atoms are enough

so, laura [musikitty on twitter], who apparently is a lightning-quick typist thanks to the surprisingly effective tutelage of a fictional italian plumber, counts herself among the generation-y adherents of the 2-space rule. while it’s natural that you would prefer to do it the way you were taught, whichever way that happens to be, after doing some digging around on the web it seems pretty evident to me that the trend is definitely in the direction of a single space between sentences, and that the 2-space rule is indeed a legacy of the typewriter era.

there’s a good explanation over at about.com:

It is generally accepted that the practice of putting two spaces at the end of a sentence is a carryover from the days of typewriters with monospaced typefaces. Two spaces, it was believed, made it easier to see where one sentence ended and the next began. Most typeset text, both before and after the typewriter, used a single space. Today, with the prevalence of proportionally spaced fonts, some believe that the practice is no longer necessary and even detrimental to the appearance of text. With monospaced typefaces every character takes up the same amount of space on the page. M uses the same amount of space as i. With proportionally spaced fonts, the characters take up an amount of space relative to their actual width - the i needs less space than the M. (as illustrated by the graphic in the sidebar)

so, since typewriters used monospaced typefaces (think something like courier for example), people put in the extra space so that you could more easily tell where the new sentence began. proportionally spaced typefaces, as are most commonly used fonts on the internet and in desktop publishing, don’t need an extra space because the letters naturally clump together, and sometimes using two spaces with those fonts can be distracting, or it can seem like you’re making holes in the text. in fact, the style guides have now unambiguously moved toward advocating the use of just one space:

Chicago Manual of Style:

A single character space, not two spaces, should be left after periods at the ends of sentences (both in manuscript and in final, published form) and after colons.

(The official guide is subscription only, but here’s a more extended Q&A from the editor about it)

APA Style:

Character spacing. Space once after all punctuation—after commas, colons, semicolons, the punctuation at the end of a sentence, and after initials in names (unless followed by a comma). Do not space after internal periods in abbreviations, such as U.S., a.m., or around the colon in a ratio (e.g., 5:1 ratio) (APA, 2001, pp. 290-291). The APA Manual encourages changes to improve readability in final manuscripts. Spacing twice at the end of a sentence may help meet this goal. As always, be consistent.

MLA also straddles the fence a bit:

Publications in the United States today usually have the same spacing after a period, a question mark, or an exclamation point as between words on the same line. Since word processors make available the same fonts used by typesetters for printed works, many writers, influenced by the look of typeset publications, now leave only one space after a concluding punctuation mark… As a practical matter, however, there is nothing wrong with using two spaces after concluding punctuation marks unless an instructor requests that you do otherwise.

anyway, i don’t think that either convention is objectively better than the other. i personally prefer one because that’s what i’m used to. it looks just fine to me in terms of readability, and it’s one fewer keystroke to make per sentence. if someone is used to two spaces and is convinced that it helps the reader, then by all means put two spaces in, as it doesn’t hurt anything. i do think that two-spacers are ultimately going to go the way of the buffalo, though.