Feasibility of a Dune Ornithopter | Hacker News Reader

Feasibility of a Dune Ornithopter

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The German industrial control and automation company Festo [0] created a bionic swift [1] as an engineering demo this year. The flapping wings are no longer as rigid as in their earlier flapping bird model [2]. Go and check out their other stuff (e.g. a dragonfly: [3], a flying fox or aquatic animals), it's great! Here is a Youtube search for Festo Animals for your convenience [4].

[0] https://en.wikipedia.org/wiki/Festo

[1] BionicSwift: https://www.youtube.com/watch?v=hUE8o056Cpc

[2] SmartBird: https://www.youtube.com/watch?v=nnR8fDW3Ilo

[3] Dragonfly: https://www.youtube.com/watch?v=nj1yhz5io20

[4] https://www.youtube.com/results?search_query=Festo+Animals

Reminds me of Tyrell Corporation: https://www.youtube.com/watch?v=VSOzdFoZsho

How does that make you feel?

Let me tell you how it makes me feel.

Do you like our owl?

A friend of mine lives a few cities from a Festo factory.

She didn't know what they build, but she always said the name Festo sounds like being an evil corp in a scifi story.

She was a bit shook, when I told her about the robots, haha

My friend, the late Michael Polatnick, coined a word to describe your friend. “Stupido.”

Festo got big making pneumatic devices and grippers, parts that are used in almost every automated factory. And almost every mechanical engineer involved with mechanisms knows of Festo.

Hate to break it to you but "stupido" is conventional Italian for stupid/idiot.

https://translate.google.com/?sl=it&tl=en&text=stupido&op=tr...

This is very impressive. However - is there not a problem of scale? As you scale, surface area is squared, but mass is cubed. I mean, ok, you could have a lighter central fuselage, but then how effective can this be in carrying passengers or cargo?

Bigger wings?

Bigger wings means heavier wings, and greater torque needed to actuate the wings, which means more power needed as well as greater stresses involved, all of which means even more mass, which eats into your payload budget.

Planes aren't filled solidly, though. They are more like a shell around a volume, so I'd think the mass would rather scale like the surface area than the volume of the plane. Beside that, I would agree that it seems impossible to get such a solution working in dimensions of dozens of meters. A pun: maybe they just took "do things that don't scale" too literally? ;)

I just watched the new movie today; it's good. The dragonfly-like wings were an interesting choice. It seems like they'd be less efficient at lift than a jointed wing, but then I thought, maybe an unusual wing surface material could be used?

The problem is that when the wings go up, they're pushing air in the wrong direction and propelling the ornithopter down. But suppose the wing was covered in tiny little hinged flaps that close on a downstroke, but open on an upstroke? That way the upstroke would push the aircraft down much less than the downstroke lifts.. (These wouldn't even need to be controlled in any way, they could just be passive flaps. Though being able to lock them closed might be useful for certain acrobatic maneuvers.)

You just change the angle of the wing on the upstroke so it's slicing through the air. It's not actually a problem. :) Same thing real dragonflies and even birds do (though birds fold up their wings too).

I kind of assumed that's what actual dragonflies do (I mean, they have to get lift somehow), but for a very large wing that rotation must cause quite a bit of drag in itself. In the movie, the ornithopter wings are maybe 50 to 100 feet long and usually moving too fast to see. I would tend to assume that the aerodynamics would be different for something that huge than an insect, but I don't have any good intuition for what would be most efficient. Maybe a combination of wing rotation and self-opening flaps would be best? Or a wing that splits itself into multiple parallel wings on the upstroke and combines into one on the downstroke?

It's interesting that dragonfly wings are so long and thin, which I suppose minimizes the amount of drag as they rotate between the downstroke angle and the upstroke angle.

>> the aerodynamics would be different for something that huge

With such a large moving airfoil there are inefficiencies. Pretending that the wing is a solid object, very quickly the tips will be moving faster than the speed of sound. At such speeds void/shockwaves start to form, radically changing everything. The root of the wing is barely moving, the tips are supersonic, and somewhere along the middle is a transition zone that moves back and forth depending on speed. Good luck designing that airfoil. (This is what makes the TU-95 Bear so loud. Its propeller tips are supersonic while the rest of the aircraft isn't.)

