Today I'm chatting with Sergey Levine, who
is a co-founder of Physical Intelligence, which is a robotics foundation model company,
and also a professor at UC Berkeley and just generally one of the world's leading
researchers in robotics, RL, and AI.
0:14
Sergey, thank you for coming on the podcast.
0:14
Thank you, and thank you for the kind introduction.
0:17
Let's talk about robotics.
0:17
Before I pepper you with questions, I'm wondering if you
can give the audience a summary of where Physical Intelligence is at right now.
0:25
You guys started a year ago.
0:28
What does the progress look like?
0:28
What are you guys working on?
0:31
Physical Intelligence aims to
build robotic foundation models.
0:36
That basically means general-purpose
models that could in principle control any robot to perform any task.
0:39
We care about this because we see this as a very fundamental aspect of the AI problem.
0:44
The robot is essentially encompassing all AI technology.
0:50
If you can get a robot that's truly general, then you can do, hopefully,
a large chunk of what people can do.
0:58
Where we're at right now is that we've
kind of gotten to the point where we've built out a lot of the basics.
1:02
Those basics actually are pretty cool. They work pretty well.
1:08
We can get a robot
that will fold laundry and that will go into a new home and try to clean up the kitchen.
1:12
But in my mind, what we're doing at Physical Intelligence right now is really
the very, very early beginning.
1:19
It's just putting in place the basic
building blocks, on top of which we can then tackle all these really tough problems.
1:22
What's a year-by-year vision?
1:22
One year in, I got a chance to watch some of the robots,
they can do pretty dexterous tasks like folding a box using grippers.
1:34
It's pretty hard to fold the box even with my hands.
1:37
If you had to go year by year until we get to the full robotics explosion,
what is happening every single year?
1:44
What is the thing that needs
to be unlocked, et cetera?
1:47
There are a few things that we need to get right.
1:47
Dexterity obviously is one of them.
1:52
In the beginning we really want to make sure
that we understand whether the methods that we're developing have the ability to tackle
the kind of intricate tasks that people can do.
2:01
As you mentioned, folding a box, folding different
articles of laundry, cleaning up a table, making a coffee, that sort of thing.
2:07
That's
good, that works.
2:07
The results we've been able to show are pretty cool, but the end
goal of this is not to fold a nice T-shirt.
2:16
The end goal is to just confirm our initial
hypothesis that the basics are solid.
2:22
From there, there are a number
of really major challenges.
2:25
Sometimes when results get abstracted to the level
of a three-minute video, someone can look at this video and it's like, "Oh, that's cool.
2:31
That's what
they're doing." But it's not.
2:31
It's a very simple and basic version of what I think is to come.
2:36
What you really want from a robot is not to tell it like, "Hey, please fold my T-shirt."
2:41
What you want from a robot is to tell it like, "Hey, robot, you're now doing
all sorts of home tasks for me.
2:50
I like to have dinner made at 6:00 p. m.
2:50
I wake up and go to work at 7:00 a. m.
2:55
I like to do my laundry on Saturday, so make
sure that it's ready. This and this and this.
3:00
By the way, check in with me every Monday to
see what I want you to pick up when you do the shopping." That's the prompt.
3:06
Then the robot
should go and do this for six months, a year.
3:12
That's the duration of the task.
3:12
Ultimately if this stuff is successful, it should be a lot bigger.
3:17
It should have that ability to learn continuously.
3:23
It should have the understanding of the physical
world, the common sense, the ability to go in and pull in more information if it needs it.
3:28
Let’s say I ask it, "Hey, tonight, can you make me this type of salad?"
3:32
It should figure out what that entails, look it up, go and buy the ingredients.
3:36
There's a lot that goes into this.
3:36
It requires common sense.
3:39
It requires understanding
that there are certain edge cases that you need to handle intelligently, cases
where you need to think harder.
3:46
It requires the ability to improve continuously.
3:46
It requires understanding safety, being reliable at the right time, being able to fix your
mistakes when you do make those mistakes.
3:56
There's a lot more that goes into this.
3:56
But the principles there are: you need to leverage prior knowledge and
you need to have the right representations.
4:05
This grand vision, what year?
4:05
If you had
to give an estimate. 25 percentile, 50, 75?
4:12
I think it's something where it's not going to
be a case where we develop everything in the laboratory and then it's done and then come
2030-something, you get a robot in a box.
4:24
Again, it'll be the same as what
we've seen with AI assistants.
4:27
Once we reach some basic level of competence
where the robot is delivering something useful, it'll go out there in the world.
4:32
The cool thing is that once it's out there in the world, they can collect experience
and leverage that experience to get better.
4:40
To me, what I tend to think about in terms of
timelines is not the date when it will be done, but the date when the flywheel starts basically.
4:45
When does the flywheel start? That could be very soon.
4:50
There's
some decisions to be made.
4:54
The trade-off there is that the more
narrowly you scope the thing, the earlier you can get it out into the real world.
4:58
But this is something we're already exploring.
5:04
We're already trying to figure out what
are the real things this thing can do that could allow us to start spinning the flywheel.
5:07
But in terms of stuff that you would actually care about, that you would want to see… I don't
know but single-digit years is very realistic.
5:17
I'm really hoping it'll be more like one or
two before something is actually out there, but it's hard to say.
5:21
Something being out there means what? What is out there?
5:23
It means that there is a robot that does a thing that you actually care about, that you want done.
5:27
It does so competently enough to actually do it for real, for real people that want it done.
5:34
We already have LLMs which are broadly deployed.
5:40
That hasn't resulted in some sort of flywheel,
at least not some obvious flywheel for the model companies where now Claude is learning how to do
every single job in the economy or GPT's learning how to do every single job in the economy.
5:50
So, why doesn’t that flywheel work for LLMs?
5:55
Well, I think it's actually very close
to working and I am 100% certain that many organizations are working on exactly this.
6:03
In fact, arguably there is already a flywheel.
6:08
It’s not an automated flywheel
but a human-in-the-loop flywheel.
6:13
Everybody who's deploying an LLM is of course
going to look at what it's doing and it's going to use that to then modify its behavior.
6:16
It's complex because it comes back to this question of representations and figuring out the
right way to derive supervision signals and ground those supervision signals in the behavior of
the system so that it improves on what you want.
6:35
I don't think that's a
profoundly impossible problem.
6:38
It's just something where the details get
pretty gnarly and challenges with algorithms and stability become pretty complex.
6:42
It's something that's taken a while for the community collectively to get their hands on.
6:47
Do you think it'll be easier for robotics?
6:51
Or do you think that with these kinds of
techniques to label data that you collect out in the world and use it as a reward, the whole
wave will rise and robotics will rise as well?
7:06
Or is there some reason robotics
will benefit more from this?
7:09
I don't think there's a profound
reason why robotics is that different.
7:12
There are a few small differences that
make things a little bit more manageable.
7:17
Especially if you have a robot that's doing
something in cooperation with people, whether it's a person that's supervising it or directing
it, there are very natural sources of supervision.
7:25
There's a big incentive for the person to provide
the assistance that will make things succeed.
7:30
There are a lot of dynamics where you can
make mistakes and recover from those mistakes and then reflect back on what happened
and avoid that mistake in the future.
7:38
When you're doing physical
things in the real world, that stuff just happens more often than it does
if you're an AI assistant answering a question.
7:46
If you answer a question and just answer it wrong, it's not like you can just go
back and tweak a few things.
7:52
The person you told the answer to
might not even know that it's wrong.
7:55
Whereas if you're folding the T-shirt and you
messed up a little bit, it's pretty obvious.
7:58
You can reflect on that, figure out what
happened, and do it better next time.
8:01
Okay, in one year we have robots
which are doing some useful things.
8:06
Maybe if you have some relatively simple
loopy process, they can do it for you, like keep folding thousands of boxes or something.
8:12
But then there's some flywheel… and there's some machine which will just run my house for
me as well as a human housekeeper would.
8:26
What is the gap between this thing which
will be deployed in a year that starts the flywheel and this thing which is
like a fully autonomous housekeeper?
8:34
It's actually not that different from what we've
seen with LLMs in some ways. It's a matter of scope.
8:38
Think about coding assistants.
8:38
Initially the best tools for coding, they could do a little bit of completion.
8:44
You give them a function signature and they'll try their best to type out the whole
function and they'll maybe get half of it right.
8:53
As that stuff progresses, then you're willing
to give these things a lot more agency.
8:58
The very best coding assistance now—if you're
doing something relatively formulaic, maybe it can put together most of a PR for you for something
fairly accessible. It'll be the same thing.
9:03
We'll see an increase in the scope that we're willing to
give to the robots as they get better and better.
9:15
Initially the scope might be
a particular thing you do.
9:19
You're making the coffee or something.
9:19
As they get more capable, as their ability to have common sense and a broader repertoire of tasks
increases, then we'll give them greater scope.
9:28
Now you're running the whole coffee shop.
9:28
I get that there's a spectrum.
9:31
I get that there won't be a specific
moment that feels like we've achieved it but if you had to give a year for your
median estimate of when that happens?
9:39
My sense there too is that this
is probably a single-digit thing rather than a double-digit thing.
