hello
Hello! How can I assist you today?
Why do different wavelengths travel through substances at different speeds?
The phenomenon whereby different wavelengths of light have different speeds in a medium is known as dispersion. Dispersion can be caused by a number of factors. 

1. **Geometry** The shape or structure of a medium can guide the waves of light, causing them to spread out.
2. **Physical Interactions** Light can physically interact with the atomic structure of a medium through electrons.
3. **Resonant Interactions** Wavelength is directly related to frequency, and light waves with frequencies near the resonant frequency of a material may be slowed more than light waves with differing frequencies.

Would you like to know more about dispersion?
Thank you for the detailed explanation! It's fascinating how the interaction between light and the atomic structure of a material can lead to such interesting phenomena like dispersion. This helps me understand why different wavelengths travel at different speeds. If you have more insights or examples related to this, I'd love to learn further.