There's an interesting book on this subject called "Pandora's Seed: The Unforeseen Cost of Civilization" by Spencer Wells. Basically says that agriculture and its trappings (towns, etc) is a bad idea.
many of the chemicals contained in Aspirin
Say what? Aspirin contains only one chemical: acetylsalicylic acid. Nothing else.
It's not the number of decimal plaaces that's the issue. Mainframes can store and manipulate a number like 1.23 as EXACTLY 1.23, whereas a lesser machine would have to use some binary floating-point approximation (1.230000001234 or 1.229999999993241 for example) with rounding, etc. Even the programming languages used on mainframes (mainly COBOL and PL/I but also RPG) have specific provision for fixed-point decimal data types, whereas C and its derivatives (C++, C#, Java, Objective-C, D, etc) are utterly clueless.
But mainframe financial applications do relatively little actual arithmetic. Most of their time is spent moving strings and structures around - something that C and its derivatives also just can't do efficiently, if at all, whereas COBOL and PL/I do it easily and quickly.
In mainframe software, anything that can be static is static; data is only dynamic if it absolutely has to be. This is the basis for the high efficiency of mainframe software. COBOL has no equivalent of C's 'new'; PL/I does (of course - 'ALLOCATE') but it's used relatively rarely. You therefore almost NEVER see memory leaks in mainframe software.
The Glicko chess rating system and its successor Glicko2 (creative, huh?) are better than Elo and have been around for years. Various online chess sites use it, as does the Australian Chess Federation.