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Boballoo
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What can we tell about the medium a wave has traveled through?
Summary: What can we tell about the medium a wave has traveled through?

What can a wave tell us about the media, whether it is space, water, air or whatever, that it has passed through? Does it have some "memory" or hint of what it has previously passed through? I am thinking mostly of different densities in space that a wave such as a gravity wave, has traveled through. Can we sort the waves out somehow like we can with light?

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Well, nearly everything we know about the properties of matter we know from investigating it with electromagnetic waves of different wavelengths. E.g. with X rays for the first time the crystal-lattice structure of solids has been demonstrated in 1912 by Max von Laue (Nobel prize 1914).

Gold Member
The science of acoustics provides methods to measure and understand the physical media through which mechanical waves travel. Sonar analyses objects and conditions in water. Echo-location provides information for bats in air and cetaceans in water and air.

As stated above RADAR and similar electromagnetic technology provides a wealth of information about conditions and objects subject to electromagnetic fields.

Gold Member
Essential to seismography and tomography (MRIs & CAT scans for example); even simple xrays. You could look those up. To first order the characteristics of the medium are velocity of propagation, the impedance of the material, and loss (absorption). When waves cross a boundary between different materials (different impedances) they can reflect (all or partially). This can be analyzed by many different techniques.

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Mentor
Welcome to the PF.
What can a wave tell us about the media, whether it is space, water, air or whatever, that it has passed through?
Waves, Optics and EM propagation are fascinating subjects. What is your background in math so far? It is easier to describe the Wave Equation and related topics and wave propagation in various media if you are comfortable with calculus. If you haven't studied calculus yet, that's okay, we can try to help you get an intuitive understanding of how waves propagate through media and across the boundaries between media.