Albert_Einstein
Disgyrchiant
Twll_du
Gofod-amser
Perthnasedd_cyffredinol
Cyflymder_golau
David_Hilbert
Deddf_disgyrchedd_cyffredinol_Newton
Ton_ddisgyrchol
Gofod_pedwar_dimensiwn
Perthnasedd_arbennig
Microlensio_dwysterol