Very good.And if you turn the element the element it turns
the deflected missile or what ever impinged on it, in a different
direction. This is exactly why the question was stated the way that it
was, a little bit of knoweledge based on conventional
teachings(waves) that becomes distorted when people reverse the notion
that a yagi design is a subset of radiation. in the exploration of the
field and waves subject, When exploring radiation in its truest sense
you are dealing with the interaction of different fields which is not
predicated solely on element length
Since the yagi is designed for a specific purpose or parameters
one can then parrot other factors that are relavent only to this
particular design such as the idea element length determines what is a
director or a reflector such as a pin ball machine in a arcade which
generate sweeping terms or semantics.It is always better to pass on
accepted teachings in answer to any question than generating an answer
you think should have been asked on the assumption that the receiver is
not smart enough
to understand the correct response and is to be given a simplistic
response without caveates.
Art