The author makes a good point that it's important to define what "a good simulation" means.
On one extreme, we cannot even solve the underlying physics equations for single atoms beyond hydrogen, let alone molecules, let alone complex proteins, etc. etc. all the way up to cells and neuron clusters. So that level of "good" seems enormously far off.
On the other hand, there are lots of useful approximations to be made.
If it looks like a duck and quacks like a duck, is it a duck?
If it squidges like a nematode and squirms like a nematode, is it a [simulation of a] nematode?
(if it talks like a human and makes up answers like a human, is it a human? ;)
> If it looks like a duck and quacks like a duck, is it a duck?
ISTM that the answer is "in a way yes, in a way no".
Yes, in that we reasonably conclude something is a duck if it seems like a duck.
No, in that seeming like a duck is not a cause of its being a duck (rather, it's the other way round).
When we want to figure out what something is, we reason from effect to cause. We know this thing is a duck because it waddles, quacks, lays eggs, etc etc. We figure out everything in reality this way. We know what a thing is by means of its behavior.
But ontologically -- ie outside our minds -- the opposite is happening from how we reason. Something waddles, quacks & lays eggs because it is a duck. Our reason goes from effect (the duck's behavior) to cause (the duck), but reality goes in the other direction.
Our reasoning (unlike reality) can be mistaken. We might be mistaking the model of a duck or a robot-duck for a real duck. But it doesn't follow from this that a model duck or a robot-duck is a duck. It just means a different cause is producing [some of] the same effects. This is true no matter how realistic the robot-duck is.
So we may (may!) be able to theoretically simulate a nematode, though the difficulty level must be astronomical, but that doesn't mean we've thereby created a nematode. This seems to be the case for attempting to simulate anything.
At least this is my understanding, I could be mistaken somewhere.
I think this is also one possible answer to the famous 'zombie' question.
(aside: I'm not especially arguing with you; just thinking out loud in response to what you wrote)
> Something waddles, quacks & lays eggs because it is a duck.
Or: something does those things, period. We notice several such somethings doing similar things, and come up with an umbrella term for them, for our own convenience: "duck." I'm not sure how far different that is from "is a duck", but it feels like a nonzero amount.
I guess where I'm going is: our labels for things are different from the "is-ness" of those things. Really, duck A and duck B are distinct from each other in many ways, and to call them by one name is in itself a coarse approximation.
So if "duckness" is a label that is purely derived from our observations, and separate from the true nature of the thing that waddles and quacks, then does some other thing (the robot duck) which also produces the same observations, also win the label?
Luckily, I'm a solipsist, so I don't have to worry about other things actually existing. Phew.
> If it looks like a duck and quacks like a duck, is it a duck?
No, if it doesn't do everything else a duck does. You can have a robot dog, but you won't need to take it to the vet, feed it, sweep up it's hair, let it go outside to go potty, put up a warning sign for the mailman, or take it for a walk. You can have a simulated dog do all those things, but then how accurate will the biological functions be in trying to model it's physiology over time?
Will it give us insights into real dog psychology so we can better interact with our pets? Or does that need to happen with real dogs and real human researchers? Wildlife biologists aren't going to refer to simulated ducks to research their behavior in more depth. They'll go out and observe them, or bring them into the lab.
I suppose that's where a nematode is interesting — it's maybe juuuust simple enough that a real nematode on a plate of agar (as described in the article) might be able to be simulated well enough that we could actually make useful, and even long-term predictions about it based on a mere model.
Not to say I'm fully convinced, but I can see the appeal.
This is an interesting point really. At what level of duck-ness do we decide that it's acceptably close to a duck? I agree that taken ad-absurdum, just because something looks like a duck and quacks like a duck, it doesn't mean at all that it is a duck. I can enclose a raspberry pi in a fake duck and it will fulfil the above criteria, and perhaps from a distance it can be mistaken for a duck, but it has practically nothing to do with ducks. At the same time, it might be enough if our objective is to make some low cost garden decorations :)
What I'm trying to say is: as long as the simulation fulfils the objectives set out, it's useful, even if it is very far from the real thing.
Then the next question is: what are the objectives here?
>Wildlife biologists aren't going to refer to simulated ducks to research their behavior in more depth.
I'm pretty sure behavior is simulated all the time in everything from migration to predator prey dynamics, to population dynamics, and so on. If we don't use simulations to understand all the little nuances and idiosyncrasies of behavior right now that's probably just because at present that's extremely difficult to model. But I suspect they absolutely would be used if such things were available. Of course, they would be treated as complementary to other forms of data, but wouldn't be disregarded outright.