9:43
The reason it's hard to really pin down is because, as with all research, it does
depend on figuring out a few question marks.
9:52
My answer in terms of the nature of those question
marks is that I don't think these are things that require profoundly, deeply different ideas
but it does require the right synthesis of the kinds of things that we already know.
10:02
Sometimes synthesis, to be clear, is just as difficult as coming up with profoundly new stuff.
10:09
It's intellectually a very deep and profound problem.
10:15
Figuring that out is going to be very exciting.
10:20
But I think we kind of know roughly the puzzle
pieces and it's something that we need to work on.
10:28
If we work on it and we're a bit lucky
and everything kind of goes as planned, single-digit is reasonable.
10:32
I'm just going to do binary search until I get a year.
10:34
It's less than 10 years, so more than five years, your median estimate? I know there's a range.
10:40
I think five is a good median. Okay, five years.
10:43
If you can fully
autonomously run a house, then you can fully autonomously do most blue-collar work.
10:50
Your estimate is that in five years it should be able to do most blue-collar work in the economy. There's a nuance here.
10:55
It becomes more obvious if we consider the analogy to coding assistants.
11:04
It's not like the nature of coding assistants today is that there's a switch that
flips and instead of writing software, suddenly all software engineers get fired
and everyone's using LLMs for everything.
11:22
It actually makes a lot of sense that the
biggest gain in productivity comes from experts, which is software engineers, whose productivity
is now augmented by these really powerful tools.
11:34
Separate from the question of whether people
will get fired or not, a different question is, what will the economic impact be in five years?
11:39
The reason I'm curious about this is because with LLMs, the relationship between the
revenues for these models to their seeming capability has been sort of mysterious.
11:50
You have something which feels like AGI.
11:56
You can have a conversation where
it really passes the Turing test.
12:00
It really feels like it can
do all this knowledge work.
12:03
It's obviously doing a bunch of coding, et cetera.
12:03
But the revenues from these AI companies are cumulatively on the order of $20-30
billion per year and that's much less than all knowledge work, which is $30-40 trillion.
12:14
In five years are we in a similar situation to what LLMs are in now, or is it more like we have
robots deployed everywhere and they're actually doing a whole bunch of real work, et cetera?
12:26
It's a very subtle question.
12:26
What it probably will come down to is this question of scope.
12:32
The reason that LLMs aren't doing all software engineering is because they're good within
a certain scope, but there's limits to that.
12:42
Those limits are increasing,
to be clear, every year.
12:45
I think that there's no reason that we wouldn't
see the same kind of thing with robots.
12:51
The scope will have to start out small
because there will be certain things that these systems can do very well and certain
other things where more human oversight is really important. The scope will grow.
13:00
What that
will translate into is increased productivity.
13:07
Some of that productivity will come from
the robots themselves being valuable.
13:12
Some of it will come from the people using the
robots are now more productive in their work.
13:16
But there's so many things
which increase productivity.
13:17
Like wearing gloves increases
productivity or I don't know.
13:22
You want to understand something which
increases productivity a hundredfold versus something which has a small increase.
13:25
Robots already increase productivity for workers.
13:35
Where LLMs are right now in terms of the share
of knowledge work they can do, is I guess like 1/1000th of the knowledge work that happens
in the economy, at least in terms of revenue.
13:49
Are you saying that fraction will be possible
for robots, but for physical work, in five years?
13:55
That's a very hard question to answer.
13:55
I'm probably not prepared to tell you what percentage of all labor work can be done
by robots, because I don't think right now, off the cuff, I have a sufficient understanding
of what's involved in that big of a cross-section of all physical labor.
14:12
What I can tell you is this.
14:16
It's much easier to get effective systems rolled
out gradually in a human-in-the-loop setup.
14:24
Again, this is exactly what
we've seen with coding systems.
14:28
I think we'll see the same thing with automation,
where basically robot plus human is much better than just human or just robot.
14:33
That just makes
total sense.
14:33
It also makes it much easier to get all the technology bootstrapped.
14:40
Because when it's robot plus human now, there's a lot more potential for the robot to
actually learn on the job, acquire new skills.
14:49
Because a human can label what's happening?
14:49
Also because the human can help, the human can give hints.
14:53
Let me tell you this story.
14:58
When we were working on the π0.
14:58
5 project,
the paper that we released last April, we initially controlled our robots with
teleoperation in a variety of different settings.
15:09
At some point we actually realized that
we can actually make significant headway, once the model was good enough, by supervising
it not just with low-level actions but actually literally instructing it through language.
15:19
Now you need a certain level of competence before you can do that, but once you have that
level of competence, just standing there and telling the robot, "Okay, now pick up the cup,
put the cup in the sink, put the dish in the sink," just with words already, actually gives the
robot information that it can use to get better.
15:37
Now imagine what this implies
for the human plus robot dynamic.
15:41
Now basically, learning for these systems
is not just learning from raw actions, it's also learning from words.
15:46
Eventually it’ll be learning from observing what people do from the kind of
natural feedback that you receive when you're doing a job together with somebody else.
15:54
This is also the kind of stuff where the prior knowledge that comes from these big
models is tremendously valuable, because that lets you understand that interaction dynamic.
16:03
There's a lot of potential for these kinds of human plus robot deployments
to make the model better.
17:26
In terms of robotics progress,
why won't it be like self-driving cars, where it's been more than
10 years since Google launched its… Wasn't it in 2009 that they
launched the self-driving car initiative?
17:39
I remember when I was a teenager, watching demos
where we would go buy a Taco Bell and drive back.
17:47
Only now do we have them actually deployed.
17:47
Even then they may make mistakes, etc.
17:53
Maybe it'll be many more years before
most of the cars are self-driving.
18:00
You're saying five years
to this quite robust thing, but actually will it just feel like 20 years?
18:03
Once we get the cool demo in five years, then it'll be another 10 years before we
have the Waymo and the Tesla FSD working.
18:14
That's a really good question.
18:14
One of the big
things that is different now than it was in 2009 has to do with the technology for machine learning
systems that understand the world around them.
18:28
Principally for autonomous
driving, this is perception.
18:30
For robots, it can mean a
few other things as well.
18:34
Perception certainly was
not in a good place in 2009.
18:38
The trouble with perception is that it's one
of those things where you can nail a really good demo with a somewhat engineered system, but
hit a brick wall when you try to generalize it.
18:47
Now at this point in 2025, we have much
better technology for generalizable and robust perception systems and, more
generally, generalizable and robust systems for understanding the world around us.
18:56
When you say that the system is scalable, in machine learning scalable
really means generalizable.
19:04
That gives us a much better starting point today.
19:04
That's not an argument about robotics being easier than autonomous driving.
19:09
It's just an argument for 2025 being a better year than 2009.
19:11
But there's also other things about robotics that are a bit different than driving.
19:16
In some ways, robotic manipulation is a much, much harder problem.
19:20
But in other ways, it's a problem space where it's easier to get rolling,
to start that flywheel with a more limited scope.
19:30
To give you an example, if you're learning
how to drive, you would probably be pretty crazy to learn how to drive on your
own without somebody helping you.
19:39
You would not trust your teenage child
to learn to drive just on their own, just drop them in the car and say, "Go for it."
19:44
That's also a 16-year-old who's had a significant amount of time to learn about the world.
19:50
You would never even dream of putting a five-year-old in a car and
telling him to get started.
19:56
But if you want somebody to clean
the dishes, dishes can break too.
20:00
But you would probably be okay with a child trying
to do the dishes without somebody constantly sitting next to them with a brake, so to speak.
20:07
For a lot of tasks that we want to do with robotic manipulation, there's potential to
make mistakes and correct those mistakes.
20:19
When you make a mistake and correct it, well first
you've achieved the task because you've corrected, but you've also gained knowledge that allows
you to avoid that mistake in the future.
20:26
With driving, because of the dynamics of how it's
set up, it's very hard to make a mistake, correct it and then learn from it because the mistakes
themselves have significant ramifications.
20:37
Not all manipulation tasks are that.
20:37
There are truly some very safety-critical stuff.
20:42
This is where the next thing
comes in, which is common sense.
20:45
Common sense, meaning the ability to
make inferences about what might happen that are reasonable guesses, but that do not
require you to experience that mistake and learn from it in advance.
20:55
That's tremendously
important.
20:55
That's something that we basically had no idea how to do about five years ago.
21:00
But now we can use LLMs and VLMs and ask them questions and they will make reasonable guesses.
21:08
They will not give you expert behavior, but you can say, "Hey, there's
a sign that says slippery floor.
21:14
What's going to happen when I walk
up over that?"
21:14
It's pretty obvious, right?
21:18
No autonomous car in 2009 would
have been able to answer that question.
21:22
Common sense plus the ability to make
mistakes and correct those mistakes, that's sounding an awful lot what a person
does when they're trying to learn something.
21:30
All of that doesn't make robotic manipulation easy
necessarily, but it allows us to get started with a smaller scope and then grow from there.
21:36
So for years, I mean not since 2009, but we've had lots of video data, language
data, and transformers for 5-8 years.
21:51
Lots of companies have tried to build
transformer-based robots with lots of training data, including Google, Meta, et cetera.
