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Infinite Grid of Resistors

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Re: Infinite Grid of Resistors

#31

Post by pixl97 »

staplung wrote: post #29
pixl97 wrote: post #21

Earlier quoted context omitted.

Thats what I'm not sure about here... If we assume this is an infinite grid in its own universe then nothing can actually move. The gravitational pull should be the same from every direction. If we assume the grid is perfect then there is no nucleation sites to start a collapse. The grid would be in perfect balance. The same is thought about our universe. If there hadn't been small quantum fluctuations during the inf…

In fact, we might have a different problem: dark energy should tear the grid up into (very large) bits. I guess the question is then would the bits then collapse into black holes or not. I assume so since the mass would not longer be perfectly balanced.

Guess we'll have to wait for an actual answer on dark energy and universal expansion.

What it collapses into depends on the time for the bits to coalesce into. If it's a slow collapse you could get a mass large enough to form a neutron star (like thing) instead of black holes.

If those neutron stars crash into each other they can release a large amount of 'recycled' matter from all over the atomic spectrum back into this universe.

Re: Infinite Grid of Resistors

#33

Post by temp0826 »

inopinatus wrote: post #16
corysama wrote: post #6

Earlier quoted context omitted.

They say hydrogen is an odorless colorless gas which, in sufficient quantities, given enough time, turns into people. I’m sure the same could be true of resistors.

People are resistors too.

I resist that statement

Re: Infinite Grid of Resistors

#35

Post by causality0 »

My math isn't strong enough to follow the whole article, but my intuition as someone who works in electronics is that when a quantized system interacts with an infinity, the infinity is restricted based on the magnitude of the quantized factor. Electric charge is quantized. Less than one electron cannot pass through a node, therefore an infinite grid of resistors is effectively a finite grid of resistors whose size changes based on how much charge is dumped into the system.

Re: Infinite Grid of Resistors

#36

Post by nerdsniper »

sandworm101 wrote: post #20
neepi wrote: post #3

I'm a bit mathematician and a bit electrical engineer. The electrical engineer suggests it's not measurable unless you apply current and also asks "when" after the current is applied referring to the distributed inductive and capacitive element and the speed of field propagation. The mathematician goes to a bar and has a stiff drink after hearing that.

And the electrician knows he can get a 99% answer out of a 10x10 grid on a workbench. The engineer is free to then add more resisters to the periphery until either the grant money runs out or the physicist's publishing deadline approaches. A really difficult question: At each distance, what percentage of soldering errors in the grid can be tolerated before the fluke meter across the center square detects the fault? (…

For measuring corrosion in conductive surfaces, “eddy current” testing is often used. It uses AC current of some frequency, so it’s technically measuring inductance rather than resistance.

Re: Infinite Grid of Resistors

#37

Post by bsder »

steamrolled wrote: post #18

I don't get why EE education emphasizes problems of this sort. The infinite grid is an extreme example, but solving weirdly complicated problems involving Kirchoff's laws and Thevenin's theorem was a common way to torture students back in my day... Here, I don't think it's even useful to look at this problem in electronic terms. It's a pure math puzzle centered around an "infinite grid of linear A=B/C equations". Not…

> I don't get why EE education emphasizes problems of this sort

Last I checked, they don't. I certainly never hit an "infinite grid of resistors" in general circuits and systems except as some weird "bonus" problem in the textbook.

Occasionally, I would hit something like this when we would be talking about "transmission lines" to make life easier, not harder. ("Why can we approximate an infinite grid of inductors and capacitors to look like a resistor?")

It's possible that infinite grid/infinite cube might have some pedagogical context when talking about fields and antennas, but I don't remember any.

Re: Infinite Grid of Resistors

#38

Post by dwattttt »

choonway wrote: post #25
steamrolled wrote: post #18

I don't get why EE education emphasizes problems of this sort. The infinite grid is an extreme example, but solving weirdly complicated problems involving Kirchoff's laws and Thevenin's theorem was a common way to torture students back in my day... Here, I don't think it's even useful to look at this problem in electronic terms. It's a pure math puzzle centered around an "infinite grid of linear A=B/C equations". Not…

There are two parts to education. One is to impart knowledge, the other is to filter the students.

You're missing general problem solving. If all people do is encounter problems they've already seen before, well, we have lookup tables for that kind of thing.

Re: Infinite Grid of Resistors

#39

Post by Workaccount2 »

steamrolled wrote: post #18

I don't get why EE education emphasizes problems of this sort. The infinite grid is an extreme example, but solving weirdly complicated problems involving Kirchoff's laws and Thevenin's theorem was a common way to torture students back in my day... Here, I don't think it's even useful to look at this problem in electronic terms. It's a pure math puzzle centered around an "infinite grid of linear A=B/C equations". Not…

One of my core grips with STEM education, mainly the math heavy part of it, which frankly is most of it, is that it is taught primarily by people who love math.

The people who loved application and practical solutions went to industry, the people who got off spending a weekend grinding a theoretical infinite resistor grid solution went into academia.

Re: Infinite Grid of Resistors

#40

Post by Nevermark »

choonway wrote: post #25
steamrolled wrote: post #18

I don't get why EE education emphasizes problems of this sort. The infinite grid is an extreme example, but solving weirdly complicated problems involving Kirchoff's laws and Thevenin's theorem was a common way to torture students back in my day... Here, I don't think it's even useful to look at this problem in electronic terms. It's a pure math puzzle centered around an "infinite grid of linear A=B/C equations". Not…

There are two parts to education. One is to impart knowledge, the other is to filter the students.

The third is to challenge students. With unusual concepts, preferably.

How else to create students capable of solving problems we cannot anticipate today?

Not to mention, that understanding strange problems is a very efficient way to broaden horizons.

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