Spaced Out

I just heard yesterday that it is now standard in writing to put only one space after a period.  All the sources I read indicated that single-spacing is now required in submitting any kind of manuscript.  I hadn't realized this was such a hot topic.  People get very animated about it.  Did you know this?  I'd never heard it before.  That's awkward, since one's hands are trained for two spaces and not likely to change easily.  I looked it up, and according to the article below, one space has always been correct, but manual typewriters required two.  Hmm.

http://www.slate.com/articles/technology/technology/2011/01/space_invaders.html

But the plot thickens!  This guy has a completely different view.  He says that double-spacing was fashionable all the way up until 1960, typewriters notwithstanding, and provides examples from a number of texts.  If that's true, then even when we learned to type, double-spacing was out of fashion, owing, apparently to the technology of Phototypesetting.

http://theworldsgreatestbook.com/how-many-spaces-after-a-period/

I hope your grammar nerd hat is on today, or you'll likely find this deadly dull.  But I was intrigued to learn that I've been so wrong for so long!

This guy has even more to say on the subject.  He's inclined to find the Space Invaders article (above, top) fictitious.

http://www.heracliteanriver.com/?p=324

The style manuals apparently all say one space, when they mention it at all.  I just read that Strunk & White is silent on the matter, but uses single spacing in its text.

The articles I read attributed blame for the change to several sources.  One guy, who was roundly dissed in another article I read, blames the typewriter, because typewriter font letters are all the same size, so letters look a little more randomly spaced, and an additional space is needed at the end of a sentence to distinguish.  Trouble is, double spacing preceded the typewriter by several hundred years, so that's debunked.  Another guy blames Photo-whatsit that I mentioned earlier, and the timing of the switch suits that argument.  Several sources agreed that single spacing began to come into fashion in the 1960's, in typesetting, anyway.  

Since the 1960's.  That's my whole life.  How did I not know this?  I've never heard of it.  I feel like I must exist in a cave.  How's that possible?  I mean, I'm on the internet almost daily, and yet this is the first I've heard of it.  I gotta get out more.