Comment by jve
2 days ago
I don't know if I have critical thinking or not. But I often question - WHY is this better? IS there any better way? WHY it must be done such a way or WHY such rule exists?
For example in electricity you need at least that amount of cross section if doing X amount of amps over Y length. I want to dig down and understand why? Ohh, the smaller the cross section, the more it heats! Armed with this info I get many more "Ohhs": Ohh, that's why you must ensure the connections are not loose. Oohhh, that's why an old extension cord where you don't feel your plug solidly clicks in place is a fire hazard. Ohh, that's why I must ensure the connection is solid when joining cables and doesn't lessen cross section. Ohh, that's why it's a very bad idea to join bigger cables with a smaller one. Ohh, that's why it is a bad idea to solve "my fuse is blowing out" by inserting a bigger fuse but instead I must check whether the cabling can support higher amperage (or check whether device has to draw that much).
And yeah, this "intuition" is kind of a discovery phase and I can check whether my intuition/discovery is correct.
Basically getting down to primitives lets me understand things more intuitively without trying to remember various rules or formulas. But I noticed my brain is heavily wired in not remembering lots of things, but thinking logically.
We don't have enough time to go over things like this over and over again. Somebody already analyzed/tried all this and wrote in a book and they teach you in school from that book how it works and why. Yeah if you want to know more or understand better you can always dig it out yourself. At least today you can learn tons of stuff.
We don't have enough time to derive everything from first principles, but we do have the time to go over how something was derived, or how something works.
A common issue when trying this is trying to teach all layers at the same level of detail. But this really isn't necessary. You need to know the equation for Ohms law, but you can give very handwavy explanations for the underlying causes. For example: why do thicker wires have less resistance? Electricity is the movement of electrons, more cross section means more electrons can move, like having more lanes on a highway. Why does copper have less resistance than aluminum? Copper has an electron that isn't bound as tightly to the atom. How does electricity know which path has the least resistance? It doesn't, it starts flowing down all paths equally at a significant fraction of the speed of light, then quickly settles in a steady state described by Ohm's law. Reserve the equations and numbers for the layers that matter, but having a rough understanding of what's happening on the layer below makes it easier to understand the layer you care about, and makes it easier to know when that understanding will break down (because all of science and engineering are approximations with limited applicability)
Oh you put this nicely.
> How does electricity know which path has the least resistance? It doesn't, it starts flowing down all paths equally at a significant fraction of the speed of light, then quickly settles in a steady state described by Ohm's law.
> because all of science and engineering are approximations with limited applicability
Something I heard but haven't dig into, because my use case (DIY, home) doesn't care. In some other applications approximation at this level may not work and more detailed understanding may be needed :)
And yeah, some theory and telling of things others discovered for sure needs to be done. That is just the entry point for digging. And understanding how something was derived is just a tool for me to more easily remember/use the knowledge.
Are you being serious or is this satire? What an odd perspective to share on Hacker News. We're a bunch of nerds that take pleasure in understanding how things work when you take them apart, whether that's a physics concept or a washing machine. Or am I projecting an ethos?
Are we hackers? I see posters griping about the pointlessness of learning CS theory and other topics during their college on HN all the time.
No you’re not projecting they’re being weird.