Well into the late 1800s, people were fairly content to think of electricity and magnetism as two different things. Today, electric fields and magnetic fields are treated as separate entities, when in fact that line of thinking is remnants of when electricity and magnetism were thought to be fundamentally different.
The following is an explanation of magnetic fields from the perspective of connected monopolar, equi-charged bodies - in other words, equally charged electric field sources.
The screenshots were taken from an electrostatic particle simulation that I wrote, which can be found here. The simulation is 2d, for the benefit of the field rendering method. The field coloring was set to the highest scaling factor, in order to make visible (within the allowed color rendering range) the otherwise very small scale force values. If you are interested in running the program yourself, you will need the following :
This page is very image heavy. While the images themselves aren't too large, there is a fair number of them. Please allow the images to load fully.
The field rendered is one of vector forces that would be acting on a charged body at that pixel. Any red color indicates a horizontal force component, while green indicates a vertical force component. Combinations of the two result in angled force vectors. It's important to note here that the force direction is actually ambiguous, and for good reason. If a negatively charged body approaches either end, the force on that body will be the exact opposite from if the body was positively charged. This means that the field we are dealing with, as with all electric field calculations, is one of potential, and the force vector, while relevant, is 180 degree ambiguous.
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This image is of two particles, of equal mass and, more importantly, equal but opposite charges. |
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The lines show more clearly the field configuration. |
What's displayed in the images above is well known as an electric dipole. It looks exactly like a magnetic field, and for a very good reason - because that is exactly what a magnetic field is. This is the primary theme of this page, and one that will be aptly demonstrated as we go.
Consider the following images :
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two equally yet oppositely charged electric field sources bound together into a single body, i.e. a representation of your typical bar magnet |
In reality, every atom presents a magnetic field, precisely due to separated electric field sources (electrons and protons). Our little bar magnet is a sufficient enough abstraction of that arrangement to make the next series of images meaningful.
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What we see in this configuration is that where the two magnets meet, there is a local "compression" or "cancellation" of the resultant dipolar field between the meeting ends and a resultant expansion of the field strengths at the ends of the entire configuration. In the middle of the new configuration, we can see that the force experienced external to the configuration is such that it's as if the two magnets, end to end, were only one (but stronger, naturally). |
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Add another and watch the continued overall expression of a unified magnet grow... |
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And grow... |
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And grow... |
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As you can see, the progression of field strength distributed over the volume around the magnet chain leads to larger and larger single-magnet appearance to charged bodies external to the magnet. Another point of interest is that as the chain gets longer, the respective force vectors align parallel to the chain's length until in relatively close proximity to the end of the chain (relative to the length of the chain itself). |
There's another way to combine magnets, and that's in a ladder configuration, for example :
What's interesting here is that the ladder configuration exhibits the same properties as the chain configuration, but with more field complexity at the ends.
It is of utmost importance to understand that all of these images and results are calculated in real-time with my program. The only physics equation that shapes the particle behavior and field calculation is the electrostatic force - kQ1Q2/r^2 .
My field renderer does another field visualization method for charge potential. No vector information is generated here - only scalar charge strength values. This visualization shows another interesting side to what we've already looked at :
What the charge potential visualization shows is that the overall positive and negative charge influence grows at the ends of the chain configurations to an overshadowing degree over the main length of the chain itself.
In reality, electric fields neither compress, bend, balloon, nor subtract. The fields overlap, and above all else, the fields themselves are descriptions of charge on charge behavior. That being said, it appears foolish to consider magnetic fields as fundamental as electric fields. When magnetic field properties can be demonstrated by taking into consideration only electric fields, it strongly points to the true fundamental nature of magnetism - electricity!
A final word about my simulator - I wrote it not intending to challenge the nature of magnetic fields, but to enjoy playing with a real-time electric field calculator and visualization. The electrostatic force equation is the result of centuries of experimental observation of the behavior of electric currents and their fields. The simulation, relying on the electrostatic equation, shows the extreme potential for further evolution of electromagnetic theory.
If you have any comments or suggestions, feel free to e-mail me at this domain name (pfhoenix) at gmail dot com.