Yes, I have and he understands that a pressurized environment must exist for a plume to form.
Do his superiors and the engineers that designed the equipment he works on understand it?
Of course they do.
If he were to ask the people who trained him about rockets and vacuums what would they say?
Pretty much the same thing I am.
Are you smarter than them or are they lying to hide the truth?
Lying about what?
You have an admirable confidence that:
a. You have understood what your nephew means, and vice versa.
b. You nephew has fully understood what he has been taught.
c. The jet engine designers, engineers and technicians are also in accordance with you.
However;
http://www.valentiniweb.com/piermo/meccanica/mat/Rolls%20Royce%20-%20The%20Jet%20Engine.pdf This is a link to a pdf version of a go-to publication in the UK, and also much of the English-speaking world. It is called "
The Jet Engine" (ISBN 0 902121 2 35) and its published by Rolls Royce, who know a couple of things about them. The book is standard reading for anyone in the UK who is embarking on a career in aircraft engines. It outlines the principles of theory, design, construction and maintnenane, and not just of Rolls Royce products.
I draw your attention to Part 1 "Basic mechanics", page 2, Paras 6 thru 9:
6. Jet propulsion is a practical application of Sir
Isaac Newton's third law of motion which states that,
'for every force acting on a body there is an opposite
and equal reaction'. For aircraft propulsion, the 'body'
is atmospheric air that is caused to accelerate as it
passes through the engine. The force required to
give this acceleration has an equal effect in the
opposite direction acting on the apparatus producing
the acceleration. A jet engine produces thrust in a
similar way to the engine/propeller combination. Both
propel the aircraft by thrusting a large weight of air
backwards (fig. 1-3), one in the form of a large air
slipstream at comparatively low speed and the other
in the form of a jet of gas at very high speed.
7. This same principle of reaction occurs in all forms
of movement and has been usefully applied in many
ways. The earliest known example of jet reaction is
that of Hero's engine (fig. 1-4) produced as a toy in
120 B.C. This toy showed how the momentum of
steam issuing from a number of jets could impart an
equal and opposite reaction to the jets themselves,
thus causing the engine to revolve.
8. The familiar whirling garden sprinkler (fig. 1-5) is
a more practical example of this principle, for the
mechanism rotates by virtue of the reaction to the
water jets. The high pressure jets of modern firefighting equipment are an example of 'jet reaction',
for often, due to the reaction of the water jet, the hose
cannot be held or controlled by one fireman. Perhaps
the simplest illustration of this principle is afforded by
the carnival balloon which, when the air or gas is
released, rushes rapidly away in the direction
opposite to the jet.
9.
Jet reaction is definitely an internal phenomenon
and does not, as is frequently assumed, result from
the pressure of the jet on the atmosphere. In fact, the
jet propulsion engine, whether rocket, athodyd, or
turbo-jet, is a piece of apparatus designed to
accelerate a stream of air or gas and to expel it at
high velocity. There are, of course, a number of ways .....
I can find no mention of "
plume" in the book, but be my guest. Perhaps you could discuss this further with your nephew.
Edit; my Bold, btw.