There are several kinds of machines called spectrographs, used to look at different waves.

It is very important to recognize that feminism has gone through its own transitions with the different waves.

How do scientists calculate the origin of an earthquake by detecting these different waves?

They do this with a seismograph, a machine that registers the different waves.

Then, some of the waves can be one way, while different waves are the other.

Some scholars believe they were different tribes who came as different waves of immigrants.

In this case, focusing is primarily due to different waves coming into phase, rather than any energy transfer processes.

It is called a complex because there are three different waves in it.

A second and totally different wave of anxiety swept over Quinn.

As you might suspect, there has been of late a tendency for strong alignment, and many different waves are running together, in phase.