Comment by kleton
9 hours ago
It would be possible to build an ornithopter, evidenced by the existence of avians, but it turned out the easiest ways to make flying machines were otherwise.
9 hours ago
It would be possible to build an ornithopter, evidenced by the existence of avians, but it turned out the easiest ways to make flying machines were otherwise.
I like the comparison, but with aviation on a fundamental level we made it simpler (removing actuation), not added more (senses we dont need)
What counts is the overall complexity, not the complexity of a single subsystem.
Using more senses allows simpler processing of the sensor data, especially when there is a requirement for high reliability, and at least until now this has demonstrated a simpler complete system.
Others in this subthread discussed the comparison of the complexity of different ways of achieving flight itself, but I think there is an interesting discussion in that... well... we do add senses we don't technically need to achieve stable flight (but are very useful for safe flight and have reduced the incidence of aviation incidents and accidents dramatically).
Whether it be altimeters based on radio[1] or air pressure[2], avoidance and surveillance systems that use radio waves to avoid collisions with other aircraft[3][4], airborne weather radars[5], sensors that measure angle of attack (AoA), GNSS location, attitude, etc, many aircraft (even unpowered gliders!) have some combination of special sensing systems that aren't strictly necessary to take off, fly to a destination, and land, even if some are required for what many would consider safe flight in some scenarios.
Many of these systems have redundancies built in in some form or another and many of these systems are even built into unmanned aerial systems (UASes) big and small.
[1]: https://en.wikipedia.org/wiki/Radar_altimeter
[2]: https://en.wikipedia.org/wiki/Pressure_altimeter
[3]: https://en.wikipedia.org/wiki/Traffic_collision_avoidance_sy...
[4]: https://en.wikipedia.org/wiki/Automatic_Dependent_Surveillan...
[5]: https://skybrary.aero/articles/weather-radar
I'm not sure I agree. I think just having wings that flex a bit is mechanically simpler than having an additional rotating propellor. After all, rotating axles are so hard to evolve they never almost never show up in nature at a macro scale. Sort of a perfect analogy to lidar actually. We create a new approach to solve the problem in a more efficient way, that evolution couldn't reach in billions of years
Rotating axles have not evolved in animals not because they were complex, but because any part of an animal requires permanent connections with the other parts, not only for the supply with energy but also for the continuous repairing that is required by any living body, to avoid death.
Artificial machines rely on spare parts manufactured elsewhere, which are used by external agents to replace the worn out parts.
For an animal to have wheels, it would have to grow wheels in some part of the body, periodically, then use its limbs to detach the wheels and attach them on the axles, after removing the old wheels. This is something sufficiently complex to be extremely unlikely to appear from evolution.
Even this huge complication would be enough only for passive wheels. For active wheels there exists no suitable motor, as the rotational motors with ionic currents are suitable only for the size of a bacteria. All bigger living beings use contractile motors, which cannot be used for a rotation of unlimited angle. So active wheels would also need a different kind of motor, which can work without a solid connection between the 2 moving parts. The artificial motors of this kind use either electromagnetic forces or fluid expansion due to temperature or pressure variation. Both would be very difficult to evolve by a living being, though electric fish and bombardier beetles show some possible paths.
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Jet engines do not strike me as being inherently simpler than muscles, not by a long shot.
They're still the best way we know of going about the business of building a flying machine, for various reasons.
Piston engines surely are more complex than jet engines though? Which replaced the "flapping engines".
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I would posit that the human brain is complex, and adding senses is simpler than replicating an aspect of the mind more accurately.
> easiest
This is the keyword here, just because the other approach is harder does not mean it is impossible.
It's a decent gamble to try and do things the hard way if it is possible to be deployed on cheaper/smaller hardware (eg: no lidars, just cameras).
Is it still a decent gamble after you've been trying (and failing) for a decade, and numerous well funded competitors are going the easy way, and when there is huge upside to being first, and when the value of FSD easily covers the rapidly falling cost of LIDAR?
No. It's not a good idea. It's not a good gamble. It's stupid, and the engineers can see it's stupid. A lot of them have quit, reducing the very slim chances of it working even further.
But why is FSD "failing" is the key question.
Hint: it's not the sensor inputs that are the bottleneck!
Yeah you could be right.
Not my area of expertise, so I’d rather not try to predict what will work and what won’t.