# Why did it take us so long to invent flying in balloons? **URL:** \ **Category:** Factual Questions\ **Created:** [March 26, 2020, 3:19am UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298 "2020-03-26T03:19:59Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [March 28, 2020, 4:08pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/61 "2020-03-28T16:08:22Z")
> [@EdelweissPirate](#): > > And all of this is after I pointed out that the Chinese, who 2000 years ago had both silk and paper in spades, made their balloons out of paper. Even if that were a coincidence at first, they’d have switched to silk if it were a better material—the benefits would have been obvious for certain applications. > > But that’s not what happened. That’s not the point in question. It’s not a question of whether silk is the best material for making a balloon. It definitely is not. There are many materials which are better. The question is whether silk is a possible material for making a balloon. Which it is, as evidenced by the fact that it’s been done. ---
**Author:** ![GreenWyvern](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/greenwyvern/32/2834_2.png) [@GreenWyvern](https://boards.straightdope.com/u/GreenWyvern)\ **Post date:** [March 28, 2020, 4:10pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/62 "2020-03-28T16:10:10Z")
> [@Little\_Nemo](#): > > So me being asked if I could build a balloon was okay. But me answering the question was ludicrous. It was the answer that was ludicrous. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [March 28, 2020, 4:13pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/63 "2020-03-28T16:13:51Z")
> [@AK84](#): > > … > We often describe inventions and new technologies as being the result of dozens of inventions and innovations over time rather than one single breakthrough. That is accurate, however, there are often individual crucial technologies that make something practicable. Like burners for hot air balloons. > … I can sum up this concept in one word: Convergence. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [March 28, 2020, 4:24pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/64 "2020-03-28T16:24:21Z")
> [@Little\_Nemo](#): > > That’s not the point in question. > > It’s not a question of whether silk is the best material for making a balloon. It definitely is not. There are many materials which are better. > > The question is whether silk is a possible material for making a balloon. Which it is, as evidenced by the fact that it’s been done. This is such an obvious straw man that I couldn’t quite believe my eyes when I read your post. No one here has ever argued that silk couldn’t be used to make a balloon. That was never “the question,” and you know it. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [March 28, 2020, 7:07pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/65 "2020-03-28T19:07:01Z")
380m^2 is a bit over 600 feet of a 6-foot wide bolt of cloth. Before the days of mass production, that would have been a king’s ransom. Simply shipping it from China (impossible until the later 1500’s) would have been expensive. Even hand-made thinner linen cloth would be expensive. Ditton for paper and rope. By the time the Montgolfiers were playing with balloons, a pair of minor nobility with a factory family business could afford this sort of luxury disposable material from their petty cash drawer. Again, we forget the effect of the industrial revolution on production volume. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [March 28, 2020, 8:24pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/66 "2020-03-28T20:24:58Z")
Also, silk can be used for a balloon if it’s sealed properly - especially a gas balloon. I assume they had a process for rubber-coating or something, that was not too heavy. Hot air balloons can be leaky, because the supply is always being replenished (has to be). For gas balloons, a bit more difficult. BTW, what was the process for making hydrogen? That too probably required industrial-scale tech to produce in quantity. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [March 28, 2020, 8:35pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/67 "2020-03-28T20:35:03Z")
> [@md2000](#): > > … what was the process for making hydrogen? That too probably required industrial-scale tech to produce in quantity. It can be produced rather simply, by mixing hydrochloric acid and iron filings. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 28, 2020, 10:37pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/68 "2020-03-28T22:37:06Z")
Which reduces the question to, how do you produce hydrochloric acid? ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [March 28, 2020, 11:36pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/69 "2020-03-28T23:36:45Z")
> [@Chronos](#): > > Which reduces the question to, how do you produce hydrochloric acid? You can make it by mixing sulfuric acid and salt. Now let me guess what you next question is. You need to find some pyrite, which is a naturally occurring mineral. Heat it up and collect the gas - sulfur dioxide - which comes off of it. You mix the sulfur dioxide gas with some chlorine gas. This produces sulfuryl chloride, which you can dilute with water to make sulfuric acid. But here’s the punchline; you produce chlorine by running electricity through salt water. When you do that the water will emit chlorine - and hydrogen. So if you have the electricity you need to make the chemicals you can use to make hydrogen, you can skip all the chemistry and make hydrogen directly. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [March 28, 2020, 11:48pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/70 "2020-03-28T23:48:54Z")
> [@EdelweissPirate](#): > > No one here has ever argued that silk couldn’t be used to make a balloon. Really? > [@EdelweissPirate](#): > > Paper was the first practical material for balloon envelopes that I’m aware of. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [March 29, 2020, 12:42am UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/71 "2020-03-29T00:42:18Z")
