Just found this article on our ABC(TV) national science show website,
Are we teaching electricity the wrong way around? › Opinion (ABC Science) .its a new way of explaining about the way electricity works,.... any thoughts? I am still trying to get my head around it after being brought up with the "old" water plumbing analogy..
Are we teaching electricity the wrong way around? › Opinion (ABC Science) .its a new way of explaining about the way electricity works,.... any thoughts? I am still trying to get my head around it after being brought up with the "old" water plumbing analogy..
Yes.
The hardest concept I find people have is getting to grips with the fact that electrons only move at about 0.2mm/sec when a current is being passed through a wire.
Understanding how it really flows (waves) is a must for high speed digital layout.
A good read is Ralph Morrison, The Fields of Electronics.
The hardest concept I find people have is getting to grips with the fact that electrons only move at about 0.2mm/sec when a current is being passed through a wire.
Understanding how it really flows (waves) is a must for high speed digital layout.
A good read is Ralph Morrison, The Fields of Electronics.
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That (the stuff linked from post 1) will replace one set of confusions with another one. You should be very suspicious of anything involving the Poynting vector, as almost everyone misunderstands Poynting's conjecture. Integrating the Poynting vector over a closed surface gives you the power flow through that surface. It is a tool to calculate something; that is all. The Poynting vector does not tell you how the power gets there, yet most people who have heard of it assume that it does. That leads them to say silly things like "Energy is not transferred by moving electrons".
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Electronics teaching in some UK institutions has moved further and further away from any physics, in fact I think UK education in general is being dumbed down.
I think a mixture of conventional electronics with some of the physics behind it is the best option.
A teacher at my Lads school told him they wouldn't do o levels these days because not enough pupils would pass!!
I think a mixture of conventional electronics with some of the physics behind it is the best option.
A teacher at my Lads school told him they wouldn't do o levels these days because not enough pupils would pass!!
I know UK education has been dumbed down. Unlike most people, I actually went back to university 25 years after I was first there. I found that a Masters degree contained mainly topics at the level of second-year undergraduate of a generation earlier. My maths by now was decidely rusty yet I still did well. No way could I have done well in my original undergraduate course 25 years later.
Hi,
Its completely clueless nonsense in a nutshell, written by an idiot,
who wouldn't know where to start about teaching electricity properly.
An old adage is if you can't do it, teach it. Perhaps one could add
if you can't do it or teach it write some utter drivel about it.
(Disparaging perhaps, but I've met some very poor teachers,
including a lecturer teaching project management that clearly
couldn't even manage his own lessons / lectures effectively.)
There is no such thing as a good science teacher who is a non-physicist.
Physics and mathematics is fundamental to all science.
Otherwise they would understand the inevitable glacial drift velocity
of electrons in wires, AC or DC, and that such a velocity has nothing
to do with the field propogation velocities at all. Is it a straightforward
consequence of the charge on an electron, the electron density and
the fact current is charge per second.
Electron (and hole) speeds increase dramatically with low carrier
densities, as they must in semiconductors, which make poor wires.
rgds, sreten.
Its completely clueless nonsense in a nutshell, written by an idiot,
who wouldn't know where to start about teaching electricity properly.
An old adage is if you can't do it, teach it. Perhaps one could add
if you can't do it or teach it write some utter drivel about it.
(Disparaging perhaps, but I've met some very poor teachers,
including a lecturer teaching project management that clearly
couldn't even manage his own lessons / lectures effectively.)
There is no such thing as a good science teacher who is a non-physicist.
Physics and mathematics is fundamental to all science.
Otherwise they would understand the inevitable glacial drift velocity
of electrons in wires, AC or DC, and that such a velocity has nothing
to do with the field propogation velocities at all. Is it a straightforward
consequence of the charge on an electron, the electron density and
the fact current is charge per second.
Electron (and hole) speeds increase dramatically with low carrier
densities, as they must in semiconductors, which make poor wires.
rgds, sreten.
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No wonder the students haven't got a clue these days...
