- #1
DoobleD
- 259
- 20
The E and B field lines of a dipole radiating EM waves looks like that (sorry for the poor quality) :
What I wonder is how can we see that the amplitude of the fields decrease as 1 / r? When you look as such a picture it actually feels likes the amplitude should rises. The E field gets "elongated".
But I know that the radiated energy is spread over a growing sphere/torus like shape, thus the fields amplitude must weaken over time and distance.
I don't understand how the fields weakens when I look at those EM radiation drawings.
What I wonder is how can we see that the amplitude of the fields decrease as 1 / r? When you look as such a picture it actually feels likes the amplitude should rises. The E field gets "elongated".
But I know that the radiated energy is spread over a growing sphere/torus like shape, thus the fields amplitude must weaken over time and distance.
I don't understand how the fields weakens when I look at those EM radiation drawings.