> [@Little\_Nemo](#): > > Really? Really. History is outside my wheelhouse, but AFAIK the first practical application of hot air balloons was for military signaling about 2000 years ago. To the best of my knowledge, those balloons had paper envelopes. Was a silk balloon theoretically possible at the time? Yeah, it was. But as far as I know, the first balloons were paper. Silk could have worked if it could be sealed, sure. But paper seems to have been a better overall tradeoff between permeability and strength. No one is saying a silk balloon couldn’t be done, but since it seems not to have been done prior to paper, there might be a compelling reason. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [March 30, 2020, 6:12pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/72 "2020-03-30T18:12:27Z")
Again, a matter of scale. Something a yard or so in diameter and carrying a candle can be made out of paper - or silk coated with something. Make it carry 400 to 600 pounds (300kilos) and now we’re talking a whole different range of engineering. Also, it’s a matter of experimentation. The Wright brothers were building on the backs of people who built kites, even Lillenthal’s gliders launched off hills, and people who built internal combustion engines (with the weight-to-power ration that worked for flight.) In fact, their major contribution was wing-warping to control flight, as once you added an engine weight-shifting was insufficient. Many previous attempts by others failed from inability to control and loss of stability. That wings could support a considerable weight for distances was already proven, and sails had proven the power of air. For balloons, what’s between a signal balloon a foot or three across and something carrying a useful load? What other useful load is there besides dropping incendiaries on a besieged town - and how reliable (safe for the launchers) is a hot-air balloon full of flammables? Flaming arrows seem to be a better bet. The man-sized balloon had to wait for a bunch of experimenters with the time, money, and obsession to see the enterprise through. Nobody had found a reason to build, say. a 10-foot-diameter hot air balloon and say - “Look, it works”. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [March 31, 2020, 11:58am UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/73 "2020-03-31T11:58:18Z")
> [@md2000](#): > > The Wright brothers were building on the backs of people who built kites, even Lillenthal’s gliders launched off hills, and people who built internal combustion engines (with the weight-to-power ration that worked for flight.) This is a bit muddled. The contribution of kite technology to what the Wrights did was scant. Lilienthal was a big inspiration, but his tables of lift proved misleading - his most useful contribution probably was (as you note) a demonstration that weight-shift was inadequate for proper control. And they wound up building their own engine, having found (to their surprise) that nothing suitable was available from others. > [@](#): > > In fact, their major contribution was wing-warping to control flight Their major contribution was 3-axis control. Wing warping controls one of the three axes (roll). ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [March 31, 2020, 8:23pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/74 "2020-03-31T20:23:20Z")
> [@Xema](#): > > This is a bit muddled. The contribution of kite technology to what the Wrights did was scant. Lilienthal was a big inspiration, but his tables of lift proved misleading - his most useful contribution probably was (as you note) a demonstration that weight-shift was inadequate for proper control. And they wound up building their own engine, having found (to their surprise) that nothing suitable was available from others. > Their major contribution was 3-axis control. Wing warping controls one of the three axes (roll). I think their major contribution was their systematic, scientific way they went about it. I recall that there were 7 basic ‘ideas’ that the Wright brothers came up with; I think most of those received patents. One example was the ‘invention’ of the wind tunnel. This allowed them to actually test various shapes of wings, and confirm (or disprove) the aerodynamic properties of these. Iy was this kind of experimentation & “stepwise refinement” that seems to explain their success, I think. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 31, 2020, 8:34pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/75 "2020-03-31T20:34:23Z")
This is true. Most of the experimenters in flight before them, and many since, took the approach of slapping something together, trying to fly it, and if they survived, trying some other slapped-together design. The Wrights, by the time of the Kitty Hawk flight, pretty much knew that their design would work, because they’d done all the experiments and calculations. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [March 31, 2020, 11:41pm UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/76 "2020-03-31T23:41:44Z")
> [@md2000](#): > > Again, a matter of scale. Something a yard or so in diameter and carrying a candle can be made out of paper - or silk coated with something. Make it carry 400 to 600 pounds (300kilos) and now we’re talking a whole different range of engineering. I follow your point, and it’s worth making. But some scaling factors work in the aeronaut’s favor: as balloon diameter increases, envelope weight goes up, but the enclosed volume—lifting power—increases even faster.[sup]1[/sup] The material with the best net strength-to-weight ratio is what you want for your envelope. If a sealed silk envelope is structurally viable for a 1-meter balloon, it’s structurally viable for a 25-meter balloon. But supply chains don’t scale like this, of course, and while sourcing enough silk for a 1-m diameter balloon (~3.14 m[sup]2[/sup]), sourcing the 2000 m[sup]2[/sup] required for a 25-m diameter balloon would be much harder. If you could pull that off, the larger envelope would weigh 625 times what the smaller one does, but its lifting power is over _15,000 times_ that of the smaller balloon (all of this is to a first approximation). I fully agree that scaling balloons to carry people is hard for a number of reasons, but envelope size is an exception to that. [sup]1[/sup] Many here know this, but it’s always good to show your work: a sphere’s surface area increases with the square of the diameter, while its volume increases with the cube of the diameter. And yes, a larger envelope size requires lots of other things to be bigger, and most of those don’t scale well at all. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [April 1, 2020, 12:24am UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/77 "2020-04-01T00:24:55Z")
