# Wavefront of a wave?

I'm trying to understand the idea behind a wavefront in a visual manner.

Take a look at these surface waves in water Now imagine if I sliced it twice, through the origin, in a vertical plane. I'd get something like this: 1. So one can imagine a wave in 3D as being comprised of infinitely many squiggly 2D waves (height, time), all aligned in a circular fashion, perpendicular to the plane of the paper, correct? This wave would have no thickness (depth in water) at all, correct? It would resemble a very thin film with a peak and trough (squiggly) surface?

The first circle with origin at the point source, passes through all the peaks of the waves; the second circle passes through all the troughs.

1. The outermost expanding circle (not drawn) represent the 'wavefront' of the wave because the wave is traveling through the medium? This circle is growing larger with the passage of time and eventually at infinity, will look like a line to a point-observer in 2D (time, distance-from-origin)

2. In 3D this circle would represent a plane IF THE wave has thickness which it didn't when we imagined it! ? Otherwise it would remain a circle in 3D?

In the wikipedia, about Wavefronts when he says "The wavefronts of a plane wave are planes." plane-waves would have thickness and depth like in water? So, it's like infinitely many sine waves stacked one on top of another as they travel through water, each sin waves end would represent a single point in the plane that the observer would see traveling towards him?

• In physics, a wavefront is the locus of points having the same phase: a propagation of a line in 1d, a curve in 2d or a surface for a wave in 3d. - see the definition in Wikipedia. – Sofia Jan 22 '15 at 13:43
• yep, seen that - didn't understand. In school we talk of sine waves, right - And we draw them as a squiggle and then we get it's amplitude, frequency, phase etc with just that single squiggly thing. However in 3d space what is this wave? It can be visualized as infinitely many squiggly single waves ALL of them perpendicular to the plane of an infinitely dimensioned piece of paper, with the waves traveling in 360 degrees from center, right? Like if a stone is dropped into a pond: what is the wavefront? It's a circle? Or the ocean waves, the surfer is a point on the wavefront (of a plane wave)? – user41776 Jan 22 '15 at 14:28
• It seems you are badly confused.you need to read more about waves from your book. then come here . – Paul Jan 22 '15 at 15:22
• would the height (measured on the y-axis) of the wavefront vary with time (measured on the x-axis)? – user41776 Jan 22 '15 at 17:32