There is a Russian saying about helicopters: You can place every problem in all aerodynamics on the tip of a rotor blade.

In the dune universe they have some kind of antigravity technology, so perhaps this is used to dampen the shockwave at the tips?

In our universe given enough power there is probably a way to generate an opposite wave to counter the shockwave.

But if you have antigravity, why do you need wings?

(Same also applies to having force fields, but the whole “slow blade” vs fast blade thing is enough to at least handwave that away)

Possibly cost. But also suspensors only seem to give lift, or very small amounts of lateral thrust. All the pure suspensor vehicles we see move extremely slowly. It's possible the 'thopters use suspensors for primary lift, maybe 80% of vehicle weight, and the wings are just for manoeuvring lift and thrust.

The aversion to using force fields is more about their interaction with laser guns, when shot by one they cause an explosion equivalent to a small nuclear weapon. Not ideal to have wrapping a vehicle you may be flying in formation on an attack run.

The problem with the supersonic tips is identical for normal aircraft propellers.

For aircraft with fixed wings for generating lift, the propellers can be small, so supersonic speed is reached only at a higher rpm, but for a helicopter there is no difference from this point of view compared with an ornithopter.

The blades of a helicopter propeller must also be able to rotate along their longitudinal axis, like those of an ornithopter, but nonetheless they are more efficient than flapping wings, because there is no dead time and no energy lost for the reversing motions, and the fatigue resistance need not be as extreme as it would be required for flapping wings.

All these conversations are lacking a discussion about the atmosphere on Arrakis. We have only hints about the composition and density of the atmosphere. We can assume that the atmosphere isn't toxic and contains quantities of oxygen and carbon dioxide that make breathing both possible and comfortable. We can be sure it doesn't crush humans or explode their lungs.

We also don't know the gravity of the planet. It might be 1.2g or 0.85g.

So we don't know how much lift is generated per stroke, how much lift is required, or what the speed of sound actually is on the planet.

Ornithopters seem to be an Imperium-wide vehicle and not a Arrakis-only device which blunts the urgency of these questions and variances.

To be used on many different imperium planets seem to imply that it operates across an acceptable range of gravities and pressures, etc.

Ornithopter is a type of vehicle. It's unlikely any specific vehicle of the type would be generic enough to operate across the variety of planets that likely exist within the Imperium without modification to the design.

This particular branch of the discussion was focusing specifically on the feasibility of the 'dragonfly' ornithopters operating on Arrakis as represented in the new film.

In real insects there is no problem with the drag for wing rotation, because the rotation is not an active motion, but a passive motion caused by the flow of the air.

The insect wings have a rigid front edge, which is moved up and down, while the rest of the wing is flexible. When the front edge goes down, the rear part of the wing is pushed by the air upwards until it assumes a slanted position that pushes the air backwards. The reverse happens on the upwards beat.

So in most insects only the rigid front edge of the wing is moved actively while the rest of the wing assumes passively various shapes that are determined by the distribution of rigid veins and flexible membranes in the wing, which ensure that the shape of the wing is the right one for good efficiency.

>You just change the angle of the wing on the upstroke

In fact we see that the wing joints can do this in the movie. When the wings fold up for deployment, the joint rotates them into orientation.

The fatigue life seems to be the biggest problem next to power production. Superelastic alloys might survive though.

If the intuition is some kind of supersonic reverberation that lets the wings operate in a local low air density then it might not be that hard to find an envelope of lift in that regime.

However, momentum is a problem. The vibrations, and thus stresses, induced on the body of the thopter must be ludicrous. When the wings go up, the body must go down, and vice versa.

Actually this can be an explanation for the fact that in the movie the ornithopters have 8 wings instead of 4, like an insect.

On each wing position there are a pair of wings, one above the other. If when one goes up, the other goes down, and vice-versa, that eliminates the vertical oscillation of the body.

Good point!

Interesting, I hadn't noticed that the ornithopters in the movie had 8 wings rather than 4.

Yeah, it's horribly inefficient to do this (flapping wings) at larger sizes. Birds, bats, insects actually evolved to flap less as they get larger: https://www.researchgate.net/figure/Wingbeat-frequency-versu...

A condor with a 10-ft wingspan might not flap for hours - so it glides, just like an airplane: https://www.sciencealert.com/giant-andean-condors-can-fly-fo...

