Haskell's Monads
Ask HN: What scientific phenomenon do you wish someone would explain better?
351–360 of 839 posts
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#352Law. How much of it rests on technicalities, and how much do judges care about the essence of the facts of a case? You only hear about the weird outcomes on the news. For example, I was once working with an attorney because my landlord didn’t supply heat in the apartment. I started keeping a temperature log, but how would a judge know that the log was accurate? Do I need to prove that my thermometer is accurate... et…
IANAL, but if your log was introduced in evidence in your suit, you would be attesting under oath it was correct to the best of your knowledge. If it later turned out you faked the data, that would be perjury. So it's the threat of punishment for perjury that motivates honesty in court.
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#353Earlier quoted context omitted.
Cells are tiny and the speed of sound is how fast air molecules move. Proteins are also not bouncing around as fast but it’s very still quick relative to their size. Next, often there are multiple copies of each component. That’s half the story, larger cells also have various means to clump things together to improve the odds. https://en.wikipedia.org/wiki/Endoplasmic_reticulum PS: Speed of sound is 343 m/s, diameter…
Speed of sound in water is faster.
Yep, and speed of sound is lower than the average speed of individual molecules. But, I was aiming for an intuitive understanding rather than accuracy involving brownian motion etc.
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#354When I hear explanations like “space is expanding like the surface of a balloon” it’s always confusing. Because a surface is an object, separate from anything on it, but space is the thing we’re all embedded in, so we’re like drawings on the balloon. If space is expanding why aren’t the radii of fundamental particles and their orbits and molecules also expanding? And if that were the case we couldn’t notice space exp…
> If space is expanding why aren’t the radii of fundamental particles and their orbits and molecules also expanding? And if that we’re the case we couldn’t notice space expanding. > Does space only expand somewhere else? Only between me and the Andromeda galaxy, and not _within_ me and the Andromeda galaxy? How would it know to do that? If you start with expanding space in general relativity, and then carefully take…
So molecules are like bits of glitter stuck to the surface of the balloon?
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#355* Lie algebras and Lie groups - I still don't understand this, what they're used for or how to use them in any practical sense. * Galois Theory - I have a basic understanding of abstract algebra but for some reason Galois theory confounds me, especially as it relates to the inability of radical solutions to fifth and higher degree polynomials * "State-of-the-art" Quantum Entanglement experiments and their purported s…
I think the best motivation for the theory of Lie groups and Lie algebras is representation theory. Like you don't need anything besides linear algebra to know what SO_n is, but if you want to know about how it can act on a vector space then you need to think about the Lie algebra.
The other great thing about Lie groups is you can discover new and valuable groups just from pretty basic topology. Like the Spin group, which you know has to be out there as soon as you know the fundamental group of SO_n, but otherwise would be very hard to think of.
The fancypants but I think most intuitive way to think about Galois theory is also with topology. It's an algebraic version of a much more geometric, visible story, the correspondence between {subgroups of the fundamental group} and {normal covering spaces}.
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#356How depression, autism and gender dysphoria work on a molecular level.
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#357Quantum spin. Electrons aren't really spinning, right? But why do we call it spin? I know it has something to do with angular momentum. What are the possible values? Is it a magnitude or a vector? Is there a reason we call it "spin" instead of "taste" or some other arbitrary name? How do you change it? What happens to it when particles interact?
> Electrons aren't really spinning, right? Correct. > But why do we call it spin? Because it is a physical quantity whose units are those of angular momentum, and we have to call it something . > What are the possible values? +/- h/4pi where h is Planck's constant. (It is usually written has h-bar/2 where h-bar is h/2pi.) > Is it a magnitude or a vector? It's a vector that always points in a direction corresponding t…
> It's a vector
It's not exactly a vector...
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#358Earlier quoted context omitted.
Did you try LSD after that time in your teens? I think it is a bit too reductive to say they're neutral, just yet, but I am willing to say they can be used responsibly if the right information actually existed - but like with any science I am open to changing that if the conclusions were found to be different. Again let's just stick with acid instead of all psychedelics.
I tried once or twice after that, both times it turned immediately into flashbacks and led to horrid experiences so I called it quits for good. I had done it probably ~20-25 times by that point, along with a bunch of other stuff. LSD Mushrooms 2C-B 2C-C 2C-I DMT 4-AcO-DMT 5-MeO-DMT 5-MeO-MiPT DOM There might be some others I've forgotten, it's been a long time. > Again let's just stick with acid instead of all psyche…
> Though most people (when I was in that scene as a teen) couldn't really empathize after my bad trip because they'd never had one, so it's a rare occurrence.
Yeah this is another thing I've seen.
Online there are lots of stories of "bad trips", like this one.
In person its "what happened? I've never had a bad trip [so what's wrong with you]". It is very unscientific, and for the people that do empathize, it is very reductive to "bad trip". No discussion about PTSD. And then you can't talk to anybody else about it because they are illicit substances.
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#359Bell's theorem. It somehow proves that quantum physics is incompatible with local hidden variables, but I could never see an understandable explanation (for me at least) of just how it works.
I can recommend Ball's _Beyond Weird_ for the best explanation targeting a lay audience that I've read.
Re: Ask HN: What scientific phenomenon do you wish someone would explain better?
#360I would like to understand how cellular biology processes actually work. Like, how do all the right modules and proteins line up in the right orientation every time? Every time I watch animations, it seems like the proteins and such just magically appear when needed and disappear when not needed [0]. Sometimes it's an ultra-complex looking protein and it just magically flys over to the DNA, attaches to the correct sp…
I studied bioinformatics and found the standard textbook, Albert's "Molecular Biology of the Cell"[0] to be one of the most captivating books I've read. It's like those extremely detailed owners' manuals for early computers, except for cells.
The amount of complexity is just absolutely insane. My favourite example: DNA is read in triplets. So, for example, "CAG" adds one Glutamine to the protein it's building[1].
There are bacteria that have optimised their DNA in such a way that you can start at a one-letter offset, and it encodes a second, completely different, but still functional protein.
I found the single cell to be the most interesting subject. But of course it's a wild ride from top to bottom. The distance from brain to leg is too long, for example, to accurately control motion from "central command". That's why you have rhythm generators in your spine that are modulated from up high (and also by feedback).
Every human sensory organ activates logarithmically: Your eye works with sunlight (half a billion photons/sec) but can detect a single photon. If you manage to build a light sensor with those specs, you'll get a Nobel Prize and probably half of Apple...