Why today's humanoids won't learn dexterity

You don't lose pressure or touch sensitivity from wearing even thick welding gloves. You can still feel how hard you are gripping the rod quite easily.

What about full control of a claw machine to pick up said glass?

Depends heavily on the use case. Indeed many tasks humans carry out are done without touch feedback - but many also require it.

An example of feed-forward manipulation is lifting a medium-sized object. Classic example is lifting a coffee cup. If you misjudge a full cup for empty you may spill the contents before your brain manages to replan the action based on sensory input. It takes around 300ms for that feedback loop to happen. We do many thing faster than that would allow.

The linked article has a great example of a task where a human needs feedback control: picking up and lighting a match.

Sibling comments also make a good point on that touch may well be necessary to learn the task. Babies do a lot of trial-and-error manipulation and even adults will do new tasks slower first.

This is a good point, but I’m not convinced it negates the author’s argument.

Consider whether you could pick up that same fragile glass with your eyes closed? I’d wager you could, as you’d still receive (diminished) textile feedback despite the thick gloves.

And yet, when you pick up a glass expecting it to be full but it turns out to be empty, you'll overdo the motion; part of dexterity is expectations.

Because you have learnt it already and you can make predictions. And you don’t lose pressure sensitivity, you still feel the pressure of your hand to the glove, a better example would be using an exoskeleton or robotic arm or inactivate certain nerves. Still you risk more of breaking it imo and you have to be more careful in the beginning until you learn again.

Edit: and you probably are not gonna be as fast doing it

Only because of your training otherwise.

> I am unaware of any barrier, or any reason to infer there is one, for dextrous robots.

Pretraining data?

One very important task to solve is the ability to select a box from a shelf and set it neatly on a pallet, as well as the reverse. People have been working very hard on this problem for a long time, there are impressive demos out there, yet still nobody is ready to set their best box manipulating robots loose in a real warehouse environment.

How hard can it be to consistently pick up boxes and set them down again in a different location? Pretty hard, apparently.

> I am unaware of any barrier, or any reason to infer there is one, for dextrous robots.

I don't think there's a fundamental barrier to building a humanoid robot but the cost will be an extremely high barrier to adoption.

A human is nature's ultimate robot: hundreds of servos, millions of sensors, self-assembling from a bag of rice, self-repairing for minor damage. You just can't beat that, not for a very long time.

Touch is a 2D field of 3D vectors. Easily stored and transmitted as images, and easily processed by neural nets. You could add temperature and pain/damage channels if you want, though they don't seem essential for most manipulation tasks. (Actually I don't believe touch is as essential as he argues anyway. Of course someone who learned a task with touch will struggle without it, but they can still do it and would quickly change strategies and improve.)

The problem with touch is making sensors that are cheap and durable and light and thin and repairable and sensitive and shape-conforming. Representation is trivial in comparison.

There actually has been some recent work on digitizing smell, most notably Osmo, which was founded by some ex-Google ML researchers: https://www.salon.com/2025/01/05/digital-smell-has-arrived-a...

I'm not sure describing it in words is very helpful, and there's probably a good amount of such data available already.

I would think the way to do it is build the touch sensors first (and it seems they're getting pretty close) then just tele-operate some robots and collect a ton of data. Either that, or put gloves on humans that can record. Pay people to live their normal lives but with the gloves on.

What would be the evolutionary pressure to grow wheels? They are useless without roads

> if there was an evolution pathway to wheels

It's hard to see one. Even a nice flat world with ample incentive and taking good "bearings" for granted, how can you evolve a wheel-organ that maintains a biological connection as well as being able to rotate an indefinite number of time?

A few difficult and grotesque endpoints:

* The wheel only rotates a fixed number of times before the creature must pivot and "unwind" in the opposite direction. This one seems most plausible, but it's not a real wheel.

* The main body builds replacement wheels internally (like tooth enamel) and periodically ejects a "dead" wheel which can be placed onto a spoke. This option would make it easier to generate very tough rim materials though.

* A biological quick-release/quick-connect system, where the wheel-organ disconnects to move, but then reconnects to flush waste and get more nutrients.

* A communal organism, where wheel-creatures are alive and semi-autonomous, with their own own way to acquire nutrients. Perhaps they would, er... suckle. Eeugh.

Wheels are great until the robot encounters uneven surfaces, such as a stairway, or a curb. So some kind of stepping functionality would still be necessary.

> Wheels are [...] more effective than legs.

Maybe in your living room. But step into a dense forest (which is what we are made for) and that statement will be far away from reality.