A hummingbird (4 inch wingspan) flaps at 60 Hz though. It can hover too, just like an insect.

>A hummingbird (4 inch wingspan) flaps at 60 Hz though. It can hover too, just like an insect.

during hover hummingbird doesn't flap the wings up/down, instead it flaps it in horizontal plane. On each stroke, back and forward, the wing is set at an angle of attack and thus is kind of like propeller during each flapping stroke pushing air down :

https://youtu.be/naE7fK-gCPs?t=110

Hummingbird weights 3 grams. An APC 4x4 prop at 3000 rpm would generate 4 grams thrust consuming 0.2 Watt. Such energy density would mean 6 KWt for human, ie. 60x our regular power. So no wonder :

https://www.lib.niu.edu/2000/oi000811.html

"Hummingbirds are sugar addicts. Their metabolism is so incredibly fast that they need to refuel about every 10 minutes. Each day they consume 50 percent of their body weight just to maintain their normal weight. Hummingbirds burn from 6,600 to 12,000 calories per day. If a man had the metabolism of a hummingbird, he would have to eat almost 300 pounds of hamburger a day to keep from wasting away."

Just so you know, those numbers are way off. If you think about it how would a hummingbird consume that amount of calories in half its bodyweight? See https://www.birdspot.co.uk/bird-brain/how-many-calories-do-h...

I mean, when extrapolated to human size it's still 125k calories a day, but 6600 for a bird of 3g is just not possible.

They are (deliberately?) juxtaposing calories (the scientific unit of energy) and kilo-calories (the nutritional unit of energy).

Unfortunately, the latter are, confusingly, also called called 'calories', despite one nutritional 'calorie' being 1000x of a 'regular' calorie.

Yes, that must be the source of confusion.

6000 to 12000 calories, not kilocalories, per day, means 1.5 g to 3 g per day of sugar, which is plausible for a humming bird.

I thought it was accurate - k-cal are usually represented as Calories (capital C) as opposed to the individual unit of measure: calories.

See: https://en.wikipedia.org/wiki/Calorie

125k calories is about half a chocolate bar. It’s not a lot.

Only the "6,600 to 12,000 calories per day." is way off, because it's physics cal not nutritional (k)cal.

And it's more like 100lb of hamburger for a human, not 300lb.

By that data we already build our planes like birds.

If a 10ft bird flaps its wings less than once an hour a plane sized bird would probably fly for days without flapping its wings

The dragonfly wings were in the video games too I think

Dune2’s ornithopter has bird-like wings. That game had a really unique aesthetic

You might like this post also from today describes a simple science fair like way to demonstrate the effects of hinged flap surfaces. I called it a Venetian valve wing but whatever..

https://news.ycombinator.com/item?id=28950161

I thought about it a year ago but put it away due to no interest from my peers. I only brought it up to news.ycombinator recently because of the cut scenes from the new dune movie. You can try the experiment for yourself. It does in fact work. The only immediate benefit I see so far is that trust power does not get sheered at the edges with super sonic helicopter edges. Meaning the flaps, even if they are traveling at a whopping 100 meters per second are moving far less than would cause a super sonic shock wave like helicopter blades. An aircraft built around it would be more maneuverable, and have more lift power than similar sized aircraft. I can almost picture an ornithopter picking up a tank and transporting it to the battle field with the lift these things can develop. I'd animate it but there seems little point. This thing is going to show up soon and neither of us will get credit for the idea. But it does work..

Drone-sized ornithopters have become reasonably flyable outdoors. But scaling works against you. One the size of a large helicopter, capable of vertical takeoff, is tough. Mostly a power problem, like all VTOL.

Dune, like much of SF, runs on Rule of Cool. The skilled knife fighter, even shielded, is vulnerable to many of the standard anti-riot weapons, such as projectiles which throw a net. Being hit by an RPG round with a solid warhead would at least knock someone down hard, despite shielding, from sheer momentum transfer. And tanks work just fine in the desert, as has been amply demonstrated in the Middle East all the way back to Patton.

[1] https://www.youtube.com/watch?v=IJA5C-ghj4s

> And tanks work just fine in the desert, as has been amply demonstrated in the Middle East all the way back to Patton.

Probably not against sand worms.

And not for covering long distances to where the spice is...

