Straight Dope Message Board > Main Are there any regional variations in angle measure?
 Register FAQ Calendar Mark Forums Read

#1
04-23-2012, 09:17 PM
 Derleth Guest Join Date: Apr 2000
Are there any regional variations in angle measure?

OK, we all know average people tend to use either degrees or turns to measure angles, whereas mathematicians use radians, some other people use gradians, mils, or both, and there are other standards besides (points for boxing the compass, quadrants for studying your geometry, etc.).

My question is, are any of these more or less popular based on region, the way SI units give way to Imperial and/or US units based on where you go in the world?
#2
04-24-2012, 04:11 AM
 Nava Guest Join Date: Nov 2004
... Spaniards generally measure them in degrees (sexagesimal ones, the kind where a full circle is 360º), although we're taught about radians and centesimal degrees in school... what's a turn?
#3
04-24-2012, 08:50 AM
 FatBaldGuy Charter Member Join Date: Jan 2001 Location: SLC, USA Posts: 4,029
I suppose if you say, "Rotate the wheel a quarter turn clockwise," that would be equivalent to 90 degrees, but I've never heard anyone actually using that as a way of measuring degrees. Is this what the OP is referring to?
#4
04-24-2012, 10:28 AM
 Candyman74 Registered User Join Date: Sep 2008
Degrees. I've never heard of "turns".
#5
04-24-2012, 11:03 AM
 Derleth Guest Join Date: Apr 2000
I suppose the 'turn' system is so informal nobody recognizes it as a system of angle measure.
#6
04-25-2012, 08:54 AM
 ftg Guest Join Date: Feb 2001
Two realms where angles are expressed differently are in grade (usually in % slope but other systems are used) and in roof slopes using a ratio. But they seem to be fairly universal in Western society. Anyone know if other cultures use their own versions for these?
#7
04-25-2012, 08:55 AM
 Candyman74 Registered User Join Date: Sep 2008
Quote:
 Originally Posted by Derleth I suppose the 'turn' system is so informal nobody recognizes it as a system of angle measure.
So are you actually going to tell us what this "turn" system is, or is it a secret?
#8
04-25-2012, 08:59 AM
 johnpost Guest Join Date: Jul 2009
a turn is 360 degrees.
#9
04-25-2012, 09:34 AM
 Nava Guest Join Date: Nov 2004
Quote:
 Originally Posted by FatBaldGuy I suppose if you say, "Rotate the wheel a quarter turn clockwise," that would be equivalent to 90 degrees, but I've never heard anyone actually using that as a way of measuring degrees. Is this what the OP is referring to?

Quote:
 Originally Posted by Derleth I suppose the 'turn' system is so informal nobody recognizes it as a system of angle measure.
That's what happened to me, yes. Not only is it informal, but extremely imprecise. Quarter turns and half turns are on the same metrological league as pinches of salt and small amounts of sugar. I might use it to give instructions on how much to rotate something, but not to measure how much it was actually rotated.
#10
04-25-2012, 09:42 AM
 Derleth Guest Join Date: Apr 2000
Quote:
 Originally Posted by Candyman74 So are you actually going to tell us what this "turn" system is, or is it a secret?
One turn is 360°, smaller angles are expressed as fractions thereof, and direction is usually expressed in terms of either left-hand/right-hand or counterclockwise/clockwise (or, if you speak Commonwealth English, anticlockwise/clockwise).

It's fundamentally equivalent to radians if you replace pi with tau.
#11
04-25-2012, 09:56 AM
 Pleonast   Charter Member Join Date: Aug 1999 Location: Los Obamangeles Posts: 4,979
There's also "revolutions" and "cycles" for measuring rotations.
#12
04-26-2012, 04:59 PM
 Candyman74 Registered User Join Date: Sep 2008
Quote:
 Originally Posted by Derleth One turn is 360°, smaller angles are expressed as fractions thereof, and direction is usually expressed in terms of either left-hand/right-hand or counterclockwise/clockwise (or, if you speak Commonwealth English, anticlockwise/clockwise). It's fundamentally equivalent to radians if you replace pi with tau.
So you'd say "turn the wheel a quarter of a turn to the left"?
#13
04-26-2012, 05:12 PM
 scr4 Guest Join Date: Aug 1999
Actually my colleagues and I often use "turns" when working in the lab, when turning adjustment knobs on various instruments. Often one rotation of the knob doesn't translate to a physical quantity, but we still want to record how far it was turned. I've been in situations where I was recording at a resolution of 1/16 turn.
#14
04-26-2012, 06:03 PM
 Disheavel Guest Join Date: Nov 2006
Quote:
 Originally Posted by scr4 Actually my colleagues and I often use "turns" when working in the lab, when turning adjustment knobs on various instruments. Often one rotation of the knob doesn't translate to a physical quantity, but we still want to record how far it was turned. I've been in situations where I was recording at a resolution of 1/16 turn.
I hadn't really thought about it, but we do something similar around the lab and my house too. Except we do it in terms of "hours". as in "I turned it about 4 hours clockwise/forward". We find it works better for things more than a 6 hour turn to decrease ambiguity and works well in breaking up the circle into mentally recognized fractions.
#15
04-27-2012, 12:02 AM
 Monty Straight Dope Science Advisory Board Join Date: Feb 1999 Location: Maoming, China Posts: 16,811
My car's navigation system gives turn directions as "Turn left" for a turn to 270 degrees, "Turn right" for a turn to 90 degrees, and the face of the clock for other turns (e.g., "Turn right in the direction of One O'clock" for a turn to 30 degrees).

 Bookmarks

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is Off HTML code is Off
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Main     About This Message Board     Comments on Cecil's Columns/Staff Reports     Straight Dope Chicago     General Questions     Great Debates     Elections     Cafe Society     The Game Room     In My Humble Opinion (IMHO)     Mundane Pointless Stuff I Must Share (MPSIMS)     Marketplace     The BBQ Pit Side Conversations     The Barn House

All times are GMT -5. The time now is 11:33 AM.