21:57
What is the reason that they've been hitting roadblocks? What has changed now?
22:03
That's a really good question.
22:03
I'll start out with a slight modification to your comment.
22:09
They've made a lot of progress.
22:14
In some ways, a lot of the work that we're
doing now at Physical Intelligence is built on the backs of lots of other great work
that was done, for example, at Google.
22:23
Many of us were at Google before.
22:23
We were involved in some of that work.
22:26
Some of it is work that we're
drawing on that others did.
22:29
There's definitely been a lot of progress there.
22:29
But to make robotic foundation models really work, it's not just a laboratory science experiment.
22:35
It also requires industrial scale building effort.
22:48
It's more like the Apollo program
than it is a science experiment.
22:55
The excellent research that was done
in the past industrial research labs, and I was involved in much of that, was very much
framed as a fundamental research effort. That's good.
23:05
The fundamental research is really
important, but it's not enough by itself.
23:08
You need the fundamental research and you
also need the impetus to make it real.
23:14
Making it real means actually putting the robots
out there, getting data that is representative, the tasks that they need to do in the real
world, getting that data at scale, building out the systems, and getting all that stuff right.
23:22
That requires a degree of focus, a singular focus on really nailing the robotic foundation model
for its own sake, not just as a way to do more science, not just as a way to publish a paper,
and not just as a way to have a research lab.
23:43
What is preventing you now from
scaling that data even more?
23:49
If data is a big bottleneck, why can't you
just increase the size of your office 100x, have 100x more operators operating
these robots and collecting more data.
24:01
Why not ramp it up immediately 100x more?
24:01
That's a really good question.
24:01
The challenge here is understanding which axes of scale
contribute to which axes of capability.
24:14
If we want to expand capability
horizontally—meaning the robot knows how to do 10 things now and I'd like it to do 100 things
later—that can be addressed by just directly horizontally scaling what we already have.
24:23
But we want to get robots to a level of capability where they can do practically
useful things in the real world.
24:32
That requires expanding along other axes too.
24:32
It requires, for example, getting to very high robustness.
24:36
It requires getting them to perform tasks very efficiently, quickly.
24:39
It requires them to recognize edge cases and respond intelligently.
24:43
Those things can also be addressed with scaling.
24:48
But we have to identify the right axes for that,
which means figuring out what data to collect, what settings to collect it in, what methods
consume that data, and how those methods work.
25:00
Answering those questions more thoroughly
will give us greater clarity on the axes, on those dependent variables, on
the things that we need to scale.
25:10
We don't fully know right
now what that will look like.
25:13
I think we'll figure it out pretty soon.
25:13
It's something we're working on actively.
25:17
We want to really get that right
so that when we do scale it up, it'll directly translate into capabilities
that are very relevant to practical use.
25:25
Just to give an order of magnitude, how
does the amount of data you have collected compare to internet-scale pre-training data?
25:29
I know it's hard to do a token-by-token count, because how does video information compare
to internet information, et cetera.
25:38
But using your reasonable
estimates, what fraction?
25:42
It's very hard to do because robotic
experience consists of time steps that are very correlated with each other.
25:47
The raw byte representation is enormous, but probably the information
density is comparatively low.
25:56
Maybe a better comparison is to the datasets
that are used for multimodal training.
26:02
And there, I believe last time we did that count,
it was between one and two orders of magnitude.
26:08
The vision you have of robotics,
will it not be possible until you collect what, 100x, 1000x more data?
26:12
That's the thing, we don't know that.
26:19
It's certainly very reasonable to
infer that robotics is a tough problem.
26:24
Probably it requires as much
experience as the language stuff.
26:28
But because we don't know the answer to that,
to me a much more useful way to think about it is not how much data do we need to get
before we're fully done, but how much data do we need to get before we can get started.
26:39
That means before we can get a data flywheel that represents a self-sustaining and
ever-growing data-collection recipe.
26:48
When you say self-sustaining, is it just learning
on the job or do you have something else in mind?
26:52
Learning on the job or acquiring data in a way
such that the process of acquisition of that data itself is useful and valuable. I see. Some kind of RL.
27:04
Doing something actually real.
27:04
Ideally I would like it to be RL, because with RL you can get away with the
robot acting autonomously which is easier.
27:12
But it's not out of the question
that you can have mixed autonomy.
27:16
As I mentioned before, robots can
learn from all sorts of other signals.
27:20
I described how we can have a robot
that learns from a person talking to it.
27:24
There's a lot of middle ground in between fully
teleoperated robots and fully autonomous robots.
27:30
How does the π0 model work?
27:30
The current model that we have basically is a vision-language model
that has been adapted for motor control.
27:40
To give you a little bit of a fanciful brain
analogy, a VLM, a vision-language model, is basically an LLM that has had a little pseudo
visual cortex grafted to it, a vision encoder.
27:53
Our models, they have a vision encoder,
but they also have an action expert, an action decoder essentially.
27:56
It has a little visual cortex and notionally a little motor cortex.
27:59
The way that the model makes decisions is it reads in the sensory information from the
robot.
28:04
It does some internal processing.
28:04
That could involve outputting intermediate steps.
28:08
You might tell it, "Clean up the kitchen."
28:12
It might think to itself,
"Hey, to clean up the kitchen, I need to pick up the dish and I need to pick
up the sponge and I need to put this and this."
28:19
Eventually it works its way through that
chain-of-thought generation down to the action expert, which produces continuous actions.
28:23
That has to be a different module because the actions are continuous, they're high frequency.
28:28
They have a different data format than text tokens.
28:33
But structurally it's still an end-to-end transformer.
28:35
Roughly speaking, technically, it corresponds to a mixture-of-experts architecture.
28:40
And what is actually happening is that it's predicting "I should do X thing."
28:46
Then there's an image token, then some action tokens –what it actually
ends up doing– and then more image, more text description, more action tokens.
28:54
Basically I'm looking at what stream is going on.
28:59
That's right, with the exception that the
actions are not represented as discrete tokens.
29:04
It actually uses flow matching and diffusion
because they're continuous and you need to be very precise with your actions for dexterous control.
29:08
I find it super interesting that you're using the open-source Gemma model, which is
Google's LLM that they released open source, and then adding this action expert on top.
29:19
I find it super interesting that the progress in different areas of AI is based on not only the
same techniques, but literally the same model.
29:33
You can just use an open-source LLM
and add this action expert on top.
29:39
You naively might think that, "Oh, there's a
separate area of research which is robotics, and there's a separate area of research called
LLMs and natural language processing."
29:43
No, it's literally the same.
29:47
The considerations
are the same, the architectures are the same, even the weights are the same.
29:53
I know you do more training on top of these open-source models,
but I find that super interesting.
29:59
One theme here that is important to keep in mind
is that the reason that those building blocks are so valuable is because the AI community has
gotten a lot better at leveraging prior knowledge.
30:12
A lot of what we're getting from the pre-trained
LLMs and VLMs is prior knowledge about the world.
30:19
It's a little bit abstracted knowledge.
30:19
You can identify objects, you can figure out roughly where things are
in image, that sort of thing.
30:26
But if I had to summarize in one
sentence, the big benefit that recent innovations in AI give to robotics
is the ability to leverage prior knowledge.
30:38
The fact that the model is the same model,
that's always been the case in deep learning.
30:42
But it's that ability to
pull in that prior knowledge, that abstract knowledge that can come from
many different sources that's really powerful.
31:58
I was talking to this researcher, Sander at
GDM, and he works on video and audio models.
32:07
He made the point that the reason, in his
view, we aren't seeing that much transfer learning between different modalities.
32:12
That is to say, training a language model on video and images doesn't seem to necessarily
make it that much better at textual questions and tasks because images are represented at
a different semantic level than text.
32:30
His argument is that text has this high-level
semantic representation within the model, whereas images and videos are just compressed pixels.
32:35
When they're embedded, they don't represent some high-level semantic information.
32:43
They're just compressed pixels.
32:43
Therefore there's no transfer learning at the level
at which they're going through the model.
32:53
Obviously this is super relevant
to the work you're doing.
32:56
Your hope is that by training the model
on the visual data that the robot sees, visual data generally maybe even from YouTube or
whatever eventually, plus language information, plus action information from the robot itself, all
of this together will make it generally robust.
33:14
You had a really interesting blog post about why
video models aren't as robust as language models.
33:19
Sorry, this is not a super well-formed question.
33:19
I just wanted to get a reaction.
33:22
Yeah, what’s up with that?
33:22
I have
maybe two things I can say there.
33:28
I have some bad news and some good news.
33:28
The bad news is what you're saying is really getting at the core of a long-running
challenge with video and image generation models.
33:46
In some ways, the idea of getting
intelligent systems by predicting video is even older than the idea of getting
intelligent systems by predicting text.
33:55
The text stuff turned into practically useful
things earlier than the video stuff did.
34:02
I mean, the video stuff is great.
34:02
You
can generate cool videos.
34:02
The work that's been done there recently is amazing.
34:05
But it's not like just generating videos and images has already resulted in systems that
have this deep understanding of the world where you can ask them to do stuff beyond
just generating more images and videos.
34:20
Whereas with language, clearly it has.