Tanks are no weapon of choice. The rhythmic nature of the slats in the tank treads as it drives will surely attract a worm. Heh, they'll never learn.

Worth posting just because it is still a fun watch: https://www.youtube.com/watch?v=XQ7z57qrZU8

This might be from the later Brian Herbert books, but I recall ornithopters having jets or thrusters for VTOL.

TFA is citing jets from the original Dune novel.

Thrust-based VTOL requires huge amounts of engine power. Which is why it's rarely seen on anything other than fighters, which are mostly engine anyway.

There were some exceptions in the 1940s and 1950s, when jet engines didn't quite have enough power to get aircraft up to flying speed quickly. There were some attempts to use rocket-assisted takeoffs ("RATO" or "JATO") during WWII, and by the 1950s, this worked reasonably well. This peaked with the B-47 bomber, which was basically a jet fighter scaled up to heavy bomber size. Here's a JATO-assisted B-47 takeoff.[1] And here's a jet fighter zero-length takeoff from a rack on the back of a truck.[2] That was pushing it; there were a lot of crashes.

Awesome, but impractical, the technology was discarded in favor of aircraft with enough main engine power to get off the ground on short runways.

Another dead end was the Avro-Car, which was supposed to be a VTOL for the Army. This is the famous flying saucer.[3] It was supposed to be a supersonic VTOL. It had nowhere near enough power for that, and could barely get out of its own ground effect. Plus it was unstable, although today it could probably be stabilized automatically. The prototype finally ended up at what's now NASA Ames, bouncing around the back lots in hovercraft mode. The U.S. Army was also funding the UH-1 helicopter, which was less awesome, but far more useful, so they cancelled the Avro-Car and ordered lots of Hueys.

If you like weird VTOL craft and are in Silicon Valley, visit the Hiller Aviation Museum. Many of those strange ideas from the 1950s ended up there.

So, using a booster to get a large ornithopter off the ground is, while not impossible, probably not something you'd do often. Although you could imagine some fortress having such a rig, so the leaders could escape when they were losing.

[1] https://www.youtube.com/watch?v=vKQYG_fA2uM

[2] https://www.youtube.com/watch?v=uxazX7Z_4iQ

[3] https://en.wikipedia.org/wiki/Avro_Canada_VZ-9_Avrocar

The baron was flying by himself, so in that universe they definitely had other ways to generate lift but trust-based propulsion.

Suspensors aren't really used for thrust, but as a way to augment or nullify the effect of gravity on an object.

In the books, the kernel of fictional science used for multiple effects, including suspensors which is what the Baron uses, is called the Holtzman Effect [1]. The movie doesn't mention it at all, but the depictions of suspensors with all the massive vehicles, as well as floating furniture, glow globes, etc, are all consistent with how the books describe them.

[1] https://dune.fandom.com/wiki/Holtzman_Effect

I didn't say 'thrust', I said 'lift', and suspensors did lift the baron. It could be used to lift ornithopters as well, so it could, you know, flap wings for propulsion.

trust != thrust, just so you know.

Tell it to autocorrecting keyboard on my android.

That's what happens when you put your trust in autocorrect: you lose all the thrust ))))

I've turned off the autocorrect, and now I get all kinds of stupid touch interface mistypes, and lose time over correcting them, but at least i'm not miscorrected all the time.

the most infuriating thing is that autocorrect sometimes inputs a correct word, but THEN changes in to another when you continue typing. Aaaargh. That is further complicated by my dependence on swipe-typing on smartphones. It works 98% of the time, but the remaining 2% might come out embarassing :(

What I want to know, that I haven't seen someone mention yet, is why autocorrect or whatever (on Android) inserts periods in my text sometimes and won't quit.

Mainly if they are going to fight with medieval weapons but with force shields, they should be wearing medieval armor. That combination would make them much less mushy.

>And tanks work just fine in the desert, as has been amply demonstrated in the Middle East all the way back to Patton.

Tanks were being used to great effect by Rommel (and less successfully by others) for a long time before Patton graced the desert! In fact the battle of El Alamein where Rommel was severely pushed back was well underway when Patton landed. The Western Desert war began in mid 1940, Patton landed in late 1942.

As my companion poster noted, none of this was against sand worms though

Tanks do work fine in the desert, but if they were rumbling along on tracks they’d quickly attract sand worms and be swallowed. I imagine suspensor propelled tanks would be similar since in the novels force fields will attract worms from far and wide, much more so than just rhythmic noise.

