Einstein's Mass-Energy Equivalence

[quasar987]

........

 

[dextercioby]

Who's ita_{0,x,y,z) ??

Daniel.

 

[quasar987]

As it often happens I found the answer to my question while typing it

\eta was for the proper speed... i.e. \eta_{0,x,y,z} are the components of the four-velocity. What symbol do you use?

 

[dextercioby]

Ita is for the metric...u_{\mu} is the four-velocity...

Daniel.

 

[quasar987]

What's a 'metric' ?

 

[dextercioby]

A distance,in mathematics (a metric space is a topological space with a metric)...Here,in physics jargon,it stands for the metric tensor g_{\mu\nu} for spacetime and for the flat Minkowski spactime \eta_{\mu\nu}

Daniel.

 

[krab]

quasar: \eta is pronounced like something between etta and ayta; not eeta.

 

[dextercioby]

In Neogreek it is pronounced ITA (eeta,if u want to).True,in Anciant Greek it's ETA...

Daniel.