34:20
This point about representations is really key to it.
34:23
One way we can think about it is this.
34:29
Imagine pointing a camera outside this building,
there's the sky, the clouds are moving around, the water, cars driving around, people.
34:34
If you want to predict everything that'll happen in the future, you can
do so in many different ways.
34:41
You can say, "Okay, there's people around.
34:41
Let me get really good at understanding the psychology of how people behave in
crowds and predict the pedestrians."
34:47
But you could also say, "Well,
there's clouds moving around.
34:49
Let me understand everything about water
molecules and ice particles in the air."
34:53
You could go super deep on that.
34:53
If you want to fully understand down to the subatomic level everything that's
going on, as a person you could spend decades just thinking about that and you'll never
even get to the pedestrians or the water.
35:06
If you want to really predict everything
that's going on in that scene, there's just so much stuff that even if you're
doing a really great job and capturing 100% of something, by the time you get to
everything else, ages will have passed.
35:19
Whereas with text, it's already been abstracted
into those bits that we as humans care about.
35:23
The representations are already there.
35:23
They're not just good representations, they focus on what really matters. That's the
bad news. Here's the good news.
35:26
The good news is that we don't have to just get everything
out of pointing a camera outside this building.
35:38
When you have a robot, that
robot is trying to do a job.
35:42
It has a purpose, and its perception is
in service to fulfilling that purpose.
35:49
That is a really great focusing factor.
35:49
We know that for people, this really matters.
35:54
Literally what you see is affected
by what you're trying to do.
35:58
There's been no shortage of psychology experiments
showing that people have almost a shocking degree of tunnel vision where they will literally
not see things right in front of their eyes if it's not relevant to what they're trying to
achieve.
36:06
That is tremendously powerful.
36:06
There must be a reason why people do that.
36:10
Certainly if you're out in the jungle, seeing more is better than seeing less.
36:13
If you have that powerful focusing mechanism, it must be darn important for
getting you to achieve your goal.
36:20
Robots will have that focusing mechanism
because they're trying to achieve a goal.
36:23
The fact that video models aren't as
robust, is that bearish for robotics?
36:31
So much of the data you will have to use… I
guess you're saying a lot of it will be labeled.
36:38
Ideally, you just want to be able to throw
everything on YouTube, every video we've ever recorded, and have it learn how the
physical world works and how to move about.
36:48
Just see humans performing
tasks and learn from that.
36:51
I guess you're saying it's hard to learn just from
that and it needs to practice the task itself. Let me put it this way.
36:56
Let's say that I gave you lots of videotapes or lots of recordings of different sporting
events and gave you a year to just watch sports.
37:08
After that year, I told you, "Okay, now your
job, you're going to be playing tennis."
37:08
Okay, that's pretty dumb right?
37:12
Whereas if I told
you first you're going to be playing tennis and then I let you study up, now you
really know what you're looking for.
37:24
There's a very real challenge here.
37:24
I don't want to understate the challenge.
37:26
But there's also a lot of potential for foundation
models that are embodied, that learn from interaction, from controlling robotic systems,
to be better at absorbing the other data sources because they know what they're trying to do.
37:38
I don't think that by itself is a silver bullet.
37:41
I don't think it solves
everything, but it does help a lot.
37:48
We've already seen the beginnings of that where
we can see that including web data in training for robots really does help with generalization.
37:54
I have the suspicion that in the long run, it'll make it easier to use those sources of
data that have been tricky to use up until now.
38:04
Famously, LLMs have all these emergent
capabilities that were never engineered in, because somewhere in internet text is the data
to train and to be able to give it the knowledge to do a certain kind of thing.
38:11
With robots, it seems like you are collecting all the data manually.
38:15
So there won't be this mysterious new capability that is somewhere in the dataset
that you haven't purposefully collected.
38:23
Which seems like it should make it
even harder to then have robust, out-of-distribution capabilities.
38:29
I wonder if the trek over the next 5-10 years will be like this: Each subtask,
you have to give it thousands of episodes.
38:42
Then it's very hard to actually automate
much work just by doing subtasks.
38:47
If you think about what a
barista does, what a waiter does, what a chef does, very little of it involves
just sitting at one station and doing stuff.
38:55
You got to move around, you got to
restock, you got to fix the machine, et cetera, go between the counter and
the cashier and the machine, etc.
39:07
Will there just be this long tail of
things and skills that you have to keep adding episodes for manually and
labeling and seeing how well they did?
39:15
Or is there some reason to think that it
will progress more generally than that? There's a subtlety here.
39:25
Emergent
capabilities don't just come from the fact that internet data has a lot of stuff in it.
39:28
They also come from the fact that generalization, once it reaches a certain
level, becomes compositional.
39:37
There was a cute example that one of my students
really liked to use in some of his presentations.
39:46
You know what the International
Phonetic Alphabet (IPA) is? No.
39:49
If you look in a dictionary, they'll have the pronunciation of a word written in funny
letters.
39:52
That's basically International Phonetic Alphabet.
39:56
It's an alphabet that is pretty much
exclusively used for writing down pronunciations of individual words and dictionaries.
40:01
You can ask an LLM to write you a recipe for making some meal in International Phonetic
Alphabet, and it will do it. That's like, holy crap.
40:12
That is definitely not something that
it has ever seen because IPA is only ever used for writing down pronunciations of individual
words.
40:18
That's compositional generalization.
40:18
It's putting together things you've seen in new ways.
40:22
Arguably there's nothing profoundly new here because yes, you've seen different words written
that way, but you've figured out that now you can compose the words in this other language the
same way that you've composed words in English.
40:38
That's actually where the
emergent capabilities come from.
40:42
Because of this, in principle, if we
have a sufficient diversity of behaviors, the model should figure out that those
behaviors can be composed in new ways as the situation calls for it.
40:51
We've actually seen things even with our current models.
40:55
In the grand scheme of things, looking back five years from now, we'll
probably think that these are tiny in scale.
41:02
But we've already seen what I
would call emerging capabilities.
41:05
When we were playing around with
some of our laundry folding policies, we actually discovered this by accident.
41:08
The robot accidentally picked up two T-shirts out of the bin instead of one.
41:12
It starts folding the first one, the other one gets in the way, picks up
the other one, throws it back in the bin.
41:19
We didn't know it would do that. Holy crap.
41:19
Then we tried to play around with it, and yep, it does that every time. It's doing its work.
41:22
Drop something else on the table, it just picks it up and puts it back. Okay, that's cool.
41:26
It starts putting things in a shopping bag.
41:32
The shopping bag tips over, it picks
it back up, and stands it upright.
41:35
We didn't tell anybody to collect data for that.
41:35
I'm sure somebody accidentally at some point, or maybe intentionally picked up the shopping bag.
41:38
You just have this kind of compositionality that emerges when you do learning at scale.
41:44
That's really where all these remarkable capabilities come from.
41:48
Now you put that together with language.
41:52
You put that together with all
sorts of chain-of-thought reasoning, and there's a lot of potential for the
model to compose things in new ways. Right.
41:58
I had an example like this when
I got a tour of the robots at your office. It was folding shorts.
42:03
I don't know
if there was an episode like this in the training set, but just for fun I took one
of the shorts and turned it inside out.
42:16
Then it was able to understand that
it first needed to get… First of all, the grippers are just like this, two
opposable finger and thumb-like things.
42:29
It's actually shocking how
much you can do with just that.
42:32
But it understood that it first needed to fold
it inside out before folding it correctly.
42:37
What's especially surprising
about that is it seems like this model only has one second of context.
42:40
Language models can often see the entire codebase.
42:47
They're observing hundreds of thousands of
tokens and thinking about them before outputting.
42:51
They're observing their own chain of thought
for thousands of tokens before making a plan about how to code something up.
42:55
Your model is seeing one image, what happened in the last second, and it
vaguely knows it's supposed to fold this short.
43:05
It's seeing the image of what happened in
the last second. I guess it works.
43:05
It's crazy that it will just see the last thing that
happened and then keep executing on the plan.
43:15
Fold it inside out, then fold it correctly.
43:15
But it's shocking that a second of context is enough to execute on a minute-long task. Yeah.
43:22
I'm curious why you made that choice in the first place and why it's possible to
actually do tasks… If a human only had a second of memory and had to do physical work,
I feel like that would just be impossible.
43:37
It's not that there's something good
about having less memory, to be clear.
43:41
Adding memory, adding longer context, all
that stuff, adding higher resolution images, those things will make the model better.
43:45
But the reason why it's not the most important thing for the kind of skills
that you saw when you visited us, at some level, comes back to Moravec's paradox.
43:57
Moravec's paradox basically, if you want to know one thing about robotics, that's the thing.
44:04
Moravec's paradox says that in AI the easy things are hard and the hard things are easy.
44:11
Meaning the things that we take for granted—like picking up objects, seeing,
perceiving the world, all that stuff—those are all the hard problems in AI.
44:19
The things that we find challenging, like playing chess and doing calculus,
actually are often the easier problems.
44:26
I think this memory stuff is actually
Moravec’s paradox in disguise.
44:29
We think that the cognitively demanding tasks that
we do that we find hard, that cause us to think, "Oh man, I'm sweating. I'm working hard."
