Thank you, Dr.
Let's examine the classical experiment you do at school. You take a bar magnet and sprinkle iron filings around it. What do you see? You see the iron filings form lines. It's why these lines appear which is the key understanding of magnetism.
What ever is in the field, and is effected by the field, will arrange itself into lines, evenly displaced. Why it does this is take the lowest state of the electrostatic forces.
There are no pre-existing lines, before the filings were thrown into the field. The number and positions of lines depends upon the amount of filings thrown in.
I think you need to define current here. I know what I mean what I refer to as a current but I am no longer convinced that we're talking about the same thing. We cannot see currents.
A current is a stream of bodies. An electric current is a stream of bodies where at least some of the bodies are charged.
Normally we cannot see electric currents. But highly energized electric currents can be observed for the light they emit.
And you can see a river, which is also a current.
Those loops in the NASA video are the quintessential example of electric current in arc mode. Remember we are looking at highly filtered images, which are probably brighter than lightning in the darkest areas of the images. Those loops are electrical arcing.
Not really. Currents can be the curl of a magnetic field or then can be the flow of free electrons in a solid. The analogy with streamlines was really to show how the fieldlines are defined not an admission of a flow.
I believe it is good to stay true to the original meanings of words. If you start redefining words, confusion sets in.
Currents are flows. Flows of something.
Fields are paddocks. An area on a surface, or a volume in three dimensional space.
An undulation in a field is not a current.
You need maths in physics.
This is the underlying presumption.
Eyes can deceive you, imagination without restraint can lead to incorrect ideas. Common sense really has no place in science. Basic principles are okay for basic things but we're not talking about basic things here.
You aught to see where math has taken the physicists.
But then, you would just say my eyes are deceiving me, and my imagination has run wild.
Be aware that appearances can be deceiving, keep the imagination restrained, and be sensible.
Good sense is required to do good science.
When math leads to such imaginations that break the basic scientific principles, then common sense is lost.
Pretty much you were. That's the problem without using maths, you can only talk in relatively vague terms.
If someone says a thing, and shows some maths, I see many will believe them,
whether what they said was right or wrong.
You're implying I can't explain anything physical except with math.
I can explain with words. But there is also the matter of whether people can receive.
I have no real idea about what you're talking about. I think you're talking about the flux of the field lines?
I was talking about the loops we observe in the NASA video.
Not really, they're dependent upon the topology of the field lines.
The fields lines are on our contour map of the topology.
The topology is the direction and strength of the force of the field at each location within the field.
If there were actual lines, our diagrams of magnetic fields would look something like contour maps of valleys and ridges, to show the lines.
As I have told you, this is incorrect and i've even written down the definition of the field lines.
OK. Now I have a field in my backyard. Tell me how you mathematically define the lines in it, using your definition?
The cows have defined some lines in it, by their meanderings.
You need more variables in your definition, and then you have what is necessary to predict where the lines will form, under these conditions: What kind of field it is. And the nature and quantity of the trajectories within the field.
If there are no trajectories, there are no lines.
Don't confuse electromagnetism with gravity.
We're talking about fields aren't we?
I believe the planets' orbits are held by the Sun's electric field.
But do tell us, in your model, what does happen when gravity field lines merge, and break.
`Paul
