Closer examination shows that like most human inventions, these breakthrough moments are the final incremental accumulation of ideas that were a long-time coming. In the case of flight, there were centuries of lighter than air flying methods based on buoyancy and displacement [3]. Then gradually an understanding of fixed wing aerodynamics evolved (e.g. the impressive work of people like George Cayley [4] and Otto Lilienthal [5]). It was the parallel development of combustion engines that made the Kitty Hawk and Waitohi moments eventually possible (which I think might really the answer to your question "why heavier-than-air flight was not invented earlier?"). While the invention of the steam engine gave rise to the entire industrial revolution, piston steam engines of the time were too heavy to power flight. The internal combustion engine was finally applied to the automobile by Karl Benz in 1885 [6] and within the relatively short span of 18 years had evolved to the point where powering an aerodynamic surface was feasible. Just 66 years later man walked on the moon.
[1] https://en.wikipedia.org/wiki/Richard_Pearse
[2] https://en.wikipedia.org/wiki/Wright_brothers
[3] https://en.wikipedia.org/wiki/Early_flying_machines
[4] https://en.wikipedia.org/wiki/George_Cayley
Consider the telephone, which is attributed to Alexander Graham Bell in most of the world and to Antonio Meucci in my native Italy. Or radio, which is broadly attributed to Marconi or Tesla. In hindsight it seems like one person triumphed upon others, but really if you look at it from their point of view they work with urgency and secrecy because they perceive themselves to be in neck-to-neck competition with their cohorts. They perceive their technological environ very differently from how we do ex post facto.
The US congress did vote a resolution that cleared the matter (in 2002, a bit late I would say):
https://www.congress.gov/congressional-record/volume-148/iss...
But in this case Bell and Meucci weren't much disparate sources.
https://en.wikipedia.org/wiki/Invention_of_the_telephone
https://web.archive.org/web/20141222093046/http://www2.parl....
> In the early 1890s, Captain B.F.S Baden-Powell ... developed his "Levitor" kite, a hexagonal-shaped kite intended to be used by the army in order to lift a man for aerial observation or for lifting large loads such as a wireless antenna.
A glider may not have been suitable for carrying an antenna, but aerial observation via glider is an idea that must have occurred to people in the army, even before the invention of the IC engine.
There was a large enthusiastic group of people working on heavier-than-air flight, with with meetings and newspaper publications. The Spectator has an article titled "Flying Motor-Cars" at https://archive.org/details/sim_spectator-uk_1901-08-31_87_3... which comments:
] The mechanical skill of the world, which is very great, greater perhaps than its originality in scientific investigation, is directing itself for the moment to two definite ends, — the construction of an efficient submarine boat, and the invention of a machine that can travel with at least two persons on board through the air.
That the Wright Brothers didn't know Pearse is besides the point - both drew from shared materials, and a lot of people were trying. Here's a couple of reports from the New York Times:
"TO FLY FROM PIKE'S PEAK.; W.F. Felts Tries His New Aeroplane at Different Altitudes. [Aug. 4, 1897] (followed soon by SNOWSTORM ON PIKE'S PEAK.; W. B. Felts Did Not Attempt His Aeroplane Flight Yesterday.)"
Or "EXPECTS TO BE ABLE TO FLY.; Prof. Bell Believes He Has Mastered the Two Great Difficulties of Aerial Navigation.". That's Alexander Graham Bell.
Your [4] even mentions 'The Wright brothers acknowledged [Cayley's] importance to the development of aviation'.
> here in the US we ethnocentrically recite the Kitty Hawk event of the Wright Brothers as if it appeared in a vacuum out of nowhere
Where do you get that impression?
Here's a children's book from the US about the Wright Brothers. https://archive.org/details/letsflywilburorv00roop/page/36/m...
] In 1896, when he was twenty-five years old, Orville was very sick with typhoid fever and almost died. Wilbur and Katharine cared for him. Wilbur read while sitting with Orville. He read about Otto Lilienthal, who was trying to fly. Lilienthal built gliders and had flown farther than anyone else in the world. But Otto Lilienthal had a gliding accident and died. The Wright brothers were saddened by this news because they admired Mr. Lilienthal and his attempts to fly.
] ... In England, France, the United States, and other countries, people were trying to unlock the mystery of flight.
] ... Wilbur learned all he could about flying. He took every book about it out of the Dayton library. Samuel Langley the head of the Smithsonian Institution, was trying to learn how to fly Wilbur decided to write the Smithsonian. A man there sent Wilbur information.
