Astronomy Fundamentals

Time, Waves, and Particles

What is space?

Most people think of space as merely the absence of anything else—the “nothing” that surrounds objects in the universe. Actually, space is the fabric in which everything in the universe is embedded and through which all things travel. Imagine, for example, a gelatin dessert with pieces of fruit suspended within it. The fruit represents the objects in the universe, while the gelatin represents space. Space is not “nothing”; rather, it surrounds everything, holds everything, and contains everything in the universe.

Space has three dimensions, usually thought of as length (forward-and-back-ward), width (left-and-right), and height (up-and-down). It is possible to curve space, though, so that a dimension might not represent a straight line.


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