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Why is electricity so hard to understand? (1989)

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Re: Why is electricity so hard to understand? (1989)

#61

Post by justifier »

nilkn wrote: post #56
justifier wrote: post #35

Earlier quoted context omitted.

From the linked notes: I never really understood capacitors until I started trying to construct proper water-analogies for them. Then I discovered that my electronics and physics classes had sent me down a dead-end path with their garbage about "capacitors store electric charge." Since my discovery, I've gained significantly more expertise in circuit design, which leads me to a sad thought. Maybe the more skilled of…

I still remember struggling with fractions when I was young. The funny thing is that I ended up majoring in math in college (at a highly ranked one at that), and I did very well, even publishing research in differential topology as an undergrad. How can someone who struggled to even grok fractions end up being successful in pure mathematics? I think it's because all my teachers operated off the assumption that kids c…

Your desired explanation also would prime kids for introduction to other similar number sets, like the complex plane.. easing understanding significantly in comparison to referring to them as 'imaginary numbers'

Re: Why is electricity so hard to understand? (1989)

#63

Post by geoka9 »

rubberstamp wrote: post #58
tantalor wrote: post #22

Earlier quoted context omitted.

Accounting in 8 steps, 1. Memorize this: Assets + Expenses = Liabilities + Capital + Income 2. Everything is positive, no negative numbers! 3. For every transaction, Total Debits = Total Credits 4. "Credit" is source of money, "debit" is destination of money 5. Assets and expenses increase with debits 6. Liabilities, capital, and income increase with credits 7. Expenses and income may only be increased (debited & cre…

shouldn't the cash be listed as capital instead of asset?

Capital is a liability (something you owe to investors). Cash is an asset.

When you receive capital in the form of cash, you debit your assets (cash) and credit your liabilities for the same amount (capital). It's "double-entry" accounting, total debits should equal total credits for every entry so that it balances out.

Re: Why is electricity so hard to understand? (1989)

#64

Post by justifier »

seiferteric wrote: post #49
justifier wrote: post #35

Earlier quoted context omitted.

From the linked notes: I never really understood capacitors until I started trying to construct proper water-analogies for them. Then I discovered that my electronics and physics classes had sent me down a dead-end path with their garbage about "capacitors store electric charge." Since my discovery, I've gained significantly more expertise in circuit design, which leads me to a sad thought. Maybe the more skilled of…

Not really sure I like that link. He seems to suggest that capacitors store "energy" instead of charge, which is just as ambiguous really. It's not like there is some sort of energy particle either. Of course what's really happening is that you are creating an electric potential between two plates. It's true that the net charge is the same, but you are moving electrons from one plate and forcing them (doing work) int…

i agree, I linked more for the similarity in experience between the gp and the author in regard their unlearning

I prefer your clarifications when considering the function of capacitors

That said, water does attract water.. the term used to describe the phenomena is cohesion

https://en.m.wikipedia.org/wiki/Cohesion_(chemistry)

Re: Why is electricity so hard to understand? (1989)

#67

Post by fzzzy »

bronlund wrote: post #6

In fact, it isn't so hard that they would like you to believe - it just seems that way when they remove the best parts due to national security :D You would have to go back to James Clerk Maxwell's original 20 equations to see what it's all about. Okey, quaternions are kind of hard, I'll admit to that, but all in all it makes much more sense.

I often think about how Maxwell's equations were simplified because quaternions were hard to deal with by hand. Heaviside reformulated them into calculus, which was easier work with and accurate enough for pretty much everything. But now that we have computers, which can trivially deal with quaternions, (probably even more easily than calculus) why don't we go back to using those formulae?

Re: Why is electricity so hard to understand? (1989)

#68

Post by JadeNB »

tantalor wrote: post #30
geoka9 wrote: post #29

Earlier quoted context omitted.

> "Credit" is source of money, "debit" is destination of money But it gets even more confusing when they say "we credited your account" or "your account was debited".

Yes, that is a prime source of confusion for those terms! The problem is all about perspective. From the perspective of the bank, your account is a liability , so when they deposit into it, then its value increases, hence "credit". When they say "your account" they actually mean "the account where we track how much money we owe you". From your business's perspective, your bank account is an asset , so when they depos…

> > But it gets even more confusing when they say "we credited your account" or "your account was debited".

> From your business's perspective, your bank account is an asset, so when they deposit into it, then its value increases, hence "debit".

But what you're describing (a business depositing money into your account) is not what I, as a non-business owner, understand by "your account was debited". Businesses with whom I do (well) business use this terminology to mean that they have removed money from my account. (I'm not arguing with you—I've probably just misunderstood your terminology, and am seeking clarification.)

Re: Why is electricity so hard to understand? (1989)

#69

Post by Animats »

nilkn wrote: post #56
justifier wrote: post #35

Earlier quoted context omitted.

From the linked notes: I never really understood capacitors until I started trying to construct proper water-analogies for them. Then I discovered that my electronics and physics classes had sent me down a dead-end path with their garbage about "capacitors store electric charge." Since my discovery, I've gained significantly more expertise in circuit design, which leads me to a sad thought. Maybe the more skilled of…

I still remember struggling with fractions when I was young. The funny thing is that I ended up majoring in math in college (at a highly ranked one at that), and I did very well, even publishing research in differential topology as an undergrad. How can someone who struggled to even grok fractions end up being successful in pure mathematics? I think it's because all my teachers operated off the assumption that kids c…

A practical impact of this - tool users from metric countries don't think in fractions. The notion that the next larger wrench after 1/8 is 5/32 is alien to people brought up with the metric system. Metric bolt heads are integral numbers of millimeters.

Re: Why is electricity so hard to understand? (1989)

#70

Post by nilkn »

Animats wrote: post #69
nilkn wrote: post #56

Earlier quoted context omitted.

I still remember struggling with fractions when I was young. The funny thing is that I ended up majoring in math in college (at a highly ranked one at that), and I did very well, even publishing research in differential topology as an undergrad. How can someone who struggled to even grok fractions end up being successful in pure mathematics? I think it's because all my teachers operated off the assumption that kids c…

A practical impact of this - tool users from metric countries don't think in fractions. The notion that the next larger wrench after 1/8 is 5/32 is alien to people brought up with the metric system. Metric bolt heads are integral numbers of millimeters.

Yep, there are many counter-intuitive aspects to the rational numbers. They're ordered just like the integers, and yet given any fraction there isn't a well-defined "next" fraction. But there are still "gaps" (irrational numbers). The same fraction has infinitely many representations. Despite that there are no more rational numbers than integers, yet the number of "gaps" far exceeds either of these. Not every fraction even has a finite decimal expansion. And fractions allow you to specify a level of precision for measurements that could never be achieved in the real world under any circumstances, which immediately raises questions about what these extraordinarily precise fractions actually refer to in the real world.

I honestly believe that lots of kids detect these issues on some level, but their curiosity and confusion remain unresolved, possibly for life.

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