> Being hit by an RPG round with a solid warhead would at least knock someone down hard, despite shielding, from sheer momentum transfer.

Have you ever seen Elysium?

Original inception dates back to Leonardo da Vinci, but it is not until recently that we have been able to achieve these flight characteristics on small scales.

I wonder what is meant by recently.

The first ornithopters capable of flight were constructed in France. Jobert in 1871 used a rubber band to power a small model bird.

https://en.wikipedia.org/wiki/Ornithopter

I think the work would also be improved by a mention of bio-inspired work on the PRANDTL-D wing.

The Armstrong team (supported by a large contingent of NASA Aeronautics Academy interns) built upon the 1933 research of the German engineer Ludwig Prandtl to design and validate a scale model of a non-elliptical loaded wing that reduces drag and increases efficiency. The team also applied these concepts to improve propeller blades.

https://technology-afrc.ndc.nasa.gov/featurestory/prandtl-wi...

For some reason I'd mostly seen Pénaud's model in popular accounts but googling Jobert landed me at a site that has a bunch of illustrations from Progress in Flying Machines (1894) that shows what they all looked like. Jobert's first:

https://invention.psychology.msstate.edu/i/Chanute/library/p...

And the whole lot:

https://invention.psychology.msstate.edu/i/Chanute/library/P...

Leonardo da Vinci's designs weren't ornithopters, or even anything like real birds. They were fixed-wing gliders with fanciful bat-like shapes for stylistic reasons.

If you construct a fabric+wood ribs wing, it will easily look bat-like. Many early airplanes were like that too.

>They were fixed-wing gliders with fanciful bat-like shapes for stylistic reasons.

My understanding is they were commissioned by playboy Milanese nobleman intent on bringing down the Borgia crime family, whose parents had been knifed down in an alley in front of him when still a child after exiting a wonderful setting of the Magnificat composed by Gaffurius.

Wait, is this the _original_ Batman origin story?

I'd be very wary about asserting stylistic intent to da Vinci when it comes to engineering endeavors. Many of his architectural designs were thought fanciful and entirely unfeasible until someone actually built it, or built it with the right materials.

I would hazard that there is a lot of thoughtful consideration that went into the ornithopter designs, to the extent that a breakthrough or major insight lies waiting for anyone able to decipher or parallel da Vinci's reasoning.

The idea that what works for insects or small birds should work in larger scale if you just have materials does not hold up.

Small insect wing aerodynamics is closer to high viscosity aerodynamics. Viscous forces are more important and efficacy of lift generation from an airfoil is less important. Air can be considered incompressible.

Reynolds numbers (Re) - orders of magnitude.

  10^7 for helicopter main rotor
  10^4 for large insects
  10   for small insects

Helicopter rotor aerodynamics is in laminar flow region limited from above buy the transonic region. Airfoil lift is the most important thing and laminar flow is important.

Insect flight is mostly turbulent flow. Generating enough lift using leading edge vortex and half strokes like insects do for helicopter sized object and rotor sized wing is not self evident. At least the wings should be much larger than helicopter rotors and flap very slowly.

Yeah. For insects, flying really is more like swimming. Air has very different properties at that scale.

Here's a fun and working model aircraft powered by articulated flight: https://www.youtube.com/watch?v=ysnAVwtdbYc

Things that strike me off the bat for creating "the real thing:" Ground effect with rising heat, helping with lift. Longer and lighter wingspans made out of special exotic materials that is incredibly durable, flexible and easy to articulate, perhaps with a "muscular" system. Much stronger, lighter and tuneable machines. Systems or mechanics preventing compartment shake. I think this is probably the most difficult part in order to achieve comfortable flight. The part of a bird best evolved to counteract this movement is the head, since they need that as a stable platform to observe the world despite the rest of the body moving.

Yeah this guy makes these things like everyday. Recently using direct servo drive is interesting.

I had a rubber band powered bird over 35 years ago. Looked a lot like this:

https://youtu.be/GqWkctx3Z2I

I remember those. I don't think elementary-school-aged me ever got mine to fly properly.

Outdoors on a calm day. Mine flew at least 10 feet up, and 50 feet distance.

Did anybody else find the changing tab title annoying?

