6 ms·
Nature does not use propellers. So why do people?
- oliveshell 5y agoNature has no rotating output shafts.
- klyrs 5y agoIt does though: https://en.m.wikipedia.org/wiki/Flagellum https://en.m.wikipedia.org/wiki/Flagellum
- oliveshell 5y agoOh wow, that is so damn cool. They’ve even got molecular bushings! Had no idea. I’ve got some reading to do now.
- didsomeonesay 5y agoGive yourself an Xmas gift with a print copy of "The machinery of life" by David S Goodsell. You will love it.
- rolph 5y agocheck this one out too, there is a general topic of biomechanics regarding molecular motors: https://en.wikipedia.org/wiki/Molecular_motor https://en.wikipedia.org/wiki/Molecular_motor
- klyrs 5y agoYeah, I though that flagella were just little whippy things that corkscrewed somehow... but then I looked at that page this morning and I'm still gobsmacked.
- h2odragon 5y agoCounterpoint: maple seeds. Nature doesn't do axles and rotational bearings so much.
- rolph 5y agoi think you may like this : https://en.wikipedia.org/wiki/Flagellum#Bacterial https://en.wikipedia.org/wiki/Flagellum#Bacterial >> The engine is powered by proton motive force, i.e., by the flow of protons (hydrogen ions) across the bacterial cell membrane due to a concentration gradient set up by the cell's metabolism <<
- ceejayoz 5y agoAlso fun: https://en.wikipedia.org/wiki/Issus_(planthopper)#Gear_mechanism https://en.wikipedia.org/wiki/Issus_(planthopper)#Gear_mecha...
- cblconfederate 5y ago... Because nature is a good engineer?
- fennecfoxen 5y agoBecause nature and engineers are good at different things. Nature is good at flexible materials and the control systems that drive their reciprocating impulses. Engineers are good at making rotary things go brrr and reach high speeds.
- cblconfederate 5y agoYeah nature is good at survival, which is not what you have in mind on a cruise ship
- scblock 5y ago"Nature does not use wheels. So why do people?" Regardless of how interesting a concept or development may be, check the logic of what you're writing before you hit publish.
- dylan604 5y agoI'd suggest the logic test before sitting down to write the thing. "But it's the internet and everyone has the right to hear my opinion" is too strong to resist.
- twobitshifter 5y agoWheels aren’t all too useful without roads and fixed cleared paths. Any prey can escape a wheeled predator easily and a predator could push wheeled prey to unmanageable terrain. A wheeled jaguar can’t get you when you are swinging through the trees.
- wpietri 5y agoExactly. I once did a 3-day, 150-mile, solo bike trip. My first day I thought a lot about how magical bicycles were. The next day my mind turned to how much that was really due to roads. The last day what I was really amazed by is the social systems that create and maintain systems of roads. Without humanity's unique ability for cooperation toward long-term goals, the main use of a wheel would be a wheelbarrow.
- sliken 5y agoHeh, or get better wheels. I've got a dual suspension (160mm front and rear) and 2.6" tubeless tires. I love getting away from things, exploring areas that would take a few days hike but are a day trip on a bike. Far enough out that the "trails" I end up on are game trails instead of human made roads/trails. Sure it's slower than being on a road, but way more fun to explore. A fair bit of the planet is passable on decent mountain bike, don't think humans (or lack of) would make much difference. In most mountain areas I'd rather be on a game trail, than a road.
- 5y ago
- klyrs 5y agoCounterpoint: flagella are powered by rotary motors in some organisms, and they're astonishingly effective. https://en.m.wikipedia.org/wiki/Flagellum https://en.m.wikipedia.org/wiki/Flagellum
- marcusverus 5y agoFrom the Wiki: > "The bacterial flagellum is driven by a rotary engine (Mot complex) made up of protein, located at the flagellum's anchor point on the inner cell membrane. The engine is powered by proton motive force, i.e., by the flow of protons (hydrogen ions) across the bacterial cell membrane... The rotor transports protons across the membrane, and is turned in the process. *The rotor alone can operate at 6,000 to 17,000 rpm*[!], but with the flagellar filament attached usually only reaches 200 to 1000 rpm." Nature never ceases to amaze.
- jvolkman 5y agoThanks. I was sure I'd read about rotary motors in tiny organisms before.
- causality0 5y agoNot only do many organisms have propellers in the form of flagella, but many like myxococcus xanthus are themselves propellers, using shaped proteins to corkscrew through water. It's baffling that both the author and their editor could be so ignorant.
- fennecfoxen 5y agoWhy would this ignorance be noteworthy or baffling to you, who are informing so many readers of HN of this fact for the first time?
- causality0 5y agoHave a large portion of HN readers never taken grade school biology? Have a large portion of HN readers never seen sperm? That aside, the baffling part is the author thought himself well enough informed to write the article in the first place, and then that these foolish ramblings made it to the HN front page.
- ccvannorman 5y agoMy first thought as well, thanks for this :D Here's one of 500K+ results from Google for "Flagella propeller" [] https://www.nature.com/articles/nrmicro744 https://www.nature.com/articles/nrmicro744
- rolph 5y agothis is a case in favor of well rounded life experience. the events occuring at the cellular and bacterial level dont scale up saliently. if we were to exploit molecular rotational engines or dynamos they would be engineered as an array, the final device would not reveal its molecular organisation as saliently as a wheel and axle assembly does. muscle tissue is one example, although not constructed of rotational elements, the underlying structure is likened to a linear track motor, and could perhaps be cyclized to form a stator and rotor like mechanism.