] The famous engineer Octave Chanute was also experimenting with gliders. Wilbur wrote him, too. Mr. Chanute quickly became a friend of the Wright brothers.
Hardly a vacuum!
Basic hypothesis is that once enough precondition for an invention are there then the leap can be made.
https://en.wikipedia.org/wiki/Early_flying_machines#Primitiv...
Maybe a lot of devices were invented and reinvented many times and then forgotten because there wasn't a practical purpose for them at the moment.
Generally, we only know of landmark size applications of historical technology, which tend to be rare.
Midden heaps can also close the gap.
What? https://en.wikipedia.org/wiki/Kite#Military_applications
Steering is important though, you need to a) go up, b) go the right place, not back at you, c) come down, again not where you are.
Boeing was located in Seattle to be near wood supplies needed in aircraft fabrication. (Well, that and its founder was already in the lumber business.)
Another thing is topography: Either you have (steep) local elevations as a natural starting point for gliding, but then there is usually not much of an open space to go for a real application. Or there are wide open spaces, but no natural elevations. (Mind Eilmer starting from a tower.) So, even if you know about the principles, there's not much application for human flight, rendering it rather for use as a toy. (There are hints for bird-shaped gliding toys in ancient Egypt. But was there really a human-flight scale application in an all flat landscape like this?)
And of course Lincolnshire is famous for being "bomber country" in WW2 - weather and geography helping to get the horribly overladen beasts airborn.
It's quite good at steady-power output. Throttle response is poor.
Both automobiles and aircraft operate with quite variable power requirements. Though at least for long-range air travel, once the take-off / climb portion of flight has been completed, cruise is typically at a fairly constant setting.
Once rapid design-build-test cycles were practial, the initial Wright design rapidly shifted to a monocoque fuselage with forward wings and empennage, emerging within a decade.
In just over 30 years after the Wright's first powered flight, the DC-3, an aircraft still in commercial operation was flying. It has been described as the perfection of aircraft design, and the major elements of its design are still present on contemporary aircraft, though of course jet engines have largely replace reciprocating piston engines.
Major factors in successful powered or unpowered flight have been understanding aerodynamics (largely through experimentation and test flights, increasingly through modelling), materials (pre-industrial materials are poorly suited to human-scale aircraft or gliders), controls (both theory and interfaces), powerplants (on powered aircraft).
Ultralights, hang gliders, and sailplanes all benefit greatly from specific materials: Nylon for wings, aluminium for structural members, plastics, and steel for wires and cables. Instrumentation, navigation, communications, transponders (safety) and radar (collision detection) also factor in.
Virtually all of these are dependent on earlier stages of industrialisation: smelting of iron and aluminium, petroleum chemistry and textiles fabrication for Nylon and plastics, earlier aviation engineering for general flight handling and control theory, electronics for instrumentation, radio, and radar, plus domain knowledge from other fields such as physics (instrumentation, controls, etc.).
TL;DR: Prerequisites and path dependencies.
The only thing I would change is that this makes it seem like powered flight was waiting on the engine, when it was waiting on the plane.
One thing that struck me at the Museum of Flight in Seattle is how far advanced IC technology was while the Wright brothers were gliding in wooden contraptions. They had turbocharged v12 diesel engines and Benz was already making aluminum engines for cars before the Wright brothers made their first attempt.
I found it fascinating how as soon as flight was demonstrated, it only took a few years to go from a wooden prototype to a sophisticated machine with a very complex engine.
Bonus pic of some of those early engines https://i.imgur.com/mENnuHH.png
And of course even if you survive the iterative development process, all you’ve got is a (largely) useless glider until the engine comes along and you can commercialize it.
It seems to me that for flight the construction materials (silk, bamboo, string, glue - what the early WW1-era aircraft were made from) and the propulsion (solid-fuel rocket) have been around for over a thousand years.
The original Chinese designs relied on gunpowder. This is self-oxydising and burns rapidly, but has a comparatively low power density, roughly 1/10th that of liquid petroleum fuels.
Liquid fuel such as alcohol and oil existed, but the notion let alone the availability of oxidizers didn't until the early 19th century. The first use of liquid oxygen in rockets didn't occur until 1926, by Robert Goddard.
Hypergolics or solid rocket motors would have been other options, but both are still pretty advanced. I've no idea how likely they'd have been.
One of the more viable solid fuels might have been rocket candy, made of sugar and usually potassium nitrate as an oxidizer. Both would have been available.
