Final answer:
Contour lines that are close together on a map indicate a steeper slope, reflecting a greater change in elevation over a given distance.
Step-by-step explanation:
Contour lines that are close together on a map indicate a steeper slope when compared to lines that are more separated, which indicate a shallower slope or flatter terrain. This concept is similar to how isolines represent electric potential or gravitational potential in physics, where closer lines also signify a stronger field or steeper gradient. In geography, contour lines help visualize the topography of an area on a flat map, providing a sense of three dimensions by delineating the shape and elevation of the terrain.
As an example, consider Devil's Tower in Wyoming. When looking at a topographical map of this feature, the contour lines are densely packed together, which correlates to the very steep sides of the actual tower. Thus, the more tightly packed the contour lines, the steeper the aspect of the terrain they represent.