- Tue Nov 08, 2005 11:16 am
A geodesic dome half a mile across, filled with air can generate a lift of 10,000 tons for a temperature difference of 1 deg F between inside and outside.
The catch is that even with a light weight reinforced plastic the thickness of the skin cannot be more than 1/12 of an inch for it to lift itself up. Such a structure is unlikely to have the needed mechanical stability.
There is a further complication that as the blimp rises the outside air density falls quite a bit due to altitude, which of course means additional temperature increase needed to compensate this. What has been suggested is a giant hot air ballon for commercial purposes.
My fear is that it might remain just that much hot air. Actually about 10 raised to the power 10 cubic feet of hot air for a dome half a mile across.
Please see the posting by markshian in the creativity pool on 'Helium backpacks'.