Advancing technology generally leaves a reduced material footprint in its wake - as time goes on, it takes less and less physical stuff to perform some given function. Tiny transistors replace larger vacuum tubes, thin LCDs replace heavy CRTs, oscillating quartz crystals replace complex mechanical clock movements, electric motors replace steam engines, etc. Advancing technology gives us new materials with new properties (allowing, say, substituting a large amount of masonry for a small amount of steel), greater precision and control in manufacturing (allowing smaller and smaller transistors), and new processes that can get the same outputs for fewer inputs (such as the