Demonstration here: https://piped.kavin.rocks/watch?v=12fR9neVnS8
Whether or not that would generate sufficiently strong and reliable thrust for a steampunk JATO launch, I'm not sure.
Rocket does have the trust ratio needed. But then there is questions of burn time and control. So you could get up there, with some risk. But not stay there for very long time.
Short googling for solid fuel rockets seem that longest burn times are less than 3 minutes... And that is best case scenario with 20th/21st century technology...
It could still have been possible to work things out based on JATO launch, though the hang-glider approach of low sand-dune testing / training would probably have been safer and a better overall option.
Powered aviation also helped drive and prove materials design enhancements and general aviation theory, controls, avionics, etc., all of which transfer well to gliders, but would very likely have been far more difficult to develop in a a glider-only regime.
I'm saying that having an airworthy craft once you're off the ground takes some doing, and it's probably easier to get there if you're experimenting with powered craft.
The early powered heavier-than-air craft were not especially aeronautically sound. But with the ability to perform design-build-test cycles, and not kill overly many pilots in the process, once engines existed design progressed rapidly.
Getting from the Wright Flyer to a modern sailplane would have been far more challenging without engines.
Or land it.
So you build your best guess at what a working glider might be. You don't have robotics or radio to remotely control it, so someone's got to fly the thing.
You build a kite flinger and/or ramp or rail to toss it off the side of a building or cliff or whatever.
And then you hope, desperately, that you weren't too terribly mistaken about a great many things.
Franz Reichelt wasn't quite building airplanes, but he turned out to have misjudged his own competence in a somewhat similar manner:
https://allthatsinteresting.com/franz-reichelt
Now consider the same situation, except that you've at least got a motor to buy your way out of design and/or piloting errors, at least a little bit.
Under which of those scenarios do you think actual useful design might have progressed faster?
Keep in mind that people have had the notion of flying with wing-like contraptions dating to the ancient Greeks (see the legend of Icarus). There were numerous inventors who threw themselves off hills or cliffs with various attempts. Lack of power, and the frequent short professional career track of such inventors tended to stymie progress.
Successful gliders and sailplanes almost entirely postdated powered heavier-than-air flight. The first designs appeared after WWI, and practical use didn't appear until the 1930s. My understanding is that popularity of recreational gliding didn't emerge until the 1950s or 1960s, again benefiting from aeronautical engineering, materials, radios, much better knowledge of aircraft operation, controls, and instrumentation.
Glide ratio is one measure of aerodynamic efficiency and sophistication. Early 1930s gliders achieved about a 1:17 ratio. Most modern gliders exceed 1:30, and the best 1:50 or more. This expresses altitude loss per unit foreward travel (e.g., 1 meter loss for 30 meters forward flight).
Google's Ngram viewer is a somewhat fickle guide, but suggests an initial spike in mentions in the late 1930s / 1940s, again in the 1950s, then a third in the 1970s:
https://books.google.com/ngrams/graph?content=sailplane&year...
Adding in "glider" (multiplied 10x) still lags "aeroplane" by decades.
https://books.google.com/ngrams/graph?content=%28sailplane%2...
There may have been earlier terminology used, and "glider" has other meanings which might confound matches, but at least for "sailplane", the trend line lags "aeroplane" and "airplane" considerably. (I've multiplied "sailplane" results 100x in this plot):
https://books.google.com/ngrams/graph?content=%28sailplane%2...
If you want explanation, that's a role of science, though it's often preceded by a very long period of systematic observation.
One striking example is geology, which has existed since at least the 17th century, but which didn't formally adopt its central organising and explanatory principle, of plate tectonics, until 1965. Biology (evolution and DNA), physics (celestial mechanics, particle physics, reletivity, and quantum theory), and chemistry (periodic table and electron orbitals) also come to mind.
Thermodynamics arose out of work with steam engines, and eventually developed to the point that the theoretical understanding and equations began driving, rather than being driven by, engineering accomplishments. Electrical engineering is another example where modern developments required understanding of, and calculations based on, circuit and field theory, rather than just more lab experimentation. (I'm hazy on details here, though this is my general understanding.)
There are practices which existed for many thousands of years before a deep understanding was achieved: fermentation, fire, firing ceramics, glassmaking, smelting metals, and many agricultural practices. Doing and understanding are separate undertakings.
You can discover that eating one of the dozen types of plants growing on the hillside nearby treats toothache without any overarching theory about how that could work, just try eating stuff and see what happens - but you aren't going to invent the LED lamp this way.
