Experimental Blog #144

Comments from "The Pattern on the Stone" - The Simple Ideas that Make Computers Work by Daniel Hillis

The copywright year of this book is 1998.

In the early pages of his book Daniel Hillis recounts his childhood introduction to Boolean algebra and logic.
Since all computers, so the author seems to say, operate on bits of information and in the same, or very similar way, Daniel Hillis once even made, with the help of friends, a computer with the switches and connections made out of the sticks of Tinker Toys and strings.

Besides functions that stay constant in time, there are functions that involve sequences in time. To implement such time-varying functions a finite-state machine must also include a summary of the past, or memory.

"The central idea in the theory of computation is that of a universal computer - that is, a computer powerful enough to simulate any other computing device." This is also known as "Turing universality", which refers to the British mathematician Alan Turing.

"Like digital phenomena, quantum phenomena exist only in discrete states. From the quantum point of view, the continuous ... nature of the physical world ... is an illusion ... there is no such thing as half an electron." ..and "nothing can be exactly in any place at all." !!

An algorithm is a "fail-safe procedure"; while a heuristic rule "almost always gets the right answer", but is not gauranteed to do so.