John: Your PS: Precisely for this reason, teachers will not soon be replaced by self-learning on the internet. Teachers are assured of their jobs in the near future.
I choose Newton's Laws as “more fundamental” of explaining Mechanics, Motion
To overcome gravity for something to “fly” it has to be generating lift (excluding ballistic motion as “flight” for this discussion)
The choices are buoyancy or changing the momentum of some mass – either that of the air flowing around the object or ejecting mass for rockets
No one is denying Bernoulli, or that dynamic pressure differences mediate the transfer of the forces on/around airfoils, but I view them as a “details of implementation” of a particular means of deflecting air mass flow to generate force from dp
Fluid dynamics is necessary to understand, design efficient airfoils, explain the sudden drop in efficiency when flow detaches, becomes turbulent – but the “big picture” should show/emphasize the net momentum change to truly “explain” the generation of lift
To overcome gravity for something to “fly” it has to be generating lift (excluding ballistic motion as “flight” for this discussion)
The choices are buoyancy or changing the momentum of some mass – either that of the air flowing around the object or ejecting mass for rockets
No one is denying Bernoulli, or that dynamic pressure differences mediate the transfer of the forces on/around airfoils, but I view them as a “details of implementation” of a particular means of deflecting air mass flow to generate force from dp
Fluid dynamics is necessary to understand, design efficient airfoils, explain the sudden drop in efficiency when flow detaches, becomes turbulent – but the “big picture” should show/emphasize the net momentum change to truly “explain” the generation of lift
For those of us who are mostly self taught, we also need a page on pronunciation misconceptions. Who knew that Euler was pronounced like something you'd find on the shelf in the the auto garage? What other embarrassments lie in wait for me?
While we agree in principle on all of it, the website is very misleading and provides errors with respect to airfoils and flight.
The trailing edge of a wing does not have to aim down for the wing to provide lift. To state that as a flight requirement is entirely inaccurate. A rotating cylinder for example, does not even have a trailing edge. Yet, it can provide lift. Heck, look at a rotating sphere...Same exact thing, it's rotation provides lift. Anyone who disagrees with this only has to attempt to hit a Mariano Rivera curveball.
His webpage has several fundamental flaws in thinking on that page alone.. Yes, Newton applies, but as you say, fluid dynamics provides the details. It is trivial to provide examples which show his arguments are incorrect. What is more important to me, is, will he adjust the page content now, given more accurate details?
Cheers, John
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Regarding Euler and his friends, even a knowledge of the relevant language might not help as in some cases the 'standard' pronunciation used among (English speaking) scientists is only a rough approximation to what his mother called him. An awareness of European languages will help a bit, though, provided you know or can guess where he came from.
Anyway, Wigner starts with a V sound so it is something like Vigner - the g is hard, as it is not a French word. Dirac was English, although not all his ancestors were. Feynman is pronounced Fineman. Pauli is pronounced Powlee (I think - Pow rhymes with cow). In Thevenin I think the h is silent.
Anyway, Wigner starts with a V sound so it is something like Vigner - the g is hard, as it is not a French word. Dirac was English, although not all his ancestors were. Feynman is pronounced Fineman. Pauli is pronounced Powlee (I think - Pow rhymes with cow). In Thevenin I think the h is silent.
Tey' vuhn ah, with the "ah" rhyming with "plan."
Dirac would still be pronounced the same in French, following the rule that if the last letter is a consonant, it's not pronounced, except when it is.
Dirac would still be pronounced the same in French, following the rule that if the last letter is a consonant, it's not pronounced, except when it is.
I guess we are bumping into the general question of when should we call something/someone exactly the same thing as locals call it/him/her, and when is it OK to have our own name for it? I don't insist that the French call my home city London, and I hope they won't mind if I call their capital Pariss. Generally, the more famous something is the more likely that non-locals will have their own name for it. Modern PC says we should only use the same name as the locals, but I have never been very PC.
So is it Veegknair or Vigner? Or does it depend on what company you are in?
So is it Veegknair or Vigner? Or does it depend on what company you are in?
His name was all over the news reports when Chernobyl was happening, because the accident had something to do with poor operator procedure during release of Wigner energy from the graphite core.
I was just having a little fun. You should come to Texas some time and have to listen to news reporters pronouncing every Spanish or Spanish-derived word with a proper Spanish (Mexican) accent and inflection. Or just as bad, listen to NPR and hear Pakistan pronounced Pahkistahn.🙄
John
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I was confused by the transition from Peking to Beijing, and Bombay to Mumbai. Maybe I should insist that Chinese/Indian news always refers to London using the appropriate estuary accent.
Huge communication fail: two different meanings of the word "definitions"
AHA! I think I just realized why we're failing to communicate.
In the above, when you say "definition," do you actually mean "dictionary entry?"
If so then... DOH! It's no wonder we're having problems.
Again, might you be using the word "definition" to mean the same as "dictionary entry?"
All along I've been using the word "definition" like so: undefined words have no definitions. All words in common use are defined (meaning that they have definitions.) When people converse, they don't use undefined words. The definitions of words they use, those definitions are in their heads. So, slang words have definitions, colloquial words have definitions, technical terms have definitions. If they didn't, they'd be just as undefined and meaningless as these undefined words I've just made up: fleerm. Dorpish. Smofe.
🙂
Actually I think we just have a complete failure to communicate.
