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So I used to think covariance and contravariance were related to covectors and vectors from physics, but in fact, our terminology is in fact confusing the conce

So I used to think covariance and contravariance were related to covectors and vectors from physics, but in fact, our terminology is in fact confusing the concept (almost "opposite" actually) that is now accepted in math. (See comment on wiki[0]). There we physicists go, confusing things again. [0] https://en.wikipedia.org/wiki/Functor#Covariance_and_contravariance https://en.wikipedia.org/wiki/Functor#Covariance_and_contrav...

jacobolus 9y ago
As they say, a comathematician is a device for turning cotheorems into ffee. If you’re interested in vectors/tensors, the relevant Wikipedia page is https://en.wikipedia.org/wiki/Covariance_and_contravariance_of_vectors https://en.wikipedia.org/wiki/Covariance_and_contravariance_...
filmor 9y ago
In this case it's the Category Theorists confusing things. Co- and contravariance of vectors with respect to their scale was introduced in the 1850s by Sylvester, Category Theory was formulated roughly 90 years later.