On this note, I'd like to recommend Phillip K. Dick's "Do Androids Dream of Electric Sheep?", which goes beyond the what was adapted in "Blade Runner" on many fronts, but particularly in regards to what it feels like to own a robotic animal (or a flesh one for that matter).
That's an incredibly narrow slice of properties of ducks, nematodes (and humans).
Is there truly so little that makes up the soul of a duck? No mention of laying eggs? Caring for it's young? Viciously chasing children across the lawn of the local park? (I know that's usually the prevue of Geese, however I have seen ducks launch the occasional offensive against too curious little ones)
We really have no idea whether consciousness is something that can arise from computation, or whether it is somehow dependent on the physical substrate of the universe. Maybe we can create a virtual brain that, from the outside, is indistinguishable from a physical brain, and which will argue vociferously that it is a real person, and yet experiences no more conscious qualia than an equation written on a piece of paper.
> We really have no idea whether consciousness is something that can arise from computation, or whether it is somehow dependent on the physical substrate of the universe.
I don't understand this argument. How is the computer running the computation not part of the "physical substrate of the universe"? _Everything_ is part of the universe almost by definition.
The computer is physical, but the computation is (at least) a level of abstraction above the physical layer. The physical process may be the important part, not just the (apparent) algorithm that the physical process executes.
What makes you claim that? I have not seen proof of that (on the contrary, we don't have smooth emulation of animal like movement yet, which brains figure out pretty fast)
I think an even simpler argument can be made: our brain develops in response to the physical stimulus we experience from birth (earlier even).
Basically, even if it's a simple computation engine, can we put that simulation through the stimulus our brain experiences (not easily) and will lack of that turn into entirely differently behaving system?
It's well known it in fact isn't, otherwise learning would be impossible. Learning still isn't perfectly understood but one key characteristic is likely modulating synaptic strength (the weights mentioned). Also, yes, every cell and in particular neurons are very complex systems, although synapses themselves have various simplifying properties (specially along the axon, electrical communication really is the main method of communication).
I love how it is just assumed that "we can" and "we will", a good way to confidently tell you will burn human resources until you get to the point you want.
Meanwhile, the most advanced simulations are still rough approximations with little to no realism rather than "in this specific conditions and with this specific neural arrangements I made artificially, it behaves similarly to a real nematode", a good way to make a self-fulfilled prophecy.
>In 2013, neuroscientist Henry Markram secured about 1 billion euros from the European Union to "simulate the human brain" — a proposal widely deemed unrealistic even at the time. The project faced significant challenges and ultimately did not meet its ambitious yet vague goals
Unfortunately, it's not that easy. Axon terminals of neurons release neurotransmitters. We know of dozens of different types, but are not certain that we know about all of them yet. The same synapse can release multiple different neurotransmitters too, with one or more released depending on the axonic signals. And what to these chemicals do? It depends! There are receptors on the post-synaptic cell that respond to neurotransmitters, but there can be multiple different receptors that respond differently to the same neurotransmitter. Again, we aren't sure we know about all of them. The post-synaptic neuron is probably also listening to neurons of other types that signal using different neurotransmitters that it uses to determine if it should transmit an action potential or not. Oh, and invertebrates (like nematodes) send graded potentials (not action potentials like us vertebrates usually do) where the signal strength can vary.
In short - we are a long way from being able to simulate a nervous system. Our knowledge of neuronal biochemistry is not there yet.
Readit News
C. Elegans: The worm that no computer scientist can crack - https://news.ycombinator.com/item?id=43490290 - March 2025 (130 comments)
On one extreme, we cannot even solve the underlying physics equations for single atoms beyond hydrogen, let alone molecules, let alone complex proteins, etc. etc. all the way up to cells and neuron clusters. So that level of "good" seems enormously far off.
On the other hand, there are lots of useful approximations to be made.
If it looks like a duck and quacks like a duck, is it a duck?
If it squidges like a nematode and squirms like a nematode, is it a [simulation of a] nematode?
(if it talks like a human and makes up answers like a human, is it a human? ;)
ISTM that the answer is "in a way yes, in a way no".
Yes, in that we reasonably conclude something is a duck if it seems like a duck.
No, in that seeming like a duck is not a cause of its being a duck (rather, it's the other way round).
When we want to figure out what something is, we reason from effect to cause. We know this thing is a duck because it waddles, quacks, lays eggs, etc etc. We figure out everything in reality this way. We know what a thing is by means of its behavior.
