Recent content by Raymond Beljan

That "ball placed on a rubber sheet" analogy is one I wish would not be used. Why? Well even if the curved rubber sheet is analogous to curved spacetime, the analogy is often accompanied by rolling a small ball on the sheet to show the effect of curvature. The small balls motion then depends on...

Well actually the kronecker delta but one minus sign. As noted by Ibix (I think) metric with diagonal [-1,1,1,1]

Oh, I should add that for a locally flat space the metric is the kronecker delta and the first derivitives of the metric are zero.