Posted by grim (206.162.192.39) on October 03, 2003 at 04:34:58:
In Reply to: Boyancy Drive posted by ovyyus on October 03, 2003 at 03:17:18:
That "vacuum" story is as old as lighter-than-air flight itself. There's an old illustration that depicted four spheres with a vacuum pulled inside them, lifting a passenger basket.
The only problem is that for the vacuum inside to lift, the spheres had to be very lightly constructed, and still be strong enough for the surrounding atmospheric pressure not to crush them.
Unfortunately that wasn't happening.
For his "glider" to be stout enough for a strong vacuum to be pulled in it, or any part of it, it would already be too heavy for the vacuum to lift it.
I've got a freon recovery tank here in my office that's under a 29.87" vacuum left in after I dehydrated it by that means. Guess it better be tied it down! :-))
Regards
grim