On 27 Sep, 12:04, The Natural Philosopher
wrote:
Gib Bogle wrote:
On 27/09/2010 10:12 p.m., The Natural Philosopher wrote:
Gib Bogle wrote:
On 27/09/2010 9:49 p.m., The Natural Philosopher wrote:
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.

The whole system is claimed to be self-sufficient. As I recall the
compression
is powered by the propellers acting as turbines as the plane glides
down. It's
perpetual motion.

Oh? I couldn't be arsed to listen that far.

There was one interesting idea that was mooted, that on analysis I
couldn't find
a flaw with: A wind powered boat or vehicle that could sail or drive
directly
into the wind using a turbine facing the wind to drive a water prop or
wheels..

This seems plausible

also said to be capable of going faster than the wind..directly
downwind..less sure about that, though.

Faster than the wind, downwind? *I don't think so. *As the relative
velocity goes to zero, so does the extractable power. *With a big, high
kite you could go faster than the wind at ground (or water) level.

That was more or less my thought.- Hide quoted text -

- Show quoted text -

Mistaken as usual.
http://en.wikipedia.org/wiki/Sailing..._than_the_wind