I had been nonplussed by reports that Google were "floating" the idea for a balloon-distributed Internet.
Last night I had call from my brother in the US, where we discussed family news and other things, during the course of which I asked him what was the sense in the Google balloon idea.
I should mention here that I asked him this because I knew that he of all people could be prevailed upon to give a pretty useful answer. He is a boffin - an aerodynamics engineer - and has been absorbed in aircraft design problems for most of his life from teenager onwards. He doesn't talk much about his work, and is pretty offhand about it - e.g., describing the Boeing 787 (I think that was the one) as "really just a big plastic boat - I've got a small model in my yard" (referring to an old fibreglass dinghy that he has).
His answer to my question was not quite what I had expected though, and was quite educational. He said that the Google idea was an old concept - designs having been registered with the Patents office years ago - and feasible. As he described it, the idea was a logical extension of distributing the nodes of a network via geo-stationary satellites (per A.C. Clarke) - which was a humungously expensive approach, as you needed to send them up in rockets that would position the satellite at precisely the right point in space to achieve geostationary (orbit) equilibrium. Nearer stationary satellite nodes were also feasible and cheaper to put up, used mostly for military purposes, and their orbit slowly decayed during their working life until no longer required. The balloon idea was to give you some control over where the network nodes were positioned - you could move them around by "moving gas from one bag to another", which made them go up or down, and since you knew which layers of air or jetstreams in the stratosphere were moving in which direction, you could position them pretty much where you wanted.
I recall reading from WW2 history how this technique was used by the Japanese, who bombed the US during the war - by releasing the bombs from high altitude balloons carried from Japan and over the US by these jetstreams.
However, since the balloons idea was dependent on having a power supply, they had to carry it with them, and they stopped working when the power ran out.
What Google have apparently done is used modern technology (for batteries and solar cell power) in the design, to power the computerised control systems and to enable these balloons to have quite a feasible and relatively long working life. The network could literally be "in the clouds", though the ground stations and servers couldn't move up there as they required gigawatts of power.
Quite coincidentally I found this in my feed aggregator today. It provides quite a good summary of what Google is about, including a short explanatory video cartoon: How Google plans to use balloons to bring the Internet to some of the world’s most remote regions
I could be wrong, of course, but I reckon this might be a purely philanthropic move to distribute education - which at any rate is the impression given in the video cartoon.
EDIT: Also saw this a bit later: [G] Introducing Project Loon: Balloon-powered Internet access