On Wed, 16 Jan 2008 07:00:15 -0800 (PST)
Keith Dysart wrote:

On Jan 15, 2:27*pm, Roger Sparks wrote:
On Tue, 15 Jan 2008 06:44:05 -0800 (PST)

Keith Dysart wrote:
[snip]

The difficulty is that some waves definitely transport
energy while others do not and I do not see a good
explanation for what turns the former into the latter,
as happens, for example, when the pulses collide.

Some waves transport energy, and some do not! *That distinction bothers me less now that I have participated in this thread for a while. *For me, the traveling wave always has current and voltage in phase, and always carries power. *If I can not find power, then we must have a standing wave. *For me, traveling waves is all that we really have, they are primary. *All other waves flow/result from the traveling waves. *

But then do the two travelling waves that make up the standing wave
transport
energy? When no energy crosses the voltage or current zeroes?

I can see that my question of how polarity changes on either side of a zero voltage point, and my example of a measurement accross the zero voltage point, did not shake your assumption that no energy crosses the zero voltage point. Having the assumption that energy does not pass the zero voltage point strikes at the heart of the traveling wave concept. I can not see what would reflect the waves to prevent energy passage at the zero voltage point, nor can I see a way to get the results we see between reflection points, if we disallow energy passage at zero voltage points.

And when there are multiple reflections, there are multiple travelling
waves
in each direction. Do each of these multiple travelling waves
independantly
transport energy?
Yes. They merge if they are of one frequency, so tracing of multiple traveling waves is reduced to just the last forward and reflected wave. If the waves are of different frequency, they would each be traced by frequency.

And even a standing wave has energy moving. Just not past the voltage
and
current zeroes.

Again, I would consider the traveling wave concept defeated if energy is not allowed to pass the zero voltage point. I think that the change of polarity on each side of the zero voltage point is a convincing argument that energy does pass. A change in measurement point to measure across the voltage point is also convincing to me, that energy must pass. I would hope that those arguments convince you as well.

[snip]

...Keith
73, Roger, W7WKB