The Velocity Addition Formula
Velocity Addition Formula Updated: October 19, 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. #### Left-hand-side output As in most of SRT, we use right-to-left equation logic ( an assignment operator so-called ) rather than left-to-right equality, an identity. Assignment: 5 = 2 + 3 Identity: 2 + 3 = 5 Arrow: Bring in an arrow ← for right-to-left assignment: Left ← Right 5 ← 2 + 3 #### Classical versus SRT SRT = spezielle Relativitätstheorie, Special Relativity Asterisk: Use plain-V for classical mechanics and V*-asterisk for SRT. Classical addition: V ← ( v + w )...