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Failing to Understand the Exponential, Again

julian.ac

91–100 of 266 posts

Re: Failing to Understand the Exponential, Again

#91
post #69
post #54

You'd think that boosters for a technology whose very foundations rely on the sigmoid and tanh functions used as neuron activation functions would intuitively get this...

It's all relu these days

When people want a smooth function so they can do calculus they often use something like gelu or the swish function rather than relu. And the swish function involves a sigmoid. https://en.wikipedia.org/wiki/Swish_function

Re: Failing to Understand the Exponential, Again

#93

Earlier quoted context omitted.

> But a lot of technologies turn out to be S-shaped, not purely exponential, because there are limiting factors. I'd argue all of them. Any true exponential eventually gets to a point where no computer can even store its numerical value. It's a physically absurd curve.

The narrative quietly assumes that this exponential curve can in fact continue since it will be the harbinger of the technological singularity. Seems more than a bit eschatological, but who knows. If we suppose this tech rapture does happen, all bets are off; in that sense it's probably better to assume the curve is sigmoidal, since the alternative is literally beyond human comprehension.

Barring fully reversible processes as the basis for technology, you still quickly run into energy and cooling constraints. Even with that, you'd have time or energy density constraints. Unlimited exponentials are clearly unphysical.

Re: Failing to Understand the Exponential, Again

#94

> Given consistent trends of exponential performance improvements over many years and across many industries, it would be extremely surprising if these improvements suddenly stopped. I'm sure people were saying that about commercial airline speeds in the 1970's too. But a lot of technologies turn out to be S-shaped, not purely exponential, because there are limiting factors. With LLM's at the moment, the limiting fac…

There’s a key way to think about a process that looks exponential and might or might not flatten out into an S curve: reasoning about fundamental limits. For COVID it would obviously flatten out because there are finite humans, and it did when the disease had in fact infected most humans on the planet. For commercial airlines you could reason about the speed of sound or escape velocity and see there is again a natural upper limit- although which of those two would dominate would have very different real world implications.

For computational intelligence, we have one clear example of an upper limit in a biological human brain. It only consumes about 25W and has much more intelligence than today’s LLMs in important ways. Maybe that’s the wrong limit? But Moore’s law has been holding for a very long time. And smart physicists like Feynman in his seminal lecture predicting nanotechnology in 1959 called “there’s plenty of room at the bottom” have been arguing that we are extremely far from running into any fundamental physical limits on the complexity of manufactured objects. The ability to manufacture them we presume is limited by ingenuity, which jokes aside shows no signs of running out.

Training data is a fine argument to consider. Especially since there are training on “the whole internet” sorta. The key breakthrough of transformers wasn’t in fact autoregressive token processing or attention or anything like that. It was that they can learn from (memorize / interpolate between / generalize) arbitrary quantities of training data. Before that every kind of ML model hit scaling limits pretty fast. Resnets got CNNs to millions of parameters but they still became quite difficult to train. Transformers train reliably on every size data set we have ever tried with no end in sight. The attention mechanism shortens the gradient path for extremely large numbers of parameters, completely changing the rules of what’s possible with large networks. But what about the data to feed them?

There are two possible counter arguments there. One is that humans don’t need exabytes of examples to learn the world. You might reasonably conclude from this that NNs have some fundamental difference vs people and that some hard barrier of ML science innovation lies in the way. Smart scientists like Yann LeCun would agree with you there. I can see the other side of that argument too - that once a system is capable of reasoning and learning it doesn’t need exhaustive examples to learn to generalize. I would argue that RL reasoning systems like GRPO or GSPO do exactly this - they let the system try lots of ways to approach a difficult problem until they figure out something that works. And then they cleverly find a gradient towards whatever technique had relative advantage. They don’t need infinite examples of the right answer. They just need a well chosen curriculum of difficult problems to think about for a long time. (Sounds a lot like school.) Sometimes it takes a very long time. But if you can set it up correctly it’s fairly automatic and isn’t limited by training data.

