3 ms·
> What’s 20° + 1 radian? They’re both unitless quantities that have compatible dimensions. How are they unitless if you add ° behind one and "radian" behind t
by ajuc 6y ago
> What’s 20° + 1 radian? They’re both unitless quantities that have compatible dimensions.
How are they unitless if you add ° behind one and "radian" behind the other?
- croutonix 6y agoThey're not unitless, they're dimensionless, see https://math.stackexchange.com/questions/803955/why-radian-is-dimensionless https://math.stackexchange.com/questions/803955/why-radian-i.... I think the author made a mistake.
- tantalor 6y agohttps://en.wikipedia.org/wiki/Radian https://en.wikipedia.org/wiki/Radian > the SI unit for measuring angles > defined in the SI as being a dimensionless value
- bjz_ 6y agoRelevant wikipedia article: https://en.wikipedia.org/wiki/Dimensionless_quantity https://en.wikipedia.org/wiki/Dimensionless_quantity Radians and degrees are both ratios where the units cancel out - ie. m/m. The point that is made is that adding degrees to radians without any conversions is technically fine from a dimensional analysis perspective, but it's often a bug in programming that we might want to prevent.
- ajuc 6y agoYou can define 1 meter as ratio between the measured length and a known length. Both of these have the same units so they cancel out, just like with degrees/radians. The only difference is that full circle is a little less arbitrary than Earth circumference.