Rich Posted July 26, 2012 Report Share Posted July 26, 2012 18 mile skydive! What a view though http://www.dailymail...ILES-Earth.html Quote Link to comment Share on other sites More sharing options...
Tony Posted July 26, 2012 Report Share Posted July 26, 2012 Red Ball can get you to do anything....... Quote Link to comment Share on other sites More sharing options...
Tango Posted July 26, 2012 Report Share Posted July 26, 2012 Not much progress made over the last half century then, he didn't even match the original height record which was set 50 years ago. Quote Link to comment Share on other sites More sharing options...
Rich Posted July 26, 2012 Author Report Share Posted July 26, 2012 He's hoping to break that record next month and the sound barrier using just his body. TBH though how much higher can you go before gravity carries you away. Quote Link to comment Share on other sites More sharing options...
Tony Posted July 26, 2012 Report Share Posted July 26, 2012 Surely the balloon can't float into space..... can it? Quote Link to comment Share on other sites More sharing options...
phipck Posted July 26, 2012 Report Share Posted July 26, 2012 gravity will still hold you for some distance yet! just think about the moon, which is trapped in an orbit. but the balloon couldnt get you much further out i dont believe because of the principal it uses to rise, air pressure decreases as you rise, so at some point the balloon would become inefficient at escaping further Quote Link to comment Share on other sites More sharing options...
GamithUK Posted August 3, 2012 Report Share Posted August 3, 2012 TBH though how much higher can you go before gravity carries you away. I am struggling to understand what you mean here, as philck says gravity carries for a long way. If you're thinking of geosynchronous orbit then he is (still) about 22,000 miles too short (http://www.centennialofflight.gov/essay/Dictionary/GEO_ORBIT/DI146.htm) so in the grand scheme of things he's still on the surface. The balloon is another interesting area - it will keep rising but at some point the balloon will pop. The problem is that at ground level a helium 'filled' balloon has a relatively little amount of helium in it - just enough for it to lift off. As the balloon rises the air pressure decreases and the helium inside expands to fill more of the balloon, as it gets higher the balloon will eventually be 'full', ie where it cannot get physically larger, and since helium is still lighter than the atmosphere it will keep rising - and eventually it pops. (http://www.frars.org.uk/cgi-bin/render.pl?pageid=1385) According to this the atmosphere extends to about 300 miles, so even then I suspect an extreme balloon could go a lot higher. This radio balloon got to almost 26 miles for example. hmm - enough research for now I think, have to empty the dishwasher.. ttfn Quote Link to comment Share on other sites More sharing options...
Tony Posted August 5, 2012 Report Share Posted August 5, 2012 No doubt a stupid question but could a balloon get to space if it's expansion was limitless? Quote Link to comment Share on other sites More sharing options...
Sagitar Posted August 5, 2012 Report Share Posted August 5, 2012 No doubt a stupid question but could a balloon get to space if it's expansion was limitless? No; not in any practical sense. A balloon floats in the fluid that surrounds it. If the total weight of the balloon is less than the weight of the fluid that it displaces, it will rise. If its total weight is greater than the weight of the fluid that it displaces then it will descend. Since the weight of a unit volume of the atmosphere decreases with altitude and the volume of the balloon is proportional to the pressure difference across the balloon membrane, the balloon will rise or fall until its weight is exactly balanced by the weight of of the fluid that it displaces, at which point it will be in stable equilibrium, neither rising nor falling. To continue to rise into space (which is a hard vacuum i.e. no fluid), the balloon would have to be weightless, or at least of infinite size. Quote Link to comment Share on other sites More sharing options...
GamithUK Posted August 5, 2012 Report Share Posted August 5, 2012 No doubt a stupid question but could a balloon get to space if it's expansion was limitless? Or, put another way, space is empty - a balloon needs to operate in a non-empty environment so that it's filling is 'lighter' than it's surroundings. A balloon will rise until its lift equals it's mass. So no - a balloon cannot reach space by definition. It can get a decent way up though, certainly for most people to see the curvature of our planet and say 'wow'. I find this stuff fascinating. ttfn Quote Link to comment Share on other sites More sharing options...
Sagitar Posted August 6, 2012 Report Share Posted August 6, 2012 Good stuff - but lift must equal weight, not mass. Quote Link to comment Share on other sites More sharing options...
andyelcomb Posted August 6, 2012 Report Share Posted August 6, 2012 No; not in any practical sense. A balloon floats in the fluid that surrounds it. If the total weight of the balloon is less than the weight of the fluid that it displaces, it will rise. If its total weight is greater than the weight of the fluid that it displaces then it will descend. Since the weight of a unit volume of the atmosphere decreases with altitude and the volume of the balloon is proportional to the pressure difference across the balloon membrane, the balloon will rise or fall until its weight is exactly balanced by the weight of of the fluid that it displaces, at which point it will be in stable equilibrium, neither rising nor falling. To continue to rise into space (which is a hard vacuum i.e. no fluid), the balloon would have to be weightless, or at least of infinite size. I'll bet you wish you hadn't asked now, don't you Tony?! Great answer as always Sagitar - thanks! Quote Link to comment Share on other sites More sharing options...
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