Gib Bogle wrote:
On 27/09/2010 8:51 p.m., harry wrote:
On 27 Sep, 02:20, wrote:
On 26 Sep, 19:51, wrote:

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

Gravity powered aircraft? As useful as a lead Zeppelin.

Never a mention of friction.

That's just the start of the reasons for infeasibility.

Actually its ultimately not infeasible, just impractical and inefficient.

From a cursory glance (it deserves no more) all it is conceptually, is
a glider and a balloon. Balloon lifts glider, glider glides to where
it has to go.

The energy to turn a lighter than air volume of gas into a smaller
compressed volume that then acquires sufficient weight to act as a
glider, is not mentioned.