Example: When we put a cable on the bottom of the ocean these days it's optical fibre rather than electrical. But, even with optical fibre, even the best stuff we can make, this will need amplifying for long distances or it's pretty awful. One thing you could do would be to choose reconstructing amplifiers when making the cable. So e.g. you decide this cable is Protocol X at 100Gb/s, you make amplifiers which can reconstruct a Protocol X signal at 100Gb/s and "boost" it, splice those in along the distance of the cable, and drop the whole lot into the ocean. However, somebody is going to invent 500Gb/s Protocol X+ and if you want to upgrade you will need to send teams down to the ocean floor to replace those amplifiers. Ouch.
In principle individual photons are travelling along the fibre, and physics doesn't say we can't just have one photon in => two photons out to boost this without needing to reconstruct the signal at all. There should be some way to build a device which does this, an Optical Amplifier, and it would be OK if this is quite expensive since it's saving you that enormous expense by allowing you to upgrade to 500 Gb/s X+ or to 10Tb/s XXX or whatever other future protocols just involve sending photons down a fibre without trying to upgrade equipment at the bottom of the ocean. But... how?
Turns out scientists can guess exactly how that should work if it's possible, and then direct the experiments, trying out only the handful of things which actually might work instead of just groping about at random. My alma mater was one of the places figuring out how to do this in the 1980s, they were still really proud of that when I studied there a decade later. Erbium Doped Fibre Amplifiers are the result.
Your transoceanic cable example is an interesting one, as the first electrical / telegraph cables greatly expanded the understanding of electric fields and interactions with the environment, especially in salt-water.
I'm also wondering if there's some sort of frontier between the "just blundering around" approach --- mass parallel experimentation --- and "requires a substantive theoretical understanding". To take your LED example, LEDs are the inverse of the photoelectric effect (and apparent PV panels will emit photons when a charge is applied to them). Electroluminescence dates to 1907, whilst the first LEDs were developed in the 1960s. There were earlier similar phenomena such as chemoluminescence (including numerous examples of bioluminescence) which might have suggested the possibility.
I'm agreeing in part, disagreeing in part, and wondering if there might be a more robust or systematic way of distinguishing limits of both methods.
Sometimes it's surprising what nobody was interested in inventing. I think Grace Hopper is really important because people were resistant to the idea that programming the computer involved boring mindless steps which could be done by a machine and so of course instead of hand writing the program in machine code you should write a higher level language and have the machine translate that. It's incredible now, but this very idea was once an important invention and yet her superiors were not enthusiastic.
Bernhard J. Stein's *Resistances to the Adoption of Technological Innovations" (1937) is a fascinating read in this regard:
https://archive.org/details/technologicaltre1937unitrich/pag...
As Markdown: https://rentry.co/szi3g
I'd heard of it via Isaac Asimov who mentions it in his biography and a few other contexts. Asimov was Stern's research assistant, and incorporated the ideas into several of his own stories.
Though I've had my concerns for what the growth in solution-without-explanation (or understanding) that ML is generating.
(parent edited)
> Then, why not make it bigger?
To what end? They were lifting bombs on kites as early as the 7th century, as well as humans as novelties (and punishments - https://en.wikipedia.org/wiki/Yuan_Huangtou).
If you want a lift a human to do something, you also need some better steering and safe landing, and those require more reliable engineering besides just the basic lift possibility.
Not sure the Wright brothers would be with you on this - neither were maths guys and their aircraft were hardly precision-built.
They also practiced fairly rapid design iteration, trying out ideas and adapting to actual experience. What they arrived at worked, though it was far from ideal and doesn't much resemble modern aircraft (beyond the notion of wings and the rough principles of control surfaces). Once other designers / engineers entered the field, and with more reliable engines, further iteration advanced rapidly.
Military aircraft played a significant role in WWI, only a decade after the Wright's first powered flight.
— https://en.wikipedia.org/wiki/George_Cayley
I think by the time the Wright brothers came around, the general theory for powered flight was in place. The Wright Flyer was precision engineered, compared to most 'kites' that came before it. It's not every day you see an internal combustion engine on a kite.
Yup. The engine was more important than the understanding of the principles of propulsion too: even if the four forces had been identified by Aristotle, that wouldn't have been much use in achieving sustained powered flight to civilisations whose closest approximation of a propellor powered by a turbine engine was a waterwheel.
Actually, not a few people did exactly that! If they had used a scaled-up paper plane, they might have lived. Or think of a modern hang-glider, but made from bamboo and silk.
https://en.wikipedia.org/wiki/Franz_Reichelt#Eiffel_Tower_ju...