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Comment by snek_case | Hacker News Reader

We can't even simulate a single cell. At least not accurately. You'd need to be able to simulate ribosomes, gene expression, epigenetic factors. Still a lot we don't understand because even single cells are incredibly complex electrochemical machines.

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I agree but we also don't know what gravity is, and yet we can compute it with some degree of error. There might be a world we can just approximate enough of this cell, that the details matter less.

This actually illustrates the crux of the problem. Gravity is a single (highly accurate) approximation when applied to 2 objects. But when you have 3 objects interacting with each other, the system is chaotic: https://en.m.wikipedia.org/wiki/Three-body_problem

Even if we could estimate all the molecules, cells, and processes of a biological entity to a similar precision as gravity, the errors would compound exponentially.

Thanks for your answer, but we either don't understand the biology of the animal models that we use.

I think that medicine and drug regulations do not use the same conceptual framework as biology. Medicine and drug regulations are pragmatic, hence the concept of clinical trial: They test if something works while minimizing the confounding factors. They do not try to understand the biology down to cellular force fields of the animal model.

So why not have the same approach with software? Anyway, drugs authorities have already approved drugs based on software simulations [0, 1].

[0] https://www.fda.gov/media/163156/download

[1] https://www.fda.gov/science-research/about-science-research-...

> Anyway, drugs authorities have already approved drugs based on software simulations

The simulations you have linked aren't on the same scale. The paper uses the phrase "are powerful tools that COMPLEMENT traditional methods for gathering evidence"

And I'd argue this is more like detailed analysis rather than a simulation. It's like hoping you've found an immersive computer world like The Matrix, but it's a 2D side-scolling video game like Mario Bros.

I'd also question "approved drugs based on..." and instead argue they "didn't reject drugs based on..."

Yes, but while animals are a black box to some extent, the outcomes of the experiments are not. And you don't have to worry about whether your results are an artifact of your simulation.

Your instincts are good - if we could simulate people in silico we could basically understand and cure every disease - but the scale of such a simulation is literally (not figuratively!) astronomical. Biological systems are way, way, way more complex than they appear and our computers are (currently) hopelessly inadequate.

I can imagine a world where you can simulate a simple organism like a worm without knowing how to simulate the cells that make it. This is because emergent behaviour of complex systems can be much simpler than the constituent parts of that system (temperature vs. knowing particle velocities).

I can write a program today that can simulate a worms "emergent behavior" without simulating the cells. Maybe a little 3D model that wriggles around. I can even do a human!

But I think what we're looking for here is something closer to emulation. In the same way that video game console emulators seek to reproduce the exact bugs that the original hardware produced - the value here does not come from abstracting away the lowest levels of behavior.

> the value here does not come from abstracting away the lowest levels of behavior

I totally agree.

How are you going to simulate the administering of a medicinal molecule? Or the knocking out of a gene?

My modelling the relevant parts of the worm that are involved in these processes.

You don't need an atomistic DFT simulator to get a good enough simulation of fluid dynamics, enough to design jets or rockets that go into space.

> modelling the relevant parts of the worm that are involved in these processes.

You mean cell chemistry?

It seems to me that if you can fully simulate a worm you're probably only an order of magnitude of difficulty away from a person, but to get there you need to have crossed dozens across many domains.

But none of that means you should take a drug bc someone’s elaborately technologized guess is that it’ll be okay

there's https://openworm.org/ for simulating a c. elegans, but think you're underestimating the complexities

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