3 ms·

Really? For me this always made intuitive sense reading it as one and zero, where zero would be off.

by master-lincoln 3y ago

wodenokoto 3y ago
You probably also work in IT and might even now what binary is not to mention what boolean means.
- master-lincoln 3y ago
  fair point
CalRobert 3y ago
It always seemed backwards to me, since a circle should represent a closed circuit
- lupire 3y ago
  An open circuit would then be a C not a |
  - crazygringo 3y ago
    Those wouldn't be easily distinguishable though.
kragen 3y ago
this is backwards from the perspective of digital logic circuits physical light switches toggle between closed-circuit and open-circuit, not high and low voltage levels. 'on', where current can flow, is a closed circuit; 'off' is an open circuit in digital logic, when there is a correspondence between closed/open and high/low, the correspondence is virtually always that closed is low and high is open. for example: ttl inputs always treat open-circuit as high; the can bus and i²c bus "recessive" states (when nobody is transmitting) are high; avrs have optional pullup resistors on their gpios but no optional pulldowns, so if you want to connect a pushbutton or toggle switch to a gpio, you have to connect it between the pin and ground, not between the pin and vcc; 8051s' 'quasi-bidirectional' i/o ports similarly feature a weak pullup and a strong pulldown, so that, again, an open circuit is a logic high level (and normally high is 1, low is 0, though sometimes this convention is also violated) the only exception i know of is that 60-milliamp and 20-milliamp digital current loop interfaces, as used on teletypes, treat a closed circuit (current flowing) as a logic 1 ('mark'), and an open circuit (no current flowing) as a logic 0 ('space') incidentally, 'closed circuit' and 'open circuit' are also confusing. a closed circuit is 'closed' in the sense that a plane curve is 'closed' if it divides the plane into an inside and an outside region. on a closed curve, you can walk around the whole circuit and return to your starting point without turning around, which is in some sense what the electrical current is doing. but of course actual electrical circuits exist in three-dimensional space, where a 'closed' curve does not divide space into an inside and an outside region, because you need a surface for that. and in all other contexts, something that is 'closed' is something that does not permit flow: a closed barn door, a closed window, a closed valve, etc. nevertheless, it is far too late to eliminate this two-dimensional flatland thinking from our vocabulary
- bee_rider 3y ago
  Oh, of course that must be what closed circuit meant. For some reason I just thought “looks like the switches are little doors, like in a floor plan, and they are all closed now” and I never examined it.
  - kragen 3y ago
    happy to help :)
wolverine876 3y ago
Most people haven't even heard of binary.
- jodrellblank 3y ago
  Silicate chemistry is second nature to us geochemists, so it's easy to forget that the average person probably only knows the formulas for olivine and one or two feldspars. https://www.explainxkcd.com/wiki/index.php/2501:_Average_Familiarity https://www.explainxkcd.com/wiki/index.php/2501:_Average_Fam... See also this comment ( https://news.ycombinator.com/item?id=39344935 https://news.ycombinator.com/item?id=39344935 ) "it's pretty obvious" that computers use the opposite symbol than the name says.
  - wolverine876 3y ago
    Yes indeed. I need to explain to IT people that most users don't even understand hierarchical folder structures; many don't understand folders. They don't believe me. [Edit: deleted possibly rude paragraph]

Really? For me this always made intuitive sense reading it as one and zero, where zero would be off.

wodenokoto 3y ago

You probably also work in IT and might even now what binary is not to mention what boolean means.

master-lincoln 3y ago
fair point

CalRobert 3y ago

It always seemed backwards to me, since a circle should represent a closed circuit

lupire 3y ago
An open circuit would then be a C not a |
- crazygringo 3y ago
  Those wouldn't be easily distinguishable though.

kragen 3y ago

this is backwards from the perspective of digital logic circuits physical light switches toggle between closed-circuit and open-circuit, not high and low voltage levels. 'on', where current can flow, is a closed circuit; 'off' is an open circuit in digital logic, when there is a correspondence between closed/open and high/low, the correspondence is virtually always that closed is low and high is open. for example: ttl inputs always treat open-circuit as high; the can bus and i²c bus "recessive" states (when nobody is transmitting) are high; avrs have optional pullup resistors on their gpios but no optional pulldowns, so if you want to connect a pushbutton or toggle switch to a gpio, you have to connect it between the pin and ground, not between the pin and vcc; 8051s' 'quasi-bidirectional' i/o ports similarly feature a weak pullup and a strong pulldown, so that, again, an open circuit is a logic high level (and normally high is 1, low is 0, though sometimes this convention is also violated) the only exception i know of is that 60-milliamp and 20-milliamp digital current loop interfaces, as used on teletypes, treat a closed circuit (current flowing) as a logic 1 ('mark'), and an open circuit (no current flowing) as a logic 0 ('space') incidentally, 'closed circuit' and 'open circuit' are also confusing. a closed circuit is 'closed' in the sense that a plane curve is 'closed' if it divides the plane into an inside and an outside region. on a closed curve, you can walk around the whole circuit and return to your starting point without turning around, which is in some sense what the electrical current is doing. but of course actual electrical circuits exist in three-dimensional space, where a 'closed' curve does not divide space into an inside and an outside region, because you need a surface for that. and in all other contexts, something that is 'closed' is something that does not permit flow: a closed barn door, a closed window, a closed valve, etc. nevertheless, it is far too late to eliminate this two-dimensional flatland thinking from our vocabulary

bee_rider 3y ago
Oh, of course that must be what closed circuit meant. For some reason I just thought “looks like the switches are little doors, like in a floor plan, and they are all closed now” and I never examined it.
- kragen 3y ago
  happy to help :)

wolverine876 3y ago

Most people haven't even heard of binary.

jodrellblank 3y ago
Silicate chemistry is second nature to us geochemists, so it's easy to forget that the average person probably only knows the formulas for olivine and one or two feldspars. https://www.explainxkcd.com/wiki/index.php/2501:_Average_Familiarity https://www.explainxkcd.com/wiki/index.php/2501:_Average_Fam... See also this comment ( https://news.ycombinator.com/item?id=39344935 https://news.ycombinator.com/item?id=39344935 ) "it's pretty obvious" that computers use the opposite symbol than the name says.
- wolverine876 3y ago
  Yes indeed. I need to explain to IT people that most users don't even understand hierarchical folder structures; many don't understand folders. They don't believe me. [Edit: deleted possibly rude paragraph]