44:34
Those
are the ones that require us to keep lots of stuff in memory, lots of stuff in our minds.
44:39
If you're solving some big math problem, if you're having a complicated technical conversation
on a podcast, those are things where you have to keep all those puzzle pieces in your head.
44:48
If you're doing a well-rehearsed task—if you are an Olympic swimmer and you're swimming
with perfect form—and you're right there in the zone, people even say it's "in
the moment." It's in the moment.
45:00
It's like you've practiced it so much you've baked
it into your neural network in your brain.
45:11
You don't have to think carefully
about keeping all that context.
45:15
It really is just Moravec's
paradox manifesting itself.
45:19
That doesn't mean that we don't need the memory.
45:19
It just means that if we want to match the level of dexterity and physical proficiency that
people have, there's other things we should get right first and then gradually go up that
stack into the more cognitively demanding areas, into reasoning, into context, into
planning, all that kind of stuff.
45:36
That stuff will be important too. You have this trilemma.
45:36
You have three different things which all take more compute during
inference that you want to increase at the same time.
45:50
You have the inference speed.
45:50
Humans are
processing 24 frames a second or whatever it is.
45:56
We can react to things extremely fast.
45:56
Then you have the context length.
46:02
For the kind of robot which is just cleaning
up your house, I think it has to be aware of things that happened minutes ago or hours
ago and how that influences its plan about the next task it's doing.
46:14
Then you have the model size.
46:18
At least with LLMs, we've seen that there's
gains from increasing the amount of parameters.
46:24
I think currently you have 100
millisecond inference speeds.
46:30
You have a second-long context and then
the model is a couple billion parameters?
46:35
Each of these, at least two of them,
are many orders of magnitude smaller than what seems to be the human equivalent.
46:40
A human brain has trillions of parameters and this has like 2 billion parameters.
46:45
Humans are processing at least as fast as this model, actually a decent bit
faster, and we have hours of context.
46:55
It depends on how you define human context,
but hours of context, minutes of context.
46:59
Sometimes decades of context. Exactly.
46:59
You have to have many order-of-magnitude improvements across all of these three
things which seem to oppose each other.
47:11
Increasing one reduces the amount of compute you
can dedicate towards the other one in inference.
47:19
How are we going to solve this?
47:19
That's a very big question.
47:19
Let's try to unpack this a little bit.
47:24
There's a lot going on in there.
47:29
One thing is a really
interesting technical problem.
47:34
It's something where we'll
see perhaps a lot of really interesting innovation over the next few years.
47:37
It’s the question of representation for context.
47:45
You gave some of the examples, like
if you have a home robot that's doing something then it needs to keep track.
47:49
As a person, there are certainly some things where you keep track of them very
symbolically, almost in language. I have my checklist. I'm going shopping.
47:59
At least for me,
I can literally visualize in my mind my checklist.
48:04
Pick up the yogurt, pick up
the milk, pick up whatever.
48:08
I'm not picturing the milk shelf with the
milk sitting there.
48:08
I'm just thinking, "milk."
48:13
But then there's other things
that are much more spatial, almost visual.
48:20
When I was trying to get to your
studio, I was thinking, "Okay, here's what the street looks like.
48:24
Here's what that street looks like.
48:27
Here's what I expect the doorway to look like."
48:27
Representing your context in the right form, that captures what you really need
to achieve your goal—and otherwise discards all the unnecessary stuff—I
think that's a really important thing.
48:42
We're seeing the beginnings of
that with multimodal models.
48:45
But I think that multimodality has much
more to it than just image plus text.
48:50
That's a place where there's a lot of
room for really exciting innovation.
48:53
Do you mean in terms of how we represent?
48:53
How we represent both context, both what happened in the past, and also plans or
reasoning, as you call it in the LLM world, which is what we would like to happen in the future or
intermediate processing stages in solving a task.
49:11
Doing that in a variety of modalities, including
potentially learned modalities that are suitable for the job, is something that has enormous
potential to overcome some of these challenges. Interesting.
49:19
Another question I have as we're
discussing these tough trade-offs in terms of inference is comparing it to the human brain.
49:28
The human brain is able to have hours, decades of context while being able to act on the order
of 10 milliseconds, while having 100 trillion parameters or however you want to count it.
49:42
I wonder if the best way to understand what's happening here is that human brain hardware
is just way more advanced than the hardware we have with GPUs, or that the algorithms for
encoding video information are way more efficient.
50:04
Maybe it's some crazy mixture of experts
where the active parameters are also on the order of billions, low billions.
50:09
Or it’s some mixture of the two.
50:14
If you had to think about why we have these
models that are, across many dimensions, orders of magnitude less efficient compared
to the brain, is it hardware or algorithms?
50:26
That's a really good question.
50:26
I
definitely don't know the answer to this.
50:31
I am not by any means well-versed in neuroscience.
50:31
If I had to guess and also provide an answer that leans more on things I know, it's something
like this.
50:37
The brain is extremely parallel.
50:43
It has to be just because of the biophysics,
but it's even more parallel than your GPU.
50:51
If you think about how a modern
multimodal language model processes the input, if you give it some images and
some text, first it reads in the images, then it reads in the text, and then proceeds
one token at a time to generate the output.
51:07
It makes a lot more sense to me for an
embodied system to have parallel processes.
51:12
Now mathematically you can make close
equivalences between parallel and sequential stuff.
51:17
Transformers aren't fundamentally
sequential.
51:17
You make them sequential by putting in position embeddings.
51:21
Transformers are fundamentally very parallelizable things.
51:24
That's what makes them so great.
51:27
I don't think that mathematically this highly
parallel thing—where you're doing perception and proprioception and planning all at the
same time—necessarily needs to look that different from a transformer, although its
practical implementation will be different.
51:40
You could imagine that the system will in parallel
think about, "Okay, here's my long-term memory, here's what I've seen a decade ago,
here's my short-term spatial stuff, here's my semantic stuff, here's what I'm
seeing now, here's what I'm planning."
51:54
All of that can be implemented in a way that
there's some very familiar attentional mechanism, but in practice all running in parallel,
maybe at different rates, maybe with the more complex things running slower, the
faster reactive stuff running faster.
53:08
If in five years we have a system
which is as robust as a human in terms of interacting with the world, then
what has happened that makes it physically possible to be able to run those models?
53:18
To have video information that is streaming at real time, or hours of prior video
information is somehow being encoded and considered while decoding in a millisecond
scale, and with many more parameters.
53:34
Is it just that Nvidia has shipped much
better GPUs or that you guys have come up with much better encoders and stuff?
53:38
What's happened in the five years?
53:44
There are a lot of things to this question.
53:44
Certainly there's a really fascinating systems problem.
53:48
I'm by no means a systems expert.
53:52
I would imagine that the right architecture
in practice, especially if you want an affordable low-cost system, would be to
externalize at least part of the thinking.
54:00
You could imagine in the future you'll have a
robot where, if your Internet connection is not very good, the robot is in a dumber reactive mode.
54:05
But if you have a good Internet connection then it can be a little smarter. It's pretty cool.
54:10
There
is also research and algorithms stuff that can help here, figuring out the right representations,
concisely representing both your past observations but also changes in observation.
54:24
Your sensory stream is extremely temporally correlated.
54:28
The marginal information gained from each additional observation is not
the same as the entirety of that observation.
54:35
The image that I'm seeing now is very
correlated to the image I saw before.
54:38
In principle, I want to represent it concisely.
54:38
I could get away with a much more compressed representation than if I
represent the images independently.
54:44
There's a lot that can be done on the
algorithm side to get this right.
54:44
That's really interesting algorithms work.
54:47
There's
also a really fascinating systems problem.
54:52
To be truthful, I haven't gotten to
the systems problem because you want to implement the system once you know the
shape of the machine learning solution.
55:01
But there's a lot of cool stuff to do there.
55:01
Maybe you guys just need to hire the people who run the YouTube data centers because
they know how to encode video information.
55:10
This raises an interesting question.
55:10
With LLMs, theoretically you could run your own model on this laptop or whatever.
55:16
Realistically what happens is that the largest, most effective models are being run
in batches of thousands and millions of users at the same time, not locally.
55:27
Will the same thing happen in robotics because of the inherent efficiencies of batching,
plus the fact that we have to do this incredibly compute-intensive inference task?
55:39
You don't want to be carrying around $50,000 GPUs per robot or something.
55:47
You just want that to happen somewhere else.
55:51
In this robotics world, should we
just be anticipating something where you need connectivity everywhere?
55:57
You need robots that are super fast.
56:01
You're streaming video information back and
forth, or at least video information one way.
56:06
Does that have interesting implications about how
this deployment of robots will be instantiated? I don't know.
56:13
But if I were to guess,
I would guess that we'll see both.
56:18
That we'll see low-cost systems with
off-board inference and more reliable systems.
56:25
For example, in settings where you have
an outdoor robot or something where you can't rely on connectivity, those will
be costlier and have onboard inference.
56:33
I'll say a few things from a technical standpoint
that might contribute to understanding this.
56:42
While a real-time system obviously needs to be
controlled in real time, often at high frequency, the amount of thinking you need to do for
every time step might be surprisingly low.
