Admit your Brain lock

[Siwastaja]

I agree about learning like that and can cope to some degree, especially with print, but stood no chance with handwriting. I still don't see the point in make it more difficult than necessary.

Well, we have the unfortunate situation that the Roman alphabet does quickly run out of letters if you want them to be intuitive (thus we may use V for voltage, L for length, A for area, C for capacitance, N for number of turns, and so on). And we have the convention in algebra that adjacent symbols are multiplied. So if we tried to use \$ang\$ for angular velocity, it could be confused with \$a \times n \times g\$. We could try to use v or V, but that is already taken for voltage. Maybe A, but that's often area. Hence history settled on Greek letter omega (\$\omega\$). It wasn't done to confuse, it was done to avoid confusion.

And just like in programming, you add over the top of the old, until your code becomes mess, and needs to be refactored. But even just suggesting this is disgrace.

Motor control theory for example is full of what totally looks like obfuscation, even if it's originally unintentional. Think about concept of "electromotive force", which is often shown with ANY of these symbols:

E


EMF (which could be confused to being E*M*F)
U
V
u
v

And guess what - it isn't a force at all, which is made more confusing by the fact that force is a related concept (e.g. in a linear motor, very directly).

But "electromotive force" already has a modern name: all you had to do is to call it voltage and use either U or V, the two most common symbols for voltage. And when you are trying to grasp motor control theory in whole, having such basic concept as fucking VOLTAGE obfuscated to some magical "new concept" is going to be a huge time sink. Same can be said about stuff like flux linkage. Linkage what? Flux linking something to something..?

There is A LOT to be improved in how we COMMUNICATE scientific concepts.

[IanB]

Motor control theory for example is full of what totally looks like obfuscation, even if it's originally unintentional. Think about concept of "electromotive force", which is often shown with ANY of these symbols:

E


EMF (which could be confused to being E*M*F)
U
V
u
v

And guess what - it isn't a force at all, which is made more confusing by the fact that force is a related concept (e.g. in a linear motor, very directly).

But "electromotive force" already has a modern name: all you had to do is to call it voltage and use either U or V, the two most common symbols for voltage. And when you are trying to grasp motor control theory in whole, having such basic concept as fucking VOLTAGE obfuscated to some magical "new concept" is going to be a huge time sink. Same can be said about stuff like flux linkage. Linkage what? Flux linking something to something..?

There is A LOT to be improved in how we COMMUNICATE scientific concepts.

Not gonna disagree.

[Zero999]

If you have the same issue as Zero999 (not registering the difference between symbols), then I'm afraid the problem is at your end (even though it isn't your fault). It is similar for a color blind not being able to work in a paint shop. And I'm not trying to make fun here. Somebody I know works at a hardware store but due to color blindness, this person can't work at the paint department. However the person can't tell the world to discard every color a color blind person can't see.

Precisely.

It is a great shame for someone to have their ambitions dashed when they find their chosen career depends on normal colour vision. I've heard of aspiring pilots discovering that rather late in the day. I feel for them - but if they railed against the "colour elite" I would thing they were twats.

It's not quite the same. Fortunately we have computers which can be programmed with plain old ASCII, so lots of this is unnecessary. It's just a shame to have to be subjected to it during education. I see it as a form of hazing.

[DiodeDipShit]

Which Witch is which? Which troubled those witches in Salem? 
     Here Yee.... Hear Yea? Yes You, come here, here me !   
         Coke or Pepsi? Pass the Mirror. 
              Where is the ware on your wear?   My Underwear.  Where?
Regional Dialects play havoc with foreign language. eh. Oui oui.
Opinions matter, what's it matter? Matter of fact, Dark Matter matters.
Pardon me, do you have any Grey Poupon?    No, I poop fine.   I meant mustard.  Sorry, I only speak French.
I order you !  Aye Aye Captain.  Then an eye for an eye?  Alas, Aye sailor.    Aye Yai Yai  ! ! !
This court is out of order !  Orderly, order for takeout.  Is that and order?
B, B, R, O, Y, G, B, V, G, W   
You can't say that !     O I B C'N U   ....... next Tuesday


 

[Circlotron]

There are some different conventions indeed. In the world of physics E can be used for Voltage and Energy. In the world of electricity E and P can be used for power. Typically the units used in a formula give a hint about what is what. I don't recall formulas where people use random symbols if there is a domain specific convention.

