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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?

#61

Post by phkahler »

qqqqquinnnnn wrote: post #15
epmaybe wrote: post #10

Earlier quoted context omitted.

Are you talking epigenetics? It's relatively closely related to mendelian inheritance. At a high level view, if genes are present in your genome that aren't "on" in a previous generation, but due to changes in behavior become more active, then in a future generation that gene could be expressed more. It's not that the genes have changed their code, they are just flipped on or off.

No, more things that are modifications without any genetic basis - like myopia. Doesn't seem to have any genetic/epigenetic basis. It's purely a physical use case, where the eye matures improperly if it's only exposed to near-field work.

One hypothesis: kids learn to do what their parents do. If near field work or hobbies cause the problem then it follows that some kids will "inherit" it through mimicry.

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

#62

Post by TheodolphusRose »

ramboldio wrote: post #55

Fourier Transforms. I'd wish I had a intuitive understanding of how they work. Until then I'm stuck with just believing that the magic works out.

3blue1brown has a great video on the topic: https://youtu.be/spUNpyF58BY

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

#63

Post by npr11 »

Automatic differentiation. It's useful to so much computational work, but most people only get a cursory introduction to the topic (a rough intro to the minimum they need to know), whereas really understanding it seems to open up a lot of research.

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

#65

Post by ben0x539 »

qubex wrote: post #56

I find most explanations of the Equivalence Principle that lies at the foundation of General Relativity to be very lax. To wit, the idea is that you cannot distinguish whether you are in an accelerated frame or in a gravitational field; alternatively stated, if you’re floating around in an elevator you don’t know whether you’re freefalling to your doom or in deep sideral space far from any gravitational source (thoug…

I'm gonna assume that for purposes of the thought experiment you're supposed to envision a point-shaped elevator, not one where you can place two baseballs next to each other.

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

#67

Post by ironmagma »

qubex wrote: post #56

I find most explanations of the Equivalence Principle that lies at the foundation of General Relativity to be very lax. To wit, the idea is that you cannot distinguish whether you are in an accelerated frame or in a gravitational field; alternatively stated, if you’re floating around in an elevator you don’t know whether you’re freefalling to your doom or in deep sideral space far from any gravitational source (thoug…

I think the elevator scenario is imagining that the earth is a point source, and you are neglecting the (much smaller) gravitational forces for the sake of illustrating a more general phenomenon.

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

#68

Post by pjungwir »

Quantum 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?

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

#70

Post by phkahler »

raverbashing wrote: post #43
wesammikhail wrote: post #34

Earlier quoted context omitted.

Is there really no intuitive way to communicate the answer to that question without needing 10 years of grad math? I find that to be somewhat hard to believe

Well, the answer is "simple": It's because the modularity theorem was proven (or better, the Tanyiama-Shimura conjecture was proven) But why that solves the problem? Because it connects two branches of mathematics (modular forms and elliptic equations) in a way that proves that equations of that form cannot exist (where the exponent is > 2) Though there probably is an easier way of explaining it, it is strongly suspe…

I still like the idea that Fermat had a legit proof and that one day a simpler one will be found.

I also like that FLT follows easily from the Beal conjecture, which seems overlooked. Maybe its overlooked because its closely related to some other (harder to understand) conjectures.

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