Che? Iforonefailtounderstandyourlogic.
Here’s a sentence in English without spaces. It is perfectly simple to distinguish the words:
FORGODSOLOVEDTHEWORLDTHATHEGAVEHISONLYBEGOTTENSONTHATWHOSOEVERBELIEVETHINHIMSHOULDNOTPERISHBUTHAVEEVERLASTINGLIFE
But, EPUB is an E-reader format that DOES attempt to flow text and graphics onto a computer screen. It’s what Take Control Books recommends for on-screen reading, and it does a much better job of maintaining an approximation of the way things look in print (other than page breaks). I wasn’t attempting to create an argument, just stating that there were ways of seeing an approximation of print in a visually pleasing manner while still using a computer.
I did err in suggesting that MOBI could accomplish that, because that’s the native format for Kindle.
And, my major point, of course, was how sad it is that Robin Williams’s excellent book can still be purchased to read on a Kindle.
In other words, I think we’re largely in agreement.
A long time ago, to assist my technical writing I obtained a copy of a 1998 NASA publication SP7084: Grammar, Punctuation, and Captilization - A Handbook for Technical Writers and Editors" ( I still can’t work out if that title was being sarcastic!)
It is very comprehensive but doesn’t mention spaces at the end of a sentence.
Copy here:
Of course NASA typeset it in LaTeX. 
Putting two spaces after a period was a norm for typewriters. Most typewriters used a ribbon of ink and the keys didn’t alway strike the paper evenly. Adding an extra space after a period helped delineate sentences. This is especially true since a period took up as much space as any other letter. Monospace type can be a bit hard on the eyes and adding a space after a sentence helped break things up.
However, this was never the norm for the print industry. The print industry used proportional print fonts, plus printed books tended to be clearer and crisper.
I agree with this. Also, these days, I’m just happy when people choose to use periods at all!
Thank goodness.
I shared this link on my FB page, and I’ve never seen such an uproar. It’s as though I posted a political comment. 
Golly, Adam, I thought the debate was settled back in the last century, around the time Adobe PageMaker became available. On a typewriter, always two spaces. On a computer, one space, except that on a computer two spaces are acceptable if using a monospaced typewriter font.
I wrote a long comment, and then discovered that the “heracliteanriver.com” article cited by “David C.” said essentially the same thing but with extensive research support. So my long comment is being posted as an essay on my own Website (www.TowerBells.org), and I’ll just make a short comment here.
The author of the article from “The Verge” referenced by Adam’s note wrote, “Typewriters used monospaced fonts, … so the extra space after the [period] was needed to make it more apparent that sentences had ended. Word and many other similar apps make fonts proportional, so two spaces is no longer necessary.” That assertion is both factually false and logically false. It is factually false because the first typists were merely imitating what skilled typesetters had done for centuries – use wider spacing at the ends of sentences. It is logically false because if an extra space is “needed” following a period that takes up just as much width as every other character in a monospaced font, then it is even more needed after a period that takes the least possible width of any character in a proportional font.
If you want to write with single spaces everywhere, you are certainly free to do so. And if you are an editor, it is certainly your prerogative to require all of your writers to follow your chosen style. But to assert that double spacing at the end of sentences is somehow “wrong” is to insult the intelligence of everyone who chooses to respect this particular aspect of literary history and the principles involved in it.
Sadly, the Heraclitean River site went down many years ago, so if you want to link to any of its pages, you must use the wayback machine.
I’ve updated the link in my quote of your post. You may want to do the same for the original.
Editing a submission this morning, I’m reminded of a tendency I’ve noticed consistently over the past 30 years of copyediting the work of hundreds of people: Those who choose to put two spaces between sentences are far more likely to be inconsistent in that practice. Sometimes it’s one space, sometimes it’s three. One-spacers are much less likely to vary. I’m about halfway through a 256-word document right now, and already I’ve found two spots with three spaces instead of the two this person clearly intended.
Yes, I discovered that, and your edit saved me from having to wrestle with the peculiarities of the Wayback Machine. So extra thanks, David.
Carl
David C.
Shamino
April 27
csz_stl:
I wrote a long comment, and then discovered that the “heracliteanriver.com” article cited by “David C.” said the essentially the same thing…
Sadly, the Heraclitean River site went down many years ago, so if you want to link to any of its pages, you must use the wayback machine.
I’ve updated the link in my quote of your post. You may want to do the same for the original.
I was skimming through the other Heraclitean River articles and I ran across a followup to that original article that I failed to notice before.
It cites a Q&A article from the Chicago Manual Of Style, that tries to make the case that anything other than single-spacing is wrong and should not be permitted.
In the folowup article (The Chicago Manual of Style and a single space after periods), the author (“Heraclitus”) points out how the justification either makes no sense today (as a result of modern publication software) or is inconsequential (the argument could justify either side of the argument).
Ultimately, he comes to a conclusion I share: If you are a publisher, feel free to pick whatever style you think looks best and make sure you hire copy editors who will enforce it (and not just run standard macros over text). But don’t pretend that there’s some scientifically justifiable “best” that you have a moral obligation to impose on the world.
And for anyone who seeks to impose a standard on the rest of the world for informal/internal document writing, get a life.
Ha! One of my gripes with Notes on macOS is that although there’s a simple keyboard equivalent to underline (cmd-u), there’s nothing to strike through. The former should have been banned ever since we gave up typewriters, while the latter is very commonly used in versioning.
This is why people with who have worked in media since the introduction of the Mac don’t double space after a period, or format copy at all other than that which is engraved in stone in the standard style sheet. Someone will have to spend time fixing it. Do it once or twice and either the proofreader or copy editor will politely remind you to stop. A third time and either one or both will beat you over the head with a big stick. A forth means the managing editor, or maybe even the art director, will come over with a machine gun and blow you to bits.
I did a little reading into the influence proportional spacing had on creating HTML, and automatic “whitespace collapse” of double spaces after a period was the default since day one. It takes special coding to preserve double spacing:
For the truly long view, read David Crystal’s excellent book
Making a Point: The Persnickety Story of English Punctuation
He begins when English was written without any spaces, like Japanese, and explores the development of word spacing, punctuation (including the interrobang‽), and various typesetting styles.
Published in US & UK in regular print and ebook
NLS downloadable audio DB 84113; paper braille BR 21585
I’m with @chart. It’s what I learned in typing class some 40 years ago, and it’s just easier for me when I’m reading. This is especially true when I’m searching back through text for something specific. The double space just stands out better. That said, when I submit my papers at school, my essays are submitted without the double spaces. Although I insert double spacing after the periods while drafting, I use Grammarly to do a basic grammar check, which strips out the double spaces. Invariably there is insufficient time to reinsert the double spacing, so I just let it go.
It’s amazing, in this time of “choice” regarding things like abortion, gender, and marijuana, that some want to force everyone typing in English to use a single method. Bill Gates shows his authoritarian tendencies!
It may be simple to distinguish the words, but I hope you agree that no one should need to… It’s nice to have periods, commas and similar niceties, whether in formal writing or informal chat software.
I’m disappointed to find in TidBITS this amount of enthusiasm for the position that there is only one, universal right answer, and that anyone who has an alternative personal practice is wrong. It’s all the more depressing to see the cheerleading for Microsoft and others who are moving to use their powers to enforce the removal of individual choices.
I agree with the postings by David C. Shamino and Ted286, and I would love to see more general availability of the power of LaTeX described by Simon in Word and on the Web.