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back to article Texan stitches stratosphere into stunning panoramas

Take one mighty hydrogen-filled orb, six panoramic vid cameras, hours of image-stitching jiggery-pokery and you too can produce fully spherical panoramic imagery from the stratosphere... Panoramic view at 29,000m The 360 degree view at 29,000m ...or capture a 360 degree movie of your balloon burst at a breathtaking 29,378m ( …

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Pint

Surely a role as US Liaison for LOHAN beckons for Caleb?

And a beer raised in his honour too.

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Happy

moan

I'm getting FED UP with being showered with shreds of latex..... Oh wait, it's not so bad.

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Happy

I wish...

That people would daisy chain about 5 ot 6 balloons together, so that they would all only provide a fraction of their potential lift, which is just enough - all things considered, to lift the load, for the duration of the flight.

This way the balloons would ascend to a much higher altitude - way, way, way higher, than a single balloon.

I am actually quite surprised that no one is making them out of metalised mylar film, like a giant chip packet.

The traditionalists "latex balloon" is rather old hat, so to speak.

I am wondering.. IF a balloon can be made that can escape the earths gravity, with a teeny little load.

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Boffin

Re: I wish...

I think your grasp of gravity may be lacking.

The atmosphere of the Earth ends at (at most) 10,000km

In practical terms its gone by 85km

Considering the Earth as a point gravity source, its radius is ~6300km

So at 6300 km you feel around 10m/s^2 (1 g)

Adding 85km to that distance makes almost no difference in the force of gravity

Even at 10,000km above the surface (16300km from the point gravitational source), the force of Earth's gravity has only dropped to a little less than a 1/4g

An actual gravity field extends infinitely, it just drop off to a negligible amount at astronomical distances

"Escaping" a planets (or anything else's) gravity is about velocity, ie you have to have sufficient velocity that the total of the gravitational fields deceleration over infinity is not sufficient to slow your relative movement to zero ( or reverse it.)

Thus the term "Escape Velocity"

If you start off further away you do need less velocity though.

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Facepalm

Re: I wish...

Or to put it more simply, the atmosphere stops before the gravity does.

(because if there wasn't gravity, then the atmosphere would just float away)

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Re: I wish...

So could you lift a small firework sized rocket on a balloon and launch it up there would it escape?

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Ru

Re: I wish...

So could you lift a small firework sized rocket on a balloon and launch it up there would it escape?

If you take the little firework rocket far enough away from earth, eventually the pull of gravity will be so weak that it will be able to exceed escape velocity and escape.

That said, escape velocity at low earth orbit is still a good 5km/s higher than orbital velocities - a challenging delta-V for firework rocket of any size, given its likely specific impulse - even if you could get a balloon to LEO, which you clearly can't.

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Re: I wish...

"I am wondering.. IF a balloon can be made that can escape the earths gravity, with a teeny little load."

Given that the balloon rises because the heated air (or whatever other method, e.g. helium etc.) in it weighs less (actually less dense, but let's stick with weighs less) than what's around it, it's not as easy as that.

The Earth is sucking everything towards it. The balloon "rises" because the stuff above it and around it is "heavier" and so it sinks to the bottom (the Earth) which literally pushes the balloon up (gap appears above, more heavy stuff appears below = you get pushed up, like a tennis ball in a box of ball bearings).

So you could get the balloon to rise to some place where it weighs roughly the same as the stuff around it, or not. But then it'd stop rising. Because it always weighs *something*, the place it stops wouldn't be the area where you are weightless, or where there's no atmosphere, but somewhere quite below that (so not really "true space"). However, if you then waited until that moment to fire some proper propellant (i.e. not relying on air-pressure differences to make you rise, but actually pushing yourself out), then you could leave the planet / atmosphere, if the propellant is strong enough.

Nobody really bothers with that - it's not very effective or controllable or saves that much compared to, say, piggybacking on a jumbo jet (which is an actual sensible launch method for a lot of similar things). The propellant weighs something. As does whatever method of firing it. That makes it harder to lift up and so you don't go as high. So you end up in the bottom of a curve somewhere on a graph that never quite touches "space", a compromise between propulsion and payload. Hence why anything tangible that's ever left this planet has done so by the application of amazingly high amounts of force over long periods of time, rather than just letting it float up.

The problem with a balloon is that what's inside the balloon is generally going to weigh some non-trivial amount. It will be pushed up to the point of the Earth's atmosphere where the air around is about the same density ("weight") as the balloon itself. And then it will stop. And actually crumple and not be balloon-shaped any more. And probably fall. And then (maybe, depends on the design, but even ideally) rise again, and fall and rise like a blob inside a lava lamp (because that's basically the best analogy anyway).

