Comment: v ∼ I sp {\displaystyle v\sim I_{\text{sp}}} v\sim I_{\text{sp}}, such that ( 1 − I sp v c 2 ) ∼ ( 1 − v 2 c 2 ) {\displaystyle (1-{\frac {I_{\text{sp}}v}{c^{2}}})\sim (1-{\frac {v^{2}}{c^{2}}})} (1-{\frac {I_{\text{sp}}v}{c^{2}}})\sim (1-{\frac {v^{2}}{c^{2}}}) = teleporation