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Herz, the unit of frequency

Herz, the unit of frequency

On the previous page you saw that the wavy lines we use to depict waves are models that help us understand the properties of waves, like frequency and wavelength. Waves with a short wavelength have a high frequency and "change" often.

Oscillation

If you would want to impress your friends you would call this periodic changing of the wave "oscillation". When a wave oscillates once per second we say that it has a frequency of 1 Herz or Hz.

Another example of frequency is your heart rate. The average heart of a human at rest beats about 70 times per minute, which corresponds to a frequency of 70/60 =1.17 beats per second, or 1.17 Hz.

Der Heinrich

The "Herz" was named after Heinrich Herz, a German phycisit who expanded on the work of  James Clerk Maxwell, the scientist we talked about earlier. Below you see Heinrich Herz having his picture taken while bathing his feet at a Tahitian beach.

Heinrich Herz on the beach

Now that you now what wavelength and frequency are and how they are related, it is time to have a closer look at electromagnetic waves.  On the next pages you will learn more about the nature of electromagnetic waves. Brace yourselves, because this is where it gets a bit complicated. Let's start of by looking into how radio waves are generated.