The three worst diagrams EE students are presented with

Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle.. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.

 

On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:

On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.

I think my prof said the exact same thing to me years ago.

 

[bitrex]

On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
> Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.

 

On Saturday, October 5, 2019 at 6:58:39 PM UTC-4, bitrex wrote:

On 10/5/19 6:44 PM, blocher@columbus.rr.com wrote:
On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.


I think my prof said the exact same thing to me years ago.


How do you represent a vector field with a smudge and got no vectors?

The point is that every point on the page needs an arrow. If you draw an arrow on every point on the page you get a black smudge across the page. A black smudge would be just as instructive as the 16 arrows from a charged point.

 

[bitrex]

On 10/5/19 6:44 PM, blocher@columbus.rr.com wrote:

On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.


I think my prof said the exact same thing to me years ago.

How do you represent a vector field with a smudge and got no vectors?

 

[Tom Del Rosso]

blocher@columbus.rr.com wrote:

On Saturday, October 5, 2019 at 6:58:39 PM UTC-4, bitrex wrote:

How do you represent a vector field with a smudge and got no vectors?

The point is that every point on the page needs an arrow. If you
draw an arrow on every point on the page you get a black smudge
across the page. A black smudge would be just as instructive as the
16 arrows from a charged point.

Then every diagram representing any kind of fluid would be a smudge too.

If the student took any geometry they know a "ray" is represented by an
arrow and it goes to infinity.

And everyone, regardless of education, knows a bunch of arrows
represents motion or force that is not limited to the boundaries of the
arrows but includes the space between them.

 

[Whoey Louie]

On Saturday, October 5, 2019 at 6:22:50 PM UTC-4, blo...@columbus.rr.com wrote:
> Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

IDK, worked OK for me. Kind of like the sun, or a hot body radiating.
I didn't think because there were arrows that ended on a simple diagram
that it meant the field just ended there instead of extending outward
everywhere. It sure seems a lot better than a smudge across the whole page..

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.

 

On Sat, 5 Oct 2019 15:22:45 -0700 (PDT), blocher@columbus.rr.com
wrote:

Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.

Sometimes you want something to settle to its final value, within some
tolerance, in some limited time. A grossly overdamped loop is stable
but slow. Critical or a bit underdamped settles clean and fast.

Your body movements are a bit underdamped for the same reason. If
somebody throws a rock at your head, you want to get out of the way
ASAP. If you want to catch a ball, you don't want your hand to go slow
or overshoot much either.

I wouldn't want my power steering to be an overdamped loop either.





--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Bill Sloman]

On Sunday, October 6, 2019 at 10:02:44 AM UTC+11, blo...@columbus.rr.com wrote:

On Saturday, October 5, 2019 at 6:58:39 PM UTC-4, bitrex wrote:
On 10/5/19 6:44 PM, blocher@columbus.rr.com wrote:
On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.


I think my prof said the exact same thing to me years ago.


How do you represent a vector field with a smudge and got no vectors?

The point is that every point on the page needs an arrow. If you draw an arrow on every point on the page you get a black smudge across the page. A black smudge would be just as instructive as the 16 arrows from a charged point.

Wrong. The black smudge has only magnitiude. Vectors have direction and length, which is a distinction you can capture with arrows.

The vector field is also continuous, but representing that on a flat page while capturing the magnitude and direction features is a bit tricky.

The aim is to instil mathematical insight, and the arrows don't get in the way of that.

--
Bill Sloman, Sydney

 

[Rick C]

On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:

On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Refresh my memory, a gradient is like the slope of a line, but in more dimensions?

--

Rick C.

- Get 2,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[whit3rd]

On Saturday, October 5, 2019 at 3:58:39 PM UTC-7, bitrex wrote:

> How do you represent a vector field with a smudge and got no vectors?

Fire up a van de Graaff, apply glue to the globe, and toss some stiff-ish fibers at it.
Wait till the glue dries before you power down.

If you can finda model with medium-length, recently washed hair...

<https://youtu.be/WS9ISUXBsa8>

 

[Cursitor Doom]

On Sat, 05 Oct 2019 20:32:15 -0400, Tom Del Rosso wrote:

And everyone, regardless of education, knows a bunch of arrows
represents motion or force that is not limited to the boundaries of the
arrows but includes the space between them.

Sorry, but a bunch of arrows indicates the movement of electrons towards
areas of positive or partially-positive charge between the steps of a
chemical reaction.
See the issue with sweeping generalisations? ;->



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

[Robert Baer]

blocher@columbus.rr.com wrote:

Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

Diagram 2. The fourier series of a square wave that has odd symmetry --- so the answer is all sin waves. OK the whole purpose of the fourier series is to teach that any repetitive signal can be broken into sine components and cosine components. SIN and COS ---(anybody listening?). So the first problem they show the student is the case where the cos waves are miraculously missing. Isn't the whole point to show that you need sin and cos components to faithfully make a repetitive waveform and the first thing you do is hide the cos waves????- WTF

Diagram 3. The 3dB overshoot diagram for a "perfect" control loop. In my experience , the perfect control loop is the slowest , most overdamped loop that you can build that is responsive enough to get the job done.

Ever heard of critical damping? There is slight overshoot..

 

[Whoey Louie]

On Sunday, October 6, 2019 at 12:31:20 AM UTC-4, Rick C wrote:

On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Refresh my memory, a gradient is like the slope of a line, but in more dimensions?

Yes. Imagine a block of some substance that has varying density
throughout it. At any point, the gradient is a vector that points
in the direction of the fastest change in density and it's magnitude
is the rate of increase.

 

[bitrex]

On 10/6/19 12:31 AM, Rick C wrote:

On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Refresh my memory, a gradient is like the slope of a line, but in more dimensions?

