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3Blue1Brown shares simulations made for a longer video about light, explains electric field vectors and contrasts a full three-dimensional view with a planar slice. The simulation uses an intermediate law derived from Maxwell’s equations.
- 1Field as vectorsEach point has a vector describing force per unit charge.
- 2A planar sliceA two-dimensional slice can make a dense three-dimensional field easier to see.
- 3A derived lawThe simulation uses an intermediate law derived from Maxwell’s equations.
ポイント
- Each point has a vector describing force per unit charge.
- A two-dimensional slice can make a dense three-dimensional field easier to see.
- The simulation uses an intermediate law derived from Maxwell’s equations.
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A moving charge and its field
Each point has a vector describing force per unit charge.
I recently had fun making simulations of how an electric field responds to a moving charge. They were created for a longer video on the fundamentals of light; here I share some of the resulting animations.
The full electric field is three-dimensional. It associates a vector with each point in space, indicating the force that would act on a unit charge placed there.
Slices and the simulation law
A two-dimensional slice can make a dense three-dimensional field easier to see. The simulation uses an intermediate law derived from Maxwell’s equations.
Three-dimensional fields are interesting to look at but can be visually busy, so it is often easier to show a slice, such as the xy plane.
In the main video I discuss the law used for these simulations. Rather than directly coding Maxwell’s equations, I use an intermediate law derived from them, which I find easier to understand for making animations and for students.
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