Signal Sleuths: Uncovering Radio Frequency Interference
Electromagnetic Waves
Figure 1: A drawing representing an electromagnetic wave. Image courtesy of petrroudny on Adobe stock.
In Figure 1, the electric field is shown in red and the magnetic field is shown in blue. These two fields are at right angles to each other, which means they form a 90-degree angle where they meet. To help understand this, try this with your hands: stretch out your right hand with your palm facing you and your fingers pointing to the ceiling. Then, turn your left hand so that your palm faces the floor and your fingers point to the right. Put your hands together, keeping both hands straight. You’ll see that where they meet, the angle between them is 90 degrees, which is called a right angle (Figure 2).
Figure 2: Modeling the position of the electric and magnetic field. Where the two hands meet it a 90 degree angle which means they are perpendicular to one another.
Figure 1 also shows something called the "propagation direction," which is the direction the energy moves in. To understand this, try the hand exercise again, but this time think of your right hand as the electric field and your left hand as the magnetic field. Scientists use something called the "right-hand rule" to figure out the direction the energy travels. If you curl the fingers of your right hand from the electric field to the magnetic field, your thumb will point in the direction the energy is moving (Figure 3).
Figure 3: Using the right-hand rule to determine the direction of energy movement.
This work is funded through NSF Award # 2232159
