1. Reflection: This is the most common interaction. When a wave hits a barrier, it bounces back. The angle of incidence (the angle the wave hits the barrier) is equal to the angle of reflection (the angle the wave bounces off at). This is why you see your reflection in a mirror.
2. Diffraction: This occurs when a wave passes through an opening or around an obstacle. The wave bends and spreads out. The amount of diffraction depends on the wavelength of the wave and the size of the opening or obstacle. For example, if you shine a light through a small hole, the light will spread out on the other side. This is why you can see around corners even if you can't see directly into them.
Important Note: The specific interaction that occurs depends on several factors, including:
* The nature of the barrier: A rigid barrier will likely cause reflection, while a porous barrier might allow some transmission.
* The wavelength of the wave: Shorter wavelengths tend to reflect more, while longer wavelengths diffract more.
* The size of the barrier relative to the wavelength: If the barrier is much larger than the wavelength, reflection is more likely. If the barrier is similar in size to the wavelength, diffraction is more likely.
Let me know if you'd like to explore these interactions in more detail or have any further questions!
