On some graphs representing waves, the horizontal axis is marked as space (
x), on other graphs the horizontal axis is marked as time (
This is the example for space:
This is the example for time:
Personally, I first started to represent waves by means of phasors: the projection of point travelling along the circumference perfectly represents some physical quantity oscillating around one specific point in space. For me it became natural to think of the circumference representing time.
Later I saw wave graphs where time was a straight line. Although this representation seemed odd to me at first, I started to realize that it's just another "system of coordinates" representing the same thing.
But then I started to read about wavelength. They used graphs with straight line and marked the wavelength on them. I was a bit puzzled how time axis may be used to show distance, until I noticed that the straight line was marked not with
t, but with
I was a little astonished. Can anybody explain why the wave graph is the same no matter if we use time or space on horizontal line. And how to show wavelength on phasor and on graph with straight line marked with