When light reflects on an object. Let’s say the object is red, does the object itself actually do anything? Like physically?

Answer 1

When light reflects off an object, the object itself plays an essential role in determining how the light is reflected and what color we perceive the object to be. Physically, here's what's happening:

1. The surface of the object interacts with the incoming light. The properties of the surface, such as its smoothness, texture, and material composition, determine how the light is reflected. For a red object, the surface is typically structured in such a way that it reflects red wavelengths of light more efficiently than other wavelengths.
2. When white light (which contains all visible wavelengths) hits the object, certain wavelengths are absorbed while others are reflected. A red object absorbs most of the non-red wavelengths and reflects the red wavelengths. This is why the object appears red to our eyes.
3. The specific molecules and atomic structures of the object’s material are responsible for the selective absorption and reflection of light. For example, pigments or dyes in the object have particular molecular structures that absorb some wavelengths of light and reflect others, contributing to the object's color.
4. Some of the light energy that is absorbed by the object may be converted into heat, causing the object to warm up slightly. This conversion happens because the absorbed light energy causes the molecules in the object to vibrate more vigorously, increasing their thermal energy.

In summary, the object does indeed "do something" physically when light reflects off it. Its material properties and molecular structure determine which wavelengths of light are absorbed or reflected, and this interaction is what gives the object its perceived color. Additionally, some of the absorbed energy is converted into heat.