Perhaps getting a bit more technical than is necessary, it's interesting to note that spaces themselves have no effect on 'weight' in compiled code. Whitespace characters [spaces, tabs, newlines (except in certain circumstances/languages)], along with comments, are thrown away by the
Lexer, the part of the compiler that is responsible for taking the source code and turning it into a sequence of
tokens, which is basically each word or symbol that appears in the source file. (Unless of course you're actually programming in
White Space) Extra lines of code, however, may (in most cases yes, but they may actually get optimized away by the compiler) add 'weight' to the final compiled program. In order to control what may be written as 0s or 1s, however, you'll have to go to a lower level, in assembly code.
But seeing as each electron is 9.109 E−31 kg, you'd probably get more benefit with one pass of a metal file somewhere discrete.
--Ryan