56:52
Again, we see this in humans and animals.
56:52
When we plan out movements, there is definitely a real planning process that happens in the brain.
57:00
If you record from a monkey brain, you will find neural correlates of planning.
57:07
There is something that happens in advance of a movement.
57:11
When that movement takes place, the shape of the movement correlates with what
happened before the movement. That's planning.
57:20
That means that you put something in place and
set the initial conditions of some process and then unroll that process, and that's the movement.
57:25
That means that during that movement, you're doing less processing and you batch it up in advance.
57:28
But you're not entirely an open loop.
57:34
It's not that you're playing back a tape recorder.
57:34
You are reacting as you go.
57:38
You're just reacting at a different level of
abstraction, a more basic level of abstraction.
57:43
Again, this comes back to representations.
57:43
Figure out which representations are sufficient for planning in advance and
then unrolling, and which representations require a tight feedback loop.
57:49
For that tight feedback loop, what are you doing feedback on?
57:53
If I'm driving a vehicle, maybe I'm doing feedback on the position
of the lane marker so that I stay straight.
57:59
At a lower frequency, I sort
of gauge where I am in traffic.
58:02
You have a couple of lectures from a few years
back where you say that even for robotics, RL is in many cases better than imitation learning.
58:08
But so far the models are exclusively doing imitation learning.
58:13
I'm curious how your thinking on this has changed. Maybe it hasn’t changed.
58:17
But then you need to do this for the RL. Why can't you do RL yet?
58:21
The key here is prior knowledge.
58:25
In order to effectively learn from your own
experience, it turns out that it's really, really important to already know
something about what you're doing.
58:33
Otherwise it takes far too long, just like
it takes a person, when they're a child, a very long time to learn very basic things, to
learn to write for the first time, for example.
58:42
Once you already have some knowledge, then
you can learn new things very quickly.
58:47
The purpose of training the models with supervised
learning now is to build out that foundation that provides the prior knowledge so they can
figure things out much more quickly later.
58:57
Again, this is not a new idea.
58:57
This is exactly what we've seen with LLMs.
59:01
LLMs start off being trained
purely with next token prediction.
59:05
That provided an excellent starting
point, first for all sorts of synthetic data generation and then for RL.
59:09
It makes total sense that we would expect basically any foundation model
effort to follow that same trajectory.
59:18
We first build out the foundation
essentially in a somewhat brute-force way.
59:22
The stronger that foundation gets, the
easier it is to then make it even better with much more accessible training.
59:26
In 10 years, will the best model for knowledge work also be a robotics model
or have an action expert attached to it?
59:36
The reason I ask is, so far we've seen advantages
from using more general models for things.
59:43
Will robotics fall into this bucket?
59:43
Will we just have the model which does everything, including physical work and knowledge work, or
do you think they'll continue to stay separate?
59:53
I really hope that they will actually be the same.
59:53
Obviously I'm extremely biased.
59:53
I love robotics, I think it's very fundamental to AI.
59:59
But optimistically, I hope it's actually the other way around, that the robotics element of
the equation will make all the other stuff better.
1:00:12
There are two reasons for this
that I can tell you about.
1:00:17
One has to do with representations and focus.
1:00:17
What I said before, with video prediction models if you just want to
predict everything that happens, it's very hard to figure out what's relevant.
1:00:25
If you have the focus that comes from trying to do a task now that acts to structure
how you see the world in a way that allows you to more fruitfully utilize the other
signals.
1:00:35
That could be extremely powerful.
1:00:35
The second one is that understanding the physical
world at a very deep, fundamental level, at a level that goes beyond just what we can articulate
with language, can help you solve other problems.
1:00:50
We experience this all the time.
1:00:50
When we talk about abstract concepts, we say, "This company has a lot of momentum."
1:00:54
We'll use social metaphors to describe inanimate objects. "My computer hates me."
1:01:02
We experience the world in a particular way and our subjective experience shapes how
we think about it in very profound ways.
1:01:11
Then we use that as a hammer to basically
hit all sorts of other nails that are far too abstract to handle any other way.
1:01:15
There might be other considerations that are relevant to physical robots in
terms of inference speed and model size, et cetera, which might be different from
the considerations for knowledge work.
1:01:31
Maybe it's still the same model, but
then you can serve it in different ways.
1:01:34
The advantages of co-training are high enough.
1:01:34
I'm wondering, in five years if I'm using a model to code for me, does it also
know how to do robotics stuff?
1:01:46
Maybe the advantages of code writing on
robotics are high enough that it's worth it.
1:01:51
The coding is probably the pinnacle of
abstract knowledge work in the sense that just by the mathematical nature of computer
programming, it's an extremely abstract activity, which is why people struggle with it so much.
1:02:00
I'm a bit confused about why simulation doesn't work better for robots.
1:02:05
If I look at humans, smart humans do a good job of, if they're intentionally
trying to learn, noticing what about the simulation is similar to real life and paying
attention to that and learning from that.
1:02:22
If you have pilots who are learning in simulation
or F1 drivers who are learning in simulation, should we expect it to be the case that as robots
get smarter they will also be able to learn more things through simulation?
1:02:32
Or is this cursed and we need real-world data forever?
1:02:35
This is a very subtle question.
1:02:38
Your example with the airplane pilot
using simulation is really interesting.
1:02:43
But something to remember is that when a pilot
is using a simulator to learn to fly an airplane, they're extremely goal-directed.
1:02:49
Their goal in life is not to learn to use a simulator.
1:02:52
Their goal in life is to learn to fly the airplane.
1:02:54
They know there will be a test afterwards.
1:02:56
They know that eventually they'll be in
charge of a few hundred passengers and they really need to not crash that thing.
1:02:59
When we train models on data from multiple different domains, the models don't know that
they're supposed to solve a particular task.
1:03:11
They just see, "Hey, here's
one thing I need to master.
1:03:13
Here's another thing I need to master."
1:03:13
Maybe a better analogy there is if you're playing a video game where you can fly an
airplane and then eventually someone puts you in the cockpit of a real one.
1:03:21
It's not that the video game is useless, but it's not the same thing.
1:03:25
If you're trying to play that video game and your goal is to really master the video game, you're
not going to go about it in quite the same way.
1:03:35
Can you do some kind of meta-RL on this?
1:03:35
There's this really interesting paper you wrote in 2017.
1:03:42
Maybe the loss function is not how well it does at a particular video game or particular simulation. I'll let you explain it.
1:03:47
But it was about how well being trained at different video games
makes it better at some other downstream task.
1:03:54
I did a terrible job at
explaining but can you do a better job and try to explain what I was trying to say?
1:03:58
What you're trying to say is that maybe if we have a really smart model that's doing meta-learning,
perhaps it can figure out that its performance on a downstream problem, a real-world problem,
is increased by doing something in a simulator.
1:04:13
And then specifically make
that the loss function, right? That's right.
1:04:16
But here's the thing with this.
1:04:16
There's a set of these ideas that are all going to be something like, "Train to make it better
on the real thing by leveraging something else."
1:04:27
The key linchpin for all of that is the ability
to train it to be better on the real thing.
1:04:32
I suspect in reality we might not even
need to do something quite so explicit.
1:04:38
Meta learning is emergent,
as you pointed out before.
1:04:41
LLMs essentially do a kind of meta
learning via in-context learning.
1:04:44
We can debate how much that's learning or not, but
the point is that large powerful models trained on the right objective and on real data, get
much better at leveraging all the other stuff.
1:04:54
I think that's actually the key.
1:04:54
Coming back to your airplane pilot, the airplane pilot is trained on a real world objective.
1:04:59
Their objective is to be a good airplane pilot, to be successful, to have a good career.
1:05:03
All of that kind of propagates back into the actions they take and leveraging
all these other data sources.
1:05:10
So what I think is actually the
key here to leveraging auxiliary data sources including simulation, is to
build the right foundation model that is really good and has those emergent abilities.
1:05:16
To your point, to get really good like that, it has to have the right objective.
1:05:24
Now we know how to get the right objective out of real world data, maybe we can get it out
of other things, but that's harder right now.
1:05:34
Again, we can look to the examples
of what happened in other fields.
1:05:37
These days if someone trains an
LLM for solving complex problems, they're using lots of synthetic data.
1:05:41
The reason they're able to leverage that synthetic data effectively is because they
have this starting point that is trained on lots of real data that gets it.
1:05:49
Once it gets it, then it's more able to leverage all this other stuff.
1:05:52
Perhaps ironically, the key to leveraging other data sources including simulation,
is to get really good at using real data, understand what's up with the world, and
then you can fruitfully utilize that.
1:06:04
Once we have, in 2035 or 2030, basically this
sci-fi world, are you optimistic about the ability of true AGIs to build simulations in
which they are rehearsing skills that no human or AI has ever had a chance to practice before?
1:06:19
They need to practice to be astronauts because we're building the Dyson sphere and
they can just do that in simulation.
1:06:28
Or will the issue with simulation continue to
be one regardless of how smart the models get? Here’s what I would say.
1:06:34
Deep
down at a very fundamental level, the synthetic experience that you create yourself
doesn't allow you to learn more about the world.