E is for EMF I would expect. But is EMF rigorously defined as the same thing as voltage? If so, why are there two terms for the same thing?

Edit - already covered by Siwastaja above.

[Sredni]

In an electromagnetic circuit, the EMF is the line integral of the induced (nonconservative) electric field; voltage on the other hand is the line integral of the total electric field and is the sum of the scalar potential difference (line integral of the conservative part of the electric field) and the EMF contribution along that path.

Sorry, I could not help myself.
I felt like Roger Rabbit when someone is singing "shave and a haircut"...

[IanB]

Motor control theory for example is full of what totally looks like obfuscation, even if it's originally unintentional. Think about concept of "electromotive force", which is often shown with ANY of these symbols:

E


EMF (which could be confused to being E*M*F)
U
V
u
v

And guess what - it isn't a force at all, which is made more confusing by the fact that force is a related concept (e.g. in a linear motor, very directly).

But "electromotive force" already has a modern name: all you had to do is to call it voltage and use either U or V, the two most common symbols for voltage. And when you are trying to grasp motor control theory in whole, having such basic concept as fucking VOLTAGE obfuscated to some magical "new concept" is going to be a huge time sink. Same can be said about stuff like flux linkage. Linkage what? Flux linking something to something..?

In an electromagnetic circuit, the EMF is the line integral of the induced (nonconservative) electric field; voltage on the other hand is the line integral of the total electric field and is the sum of the scalar potential difference (line integral of the conservative part of the electric field) and the EMF contribution along that path.

Sorry, I could not help myself.
I felt like Roger Rabbit when someone is singing "shave and a haircut"...

Notwithstanding my earlier comment, it is possible to shed some light on the choice of symbol used for EMF.

In electrochemical thermodynamics, the following formula may be found for the change in Gibbs free energy:
$$\mathrm{d}G=-S\mathrm{d}T+V\mathrm{d}P+\mathcal{E}\mathrm{d}Q$$
In which \$G\$ is Gibbs free energy, \$S\$ is entropy, \$T\$ is temperature, \$V\$ is volume, \$P\$ is pressure, \$\mathcal{E}\$ is EMF, and \$Q\$ is charge.

We find here a dilemma, since in thermodyamics \$E\$ is already taken for total energy, \$V\$ is taken for volume, and \$U\$ is taken for internal energy. All the regular letters are therefore already accounted for, and using \$\mathcal{E}\$ for EMF becomes a somewhat forced choice.

[Sredni]

I use double struck capital letters for Energy , Power, potential energy (U) and kinetic energy (T), work and a few others. They stick out pretty well.

[tggzzz]

Which Witch is which? Which troubled those witches in Salem? 
     Here Yee.... Hear Yea? Yes You, come here, here me !   
         Coke or Pepsi? Pass the Mirror. 
              Where is the ware on your wear?   My Underwear.  Where?
Regional Dialects play havoc with foreign language. eh. Oui oui.
Opinions matter, what's it matter? Matter of fact, Dark Matter matters.
Pardon me, do you have any Grey Poupon?    No, I poop fine.   I meant mustard.  Sorry, I only speak French.
I order you !  Aye Aye Captain.  Then an eye for an eye?  Alas, Aye sailor.    Aye Yai Yai  ! ! !
This court is out of order !  Orderly, order for takeout.  Is that and order?
B, B, R, O, Y, G, B, V, G, W   
You can't say that !     O I B C'N U   ....... next Tuesday

For a more, um, accomplished exasperated variant of that, I refer you to this old chestnut: http://ncf.idallen.com/english.html or the version I posted here https://www.eevblog.com/forum/blog/perverse-language/msg607129/#msg607129

[CatalinaWOW]

In some sense these last couple of pages have been a variant of "Why can't we all just use the same words for everything."  It would be so much easier if everybody just spoke English, or Chinese or Spanish or whatever.  Much of the confusion described here comes because many different fields of expertise developed as independent islands.  Whether that island consisted of a technology area, a university group, a scientific society or geographical unit doesn't matter.  They developed conventions that made sense in the context, and passed those conventions on to their own peers and successors. 

