I'm on the verge of ripping my hair out(adsbygoogle = window.adsbygoogle || []).push({});

I understand the basics of tensors but I just can't get my head around the need have having contra and covariant vectors.. what is the point??! A vector is a vector right? why have a sub and superscripts why can't they just stick to one or the other??? I've read the definitions for both in so many text books and they all define them by the way they can be transformed but it still makes no sense to me. Is there a good website or book that explains the use of these and how they relate to cosmology??

thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# So confused: Tensors and reletivistic cosmology

**Physics Forums | Science Articles, Homework Help, Discussion**