to remove any social/legal/professional consequence for themselves or the " crazy " people there

Dipping ones toes in the water is always an option, but I heard a rumour psilocybin is the safer route, due to less likelihood of illegitimate product.

If you live in a big enough city, there should be meetup groups where you could meet some people and have long discussions.

Is your interest only curiosity, or is it medical related? Sorry, on mobile and pressed for time so can't scroll through the thread..

Re: Ask HN: What scientific phenomenon do you wish someone would explain better?

#760

Post by yters »

cambalache wrote: post #740
yters wrote: post #693

Earlier quoted context omitted.

I will have to check them out, but I remember being unimpressed with the table of contents. Looks like it will be more handwaving.

Ah OK, you are not being serious, fair enough. Magic god did it all.

I am being serious. I just purchased Dawkin's book "Blind Watchmaker". My point is no explanation should amount to "magic X did it" whether X is god, evolution, the earth spirit, aliens, etc. All the above are bad explanations.

It is not scientific to substitute one bad explanation for another. The scientific approach is to say we don't know, and then look for a good explanation.

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