Unity means just plain regular 1 ?

[kahwawashay1]

"unity" means just plain regular "1"?

Im not sure whether this is a physics or math question, but in many physics problems, instead of saying "1", the problem will say "unity", like "the sine of theta is unity" or the "index of refraction is unity". I am assuming "unity" means just plain regular "1"? Is there a particular reason for such funny word use?

 

[tiny-tim]

hi kahwawashay1!

… I am assuming "unity" means just plain regular "1"? Is there a particular reason for such funny word use?

yes, just good ol' "1"

i'm not sure why, perhaps people think that if they write "the sine is one", the reader will think "one of what?", and if they write "1" it looks like I or l …

or maybe they just like to use long words because "1" isn't big enough! ​

 

[Vanadium 50]

Unity is not just "one". It is a "dimensionless one". You can have 1 meter or 1 kelvin or 1 candela, but none of these are properly called "unity".