But ontologically -- ie outside our minds -- the opposite is happening from how we reason. Something waddles, quacks & lays eggs because it is a duck. Our reason goes from effect (the duck's behavior) to cause (the duck), but reality goes in the other direction.
Our reasoning (unlike reality) can be mistaken. We might be mistaking the model of a duck or a robot-duck for a real duck. But it doesn't follow from this that a model duck or a robot-duck is a duck. It just means a different cause is producing [some of] the same effects. This is true no matter how realistic the robot-duck is.
So we may (may!) be able to theoretically simulate a nematode, though the difficulty level must be astronomical, but that doesn't mean we've thereby created a nematode. This seems to be the case for attempting to simulate anything.
At least this is my understanding, I could be mistaken somewhere.
I think this is also one possible answer to the famous 'zombie' question.
> Something waddles, quacks & lays eggs because it is a duck.
Or: something does those things, period. We notice several such somethings doing similar things, and come up with an umbrella term for them, for our own convenience: "duck." I'm not sure how far different that is from "is a duck", but it feels like a nonzero amount.
I guess where I'm going is: our labels for things are different from the "is-ness" of those things. Really, duck A and duck B are distinct from each other in many ways, and to call them by one name is in itself a coarse approximation.
So if "duckness" is a label that is purely derived from our observations, and separate from the true nature of the thing that waddles and quacks, then does some other thing (the robot duck) which also produces the same observations, also win the label?
Luckily, I'm a solipsist, so I don't have to worry about other things actually existing. Phew.
No, if it doesn't do everything else a duck does. You can have a robot dog, but you won't need to take it to the vet, feed it, sweep up it's hair, let it go outside to go potty, put up a warning sign for the mailman, or take it for a walk. You can have a simulated dog do all those things, but then how accurate will the biological functions be in trying to model it's physiology over time?
Will it give us insights into real dog psychology so we can better interact with our pets? Or does that need to happen with real dogs and real human researchers? Wildlife biologists aren't going to refer to simulated ducks to research their behavior in more depth. They'll go out and observe them, or bring them into the lab.
Not to say I'm fully convinced, but I can see the appeal.
What I'm trying to say is: as long as the simulation fulfils the objectives set out, it's useful, even if it is very far from the real thing.
Then the next question is: what are the objectives here?
I'm pretty sure behavior is simulated all the time in everything from migration to predator prey dynamics, to population dynamics, and so on. If we don't use simulations to understand all the little nuances and idiosyncrasies of behavior right now that's probably just because at present that's extremely difficult to model. But I suspect they absolutely would be used if such things were available. Of course, they would be treated as complementary to other forms of data, but wouldn't be disregarded outright.
Is there truly so little that makes up the soul of a duck? No mention of laying eggs? Caring for it's young? Viciously chasing children across the lawn of the local park? (I know that's usually the prevue of Geese, however I have seen ducks launch the occasional offensive against too curious little ones)
For example you can simulate traffic without simulating the inner workings of every car's engine, or even understanding how the engine works.
Or maybe by "working understanding" you mean "we have a black box that does the thing we wanted."
https://en.wikipedia.org/wiki/Philosophical_zombie
We really have no idea whether consciousness is something that can arise from computation, or whether it is somehow dependent on the physical substrate of the universe. Maybe we can create a virtual brain that, from the outside, is indistinguishable from a physical brain, and which will argue vociferously that it is a real person, and yet experiences no more conscious qualia than an equation written on a piece of paper.
I don't understand this argument. How is the computer running the computation not part of the "physical substrate of the universe"? _Everything_ is part of the universe almost by definition.
The answer to that would appear to be, no.
Basically, even if it's a simple computation engine, can we put that simulation through the stimulus our brain experiences (not easily) and will lack of that turn into entirely differently behaving system?
Deleted Comment
Meanwhile, the most advanced simulations are still rough approximations with little to no realism rather than "in this specific conditions and with this specific neural arrangements I made artificially, it behaves similarly to a real nematode", a good way to make a self-fulfilled prophecy.
Ah, so this is where 45% of my salary goes.
https://www.humanbrainproject.eu/en/follow-hbp/news/2023/09/...
https://www.abc.net.au/news/science/2025-03-05/cortical-labs...
In short - we are a long way from being able to simulate a nervous system. Our knowledge of neuronal biochemistry is not there yet.
https://youtu.be/bEXefdbQDjw