If you had an infinitely large lava lamp but only one "heat source", no blob would ever make it all the way to the other end, because it would eventually meet cool oil that cooled it enough that it wasn't less dense and it would fall back towards the heat source. Same with a balloon, except the gases exerting pressure on the balloon run out a lot quicker than infinity.

And balloons fail for a reason that high up, mostly to do with lack of pressure on them and losing their shape, and all sorts. You might get a little higher with multiple balloons (i.e. maybe 5-10% higher) but by the principle of redundancy (i.e. they don't ALL fail early) rather than by any trick of physics.

Otherwise, honestly? We'd have been in space in the 1800's. Fact is that it took until the 1960's before we have enough thrust to do anything useful - even low orbit.

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Joke

Re: I wish...

"So you could get the balloon to rise to some place where it weighs roughly the same as the stuff around it"

All one needs to do is coat the balloon in Cavorite.

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Def
Bronze badge

Re: Escape Velocity

Actually, your escape velocity (or more accurately your escape speed - because direction is unimportant) is the speed required to escape without further propulsion.

If you have enough thrust <frankie>ooh err</frankie> you can escape at any speed you wish.

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Thumb Up

Re: All one needs to do is coat the balloon in Cavorite.

Of which an essential ingredient was helium if I remember the story aright!

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Coat

Re: I wish...

Well, if the balloon is a spherical cow...

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Hehhehheh

Breathtaking. V. droll.

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Next stop...

Google BalloonView?

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Pint

"Hi-tech balloon control system"

So apparently they were two sheets to the wind?

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It's the kind of way I'd do things for myself, given the project, but not really what you'd call a model way of doing things.

Seems like a bit of footage and an awful lot of photoshopping and manually aligning, really. Hell, at one point he runs the individual frames (extracted from a compressed movie) through a visual processing software only to then take the output and do the same again, and again until he gets a flat horizon. Torturous to the original footage, I should think, not to mention that he removes half the control points in the upper parts of the images so that he gets a flat horizon in the end. Sure, he's only interested in the horizon and what's below but that's basically a way of saying "sod everything else, so long as it looks flat".

And the Audacity hack? Rip the sound from the video, align the tracks by hand, steal the offsets (from the XML project file, no less) and then get FFMPEG to reassemble the video with aligned audio from the given offsets. I think any video editor software would have been able to do a better job for you rather than faffing with Audacity, FFMPEG (again, saving a compressed movie stream from a compressed movie stream) and manual offset-editing (which he does by lining up waveforms in Audacity). Hell, there are some free ones that would do it all in the one screen, I think.

It gets a good result, but it's all a bit Heath Robinson and yet - at the end of the day - just the ideas that he deliberately decided to not do (such as using a clapperboard-style sync on the image/audio in the first place) were probably the most sensible Heath Robinson way of doing it.

He compensates for the rotation of the cameras basically manually. I'm not sure about the accuracy of a digital compass in space (I presume it works just fine, actually) but at least it would have been cheap, fitted into his gear, and saved him a LOT of coding and processing time if making a panorama was actually his original intention.

Now, amateur astronomers do similar things - capturing Saturn's rings with a cheap telescope is a pain so they film it on a cheap webcam and run the individual frames (which just have a blurry mass rather than a clear ring in them) through software that "aligns" the images and composites them to get a single image of Saturn complete with rings. For science, I could see that technique being used, so long as the data were calibrated and the transformations carefully monitored. Hell, that's how VLA's basically work

Personally, I call that cheating. That's not photography, so much as photoshopping. I'm happier with a straight-forward photo (even through the eyepiece) of Jupiter than I am some composite image that software basically "made up" for me.

Same here. If he'd just put up the images / movies, I'd be happy. The stuff about making a fabricated panorama by basically forcing the image into shape using improper tools? It's just fluff that gets in the way of the real achievement.

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Pint

Brave assembly picture..

Pass me the orange boxy looking doohicky will you

Sure

*clink glug fzzzt*

Ah

*large glass of G&T with ice spreads over table, electronics and many months work*

Cattle prod and tape please.

Lovely job though. Glass raised and all that.

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Pint

"I'm Cave Johnson. I own the place."

I think we have found the real-live founder of "Aperture Science".

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6 GoPros

...at £300 a pop. Not exactly in the spirit of 'string and sealing wax back shed boffinry", is it?

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