And think you can press a button and do anything
Come back Jules Verne..
My experience is they have knowledge and absolutely no understanding..
Guess why..because the teachers are being told how to teach and do it like this or else..
Be inventive we must have student driven learning<<<here go and play with that HV supply and see what you can find out..
Regards
M. Gregg
And think you can press a button and do anything
Come back Jules Verne..
My experience is they have knowledge and absolutely no understanding..
Guess why..because the teachers are being told how to teach and do it like this or else..
Be inventive we must have student driven learning<<<here go and play with that HV supply and see what you can find out..
Regards
M. Gregg
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I have found this in so many situations..
People in charge of engineers telling them what to do that are not engineers.
People in charge of technical teachers that are not technical...
People making decisions on dangerous projects that are not engineers or have only paper knowledge and no practical experience..
I could go on and on...its all quite sad..
All I hear is evolve the teaching methods..change everything make it different....apply Kolb learning theory...etc...etc..
The theory is now more important than the content...Then after its so twisted no body can understand anything<<<you must make it better!!!!
Then the reality ..listen joe /sara...this is a piece of wire..this is a switch...
And the reality<<what is a magnetic field.... well it does this and that and you can feel it...but what is it????ah well that's another story..
Regards
M. Gregg
People in charge of engineers telling them what to do that are not engineers.
People in charge of technical teachers that are not technical...
People making decisions on dangerous projects that are not engineers or have only paper knowledge and no practical experience..
I could go on and on...its all quite sad..
All I hear is evolve the teaching methods..change everything make it different....apply Kolb learning theory...etc...etc..
The theory is now more important than the content...Then after its so twisted no body can understand anything<<<you must make it better!!!!
Then the reality ..listen joe /sara...this is a piece of wire..this is a switch...
And the reality<<what is a magnetic field.... well it does this and that and you can feel it...but what is it????ah well that's another story..
Regards
M. Gregg
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I have found this in so many situations..
People in charge of engineers telling them what to do that are not engineers.
People in charge of technical teachers that are not technical...
People making decisions on dangerous projects that are not engineers or have only paper knowledge and no practical experience..
I could go on and on...its all quite sad..
Yup, it's a challenge as an engineer to try to avoid situations where phalacy is celebrated, the more you learn and understand properly, the more clearly you will see the problems... but there are those few out there who have bothered to learn properly and develop an intuitive understanding of their subject areas.
Anyway, much more interestingly, I can clap with one hand... it's not a great sound.
Ahh yes.. the sound of no sound..
Regards
M. Gregg
No I mean... I can actually clap with one hand. You know... when someone doesn't deserve much of an applause. Sadly enough I learnt it from Bart...
It is a Lorentz-transformed electric field.M Gregg said:
A current in a wire consists (roughly) of moving electrons and stationary atoms, some of whom have lost the moving electrons and so have a net positive charge. When the current is zero the two types of object produce equal and opposite electric fields, so they cancel out externally. When the electrons start moving their electric field is affected by special relativity so the net field changes and the cancellation is incomplete due to retardation. We perceive it as a magnetic field. I forget the details, as it was too many decades ago when I understood this!
The question then becomes: what is an electric field?
It's all about Physics. It can be mind boggling!
Electricity?
What is Electricity: definitions
Electricty Misconceptions Spread By Textbooks
Electricity?
What is Electricity: definitions
Electricty Misconceptions Spread By Textbooks
Just for fun read..
What is a magnetic field? by David Sligar
Its interesting that magnetism is the link to so many basic things in electrical engineering..however we don't seem to know what is the reality of the force between two magnets.
Regards
M. Gregg
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Not fun, but depressing. Besides being very badly written, with appalling grammar, word use, and punctuation, it's apparent that the author saw some TV shows, read some popular books, then decided that he is now a physics expert.
The downside of the freedom of the internet is that anyone can write any sort of foolish thing and it will look no different in a search than something written by a real expert.
Richard Feynman Magnets - YouTube
This is the point...its like this or that..OK now we "seem to know a bit more".
Regards
M. Gregg
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