John Smith I wrote:

...
Jimmie:

Yanno, Cecil is like that, just when you think you have a handle on
things--HE chucks a monkey wrench in it!

If you are traveling away from me, at the speed of light, and you are
transmitting to me--wouldn't you be "stretching" that rf wave "flat." In
effect, what I see is a DC signal (well, actually I don't see
anything.) Owing to the doppler effect?

Now, if you exceed that speed of light, what happens to that rf you are
emitting? I'll have to think on that one a bit ...

Warmest regards,
JS

Yanno, an analogy has stuck me.

If I know what speed waves travel in water and I stand on the shore of a
lake and have a boat, making waves, travel away from me, I should be
able to see the first case. Then, when the boat exceeds that speed, I
should also be able to see the results ...

Trouble right now is, I don't know the speed of waves in water and I
don't have a boat. To tell you the truth, can't even remember what the
waves looked like when I have had past opportunities ...

Regards,
JS