1:06:46
It allows you to rehearse things, it
allows you to consider counterfactuals.
1:06:50
But somehow information about the world
needs to get injected into the system.
1:06:57
The way you pose this question
elucidates this very nicely.
1:07:01
In robotics classically,
people have often thought about simulation as a way to inject human knowledge.
1:07:04
A person knows how to write down differential equations, they can code it up and that gives
the robot more knowledge than it had before.
1:07:12
But increasingly what we're learning
from experiences in other fields, from how the video generation stuff
goes from synthetic data for LLMs, is that probably the most powerful way to create
synthetic experience is from a really good model.
1:07:27
The model probably knows more than a person
does about those fine-grained details.
1:07:31
But then of course, where does that model get
the knowledge?
1:07:31
From experiencing the world.
1:07:31
In a sense, what you said is quite right in that a very
powerful AI system can simulate a lot of stuff.
1:07:44
But also at that point it almost doesn't
matter because, viewed as a black box, what's going on with that system is that
information comes in and capability comes out.
1:07:52
Whether the way to process that information is
by imagining some stuff and simulating or by some model-free method is kind of irrelevant
in our understanding of its capabilities.
1:07:59
Do you have a sense of what
the equivalent is in humans?
1:08:02
Whatever we're doing when
we're daydreaming or sleeping.
1:08:06
I don't know if you have some sense of
what this auxiliary thing we're doing is, but if you had to make an ML analogy, what is it?
1:08:10
Certainly when you sleep your brain does stuff that looks an awful lot like
what it does when it's awake.
1:08:22
It looks an awful lot like playing
back experience or perhaps generating new statistically similar experience.
1:08:25
It's very reasonable to guess that perhaps simulation through a learned model is part of how
your brain figures out counterfactuals, basically.
1:08:41
Something that's even more fundamental than
that is that optimal decision making at its core, regardless of how you do it,
requires considering counterfactuals.
1:08:51
You basically have to ask yourself, "If I did
this instead of that, would it be better?"
1:08:55
You have to answer that question somehow.
1:08:55
Whether you answer that question by using a learned simulator, or whether you answer
that question by using a value function or something, by using a reward
model, in the end it's all the same.
1:09:07
As long as you have some mechanism for
considering counterfactuals and figuring out which counterfactual is better, you've got it.
1:09:10
I like to think about it this way because it simplifies things.
1:09:15
It tells us that the key is not necessarily to do really good simulations.
1:09:18
The key is to figure out how to answer counterfactuals. Yeah, Interesting.
1:09:23
Stepping into the big picture again.
1:09:23
The reason I'm interested in getting a concrete understanding of when this robot economy
will be deployed is because it's relevant to understanding how fast AGI will proceed in the
sense that it's obviously about the data flywheel.
1:09:39
But also, if you just extrapolate out the capex
for AI by 2030, people have different estimates, but many people have estimates in the hundreds
of gigawatts – 100, 200, 300 gigawatts.
1:09:52
You can just crunch numbers on having
100-200 gigawatts deployed by 2030.
1:09:57
The marginal capex per year is
in the trillions of dollars.
1:10:01
It's $2-4 trillion dollars a year.
1:10:01
That corresponds to actual data centers you have to build, actual chip foundries you have to build,
actual solar panel factories you have to build.
1:10:14
I am very curious about whether by 2030, the big
bottleneck is just the people to lay out the solar panels next to the data center or assemble the
data center, or will the robot economy be mature enough to help significantly in that process. That's cool.
1:10:31
You're basically saying, how much concrete should I buy now to build the data
center so that by 2030 I can power all the robots.
1:10:44
That is a more ambitious way of thinking about it
than has occurred to me, but it's a cool question.
1:10:48
The good thing, of course, is that the
robots can help you build that stuff.
1:10:52
But will they be able to by that time?
1:10:52
There's the non-robotic stuff, which will also mandate a lot of capex.
1:10:58
Then there's robot stuff where you have to build robot factories, etc.
1:11:04
There will be this industrial explosion across the whole stack.
1:11:07
How much will robotics be able to speed that up or make it possible?
1:11:11
In principle, quite a lot.
1:11:11
We have a tendency sometimes to think about robots as
mechanical people, but that's not the case.
1:11:25
People are people and robots are robots.
1:11:25
The better analogy for the robot, it's like your car or a bulldozer.
1:11:28
It has much lower maintenance requirements.
1:11:34
You can put them into all sorts of weird places
and they don't have to look like people at all.
1:11:38
You can make a robot that's 100 feet tall.
1:11:38
You can make a robot that's tiny.
1:11:44
If you have the intelligence to power
very heterogeneous robotic systems, you can probably do a lot better than
just having mechanical people, in effect.
1:11:55
It can be a big productivity boost for real
people and it can allow you to solve problems that are very difficult to solve.
1:12:00
For example, I'm not an expert on data centers by any means, but you could
build your data centers in a very remote location because the robots don't have to worry
about whether there's a shopping center nearby.
1:12:15
There's the question of where the software
will be, and then there's the question of how many physical robots we will have.
1:12:18
How many of the robots you're training in Physical Intelligence, these tabletop
arms, are there physically in the world?
1:12:28
How many will there be by 2030?
1:12:28
These are tough questions, how many will be needed for the intelligence explosion.
1:12:31
These are very tough questions.
1:12:31
Also, economies of scale in robotics so far
have not functioned the same way that they probably would in the long term.
1:12:43
Just to give you an example, when I started working in robotics in
2014, I used a very nice research robot called a PR2 that cost $400,000 to purchase.
1:12:52
When I started my research lab at UC Berkeley, I bought robot arms that were $30,000.
1:12:59
The robots that we are using now at Physical Intelligence, each arm costs about $3,000.
1:13:05
We think they can be made for a small fraction of that.
1:13:09
What is the cause of that learning rate? There are a few things.
1:13:15
One, of course,
has to do with economies of scale.
1:13:18
Custom-built, high-end research hardware,
of course, is going to be much more expensive than more productionized hardware.
1:13:22
Then of course, there's a technological element.
1:13:29
As we get better at building actuated
machines, they become cheaper.
1:13:29
There's also a software element.
1:13:37
The smarter your AI
system gets, the less you need the hardware to satisfy certain requirements.
1:13:43
Traditional robots in factories need to make motions that are highly repeatable.
1:13:48
Therefore it requires a degree of precision and robustness that you don't need if
you can use cheap visual feedback.
1:13:57
AI also makes robots more affordable and
lowers the requirements on the hardware. Interesting.
1:14:03
Do you think the
learning rate will continue?
1:14:07
Do you think it will cost hundreds of dollars
by the end of the decade to buy mobile arms?
1:14:11
That is a great question for my co-founder, Adnan
Esmail, who is probably the best person arguably in the world to ask that question.
1:14:18
Certainly the drop in cost that I've seen has surprised me year after year.
1:14:22
How many arms are there probably in the world?
1:14:27
Is it more than a million? Less than a million?
1:14:27
I don't know the answer to that question, but it's also a tricky question to answer
because not all arms are made equal.
1:14:34
Arguably, the robots that are assembling
cars in a factory are just not the right kind to think about.
1:14:39
The kind you want to train on.
1:14:43
Very few because they are not currently
commercially deployed as factory robots. Less than 100,000?
1:14:49
I don't know, but probably. Okay.
1:14:52
And we want billions of
robots, at least millions of robots.
1:15:00
If you're just thinking about the
industrial explosion that you need to get this explosive AI growth, not only do you need the
arms, but you need something that can move around.
1:15:13
Basically, I'm just trying to think whether
that will be possible by the time that you need a lot more labor to power this AI boom?
1:15:17
Well, economies are very good at filling demand when there's a lot of demand.
1:15:25
How many iPhones were in the world in 2001?
1:15:29
There's definitely a challenge there.
1:15:29
It's something that is worth thinking about.
1:15:38
A particularly important question
for researchers like myself is how can AI affect how we think about hardware?
1:15:42
There are some things that are going to be really, really important.
1:15:48
You probably want your thing to not break all the time.
1:15:50
There are some things that are firmly in that category of question marks.
1:15:53
How many fingers do we need?
1:15:57
You said yourself before that you were surprised
that a robot with two fingers can do a lot.
1:16:01
Maybe you still want more than that, but still
finding the bare minimum that still lets you have good functionality, that's important.
1:16:06
That's in the question mark box.
1:16:09
There are some things that we probably don't need.
1:16:09
We probably don't need the robot to be super duper precise, because we know that
feedback can compensate for that.
1:16:18
My job, as I see it right now, is to figure out
what's the minimal package we can get away with.
1:16:23
I really think about robots in terms
of minimal package because I don't think that we will have the one ultimate
robot, the mechanical person basically.
1:16:33
What we will have is a bunch of things that
good, effective robots need to satisfy.
1:16:38
Just like good smartphones
need to have a touchscreen.
1:16:40
That's something that we all agreed on.
1:16:40
Then they’ll need a bunch of other stuff that's optional, depending on the need,
depending on the cost point, et cetera.
1:16:47
There will be a lot of innovation where
once we have very capable AI systems that can be plugged into any robot to endow it with
some basic level of intelligence, then lots of different people can innovate on how to get the
robot hardware to be optimal for each niche.
