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Comment by Isamu | Hacker News Reader

What’s up with the ending that makes no sense?

>Where are the physical limits? According to Bremermann (1982), a computer of 1 kg of mass and 1 liter of volume can execute at most 1051 operations per second on at most 1032 bits. The trend above will hit the Bremermann limit roughly 25 decades after Z3, circa 2200. However, since there are only 2 x 1030 kg of mass in the solar system, the trend is bound to break within a few centuries, since the speed of light will greatly limit the acquisition of additional mass

They shift from talking about the transistor density to somehow considering a supermassive construct. Reminds me of LLM mashups.

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It's a natural extension of the ideas being discussed - the limit in computation per gram of mass has energetic bounds, as well, with configurations nearing the upper limit that start looking more like nuclear explosions than anything we'd regard as structured computation. The extremes are amazing to consider - things that look and act like stars, but are fantastically precise Turing machines, and so on.

It's a theme that sci-fi authors have explored deeply. Accelerando is a particularly fun and worthwhile read if you haven't already!

The Bremermann limit is about computational density. It makes sense to talk about computers that are ever more powerful but not necessarily larger.

So we talk about the supercomputers we call cell phones that are orders of magnitude more powerful than the desktop computers I used years ago.

It doesn’t make sense to talk about making super large computers before reaching the density limit, that’s a confusion of concepts.

Making computers faster has involved making them smaller because the speed of signal propagation.

Computronium! Kurzweil goes into this in the Singularity is Near.

I've always wondered if Warlock from the New Mutants was made of it.

> It's a theme that sci-fi authors have explored deeply.

Having ingested every science fiction book that has been digitized, a fun evening to be had is writing your own book with ChatGPT.

It seems to refer to the previous paragraph:

> The naive extrapolation of this exponential trend predicts that the 21st century will see cheap computers with a thousand times the raw computational power of all human brains combined

i.e. putting an upper bound on the exponential with solar system mass

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