The world is full of curbs, stairs, lips, rugs, vehicles, etc. If you're a human-scale robot then your wheels need really wide base to not tip over all the time, so you are extremely awkward in any kind of moderately constrained space. I wouldn't exchange my legs for wheels. Wheelchair users have to fight all the time for oversights to be corrected. I can see maybe see a wheel-based humanoid robot, but only as a compromise.

On the other hand there is not much reason to constrain ourselves to the unstable and tricky bipedal platform or insist on having a really top-heavy human-like torso. You could have 3-4 little legs on a dog scale body with several extra long upwards reaching arms for eg.

Power to wheel sensors are the paws. Where is the CNS/brain going?

> they will likely have to collect the both the right data, and learn the right thing.

The "bitter lesson" says to stop trying to find simple rules for how to do things - stop trying to understand - and instead to use massive data and massive search to deal with all the incredibly fussy and intractable details magically.

But the article here is saying that the lesson is false at its root, because in fact lots of understanding is applied at the point of choosing and sanitising the data. So just throwing noise the model won't do.

This doesn't seem to match experience, where information can be gleaned from noise and "garbage sources of data ... become valuable with a model large enough", but maybe there's something illusory about that experience, IDK.

From the article: a human hand has about 17,000 low-threshold mechanoreceptors in the glabrous skin (where hair doesn’t grow) of the hand, with about 1,000 of them right at the tip of each finger, but with much lower density over the rest of each finger and over the palm. These receptors come in four varieties (slow vs fast adapting, and a very localized area of sensitivity vs a much larger area) and fire when they sense pressure applied or released.

Where can you buy the artificial equivalent?

> Another possible source of data is the driving current of the motors/actuators which is proportional to the mechanical resistance the limb encounters.

The problem is precisely the actuators. A lot of a human's muscles actually come in pairs - agonist and antagonist muscles [1], and it's hard to match the way human muscles work and their relatively tiny size in a non-biological actuator.

Just take your elbow and angle it to 90 degrees, then rapidly close it so your upper and lower arm are (almost) in parallel. An absolutely easy, trivial task to do for your pair of muscles controlling the tendons. But now, try to replicate even this small feat in a motor based actuator. You either use some worm gear to prevent the limb from going in the wrong direction but lose speed, or you use some sort of stepper motor that's very hard to control and takes up a lot of space.

[1] https://en.wikipedia.org/wiki/Anatomical_terms_of_muscle

Unitree is planning to IPO in Q4 of this year, that should be a pretty hot property.

Pshaw, that's nothing, you need to invest in the companies promising to make a Greater Fool robotic investor, now that's where the market'll take off. :P

It's been tried a number of times already though, robotics companies have been around for decades, Sony, Boston Dynamics, Hyundai and many others are already in the space (and some of those are on the stonks market). I don't think it'll become any bigger than what it is. Also since many have tried to make it hype already, Tesla being the latest.

There's a number of "robotics and embodied AI" ETFs out there that should show up with a quick search. I don't have an opinion as to their quality so you'd have to do your own research.

This needs to be some sort of maxim: “The most useful robots are the ones that don’t look like (or try to be) humanoids.”

For some reason (judging by Fritz Lang, Gundam, etc.) humanity has some deep desire or curiosity for robots to look like humans. I wonder if cats want robot cats?

Right but that's very task specific, and what many people want is a single robot which can do many different tasks, and do so without modifying the existing environment. I would love a robot which could cook and clean and do laundry (including folding) but I still need to live in the same space it would use. The most obvious way to do that is a humanoid robot, which is why nanny companies are working on it, and here he's arguing that's not going to work.

A robot that isn't stationary, in a home or in a factory, wants legs. Wheels are fine for cars but not great for stepping over things (like on cluttered floors) and stairs. So legs, assuming we've got the compute and algorithms to get them to work well, only make sense. The rest allows for application of creativity. As a human, have a head, my brain is in it, as are my eyes. Humanoid robot doesn't need a head, and can have cameras in its chest and on its back, and then also have its brain in the chest. Depending on what's useful, it doesn't need to be limited to two arms. It could have one centrally mounted in its chest, with two cheaper ones on both sides. Or four, two on each side. I've wished for three hands before. The problem though is that they look weird. Any non-traditional design is going to fall into the uncanny valley, so that no matter how much better your non-traditionally armed robot is technically, it's just not gonna sell to the mass market. We only have to look at weird cars/vehicles which have a history of being boondoggles. So it's not a failure of imagination, and more a matter of practicality.

Per 5, it says here "Human hands are packed absolutely full of sensors. Getting anywhere near that kind of sensing out of robot hands and usable by a human puppeteer is not currently possible."

