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Simulating 1 second of real brain activity takes 40 minutes and 83K processors

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Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#31

Post by Dylan16807 »

lukifer wrote: post #20
cmapes wrote: post #8

Earlier quoted context omitted.

I think it becomes unethical once we see strong evidence that the system could be self-aware. Before that, it's just a simulation. Simulating storm activity doesn't make it rain.

It isn't a big leap to imagine a debate between aliens about whether the hairless apes on the third rock from Sol should be considered "sentient", or merely clever animals. I'd rather err far on the side of assuming sentience and personhood if there is a shadow of a doubt, simulated or otherwise.

Why would they debate? It's very easy to test for [sentience or fake sentience programmed by a sentient]. Unless the aliens think we're robots they can do a mirror test or something.

But such a test does not work in a possibly-tainted environment. A neural net that seems to communicate might just have a hidden encoding of ELIZA.

You can err on the side of assuming sentience if you want, but don't think it's out of self-preservation-empathy-logic.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#32

Post by anigbrowl »

oh_teh_meows wrote: post #25
anigbrowl wrote: post #2

Unfortunately, that's only for a number of cells equivalent to 1% of a human brain. A full brain's worth of simulation would take 2.5 days....although that much is probably not necessary. It will fall soon enough, though.

I'm not certain if that extrapolation you made of the time it takes to simulate a brain at the same abstraction level is valid. You're assuming the computation cycles needed will scale linearly, which might not be true considering that the brain is a network of neurons, where each neuron has a high number of in/out links to many other neurons. Consider the case where you take n seconds to simulate n neurons. Now add…

It's not my extrapolation, it's from the TFA, yes they assumed lineaar scaling.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#33

Post by pothibo »

Yes we are very far away from the human brain on many levels. However, I don't like this kind of article because it doesn't make sense on the software level.

Mathematically, we could figure out how much computing power we would need to match the human brain (24 bytes per synapse * number of synapse, etc).

I think I would be more interested in what was the specific of their experiment.

- What kind of software were they running?

- Was the software bug-free(yeah right)?

- Was the software optimized?

- Caching?

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#34

Post by jfoutz »

deletes wrote: post #15
foobarbazqux wrote: post #10

To put this claim in perspective, we are still unable to simulate a single cell by modeling everything we know from biochemistry, even if we ignore molecular dynamics. Mostly this is because we don't know what many genes and the proteins they encode do. This matters, for example, if we want to simulate neuronal plasticity or the effect of antidepressants. We're an incredibly long way from a full simulation, which wou…

To correctly model a cell you would need to simulate every atom and there are about 10^11 to 10^14 (!) of them in a single cell. I think an interesting number would be how many atoms does it take to simulate one atom reasonably well. Then you could get correct results for some ( really ) small biological functions.

What would you get from simulating both hydrogen atoms and the oxygen atom that you wouldn't get from simulating plain old water? The vast majority of a cell is just water, seems like you could cut your complexity in half with that abstraction.

I'm no molecular biologist, so i'll happily agree if you say there are some fraction of water molecules broken down, or formed by various cellular processes, but that must be a tiny fraction of the total, and could just be special cased.

It just seems like you're willfully ignoring everything physics has to say about how the universe works so you can get a big number for your calculation.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#35

Post by mischanix »

cabalamat wrote: post #26
pervycreeper wrote: post #4

Earlier quoted context omitted.

The thought that we are maybe two decades away from having the computing power to simulate a human brain in realtime (and much more than that subsequently) is astounding, even in this age of technological wonder.

Assuming (1) it's parallelisable (2) this is an accurate enough similation, and (3) a whole human brain is 100 times bigger, we'd need 40 60 83k*100 processors which is about 20 billion. We could do it now (hardware-wise), if we really wanted to.

If each processor draws down 50 Watts, 20 billion of them would draw 1 TW. The US uses on average ~3 TW across every power source (including e.g. combustion engines).

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#36

Post by moocowduckquack »

jfoutz wrote: post #34
deletes wrote: post #15

Earlier quoted context omitted.

To correctly model a cell you would need to simulate every atom and there are about 10^11 to 10^14 (!) of them in a single cell. I think an interesting number would be how many atoms does it take to simulate one atom reasonably well. Then you could get correct results for some ( really ) small biological functions.

What would you get from simulating both hydrogen atoms and the oxygen atom that you wouldn't get from simulating plain old water? The vast majority of a cell is just water, seems like you could cut your complexity in half with that abstraction. I'm no molecular biologist, so i'll happily agree if you say there are some fraction of water molecules broken down, or formed by various cellular processes, but that must be…

How would you plan on simulating all the variety of states, reactions and solutions involving plain old water without worrying about hydrogen and oxygen atoms?

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#37

Post by aa0 »

ceejayoz wrote: post #9
csallen wrote: post #6

Earlier quoted context omitted.

Even if you are a simulation, would you prefer not to exist? What, really, is the difference between reality and a perfectly-executed simulation? It's hard to condemn one without condemning the other.

If I'm a simulation, I'd prefer to exist and have a legal right to continue doing so.

If you were a simulation, you might not have free will. To even propose that you'd have a decision beyond state-machine-dynamics is a world away.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#38

Post by Osmium »

foobarbazqux wrote: post #23
deletes wrote: post #15

Earlier quoted context omitted.

To correctly model a cell you would need to simulate every atom and there are about 10^11 to 10^14 (!) of them in a single cell. I think an interesting number would be how many atoms does it take to simulate one atom reasonably well. Then you could get correct results for some ( really ) small biological functions.

Usually people modeling cells don't consider molecular dynamics, they consider concentrations of proteins, ions, and metabolites. A full MD simulation would obviously be superior, but useful predictions could be made without it. It's hard to say which is the better approach. On the one hand you have MD from which you could technically build an accurate model "from scratch", folding all of your own proteins as part of…

It depends what you mean by "full MD" too. That term can cover a multitude of sins. Truly accurate MD would be even more computationally expensive.

Re: Simulating 1 second of real brain activity takes 40 minutes and 83K processors

#39

Post by jfoutz »

moocowduckquack wrote: post #36
jfoutz wrote: post #34

Earlier quoted context omitted.

What would you get from simulating both hydrogen atoms and the oxygen atom that you wouldn't get from simulating plain old water? The vast majority of a cell is just water, seems like you could cut your complexity in half with that abstraction. I'm no molecular biologist, so i'll happily agree if you say there are some fraction of water molecules broken down, or formed by various cellular processes, but that must be…

How would you plan on simulating all the variety of states, reactions and solutions involving plain old water without worrying about hydrogen and oxygen atoms?

Again, i would assert that a cell is 70% water. some tiny fraction of water that's actually used in a reaction would just be special cased, and modeled independently.

My understanding of "solution" is stuff floating in water. If there's some value in breaking out each atom, i'm all for it, but i kind of suspect the spherical cow is good enough in that case.

Even if i'm wrong there, each atom would introduce at least 6 degrees of freedom. IIRC, water is slightly polarized, and that's likely relevant to at least some reactions. Replacing the 18 degrees of freedom with 6 to represent a rigid water, or perhaps 10 or so to represent a flexible version, modeling as the molecule will dramatically lower complexity.

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