What frequencies are present in a spark and its resulting hertzian waves?

In summary, when a high voltage capacitor generates a spark and nearby radio crackles, it shows that primitive radio waves known as hertzian waves are also generated. Similarly, a bolt of lightning also produces hertzian waves. Just like a stretched wire produces a fundamental pitch and its harmonics, hertzian waves also have a fundamental wavelength and harmonics. However, due to the properties of the medium, some frequencies may be attenuated more than others, resulting in resonant frequencies like the Schumann resonances.
  • #1
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A high voltage capacitor is charged and then the two leads are shorted together generating a spark, simultaneously a nearby radio crackles. This shows us that when the spark was generated radio waves was also generated. These primitive radio waves are sometimes called hertzian waves. A bolt of lightning also generates hertzian waves.

My question is about the nature of the waves produced. When a bolt of lightning strikes the ground dose it produce a predominant frequency wave along with its harmonics?

Let me explain with an analogy, a stretched wire when plucked produces a fundamental pitch but simultaneously pitches are produced which are harmonic multiples of the fundamental pitch. If a stretched wire produced a fundamental pitch of 100hz then it will also produce pitches of 200, 300, 400hz etc

When a hertzian wave is produced dose it also have a fundamental wavelength along with harmonics which are multiples of the first?
 
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  • #2
A spark will act as an impulse, generating a wide bandwidth. The properties of the medium in which the waves propogate will attenuate some frequencies more than others, so the long-time behavior will result in the appearance of resonant frequencies (Schumann resonances, for example).

Here's a fun website- audio recordings of the "audio" portion of the EM spectrum during thunderstorms:

http://www-pw.physics.uiowa.edu/mcgreevy/
 
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  • #3
Thanks for the info Andy...it still leaves my question unanswered though:biggrin:
 
  • #4
When a hertzian wave is produced dose it also have a fundamental wavelength along with harmonics which are multiples of the first?

i think he did in the first line...

A spark will act as an impulse, generating a wide bandwidth.

all frequencies are available in the impulse response...and generally are of the same magnitude...
the resonances (schumann) he described are the resulting peaks of atmospheric filtering...because of the size of the cavity namely height from land to top of atmosphere and space around the earth...the rest are absorbed more quickly...
 

1. What are Hertzian waves?

Hertzian waves, also known as electromagnetic waves, are a type of wave that propagate through space and carry energy in the form of electric and magnetic fields. They are named after German physicist Heinrich Hertz who first demonstrated their existence in the late 19th century.

2. How do Hertzian waves differ from other types of waves?

Hertzian waves are different from other types of waves in that they do not require a medium to propagate. This means they can travel through a vacuum, unlike mechanical waves which require a medium such as air or water to travel through.

3. What are harmonics in relation to Hertzian waves?

Harmonics refer to the frequencies that are multiples of the fundamental frequency of a wave. In the context of Hertzian waves, harmonics are the frequencies that are multiples of the frequency of the original source of the wave, such as a radio transmitter.

4. How are Hertzian waves used in everyday life?

Hertzian waves are used in various technologies that we use every day, such as radio, television, and wireless communication devices. They are also used in medical imaging, such as MRI machines, and in radar technology used for navigation and weather forecasting.

5. What are the potential risks associated with exposure to Hertzian waves?

There is ongoing debate and research on the potential health risks of exposure to Hertzian waves, particularly from sources such as cell phones and Wi-Fi. Some studies have suggested a possible link between long-term exposure to high levels of Hertzian waves and certain health issues, but more research is needed to fully understand the potential risks.

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