Not sure if this is the right area to post this, sorry!
I'm doing a 3rd year Uni (Physics) module on Theoretical Elementary Particle Physics and this is the first time I've had to use 4-vector notation, which I've struggled with grasping.Can anyone recommend any good resources for understanding it? I've looked over my lecture notes and googled resources from other Unis but I keep getting lost amongst the notation!
I don't quite understand the difference (or use) between metrics, gradients, and scalars. I understand them in the typical sense of course (scalars have no direction, gradients represent change.. not sure about metrics except in vague a space-time sense), just not in this new sense.
Also, there's an exercise of making a scalar by using a contra-variant vector and a co-variant vector, but I am not sure how it shows that scalars are the same in all (or 2) frames of reference.
Thanks for any help!
Would you pay less for a humanities degree?