Hopefully Interesting

The CPU in your laptop or desktop has a lot of transistors in it.  The Core i7-6700HQ that I'm typing this on has 1.35 billion of the little guys.  Buck back in the day on of the earliest computers, ENIAC , had only 20 thousand vacuum tubes which more or less fufilled the same role as transistors do now.  So what do all those extra transistors we've added accomplish, if we were able to do useful mathematical operations with just 20,000?  Most of the increase in the speed at which we run computers, the clock rate, has come from replacing large and slow transistors with smaller and faster transistors after all. Well first, what was ENIAC doing with it's transistors?  A single transistor isn't very useful.  If you're willing to use a resistor too you can perform an operation like making an output the logical and of one input and the inverse of a second input, call it AND(A, NOT(B)).  But that circuit is a very jury rigged thing which will be slow, unreliable, and fai

Eric Drexler is the person who came up with the name "nanotechnology" and is probably the one most responsible for public awareness of the idea.  After a pretty long haitus he's published a new book and I thought I'd take a look but before I get to the new book I think I should provide some history. Way back in 1986 Drexler published Engines of Creation .  In it he outlined a vision of a world remade by the ability to engineer chemicals the way we engineer widgets today, assembling them precisely using mechanical arms placing bits in position rather than waiting for the random thermal motion of molecules to bring parts into contact where they can stick.  In the book he envisioned tiny robots called assemblers constructed with atomic precision using tiny arms to assemble other devices - and also replicate themselves.  That ability to replicate could potentially be a big danger if an error in programming caused them to replicated without bound like a cancer.  The cell