Pretty sure the author did it as a troll, in which case it's great, I hate it.

>

^ comment on it

I thought it was neat and wasn't really bothered. Though I'm not really sure what it's supposed to depict

What comes to mind to me is a sandworm coming out of the ground, and pulling something back down underneath with it.

It was interesting to see the update rate of background tabs.

But.. why? Am I out of touch to not see the humor here? Annoying the people who you intend to read your posts?

I miss the days of quirky title bar "animations".

One of the interesting details not mentioned in the book (it's in either one of the appendices or in the Dune Encyclopedia) is that the wings are powered by muscles, not engines. It's an aspect of the minimal use of technology in that Universe.

I wouldn't say a minimal use of tech, more that they use very mature tech. Mature tech 'just works' with minimal intrusion or maintenance. I think of it like home heating systems. Once we all had fires or stoves as central objects in houses. Now we have a switch on a wall connected to a system that can go years without maintenance. Sure, there is an entire industry behind the scenes and some debate the benefits of one tech over another, but the average user only ever sees the switch. So the ornithopter's engines have been replaced by electromechanical muscles because they probably go decades without need of attention.

You're right that the technology they use is very mature, but anti-machine stigma is a definite "thing" in the Dune milieu, blowback from the Butlerian Jihad. At one point Reverend Mother Gaius Helen Mohiam says something to the Lady Jessica about the difficulties of working with a feudal culture that has "turned it's back on most technology", something like that.

Ornithopter muscles are not electromechanical, they're organic.

>blowback from the Butlerian Jihad.

Which itself is a reference to Samuel Butler's 1872 satirical novel "Erewhon" which featured a culture that had banned all complex machines due to an experience with machine intelligences revolting. https://en.wikipedia.org/wiki/Erewhon

I think the language re "machines" in the Dune context refers more to thinking devices, computers, than to mechanization.

That's the origin and emphasis of the Butlerian Jihad, for sure, but it seems to me that there's a more general disdain of machines in the galactic culture. Although they certainly do use a lot of machinery: shield generators, poison snoopers, spaceships, etc. so maybe not.

On the other hand, in Dune universe we see all that weird machinery used by a very unusual part of the society, the top 0.01%; and even they're not a product of the societies they live in but an import from the partially shunned Ixian community - so we can presume that the ordinary people don't make or use machines nearly as much. E.g. there are some instances of complex electronics, but it seems like most planets e.g. Caladan would have near-zero electronic industry, it doesn't seem that this would be a career option for some random inhabitant of Atreides' home planet to just decide to study electronics and make them.

True, but allmost all of our modern machines need lots of thinking devices to work.

I see lots of calculators that can execute programs (CPUs). I see lots of software that is great a pattern recognition or trend analysis (AI). What I haven't seen are any devices actually thinking through a problem.

Depends how you define thinking. I used it in that calculations are "thinking" work.

That seems uncomfortably close to claiming every Turing-complete device is artificial intelligence.

Well, Turing was formalizing something that his mind was doing, so in a sense, yes, Turing Machines have always been AI.

as feasible as any other tech in Dune, shields, laseguns, space folding, genetic memory, etc...

giant floating guild navigators in tanks of spice that resemble wrinkled testicles? as per the 1984 film

...but apparently not as per the 2021 film. Seriously, where did the guild navigators go in the Zendaya version?

Perhaps the CGI testicle budget was spent on salary for Jason Momoa instead

If you're gonna have giant balls in the movie, you have to do it right.

The first scene of the 1984 movie does not exist in the books, even though they were depicted correctly. In fact, they didn't appear directly in the original Dune book at all, and they were only described in later books of the series (Both the 2021 and 1984 movies are adaptations of the first book, the 2021 one adapting the first 75% ish).

SPOILER ALERT

Two Guild Navigators are in the Emperor's party on Arrakis when he confronts the "upstart duke". They are not mutant freaks, they look like normal humans, but their eyes are so blue from spice use that they appear black.

The weird fish-baby in a tank is all David Lynch being David Lynch.

Actually, that wasn't an invention of David Lynch. It was just something sort of pulled in from the second book.

I looked up that part. Indeed there are two of the "guild agents, one tall and fat, one short and fat" as part of the entourage, and they are referred to in the text as Guildsmen. Paul asks them if they are both navigators and they reply with yes. And yeah they are revealed to have blue eyes, so I think this is correct. However, later books do describe the tanks in which the navigators live.