The term interdisciplinary only became popular in the last 50 years or so.  The reality of interdisciplinary work has caused overlap in the conventions.  But no one who has spent half their career steeped in one convention enjoys the idea of uprooting for another.  The convention they grew up with isn't confusing to them, the new one is, and seems an attempt to upset the applecart.

The only way a unified symbology and terminology will take over is if the benefits seem to outweigh the drawbacks (Reprinting textbooks, retraining existing practitioners, time invested in trying to unravel all of the different needs and objectives).  I don't object to the process, but don't see how pejoratives such as obfuscation contribute to the solution.

[fourfathom]

In some sense these last couple of pages have been a variant of "Why can't we all just use the same words for everything."  It would be so much easier if everybody just spoke English [...]

Everyone should speak West-Coast American English, as God intended.

[pcprogrammer]

In some sense these last couple of pages have been a variant of "Why can't we all just use the same words for everything."  It would be so much easier if everybody just spoke English [...]

Everyone should speak West-Coast American English, as God intended.

At the risk of being punished, here in lies proof that a god does not exist. 

If there actually is one and the intent was to have every body speak West-Coast American English, would it not already be the case. You know that when "he" created it all that "he" would have made sure of this.

Or do we blame it upon the opening of Pandora's box that this is not the case. 

[VinzC]

Anybody else?

Things I've done more than a few minutes ago.
Oh, and things I've done less than a few minutes ago.

Brain locks?

It's not brain locks, I think, it's just brain slips. And it doesn't get better with age. (At least speaking for my own little self.)

[Siwastaja]

In some sense these last couple of pages have been a variant of "Why can't we all just use the same words for everything."

No, it's the exact opposite: I am showing we must admit that we are NOT using the same words for everything, and we should not even try too hard for a totally universal symbol system as it's futile, but instead should try to concentrate on:
* Making communication simple and clear
* Explain and document the terms used

There is synergy between these two points: when you simplify, you reduce your own documentation task.

For example, a voltage produced by rotating permanent magnet motor does not care about line integral versus other types of integrals. It is just voltage, which you can measure with a multimeter, a simple one-dimensional scalar which changes as function of time. Therefore, a motor-generated voltage can be called voltage, and the term "electromotive force" or "line integral" does not need to appear in motor control theory at all.

Therefore, the explanation about what "motor-generated voltage" is, will be much shorter and easier to understand, than historical review of why electromotive force is called electromotive force and... well look at Sredni's reply. To really understand what he is saying I would need ten times more explanation, make myself a few cups of coffee, and look at it carefully. This is completely wasted time if I'm interested about the voltage that appears on the wires of a rotating permanent magnet motor, which is very relevant when I want to control the motor.

[DiodeDipShit]

For a more, um, accomplished exasperated variant of that, I refer you to this old chestnut: http://ncf.idallen.com/english.html or the version I posted here https://www.eevblog.com/forum/blog/perverse-language/msg607129/#msg607129
[/quote]

Tggzzz, thank You for that link ! !   
Getting half way through was rough.

[CatalinaWOW]

In some sense these last couple of pages have been a variant of "Why can't we all just use the same words for everything."

No, it's the exact opposite: I am showing we must admit that we are NOT using the same words for everything, and we should not even try too hard for a totally universal symbol system as it's futile, but instead should try to concentrate on:
* Making communication simple and clear
* Explain and document the terms used

There is synergy between these two points: when you simplify, you reduce your own documentation task.

For example, a voltage produced by rotating permanent magnet motor does not care about line integral versus other types of integrals. It is just voltage, which you can measure with a multimeter, a simple one-dimensional scalar which changes as function of time. Therefore, a motor-generated voltage can be called voltage, and the term "electromotive force" or "line integral" does not need to appear in motor control theory at all.

