Final answer:
The 5th dimension is a theoretical concept in physics beyond the three dimensions of space that we experience in our daily lives.
Step-by-step explanation:
The 5th dimension is not related to light. In physics, the concept of dimensions goes beyond the three dimensions (length, width, and height) that we experience in our daily lives. The 5th dimension is a theoretical concept in physics, often referred to as the fifth dimension of space or extra dimensions. It is used in various theories, such as String Theory and Superstring Theory, to explain phenomena that cannot be fully explained within the framework of our current understanding of the universe.