> [@Tim\_T-Bonham.net](#): > > I think their major contribution was their systematic, scientific way they went about it. Well, they didn’t invent this - though among early experimenters only they and Lilienthal were truly systematic. What they did invent (3-axis control) was the result of their steady, careful, scientific approach. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [April 1, 2020, 12:45am UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/78 "2020-04-01T00:45:30Z")
> [@Tim\_T-Bonham.net](#): > > I think their major contribution was their systematic, scientific way they went about it. I recall that there were 7 basic ‘ideas’ that the Wright brothers came up with; I think most of those received patents. > > One example was the ‘invention’ of the wind tunnel. This allowed them to actually test various shapes of wings, and confirm (or disprove) the aerodynamic properties of these. Iy was this kind of experimentation & “stepwise refinement” that seems to explain their success, I think. As the Wikipedia article on the wind tunnel points out, others, including Lilienthal, did experiment with the passage of air over the shapes they used – they just didn’t do it static in a wind tunnel: > [@](#): > > English military engineer and mathematician Benjamin Robins (1707–1751) invented a whirling arm apparatus to determine drag[4] and did some of the first experiments in aviation theory. > > Sir George Cayley (1773–1857) also used a whirling arm to measure the drag and lift of various airfoils.[5] His whirling arm was 5 feet (1.5 m) long and attained top speeds between 10 and 20 feet per second (3 to 6 m/s). > > Otto Lilienthal used a rotating arm to accurately measure wing airfoils with varying angles of attack, establishing their lift-to-drag ratio polar diagrams, but was lacking the notions of induced drag and Reynolds numbers.[6] > … > > In a classic set of experiments, the Englishman Osborne Reynolds (1842–1912) of the University of Manchester demonstrated that the airflow pattern over a scale model would be the same for the full-scale vehicle if a certain flow parameter were the same in both cases. This factor, now known as the Reynolds number, is a basic parameter in the description of all fluid-flow situations, including the shapes of flow patterns, the ease of heat transfer, and the onset of turbulence. This comprises the central scientific justification for the use of models in wind tunnels to simulate real-life phenomena. However, there are limitations on conditions in which dynamic similarity is based upon the Reynolds number alone. > > The Wright brothers’ use of a simple wind tunnel in 1901 to study the effects of airflow over various shapes while developing their Wright Flyer was in some ways revolutionary.[8] It can be seen from the above, however, that they were simply using the accepted technology of the day, though this was not yet a common technology in America. > **[Wind tunnel](https://en.wikipedia.org/wiki/Wind_tunnel)** > > Wind tunnels are machines where an object is held stationary inside a tube, and air is blown around it to study the interaction between the object and the moving air. They are used to test the aerodynamic effects of aircraft, rockets, cars, and buildings. Different wind tunnels range in size from less than a foot across, to over 100 feet (30 m), and can have air that moves at speeds from a light breeze to hypersonic velocities. > Usually, large fans move air through the wind tunnel, while the ob... John Stringfellow built and flew his (pilotless) steam-powered monoplane in 1848. It was based on Cayley’s designs and calculations, so it had the advantage of experimental design, although I have not read anywhere of Stringfellow himself testing out the design beforehand with a “whirling arm” apparatus or wind tunnel. > **[John Stringfellow](https://en.wikipedia.org/wiki/John_Stringfellow)** > > John Stringfellow (1799 – 13 December 1883) was a British early aeronautical inventor, known for his work on the aerial steam carriage with William Samuel Henson. > Stringfellow was born in Attercliffe, England to Martha \[née Gillan\] and William Stringfellow, stone mason. Initially apprenticed to the lace making trade in Nottingham, c.1820 he relocated to Chard, Somerset to work as an engineer of bobbins and carriages for the lace industry, becoming so successful that he started his own company.... ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [April 1, 2020, 12:47am UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/79 "2020-04-01T00:47:45Z")
> [@Little\_Nemo](#): > > You can make it by mixing sulfuric acid and salt. Now let me guess what you next question is. …how do you produce salt? ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [April 1, 2020, 1:27am UTC](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298/80 "2020-04-01T01:27:30Z")
> [@Ludovic](#): > > …how do you produce salt? On the remote chance this isn’t a joke, salt is a naturally occurring mineral. [Previous page](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298.md?page=3) [Next page](https://boards.straightdope.com/t/why-did-it-take-us-so-long-to-invent-flying-in-balloons/850298.md?page=5)