Therefore, the explanation about what "motor-generated voltage" is, will be much shorter and easier to understand, than historical review of why electromotive force is called electromotive force and... well look at Sredni's reply. To really understand what he is saying I would need ten times more explanation, make myself a few cups of coffee, and look at it carefully. This is completely wasted time if I'm interested about the voltage that appears on the wires of a rotating permanent magnet motor, which is very relevant when I want to control the motor.

I agree, simple is good.  But your example is a good one to start with.  Do a thought experiment.  Connect an ideal battery (no internal impedance) to an ideal DC motor (no friction, but it does have mass).  Assuming the motor is not rotating at the start what happens over time?  The motor accelerates until the back EMF (use that term for the moment, we'll get back to that) equals the battery voltage.  The acceleration is proportional to the difference between the battery voltage and the back EMF.  Where do you attach your voltmeter to measure the back EMF?  You can't, it is a virtual voltage which must be kept separate from what your voltmeter measures across the motor terminals.  You could infer it by measuring motor speed and using the motor constant you measured in another experiment.  But it is a separate and unique voltage that must be identified separately from the supply voltage.  You could use a subscript, perhaps B for back, but that could be confusing relative to B for battery.  So now we are just quibbling over symbols.  EMF has apparently confused you because forces and voltages are not the same thing, but you have not complained about the fact that a stack of electro-chemical cells has nothing to do with an array of cannons. 

While there probably is a historical reason involving line integrals for the original use of EMF as the symbol for this term, the key is that a specific symbol is needed (just as there is a need for a specific symbol for the voltage at each node of a Kirchhoff loop) and that there will always be arguments about which mnemonic is best.  Unless you concede to sentence length subscripts, which might not need to be standardized to improve communication.

[Smokey]

In some sense these last couple of pages have been a variant of "Why can't we all just use the same words for everything."  It would be so much easier if everybody just spoke English [...]

Everyone should speak West-Coast American English, as God intended.

Dude! 

[paulca]

Regular expressions.

I won't even attempt that. My time is better spent on literally anything else.

It's better that way.  Based on the number of regular expression bugs I find and fix I figure more people need to take the approach of "I don't understand this" and ask for help.

Probably the no.1 most common bug is over-greed and un-anchored wild cards.

.*eevblog.com

to match sub-domains, as an example. 

A better example, but still very, very wrong, would then be:

.*.eevblog.com

Nope!

.*\.eevblog.com

Nope!

.*\.eevblog\.com$

Now we are getting somewhere.

trojan.eevblog.com.h8xzor.xx.tt




What definitely goes into my pile of "I don't understand this", is anything beyond about middle school mathematics.  Once the material comes from Mathematicians and not "normal people" I just stop following.  For some reason, maths or particularly the language of maths ended up in the bin.  I'm usually okay when the concepts are explained, but when I then get presented with a formula in a datasheet which contains greek, I'm immediately "Nope".  Not worth my time.

On a more micro level, I have issues processing "inclusions" and "exclusions" on ranges.  It's not that I have a problem, it's more that I can't give straight answers to those questions like "How many days between Monday and Wednesday?", without having to stop and think carefully if it's x-y, or if it's x-(y-1) or if it's x-(y+1) or x+1-y.  If Monday and Wednesday are included then it's 3.  If they are not it's 1.  The "commonly interrupted answer" I believe is actually y-(x+1) which is 2 days.  I still have to stop and think everytime.

I have programmer "out by one" paranoia.

[Ground_Loop]

My brain  lock: transitioning from time domain to frequency domain and back.  I'm ok with the mechanics (math) of it, but just can visualize what the math is doing.

[Zero999]

My brain  lock: transitioning from time domain to frequency domain and back.  I'm ok with the mechanics (math) of it, but just can visualize what the math is doing.

That's odd because I have the opposite problem. I can visualise transitioning from the frequency to the time domain, but I struggle with the calculations, partly due to my difficulty with the notation, as I've mentioned above.