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Isamutoday at 5:38 PM2 repliesview on HN

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.


Replies

observationisttoday at 6:07 PM

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!

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B1FF_PSUVMtoday at 5:54 PM

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