The Velocity Addition Formula
Velocity Addition Formula Updated: August 3, 2026 On the Electrodynamics of Moving Bodies Einstein-EDoMB-1905-Section §5 https://www.fourmilab.ch/etexts/einstein/specrel/www/ Einstein: Relativity, The Special and the General Theory, 1920, Chapter VI page 19, Chapter XIII page 45 https://www.google.com/books/edition/Relativity/n8QKAAAAIAAJ?hl=en&gbpv=1 Both sources show the velocity-addition-formula as it is today. Shown: V = ( v + w ) / ( 1 + vw/c² ) Chapter VI uses upper case W on the left-hand-side. #### Lorentz Transforms Lorentz Transforms, minus-sign. Derived in EDoMB-1905 Section §3 and used in Section §4, length contraction and time dilation. x′ = gamma • ( x – vt ) t′ = gamma • ( t – vx / c² ) Lorentz Transforms, plus-sign. Used and shown by various text books ( Halliday & Resnick ) in connection with v-a-f derivation. Section §5 explicitly evokes the minus-sign transforms of Section §3, but no LT’s are shown or used. Chapter XIII contains, quote: “Solv...