- formerly_proven 5y agoNevermind the powerhouse of the cell.
- jatone 5y agodunno about you but the example image looks fact more complicated and likely to experience malfunctions than a propeller....
- fennecfoxen 5y agoThe material longevity is definitely going to be a factor in this design. Flexible materials like this occurring in nature generally have the advantage of being alive, and able to self-repair. On the other hand, it can presumably be replaced, much like a tire.
- rfreytag 5y agohttps://archive.md/iJ0OY https://archive.md/iJ0OY
- micromacrofoot 5y agoNature has a millions of years head start in engineering. We've figured a lot out in a short time, but everything we do is very heavy and inefficient by comparison. Ruby-throated hummingbirds, for example, migrate 500 miles over the Gulf of Mexico in a single flight. Imagine trying to build a drone that weighs 20 grams and can fly 500 miles. We've got a lot to figure out in terms of intelligence, energy efficiency, and material science.
- matthewmcg 5y agoHummingbird metabolism is incredible. At night, when they can't constantly feed, certain species go into a deep topor state to avoid starving. See https://www.nytimes.com/2020/09/08/science/hummingbirds-torpor-hibernation.html https://www.nytimes.com/2020/09/08/science/hummingbirds-torp...
- liftm 5y agoNah. Trains e.g. sure are heavy, but they're also ridiculously energy efficient when it comes to moving stuff around. And yet they're also typically faster than any land animal. Building roads or tracks doesn't make sense for animals, and freely rotating parts difficult on larger organisms. On the flip side, our human engineering often hasn't put energy efficiency so high up the priority list.
- micromacrofoot 5y agoOh sure, rail is great... but you can't exclude the amount of energy that goes into things like laying tracks, paving roads, and maintaining engines. Plus most of them still use human operators. Even considering land animals, look at African Elephants. They can walk for days without water and weigh ~6,000 - 10,000lbs. Considerably slower than a truck with a similar weight, but still likely several times more efficient traveling over unpaved dirt. We optimize for different things, and can be more efficient under very specific circumstances (consider Voyager, for example :P). But when it comes to packing efficiency into a small package we don't hold a candle to nature. We'll get there eventually, and much faster than evolution did, but our technology is still in its infancy. Consider brains! What you get out of even a tiny mouse brain is bonkers when you consider what little fuel it needs.
- Txoko 5y agoWhy can't someone invent a system to raise and lower a propeller or Outboard to follow the contour of the waterbed lessening the need and expense of channels?
- fennecfoxen 5y agoWhy make the propellors go up and down? You could just fix them in the Up position, and make them as big as you can in that position. And they do; we're at that engineering limit.
- joe_chip 5y agoWho cares?
- personalityson 5y agoIf it could it would
- jessepasley 5y agoNature does not create Transformer movies. So why do people?
- nnain 5y agoWell, nature does not use Tyres either.
- Turing_Machine 5y agoIt kinda does, in the form of hooves. Hooves are better than t[iy]res in one way: they're self-renewing.
- nnain 5y agoI meant in terms of the rotating motion, not wear and tear :)... since the OP was about Nature vs. Propellers.
- Cyclical 5y agoThe reason one does not see freely rotating bodies such as wheels or propellers in nature comes down to perhaps the most fundamental aspect of biological systems: they're alive. Because they're alive, resources need to be supplied to them and waste needs to be removed. Propagating nutrients across a freely rotating interface can be an intractable problem, and this is not even considering the question of _how_ one could induce free and unbounded rotation in a biological joint. Think of how muscles work, with discrete attachment points and it becomes clear that free rotation isn't possible with muscles. The only method of inducing rotation I can come up with off the top of my head is some sort of turbine design, with rotation being driven by fluid flow. The notable exception to the absence of free rotation in nature is the flagellum, which solves the nutrient supply issue by being so small and self-contained that it doesn't need nutrients, just the presence of an ion concentration gradient.
- xyzzyz 5y agoHere is an idea: make the rotating part dead (like mollusk shell), and use muscles to push a paddle to add impulse to rotation, like pedaling a bicycle. Should be doable.
- fennecfoxen 5y agoDead things have an unfortunate tendency to break, and cannot self-repair.
- xyzzyz 5y agoIt doesn’t have to last forever, only until it reproduces.
- carry_bit 5y agoBut how easy is it for that to evolve?
- cortesoft 5y agoNot sure if any creature has evolved ball bearings…
- Grustaf 5y agoMost people don't really use propellers all that often
- pfortuny 5y agoAnd there came a maple and produced seeds which, for whatever reason rotate. OK not “propeller” but near enough.
- jpm_sd 5y agoEngines rotate?
- TYPE_FASTER 5y agoEvolution values survival. Efficiency is defined as life and death. People value survival, but it's complex. Economical aspects come into play. The technical complexities of some natural systems are amazing (read about tuna in https://www.amazon.com/Song-Blue-Ocean-Encounters-Beneath-ebook/dp/B004IZM6PA/ref=sr_1_1?keywords=song+for+the+blue+ocean&qid=1639674401&sr=8-1 https://www.amazon.com/Song-Blue-Ocean-Encounters-Beneath-eb... for an example). Wind is free. Once you start carrying cargo, there's a tradeoff between cost and speed. When the cost of mechanical propulsion became low enough, it was widely adopted. If the company in the article can evolve their technology to the point where it's cheaper, including maintenance, the fact that not everybody is going know how to work on it (always a barrier for new technology), it will get adopted.