Interpreting Imaginary Component Amplitudes in Fourier Series

In summary, the conversation discusses the physical interpretation of a non-zero imaginary part of a component amplitude in a Fourier series representation of a wave. It is explained that the imaginary factor does not have a direct physical meaning, but taking the real and imaginary parts of the term can provide useful information. The imaginary factors can arise from differential equations or harmonization processes in plasma physics.
  • #1
da_willem
599
1
If you express a wave as a Fourier series like:

[tex]z(x,t)= \sum _{n=1} ^{ inf.} A_n cos(nk_0 x - \omega (n) t )[/tex]

Then what is the physical interpretation of a non-zero imaginary part of a component amplitude?
 
Mathematics news on Phys.org
  • #2
da_willem said:
If you express a wave as a Fourier series like:

[tex]z(x,t)= \sum _{n=1} ^{ inf.} A_n cos(nk_0 x - \omega (n) t )[/tex]

Then what is the physical interpretation of a non-zero imaginary part of a component amplitude?


Hi Willem

Somebody wants to prevent me from helping you out here so i have written this answer for you


regards
marlon
 
Last edited:
  • #3
I read your word document, and would like to thank you very much for that. But maybe I should have specified my question some more, it is still not very clear to me...

If you want to describe a real wave in a formula you give it's height as a function of position and time. A height cannot be imaginary. So when an imaginary component amplitude appears in you Fourier representation of that wave there must be somethig wrong. This component cannot be canceled by another component can it? Is the appearance of an imaginary component in the sum a mathematical curiosity, or does it simply never appear for a real signal, or...?
 
  • #4
da_willem said:
I read your word document, and would like to thank you very much for that. But maybe I should have specified my question some more, it is still not very clear to me...

If you want to describe a real wave in a formula you give it's height as a function of position and time. A height cannot be imaginary. So when an imaginary component amplitude appears in you Fourier representation of that wave there must be somethig wrong. This component cannot be canceled by another component can it? Is the appearance of an imaginary component in the sum a mathematical curiosity, or does it simply never appear for a real signal, or...?


The imaginary factor does not have a real and direct physical meaning. When you take the real and imaginary parts (Re and Im) of this complex term you get physical useful info, just as explained in my word-doc.

As an example : these complex factors in the wave-equation often arise from the differential-equations that describe the physical system or from a process called harmonization that is used in order to set up the MHD-equations that describe the classical plasma-physics


regards
marlin
 

Related to Interpreting Imaginary Component Amplitudes in Fourier Series

1. What are imaginary FS components?

Imaginary FS components refer to fictional or hypothetical elements that are used in scientific models or theories to represent a concept or phenomenon. They do not exist in the physical world but are used as a tool for understanding and explaining complex ideas.

2. How are imaginary FS components used in science?

Imaginary FS components are used in science to simplify complex concepts and make them easier to understand. They can also be used to test theories and make predictions about real-world phenomena.

3. Are imaginary FS components considered reliable in scientific research?

Imaginary FS components are not considered reliable in scientific research as they are not based on empirical evidence. They are used as a tool for understanding and exploring ideas, but they cannot be used as evidence to support a hypothesis or theory.

4. Can imaginary FS components be proven or disproven?

Since imaginary FS components are not based on empirical evidence, they cannot be proven or disproven. However, they can be useful in developing and testing theories, which can then be supported or refuted by real-world evidence.

5. Are there any drawbacks to using imaginary FS components in science?

One potential drawback of using imaginary FS components is that they may oversimplify complex concepts and lead to incorrect assumptions or conclusions. It is important for scientists to be aware of the limitations of using imaginary components and to validate their findings with real-world data.

Similar threads

Replies
2
Views
3K
  • General Math
Replies
33
Views
2K
Replies
1
Views
594
Replies
5
Views
966
Replies
1
Views
1K
  • General Math
Replies
1
Views
1K
Replies
23
Views
4K
Replies
15
Views
2K
  • Calculus and Beyond Homework Help
Replies
6
Views
316
Replies
9
Views
2K
Back
Top