One reason, safety experts say, is the different density of suburban development.

Because of their different density we can see a clear line there that show their ridge.

Otherwise, you'll find that each print has a different density.

"I'm getting two different densities for this patch of the hill," I said.

Think about this: How can two objects of similar volumes have different densities?

Gases, such as air, have different densities at different temperatures.

The two states have different densities, I've come to think.

Some manufacturers even offer different densities to offer better protection.

The light and dark areas on the film correspond to regions of different physical density in the patient's body.

If water contains differences in salt content or temperature, then the different densities will initiate a current.