Strictly speaking, most of Google Earth's high-res stuff is aerial photography, and not from space.... But that doesn't make it any less impressive. Or me any less jealous, haha.

Buy some small PVC fittings. Make a neat little spudgun with a pistol-grip. Build it just like the bigger ones, but scale everything down. Extra points for using pressure rated fittings. They're safer (though not strictly neccessary in tiny cannons), but they also look much nicer IMHO.

Well... No. That is rough as guts, and not really safe at all. Soda bottles are even better than what you're using, as they are designed for pressurized, carbonated drinks. The bottle you're using isn't. On the other hand, it's a very small cannon. It isn't very energetic and thus any failure will b...

I've built a few little vortex cannons before, and I think your problems are that the shape is incorrect on this scale, and you are using way too much air. One of the most effective ones I made was a long postal tube (maybe 50cm long and 10cm in diameter), with a hole drilled in the cap at the end (...

@D_Hall,

Ok, so SSTO is achievable. But do you know if it has been done? Since it's impractical for any real payload delivery purposes, do you know if anyone has successfully achieved SSTO or whether it is simply a theoretical ability?

To get into orbit, it has to be travelling a LOT faster. So far, to my knowledge this has only ever been achieved with multi-stage rockets, where excess weight can be shed as the fuel is used up allowing the last stages to reach extremely high velocity. There's never been a successful single-stage-t...

Exactly as SB15 says. Though, for a given bore and projectile, the obvious answer is of course, the most powerful one. Hybrids tend to give rather higher energy densities than combustions or pneumatics, but that doesn't mean pneumatic X can't beat hybrid Y. All depends on the specifications on the s...

Sleeving with something would only improve the strength of it, and make it a bit safer should a crack develop in the carbon fiber. However, it won't be necessary to sleeve it to prevent 'bending'. You bend carbon fiber, and it bends back. Bend it too far and (if it's a thin rod) it gives, suddenly b...

Ha... haha. 700 PSI? Have fun getting a 3L soda bottle to hold that. For a soda bottle that large, I'd keep it under 100psi, tops. They can likely hold about 120 and I'd expect them to burst before 200.

I get the feeling that the projectile is going to be exposed to the (perhaps minimal) rotational force so briefly that it would be unable to induce a significant rotation, let alone cancel any rotation the projectile may have imparted to it by its contact with the barrel. I think to get reasonable s...

@Tech, For small-ish launchers with chambers of maybe a litre or two capacity... I don't see the harm in hydro-testing by filling with water and adding a small amount of air. Sure, it's not as safe as the purely liquid method, but the amount of air we are talking is quite small provided all bubbles ...

And also, I sure as hell hope your intended targets will be willing and able, rather than this being some kind of prank. I may be underestimating your intelligence, but I feel obliged to at least make that point.

Be careful.

Twixtor's all well and good, but my issue with it is that you're not getting any extra information... It smooths things out, yes, but really... it's hopeless for any sort of analysis or for finding out what happens between those 60 frames each second.

Surely you could fashion a few lugs onto the PC case to suspend it mid-air... Word on the street is that you already have most of the fixtures.

I really must start contributing to this forum and not simply using it as a way to siphon off excess smartassery...

Buy me one and I'll be more than happy to film it.