4. Metrics, In Terms of Time and Space
It’s helpful to explain what metrics are and how they are used to determine the distance that space is expanding. A metric defines the concepts of the distances between two points in space.
It’s how we measure things throughout the universe and is known as a spatial coordinate system. This system can locate two different points in space and assign them unique positions.
The metric, or formula used, will then determine the distance between these two points. We may think that the distance between the two chosen points would be in a straight line, but in space, this isn’t always the case.