We have been able to manufacture wheels for millenia. We *still* haven’t quite nailed how to build a walking machine that is not worse than just having special wheels with a more flexible axle setup, and what we do have requires artificial intelligence to be able to walk on fairly flat terrain without eating dirt.
We have been able to manufacture wheels for millenia. We *still* haven’t quite nailed how to build a walking machine that is not worse than just having special wheels with a more flexible axle setup, and what we do have requires artificial intelligence to be able to walk on fairly flat terrain without eating dirt.
Wheels didn’t need a lot of invention. (Cut a rounding trunk into cross sections). They don’t even need to be perfectly circular to assist with moving things.
Legs, on the other hand, are fairly complex mechanisms. They need hinges, linear actuators (muscles) and something that balances and coordinates their movement. This is hard to make work purely mechanically – it is only with computing and advanced sensors that legs are even feasible that can adapt to terrain. Simple mechanical legs might work on flat and even surfaces but that is exactly where a wheel works even better.
Legs are also hard to make fail safe – a single failure very likely leads to collapse whereas a wheel not working might, at the very worst, just stop moving.
Wheels didn’t need a lot of invention. (Cut a rounding trunk into cross sections). They don’t even need to be perfectly circular to assist with moving things.
Legs, on the other hand, are fairly complex mechanisms. They need hinges, linear actuators (muscles) and something that balances and coordinates their movement. This is hard to make work purely mechanically – it is only with computing and advanced sensors that legs are even feasible that can adapt to terrain. Simple mechanical legs might work on flat and even surfaces but that is exactly where a wheel works even better.
Legs are also hard to make fail safe – a single failure very likely leads to collapse whereas a wheel not working might, at the very worst, just stop moving.
It takes more energy to move legs than it does to move wheels. It takes some energy to spin the axel which spins the wheel but, even after cutting off the source of energy the wheel will continue to spin as it’s gradually slowed by friction. Legs however, require a constant source and once it’s stopped they will fail to move. You can test this yourself by running and then freezing your legs and you will likely find that you fall immediately to the ground. Then you can take a bike and lock the handle bars in place before giving it a push and you’ll notice that it travels a ways before it slows and tips over.
It takes more energy to move legs than it does to move wheels. It takes some energy to spin the axel which spins the wheel but, even after cutting off the source of energy the wheel will continue to spin as it’s gradually slowed by friction. Legs however, require a constant source and once it’s stopped they will fail to move. You can test this yourself by running and then freezing your legs and you will likely find that you fall immediately to the ground. Then you can take a bike and lock the handle bars in place before giving it a push and you’ll notice that it travels a ways before it slows and tips over.
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