I’ve seen one multiple educational videos that draw light as two orthogonal waves traversing through space. What is that trying to represent?What exactly is going up and down?
Furthermore, why do people often make the analogy that light acts like a ripple in a pond?
In: Physics
An electric field is a map of electric potential (volts) in space. If you have a charge (like an electron) the field is negative near the negative electron and slowly goes more positive as you move away. If you move the electron around then the field moves with the electron.
A pond surface is a map of the gravitational potential of the surface over a flat plane. If you push down with a stick, the water molecules at the stick go down and have a lower potential. If you move the stick around then the spot with low potential moves with the stick.
In both cases, if you move fast enough you notice it takes time for the potential to “catch up”. In water this creates waves. In space this creates, well, waves that seem a lot like water waves.
This electric field bobbing up and down is light. When an electric field moves you get a magnetic field whether you want it or not. And that electric/magnetic bobbing up and down is light.
I will add that there is a deep connection between electric and magnetic fields and it is more complete to call them the same thing (electromagnetic…). But you can learn that a bit later. And that rabbit hole will get you to Einstein’s relativity.
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