> rbwinn wrote:

>> The speed of sound is only 1,087 feet per second. �Half of that would
>> only be 543.5 feet per second. �That is not fast enough to change the
>> frequency of the light enough to worry about.

>
> Sure it is! This is how police radar and laser guns measure the speed of
> traffic, and they do so for motions ~100 times smaller. A laboratory
> instrument could measure speed thousands of times better than that.
>
> (Henri's "riddle" is utterly ridiculous, and shows how deep are his
> misunderstandings of very basic physics.)
>
> Tom Roberts