"Sarah Hotdesking" wrote in message ...
I received this today:-

There are still people in this company who think we weigh aircraft to find
out how much they weigh, not to calculate stresses. Of course we need to
know how much the thing weighs. How are we ever going to know how many
Thrust Pixies we need to get the thing off the ground if we don't know the
weight? Or should that be "Lift Demons"? Pixies have largely fallen into
disrepute - something about Bernoulli not being representative in unbounded
conditions and cause and effect being transposed in the Newtonian model.

In fact the use of Lift Demons on civil aircraft programmes is generally not
that good an idea. The Demon binding contract tends to specify payment in
blood or souls. This is readily achievable with aircraft of military
function, but frowned upon in civilian circles as they may attempt to
acquire payment outside of the terms of their binding contract. Lift Demons
are not used on Elf bombers. We don't talk about Lift Pixies too often as it
seems to upset the self-loading cargo.

Pixies require payment in cakes, flowers or nice thoughts. These are readily
sourced either from the in-flight catering, or provided cost-free by the
passengers. Clearly this would not work well within an operational military
environment. Air force cooking is not renowned for the "light and fluffy
texture" that Thrust Pixies demand, the availability of flowers might be
problematic in desert operations, and nice thoughts may also be hard to find
during times of active operations.

There is also a scalability issue. While one rampant Lift Demon would have
few problems supporting a fighter aircraft (particularly if there is an
immediate prospect of blood), it'll struggle to achieve level controlled
flight of a 560tonne Airbus A380. Use of more than one Lift Demon on the
same flight vehicle is contra-indicated (they squabble and eat each other).
Communities of Thrust Pixies can be encouraged to work together on the same
aircraft by the provision of advanced technologies such as Lemon fondant
icing, variegated tulips or in-flight romantic comedies.

Ryanair once requested Leprachauns be installed in place of Lift Pixies, but
leprechauns have a mission statement which indicates their desire for
monetary gain, and their willingness to search all over the world for it.
This makes Lift Leprechauns expensive to keep (gold vs lemon fondant icing),
and makes it difficult to establish a regular route network as the Lift
Leprechauns don't like to continuously visit the same locations. By law,
aircraft also have to have a full complement of In-Flight Gremlins, but
these are generally not a problem unless you feed the Wingtip Vortex Faeries
after midnight.

http://www.bewilderingstories.com/special/cyrano0.html
Perhaps the Lift Pixies live in dew, example:

But Cyrano wrote for a larger audience. He wrote much flashier stuff.
It took the hero of his book, Voyage to the Moon, several attempts to
get there. And what means he used!

He surrounded his body with glasses of morning dew. When the sun drew
the water up, it drew him with it. A group of soldiers tied their
ordnance to his flying machine and, like a modern rocket, it rose into
the sky.

As yet, Cyrano has not had a chance to get a word in edgewise, let
alone evince any surprise that Earth-Moon traffic has been as heavy as
Elijah seems to suggest. But he must be taking notes on propulsion
systems. Almost all the classical elements — earth, air, fire and
water — have been used in one way or another so far. To recapitulate:

Fi Enoch uses the Heaven-bound smoke from his sacrifice. (This
might also qualify as hot air.)
Cyrano is launched from Quebec by rockets.
Water: Cyrano uses water for flight, namely the dew in the flasks that
carry him from France to Canada.
The Ark, carried by the Flood, takes Achab to the Moon.
Earth: The Moon's attraction of Cyrano's beef-marrow ointment may, at
a stretch, count as a use of dirt mode.
Air: Enoch's robe serves as a parachute.
Adam and Eve use levitation for flight. (This seems to be a special
case.)
and
"Next I had a very light iron chariot constructed. In a few months,
when all my devices were complete, I climbed onto my worthy chariot.
You may ask what it was all for. Well, the angel had told me in my
dream that if I wanted to acquire the perfect knowledge I desired, I
would have to go to the Moon. There I would find Adam's paradise and
the Tree of Knowledge. As soon as I had tasted its fruit, my mind
would be enlightened with all the truths a person could know. That is
the voyage for which I built my chariot.

"Finally, I climbed aboard and, when I was securely settled on the
seat, I tossed the magnetic ball high into the air. The chariot I had
built was more massive in the middle than at the ends; it was
perfectly balanced because the middle rose faster than the
extremities. When I had risen to the point that the magnet was drawing
me to, I seized the magnetic ball and tossed it into the air again."

The scientific world has progressed very little since the 17th
Century, the only expansion seems to be budgetary.