The other argument is what the Silicon Valley types call “self play” - the goal of having an LLM learn from itself or its peers through repeated games or thought experiments. This is how Alpha Go was trained, and big tech has been aggressively pursuing analogs for LLMs. This has not been a runaway success yet. But in the area of coding agents, arguably where AI is having the biggest economic impact right now, self play techniques are an important part of building both the training and evaluation sets. Important public benchmarks here start from human curated examples and algorithmically enhance them to much larger sizes and levels of complexity. I think I might have read about similar tricks in math problems but I’m not sure. Regardless it seems very likely that this has a way to overcome any fundamental limit on availability of training data as well, based on human ingenuity instead.

Also, if the top of the S curve is high enough, it doesn’t matter that it’s not truly exponential. The interesting stuff will happen before it flattens out. E.g. COVID. Consider the y axis “human jobs replaced by AI” instead of “smartness” and yes it’s obviously an S curve.

Re: Failing to Understand the Exponential, Again

#95
post #56

I will worry when I see Startups competing on products with companies 10x, 100x, or 1000x times their size. Like a small team producing a Photoshop replacement. So far I haven't seen anything like that. Big companies don't seem to be launching new products faster either, or fixing some of their products that have been broken for a long time (MS teams...) AI obviously makes some easy things much faster, maybe helps wi…

I think the real turning point is when there isn’t the need for something like photoshop. Creatives that I speak to yearn for the day when they can stop paying the adobe tax.

Re: Failing to Understand the Exponential, Again

#96

Earlier quoted context omitted.

That is even true for covid for obvious reasons, because Covid runs out of people it can infect at some point.

Infectious diseases rarely see actual exponential growth for logistical reasons. It's a pretty unrealistic model that ignores that the disease actually needs to find additional hosts to spread, the local availability of which starts to go down from the first victim.

If you assume the availability of hosts is local to the perimeter of the infected hosts, then the relative growth is limited to 2/R where R is the distance from patient 0 in 2 dimensions. It's becuase an area of the circle defines how many hosts are already ill but the interaction can only happen on the perimeter of the circle.

The disease is obviously also limited by the total amount of hosts, but I assume there's also the "bottom" limit - i.e. the resource consumption of already-infected hosts.

Re: Failing to Understand the Exponential, Again

#97
post #67
post #4

> Again we can observe a similar trend, with the latest GPT-5 already astonishingly close to human performance: I have issues with "human performance" as single data point in times where education keeps to excel in some countries and degrades in others. How far away are we from saying, better than "X percent of humans" ?

This reminds me -- very tenuously -- of how the shorthand for very good performance in the Python community is "like C". In the C community, we know that programs have different performance depending on algorithms chosen..

> In the C community, we know that programs have different performance depending on algorithms chosen..

Yes. Only the C community knows this. What a silly remark.

Regarding the "Python community" remark, benchmarks against C and Fortran go back decades now. It's not just a Python thing. C people push it a lot, too.

Re: Failing to Understand the Exponential, Again

#98

> Given consistent trends of exponential performance improvements over many years and across many industries, it would be extremely surprising if these improvements suddenly stopped. I'm sure people were saying that about commercial airline speeds in the 1970's too. But a lot of technologies turn out to be S-shaped, not purely exponential, because there are limiting factors. With LLM's at the moment, the limiting fac…

> a lot of technologies turn out to be S-shaped, not purely exponential, because there are limiting factors.

Yes of course it’s not going to increase exponentially forever.

The point is, why predict that the growth rate is going to slow exactly now? What evidence are you going to look at?

It’s possible to make informed predictions (eg “Moore’s law can’t get you further than 1nm with silicon due to fundamental physical limits”). But most commenters aren’t basing their predictions in anything as rigorous as that.

And note, there are good reasons to predict a speedup, too; as models get more intelligent, they will be able to accelerate the R&D process. So quality per-researcher is now proportional to the exponential intelligence curve, AND quantity of researchers scales with number of GPUs (rather than population growth which is much slower).

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