Martin Gregorie wrote:
On Thu, 04 Dec 2008 18:51:18 -0800, wby0nder wrote:

http://www.youtube.com/watch?v=1IsaM...eature=related

How about that: perpetual motion resurrected yet again.

Doesn't appear to be. One notable non-perpetual motion aspect appears to be
taking advantage of the temperature differential between the lower
atmosphere and the upper atmosphere. That point _is_ rather clever, though
whether it can be taken advantage of with sufficient efficiency is another
story. This appears to be the original web site:

http://fuellessflight.com/

I think the core idea - taking advantage of that temperature difference -
appears lost by inclusion of too many extraneous details in the video. It
was also a mistake for the inventor to claim on his web site that the
"power cycle can be repeated indefinitely to allow the craft to stay aloft
virtually forever." Words like "indefinitely" and "virtually forever" are
self-defeating from a sales pitch angle. If the inventor had said the
following instead, I think he'd have less problems with claims of perpetual
motion:

"The power cycle can be repeated for as long as a temperature difference
exists between the upper and lower layers of the atmosphere - wherein the
airship utilizes them as a vast heat sink and a vast heat source. Enough
flights could, in theory, eventually "exhaust" the available energy
potential. Inventer would insert facts and math here, showing how that is
not a serious concern."