No, the one-inside-a-circle symbol does <i>not</i> indicate a toggle between off and on, as this article "surmises".<p>Instead, it indicates <i>stands by</i>. This is off, but not fully off as a circle would suggest. It's nearly on. The symbol is great for that.<p>On a push button it means activate stand by or come back out of it (i.e., turn back on fully). Still fair enough.<p>Unfortunately, this knowledge has watered down over time. I've seen that symbol used more than once for a button that <i>only</i> turns on a device (never back to stand by). That's pretty much the opposite of its original meaning.
The 1/0 thing confused me for a while because 0 looks like a circuit (on), and 1 doesn't (0ff). I was also taking electrical engineering classes at the time, and the 1/0 true/false thing was already halfway arbitrary because of active-low pins, and even in software land, "return 0" could mean either true or false depending on the context.
And it is now in Unicode thanks (in part) to HN.<p><a href="https://unicodepowersymbol.com/we-did-it-how-a-comment-on-hackernews-lead-to-4-%c2%bd-new-unicode-characters/" rel="nofollow noreferrer">https://unicodepowersymbol.com/we-did-it-how-a-comment-on-ha...</a>
There is an exhibit right now at the Cooper Hewitt Design Museum in NYC about
the work of Henry Dreyfuss did with his Symbol Sourcebook (<a href="https://www.cooperhewitt.org/channel/give-me-a-sign/" rel="nofollow noreferrer">https://www.cooperhewitt.org/channel/give-me-a-sign/</a>) which heavily influenced the design of most symbols we use today, including this one.<p>You can view most of the exhibit online: <a href="https://collection.cooperhewitt.org/exhibitions/2318807647/" rel="nofollow noreferrer">https://collection.cooperhewitt.org/exhibitions/2318807647/</a><p>Worth taking a look!
There are other, sometimes contradictory conventions.<p>In the USA, a standard wall switch is moved "up" for on and "down" for off whereas in Europe it's the opposite. Always wondered how that came to be.
I've noticed that lots of appliances now use the On/Off power symbol to mean start/stop the appliance, <i>not</i> cutting off power.<p>Stuff like coffee makers etc. It's weird.
The one I REALLY HATE is the paper orientation icon on printer paper trays. Ones like these:<p><a href="https://static.thenounproject.com/png/4256363-200.png" rel="nofollow noreferrer">https://static.thenounproject.com/png/4256363-200.png</a><p>Do the lines on the paper mean<p>"insert the side that already has writing face up, and the side that is blank face down"<p>OR<p>"these lines represent what will happen after you print but they're just being represented here for your imagination purposes even though they aren't there yet so you should really put the blank side up even though we are drawing lines on the up side"
No discussion about use of 0/1 for power switches is complete without mention of the original IBM 5150 (original PC) power switch, which is the first place I ever remember seeing the "binary" 0/1 used to mean "power on / power off" on electronics.
There are challenges inherent in creating a set of visual symbols to communicate. We have crossed that bridge before and we call them "words".<p>I wish designers might fall back on that more for ease of use instead of creating generation after generation of arcane, fleetingly extant symbols.