Then another quote, "No one has managed to get articulated fingers (i.e., fingers with joints in them) that are robust enough, have enough force, nor enough lifetime, for real industrial applications."

So (3) and (7) are relevant to lifetime, but another point, related to sensors, is that humans will stop hurting themselves if finger strain occurs, such as by changing their grip or crying off the task entirely. Hands are robust because they can operate at the edge of safe parameters by sensing strain and strategizing around risk. Humans know to come in out of the rain, so to speak.

Yeah, it's cool and all, but I more that once was frustrated that it can't rotate freely, it has only one elbow joint, it can't extend.

I'd add an 11th point to expand on #1: supports a very wide range of movement speeds, movement force/torque and movement precision.

Take the elbow joint and the muscles it's connected to. It supports very fine precision, slow speed operations as well as high speed but at the same time the same operation at high speeds - say, lifting yourself up on a horizontal bar, assuming adequate strength you can either do a slow or a fast lift, and both at enough precision and torque to prevent your body mass from impacting to the bar which is another feat in itself.

Now try to replicate that with a classic mechanical mechanism, you'll always lose either precision, speed or torque.

As you tighten a bolt the angle you need to apply force changes. So it’s not just a fixed position plus force in 6 directions its force in 6 directions at each position. You can learn quite a bit about something from such interactions such as an objects weight, center of mass, etc.

Further robots generally have more than a single rigid manipulator.

Yeah, humans can teleop some pretty complex operations even through cheap robot arms!

That's a bit like saying speech recognition can be solved with ML and an air pressure sensor.

> That's a good problem to work on.

Not sure which lab (I think google?) it was, but there was a recent demo of a ML-model driven robot that folded paper in that style as one of the tasks.

The article points out that the human hand has over 10000 sensors with specific spatial layout and various specialised purposes (pressure / vibration / stretching / temperature) that require different mechanical connections between the sensor and the skin.

True, most of the tasks can be done with off-the-shelf hardware already. But single task robotics is already a solved problem, what the humanoid robots are about is multi-task, aimed at replacing the tasks that still require human hands / legs / eyes / brains / etc.

But I think most of those can be replaced by existing robotics as well anyway. I mean take car manufacturing, over time more and more humans were replaced by robots, and nowadays the newest car factories are mostly automated (see lights-out manufacturing: https://en.wikipedia.org/wiki/Lights_out_(manufacturing)). Interestingly a Japanese robot factory has been lights-out since 2001, where they can run for 30 days on end without any lights, humans, heating or cooling.

> because that apparently was beyond his competence.

This has almost nothing to do with nature (barring a development issue).

This has to do with nurture. Every time they went to do something with a tool a helicopter gunship of a parent showed up to tell them no. Now they have a learned helplessness when it comes to these things.

But that's not really any different then when I was a kid so very long ago. At 4 or 5 I was given a stack of old broken radios and took them to the garage for a rip and tear session. I got to look at all their pretty electronic guts that fascinated me. There were plenty of other parents of that time that would have been horrified to see their kids do something similar.

Electric motors are significantly better at the requirement that matters: endurance.

Sure it takes a bigger motor to produce the same torque, but speed and precision are actually the strengths of electric motors. The fundamental problem with them is that reducers are not impact resistant and they have internal inertia, which is something muscles do not have. Another problem is building actuators with multiple degrees of freedom. The ideal configuration for legs is a ball joint, not two consecutive rotary joints.

If you understand "cost-effective" to mean the same thing as "feasible with today's tech", maybe. As in, if we feed it all the raw data, we'd need more powerful, expensive devices and they would take years or decades to complete any training on the raw data set.

But without it being done, it's an unproven hypothesis at best.

Yeah, he also immediately starts talking about GOFAI, to further confuse the Enemy...

Q: How many Prolog programmers does it take to change a lightbulb?

A: False.

At least for me it was obvious what humanoids mean, but I have worked in the field.

I don't feel that scarecrow or sex doll dexterity is a major issue

My first though at the title was "But hominids are already quite dexterous."

For some nuts and bolts, I myself struggle with it, almost to the point of giving up.

But what the article misses: We can just rearrange our environment to make it easy to interact with by robots. There might be only standardized nuts and bolts, with IDs imprinted so the robots know exactly how to apply them. Dishes might come in certified robot-known dimensions, or with invisible marks on where to best grip them. Matchsticks might be replaced by standardized gas lighters. Maybe robot companies will even sell those themselves.

Both those tasks require very fine force-feedback perception, instantly mapped to multiple possible scenarios that could be happening inside those metal parts. E.g. does it feel like I have crossed the threads, or is there a bit of rust? Let me twist just a bit more, but gently, to find out.