Right, the one dimensional "gradient" is just the regular first
derivative, but an operator that generates the equivalent of the "slope"
when applied to a scalar function of two or more variables has to return
a vector.

Like the single variable derivative on the real line itself it's a
generalized operator and there are generalized formulations/tensor
formulations of it so it can work in every coordinate system, can use it
to map vectors to vectors too like in calculus on manifolds and
"Einstein-stuff" so it's not always clear how the analogy "slope"
applies in every context it's used.

 

[bitrex]

On 10/6/19 10:12 AM, Whoey Louie wrote:

On Sunday, October 6, 2019 at 12:31:20 AM UTC-4, Rick C wrote:
On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Refresh my memory, a gradient is like the slope of a line, but in more dimensions?


Yes. Imagine a block of some substance that has varying density
throughout it. At any point, the gradient is a vector that points
in the direction of the fastest change in density and it's magnitude
is the rate of increase.

Doing problems in electrostatics directly with the electric vector field
representation can be annoying when you have to use calculus because the
differential (like "dr", "dx" on the right hand side of an integral) is
a vector, too, so making problems tractable when working directly with
the vector equations in say Cartesian or polar coordinates usually
involves finding an axis of symmetry such that you can treat the
differentials as scalars in practice.

It's often easier to calculate the scalar potential field first and then
apply the gradient to that to get the E-field of the charge
configuration if that's what you need.

 

On Sun, 6 Oct 2019 11:55:20 -0400, bitrex <user@example.net> wrote:

On 10/6/19 12:31 AM, Rick C wrote:
On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Refresh my memory, a gradient is like the slope of a line, but in more dimensions?


Right, the one dimensional "gradient" is just the regular first
derivative, but an operator that generates the equivalent of the "slope"
when applied to a scalar function of two or more variables has to return
a vector.

Like the single variable derivative on the real line itself it's a
generalized operator and there are generalized formulations/tensor
formulations of it so it can work in every coordinate system, can use it
to map vectors to vectors too like in calculus on manifolds and
"Einstein-stuff" so it's not always clear how the analogy "slope"
applies in every context it's used.

Drop an electron there and see where it wants to go.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[bitrex]

On 10/6/19 12:45 PM, jlarkin@highlandsniptechnology.com wrote:

On Sun, 6 Oct 2019 11:55:20 -0400, bitrex <user@example.net> wrote:

On 10/6/19 12:31 AM, Rick C wrote:
On Saturday, October 5, 2019 at 6:34:52 PM UTC-4, bitrex wrote:
On 10/5/19 6:22 PM, blocher@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

The electric field is a vector field, it has a magnitude and a direction
associated with every point in space. It's the gradient of the
electrostatic potential, which could be represented by an intensity plot
for all space.

Refresh my memory, a gradient is like the slope of a line, but in more dimensions?


Right, the one dimensional "gradient" is just the regular first
derivative, but an operator that generates the equivalent of the "slope"
when applied to a scalar function of two or more variables has to return
a vector.

Like the single variable derivative on the real line itself it's a
generalized operator and there are generalized formulations/tensor
formulations of it so it can work in every coordinate system, can use it
to map vectors to vectors too like in calculus on manifolds and
"Einstein-stuff" so it's not always clear how the analogy "slope"
applies in every context it's used.

Drop an electron there and see where it wants to go.

In free space in the absence of magnetic fields or other moving charges
it's always gonna go somewhere! E = -grad(V), the divergence of E = 0 in
free space, so -div(grad(V)) = del^2(V) = 0 - the Laplacian always
describes the electric potential in free space. the Laplacian describes
a scalar field that always takes its max or min values on the boundaries
of the domain so there's no way to build some kind of "potential well"
within the space to confine a charge in one spot by any arrangement of
static charge distribution on the "walls"

It would sure make fusion a lot easier if you could, thanks nature u
bitch :[

 

[bitrex]

On 10/5/19 8:06 PM, Whoey Louie wrote:

On Saturday, October 5, 2019 at 6:22:50 PM UTC-4, blo...@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

IDK, worked OK for me. Kind of like the sun, or a hot body radiating.
I didn't think because there were arrows that ended on a simple diagram
that it meant the field just ended there instead of extending outward
everywhere. It sure seems a lot better than a smudge across the whole page.

they can print images in textbooks in color these days!

<https://en.wikipedia.org/wiki/Electric_potential#/media/File:VFPt_metal_balls_plusminus_potential.svg>

The "heat map" shows the electrostatic potential, and then the E-field
lines on top

 

[Whoey Louie]

On Sunday, October 6, 2019 at 4:10:15 PM UTC-4, bitrex wrote:

On 10/5/19 8:06 PM, Whoey Louie wrote:
On Saturday, October 5, 2019 at 6:22:50 PM UTC-4, blo...@columbus.rr.com wrote:
Diagram 1. The field coming out of a charged particle. So there are 16 arrows coming out of a dot on the center of the page ( or 8 or 24 depending on the book). This is what an electric field looks like on a charged particle. Of course the new student does not know what a field is . the correct diagram would be a black smudge across the entire page because that might give some clue to the student that the field is everywhere. The notion that the field is everywhere is not such a trivial concept and the diagram that shows 16 arrows somehow does not really drive that point home.

IDK, worked OK for me. Kind of like the sun, or a hot body radiating.
I didn't think because there were arrows that ended on a simple diagram
that it meant the field just ended there instead of extending outward
everywhere. It sure seems a lot better than a smudge across the whole page.




they can print images in textbooks in color these days!

https://en.wikipedia.org/wiki/Electric_potential#/media/File:VFPt_metal_balls_plusminus_potential.svg

The "heat map" shows the electrostatic potential, and then the E-field
lines on top

I wonder if that makes the OP happy? It's certainly way better that a smudge.