1:17:02
In terms of manufacturers, is
there some Nvidia of robotics? Not right now.
1:17:05
Maybe there will be
someday.
1:17:05
Maybe I'm being idealistic, but I would really like to see a world where
there's a lot of heterogeneity in robots.
1:17:16
What is the biggest bottleneck in the
hardware today as somebody who's designing the algorithms that run on it?
1:17:19
It's a tough question to answer, mainly because things are changing so fast.
1:17:22
To me, the things that I spend a significant amount of time thinking about on the hardware
side is really more reliability and cost.
1:17:33
It's not that I'm that worried about cost.
1:17:33
It's just that cost translates to the number of robots, which translates to the amount of data.
1:17:38
Being an ML person, I really like having lots of data.
1:17:41
I really want to have robots that are low cost, because then I can
have more of them and therefore more data.
1:17:46
Reliability is important, more
or less for the same reason.
1:17:50
It's something that we'll get more
clarity on as things progress.
1:17:57
Basically, the AI systems of today are
not pushing the hardware to the limit.
1:18:01
As the AI systems get better and better,
the hardware will get pushed to the limit, and then we'll hopefully have a
much better answer to your question.
1:18:06
This is a question I've had for a lot of guests.
1:18:06
If you go through any layer of this AI explosion, you find that a bunch of the actual source
supply chain is being manufactured in China, other than chips obviously.
1:18:26
You talk about data centers and you're like, "Oh, all the wafers for solar
panels and a bunch of the cells and modules, et cetera, are manufactured in China."
1:18:35
You just go through the supply chain.
1:18:41
Obviously robot arms are
being manufactured in China.
1:18:44
You’ll live in this world where it’s
just incredibly valuable to ramp up manufacturing of the hardware, because
each robot can produce some fraction of the value that a human worker can produce.
1:18:55
Not only is that true, but the value of human workers or any worker has tremendously skyrocketed
because we need tons of bodies to lay out the tens of thousands of acres of solar farms and
data centers and foundries and everything.
1:19:16
In this boom world, the big bottleneck there's
just how many robots can you physically deploy?
1:19:21
How many can you manufacture?
1:19:21
Because you
guys are going to come up with the algorithms now.
1:19:24
We just need the hardware.
1:19:24
This
is a question I've asked many guests.
1:19:30
If you look at the part of the chain that
you are observing, what is the reason that China just doesn't win by default?
1:19:36
If they're producing all the robots and you come up with the algorithms
that make those robots super valuable, why don't they just win by default?
1:19:45
This is a very complex question.
1:19:51
I'll start with the broader themes and then
try to drill a little bit into the details.
1:19:58
One broader theme here is that if you want to
have an economy where you get ahead by having a highly educated workforce—by having people
that have high productivity, meaning that for each person's hour of work, lots of stuff
gets done—automation is really, really good.
1:20:19
Automation is what multiplies the amount
of productivity that each person has.
1:20:24
Again, it’s the same as LLM coding tools.
1:20:24
LLM coding tools amplify the productivity of a software engineer.
1:20:28
Robots will amplify the productivity of basically everybody that is doing work.
1:20:32
Now that's a final state, a desirable final state.
1:20:41
There's a lot of complexity in how you
get to that state, how you make that an appealing journey to society, how you
navigate the geopolitical dimension of that.
1:20:52
All of that stuff is pretty complicated.
1:20:52
It requires making a number of really good decisions.
1:20:55
Good decisions about investing in a balanced robotics ecosystem, supporting both
software innovation and hardware innovation.
1:21:08
I don't think any of those
are insurmountable problems.
1:21:10
It just requires a degree of long-term
vision and the right balance of investment.
1:21:20
What makes me really optimistic
about this is the final state.
1:21:26
We can all agree that in the United States we
would like to have a society where people are highly productive, where we have highly
educated people doing high-value work.
1:21:36
Because that end state seems to me very
compatible with automation, with robotics, at some level there should be a lot
of incentive to get to that state.
1:21:46
Then from there we have to solve for
all the details that will help us get there. That's not easy.
1:21:50
There's a lot
of complicated decisions that need to be made in terms of private industry, in terms of
investment, in terms of the political dimension.
1:21:58
But I'm very optimistic about it because
it seems to me that the light at the end of the tunnel is in the right direction.
1:22:03
I guess there's a different question.
1:22:10
If the value is bottlenecked by hardware
and you just need to produce more hardware, what is the path by which hundreds of
millions of robots or billions of robots are being manufactured in the US or with allies?
1:22:20
I don't know how to approach that question, but it seems like a different question than, "Well,
what is the impact on human wages or something?"
1:22:31
For the specifics of how we make that happen,
that's a very long conversation that I'm probably not the most qualified to speak to.
1:22:36
But in terms of the ingredients, the ingredient here that is important is that
robots help with physical things, physical work.
1:22:50
If producing robots is itself physical
work, then getting really good at robotics should help with that.
1:22:54
It's a little circular, of course, and as with all circular things, you have to
bootstrap it and try to get that engine going.
1:23:03
But it seems like it is an easier
problem to address than, for example, the problem of digital devices.
1:23:09
Work goes into creating computers, phones, et cetera.
1:23:15
But the computers and phones don't themselves help with the work. Right.
1:23:17
I guess feedback loops go both ways.
1:23:21
They can help you or they can help
others and it's a positive sum world.
1:23:24
It's not necessarily bad that they help others.
1:23:24
But to the extent that a lot of the things which would go into this feedback loop—the
sub-component, manufacturing and supply chain, already exist in China—it seems like the
stronger feedback loop would exist in China.
1:23:40
Then there's a separate discussion.
1:23:40
Maybe that's fine, maybe that's good, and maybe they'll continue exporting this to us.
1:23:44
But I just find it notable that whenever I talk to guests about different things, it's
just like, "Yeah, within a few years the key bottleneck to every single part of
the supply chain here will be something that China is the 80% world supplier of."
1:24:00
This is why I said before that something really important to get right here
is a balanced robotics ecosystem.
1:24:11
AI is tremendously exciting, but we should
also recognize that getting AI right is not the only thing that we need to do.
1:24:16
We need to think about how to balance our priorities, our investment, the kind
of things that we spend our time on.
1:24:27
Just as an example, at Physical Intelligence
we do take hardware very seriously.
1:24:33
We build a lot of our own things and we want to
have a hardware roadmap alongside our AI roadmap. But that's just us.
1:24:41
For the United States,
arguably for human civilization as a whole, we need to think about these
problems very holistically.
1:24:53
It is easy to get distracted sometimes
when there's a lot of excitement, a lot of progress in one area like AI.
1:24:56
We are tempted to lose track of other things, including things you've said.
1:25:03
There's a hardware
component.
1:25:03
There's an infrastructure component with compute and things like that.
1:25:08
In general it's good to have a more holistic view of these things.
1:25:12
I wish we had more holistic conversations about that sometimes.
1:25:15
From the perspective of society as a whole, how should they be thinking about the
advances in robotics and knowledge work?
1:25:23
Basically society should be
planning for full automation.
1:25:26
There will be a period in which people's work
is way more valuable because there's this huge boom in the economy where we’re building
all these data centers and factories.
1:25:36
Eventually humans can do things with their
body and we can do things with our mind.
1:25:39
There's not some secret third thing.
1:25:39
What should society be planning for?
1:25:44
It should be full automation of humans.
1:25:44
Society will also be much wealthier.
1:25:50
Presumably there are ways to do this such that
everybody is much better off than they are today.
1:25:55
But the end state, the light at the end of the
tunnel, is the full automation but plus super wealthy society with some redistribution
or whatever way to figure that out.
1:26:04
I don't know if you disagree
with that characterization.
1:26:08
At some level that's a very
reasonable way to look at things.
1:26:13
But if there's one thing that I've learned
about technology, it's that it rarely evolves quite the way that people expect.
1:26:18
Sometimes the journey is just as important as the destination.
1:26:23
It's very difficult to plan ahead for an end state.
1:26:27
Directionally, what you said makes a lot of sense.
1:26:31
I do think that it's very important for us
collectively to think about how to structure the world around us in a way that is amenable to
greater and greater automation across all sectors.
1:26:43
But we should really think about the journey
just as much as the destination, because things evolve in all sorts of unpredictable ways.
1:26:47
We'll find automation showing up in all sorts of places, probably not the places we expect first.
1:26:53
The constant here that is really important is that education is really, really valuable.
1:27:00
Education is the best buffer somebody has against the negative effects of change.
1:27:08
If there is one single lever that we can pull collectively as a society, it's more education. Is that true?
1:27:15
Moravec's paradox is that the things which are most beneficial from education
for humans might be the easiest to automate because it's really easy to educate AIs.
1:27:25
You can throw the textbooks that would take you eight years of grad school
to do at them in an afternoon.
1:27:32
What education gives you is flexibility.
1:27:32
It's less about the particular facts you know, as it is about your ability to
acquire skills, acquire understanding.
1:27:46
It has to be a good education. Yeah.
1:27:46
Okay, Sergey, thank you so much for coming on the podcast. Super fascinating. Yeah, this was intense. Tough questions.