As light travels across the universe, its interaction with various objects and phenomena can cause it to exhibit different colors at different points in its journey. The phenomenon you are referring to is known as absorption and scattering.
When light passes through a medium such as a gas, liquid, or solid, it can interact with the atoms or molecules present. These interactions can cause certain wavelengths of light to be absorbed by the medium, while others are transmitted or scattered. The absorbed wavelengths correspond to specific colors, resulting in the perception of different colors.
For example, if white light (which contains all visible colors) passes through a prism, the light is dispersed, and you can see a spectrum of colors ranging from red to violet. This is due to the different wavelengths of light being bent or refracted at different angles as they pass through the prism.
In the context of space, there are several scenarios where light can exhibit different colors:
Atmospheric Effects: When light from celestial objects such as stars or galaxies passes through Earth's atmosphere, it can be affected by atmospheric gases, dust, and other particles. This interaction can cause scattering and absorption, resulting in the appearance of different colors. For instance, during sunrise or sunset, the scattering of shorter-wavelength blue light by Earth's atmosphere gives rise to the warm hues of red and orange.
Interstellar Medium: In the vast regions of interstellar space, there are clouds of gas and dust known as the interstellar medium. When light from stars passes through these regions, it can encounter interstellar dust grains or gas molecules. This interaction can lead to scattering and absorption, altering the light's color. The presence of different elements and compounds within the interstellar medium can contribute to the observed variations in color.
Gravitational Lensing: Massive objects like galaxies or galaxy clusters can bend the path of light due to their gravitational influence. This effect, known as gravitational lensing, can cause the light to follow a curved trajectory, resulting in magnification and distortion. In some cases, multiple images of the same source may be observed, and the colors of these images can vary due to differences in the path lengths and lensing effects.
It's important to note that the concept of "blocks" of different colors may not be a precise representation of the phenomenon. The transition between colors is typically gradual, as light interacts with different materials or encounters different conditions along its journey through space.