The responses from the professors frankly baffle me. If that's what they
said, and if they meant what you think they mean, then yes, I disagree
with the professors. Folks will have to decide whether to believe them,
or me, or learn more about antenna operation so they can come to their
own informed conclusions.

I won't comment on the Navy training manual, recalling some of the
simplifications made in the equivalent Air Force documents in an effort
to make electronics understandable by the target audience.

Roy Lewallen, W7EL

David wrote:
Various books claim that a ground plane reflects the radio wave emitted by
the vertical, and then claim that a ground plane is formed or simulated by
four elevated radials.
I emailed two Professors of antenna theory about this.

Reply from Professor Constantine Balanis:
"The radials should act more as a ground plane. Four of them are usually the
minimum. The more of them, the better the ground plane. The objective of the
ground plane is to reflect the energy from the main element; the vertical
wire".

Reply from Professor Vincent Fusco:
"My view would be that the radials form an image plane, the radials
themselves do not radiate".
. . .