The dune wiki says that Herbert apparently liked how the navigators were depicted in the movie so he added their description to his last Dune book "Chapterhouse Dune". But even earlier books described the guild navigators as humanoid fish in a tank.

Apparently the explanation for these different forms is that there is a progression, where the guild navigators start out looking like humans, and eventually they look like the two in the Lynch movie.

https://dune.fandom.com/wiki/Guild_Navigator#Physical_Descri...

So what I said about the navigators not appearing at all was wrong, as they do appear in the first book, but they appear only way later in the story.

IIRC spacing guild did try to keep their mutated navigators appearance secret from the general public, so having some normal-looking guild agents say "we're totally the navigators" does not really mean that they actually are navigators.

Ah, much respect est31. Well met. :)

There’s mention of “stages” of navigators in one (or more?) of the books. Stage 3, as I recall are the advanced form in the tank.

I think we saw guild navigators with the emperor’s envoy on Caladan. White-suited creatures with a red swirling gas behind their visors.

I just realized that several AWS icons[0] always remind me of the guild navigtor's tank[1] due to their "protruding-front" shape.

[0]: https://imgur.com/a/RnK3e9C

[1]: https://imgur.com/a/yc00FNz

And stillsuits.

While pretty hand-wavy I think they're the least hand-wavy of all the world building.

When I visit that site in firefox the name of the tab keeps changing.. A bunch of zeroes getting longer, then shorter. Is that some intentional javascript thing??

Saw same thing in Chrome

Reminds me, where or when can I buy a robobee?

https://m.youtube.com/watch?v=hEZ7rHRifVc

I always thought Dune had lower gravity, would also explain how the worms work.

Also note there is low gravity tech. Maybe it’s a hybrid.

> I always thought Dune had lower gravity, would also explain how the worms work.

On page 79 of 'Dune' (my 1973 paperback copy), when the Atreides soldiers first land on Arrakis, a group of them 'shout and roister' as they disembark. One of them says 'Nine-tenths of a G by the book'. Another says 'Feel that under your dogs? That's gravity, man.'

So not massively different from Earth-normal. Not sure if is this enough to affect the feasibility of a winged craft (or sandworms). On that note, air pressure would also affect the feasibility of winged vehicles, as in the difficulty of trying to fly a (small) helicopter on Mars.

I’ve often wondered the exact opposite. Could thrust turbines evolve naturally?

human powered ornithopter: https://en.wikipedia.org/wiki/UTIAS_Snowbird

Wow, I love those "concrete tiles". Any idea where this is?

RC Ornithopter https://www.youtube.com/watch?v=2Nd8BA3OHCc

the wings make the craft much wider than a helicopter, plus someone could easily walk into them when it is on the ground, idling.

wonder why no insects evolved with a rotating wing. rotating propulsion exists in nature, though at a microscopic level. (flagella)

I guess ability to stow wings easily is a big advantage. To stow any kind of rotating propellers is problematic.

These ornithopters can certainly stow the wings too, it just never came up in the story.

Not a huge Dune lore-head, but I kinda feel slighted by how the new movie depicted them now...

I disagree, I liked the dragonfly inspired ornithopter.

Maybe not as originally envisioned, but I like the aesthetic.

> Maybe not as originally envisioned, but I like the aesthetic.

I think you'll find that you've identified the target market for almost all modern film adaptations of science fiction novels.

Doubly true if the elided part of the quoted section is

> Maybe not as (I) originally envisioned, but I like the aesthetic.

I am guilty of this in every book to film adaptation I've ever seen.

(Also - book sales / movie audience ratios will almost always necessitate generalization.)

I might have misheard, but aren't they also referred to as "jetflies" in the chase scene? That is a bit more apt name for this particular design.

I did like how they look like helicopter blades and it is built like a gunship/AH64 style. The gliding stuff was like hmm... also generally as a side note, giant things would sink through the ground like the opening ship landing oh well.

It is more complicated than that. The book is vague though colorful on many points, so there is considerable room for interpretation. On several points in the book ornithopters are described as bug like, buzzing when active, and having bug like buzzing wings. The evocative version in the movie is consistent with one particular interpretation of what the book was depicting.

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