Columns: Condition/Parameter | Coordinate velocity v dx/dt in units of c | Velocity angle η in i-radians | Proper velocity w dx/dτ in units of c | Lorentz factor γ dt/dτ = E/mc 2
Momentum = ½mc ⇔ 0.5 map-lightyear/traveler-year | 1/√5 ≅ 0.447 | ln[(1 + √5)/2] ≅ 0.481 | ½ | √5/2 ≅ 1.118 | Rapidity of 0.5 hyperbolic radian | (e − 1)/(e + 1) ≅ 0.462 | ½ | ½(√e − 1/√e) ≅ 0.521 | ½(√e + 1/√e) ≅ 1.128 | Momentum = mc ⇔ 1 map-lightyear/traveler-year | 1/√2 ≅ 0.707 | ln[1 + √2] ≅ 0.881 | 1 | √2 ≅ 1.414 | Rapidity of 1 hyperbolic radian | (e 2 − 1)/(e 2 + 1) ≅ 0.761 | 1 | ½(e − 1/e) ≅ 1.175 | ½(e + 1/e) ≅ 1.543 | Kinetic energy = mc 2 ⇔ 2 map-years/traveler-year | √3/2 ≅ 0.866 | ln[√3 + 2] ≅ 1.317 | √3 ≅ 1.732 | 2 | Momentum = 2mc ⇔ 2 map-lightyears/traveler-year | 2/√5 ≅ 0.894 | ln[2 + √5] ≅ 1.444 | 2 | √5 ≅ 2.236 | Rapidity of 2 hyperbolic radians | (e 4 −1)/(e 4 +1) ≅ 0.964 | 2 | ½(e 2 − 1/e 2 ) ≅ 3.627 | ½(e 2 + 1/e 2 ) ≅ 3.762