When you say that colloquial definitions are an impossiblity, did you mean that "colloquial dictionary entries" don't exist?
If so, then I agree. But I've never been talking about dictionary entries. When I say that a word has a "definition," I mean "opposite of undefined." To find out the definition of a colloquial word, grab a person who uses it in conversation. Ask them what the word means and they'll give you the colloquial definition they've been using. Ask a bunch of different people, and they'll all agree. Verbal communication is based on this agreement.
So our conversation might be a perfect example of the problems with the word "electricity!"
Unless we share a common definition of the word "define," communication becomes hopeless. Everything gets crazy, and nobody can quite put their finger on the cause.
Unless we share a common definition of the word "Electricity," communication becomes hopeless. Everything gets crazy, and nobody can quite put their finger on the cause.
AHA! I think I just realized why we're failing to communicate.
In the above, when you say "definition," do you actually mean "dictionary entry?"
If so then... DOH! It's no wonder we're having problems.
Again, might you be using the word "definition" to mean the same as "dictionary entry?"
All along I've been using the word "definition" like so: undefined words have no definitions. All words in common use are defined (meaning that they have definitions.) When people converse, they don't use undefined words. The definitions of words they use, those definitions are in their heads. So, slang words have definitions, colloquial words have definitions, technical terms have definitions. If they didn't, they'd be just as undefined and meaningless as these undefined words I've just made up: fleerm. Dorpish. Smofe.
🙂
Actually I think we just have a complete failure to communicate.
When you say that colloquial definitions are an impossiblity, did you mean that "colloquial dictionary entries" don't exist?
If so, then I agree. But I've never been talking about dictionary entries. When I say that a word has a "definition," I mean "opposite of undefined." To find out the definition of a colloquial word, grab a person who uses it in conversation. Ask them what the word means and they'll give you the colloquial definition they've been using. Ask a bunch of different people, and they'll all agree. Verbal communication is based on this agreement.
So our conversation might be a perfect example of the problems with the word "electricity!"
Unless we share a common definition of the word "define," communication becomes hopeless. Everything gets crazy, and nobody can quite put their finger on the cause.
Unless we share a common definition of the word "Electricity," communication becomes hopeless. Everything gets crazy, and nobody can quite put their finger on the cause.
Not limited to that, no. As you've pointed out sometimes dictionaries are just plain wrong. Or merely out of date.
Yes, that's obviously tautologous.
That would again be tautologous. But when a new word enters a language, its usage precedes any definition. Dictionaries are only written in retrospect. So I'm not sure your claim is correct.
Obviously not. Or everyone's brain would contain a dictionary just ready to be read out and committed to paper. But of course they don't. I've quite often been asked in the past 'you used that word, can you define it?' and I found I had to answer in the negative. If I had the dictionary inside my brain, I'd be able to answer each and every query of that form.
'Undefined' and 'meaningless' don't point to the same meaning for me. They do for you? If so then I believe we've potentially homed in on the lack of communication between us.
Your three example undefined words are not only undefined, they're also unused as far as I'm aware. The meaning of a word is related to its use, not its definition.
Yes, that was why I bowed out.
No.
No, rather we need a common meaning for the words we use, not a common definition.
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Conversation A:
"What is electricity?"
"Electricity is electric charge."
"What is electric charge?"
"It is a conserved quantum number which characterises the electromagnetic interaction of elementary particles such as the electron."
"What is a quantum number, what does conserved mean in this context, what is an electromagnetic interaction, what is an elementary particle, and what is an electron?"
Conversation B:
"What is electricity?"
"Electricity is a type of energy which powers your TV and lamps."
Which conversation brings most enlightenment to the enquirer?
A definition replaces a word with a phrase. It is little help if the phrase contains words which are less familiar than the original word being defined.
"What is electricity?"
"Electricity is electric charge."
"What is electric charge?"
"It is a conserved quantum number which characterises the electromagnetic interaction of elementary particles such as the electron."
"What is a quantum number, what does conserved mean in this context, what is an electromagnetic interaction, what is an elementary particle, and what is an electron?"
Conversation B:
"What is electricity?"
"Electricity is a type of energy which powers your TV and lamps."
Which conversation brings most enlightenment to the enquirer?
A definition replaces a word with a phrase. It is little help if the phrase contains words which are less familiar than the original word being defined.
Spot on!
Conversation A - creates more barriers to understanding. Some would say it exposes the learner to more information. What it does is close down the learning process.
Conversation B - removes barriers and creates a platform to build learning or a starting point that both parties understand that can be built on.
This is also linked to Transactional analysis and respect of levels of understanding. 🙂
Regards
M. Gregg
So Bill B.isn't really saying what he says. Instead he's making this completely different point ...which has now been revealed above?
That's how the Strawman Fallacy works. "Don't listen to what my opponent actually says. Instead listen to my version of what my opponent says."
If this diyAudio thread is a game of insult-and-oneupmanship, and we're both trying to fool our audience and sway them to our side, then Strawman is a genius tactic. Strawman makes our opponent look bad, and it sways the audience to our viewpoint, both at the same time.
But it's absolutely terrible as education. If instead this diyAudio thread is a classroom on basic electricity physics, what is your goal as a professional educator?
A prime example of the strawman fallacy in action. The audience remains steadfastly unswayed.
Sorry, have I misunderstood? When you (Bill B) say "Electricity is electric charge" you assume that your hearer already knows what electric charge is? In that case, why is he asking what electricity is?
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