Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!ut-emx!ethan From: ethan@ut-emx.UUCP (Ethan Tecumseh Vishniac) Newsgroups: sci.space Subject: Re: approaching "C" Summary: I may regret getting into this Message-ID: <10116@ut-emx.UUCP> Date: 2 Feb 89 15:19:18 GMT References: Organization: The University of Texas at Austin, Austin, Texas Lines: 22 In article , rg20+@andrew.cmu.edu (Rick Francis Golembiewski) writes: > Here's a question I've alaways wondered about relativity: > Suppose there are two space ships, one going at .6 C (an attainable > theoretical velocity) and one going .6 in the opposite direction, > what would observers inside each see? Each one would see the other receding at a velocity of 1.2/1.36 times c. Velocities do not add in the simple way you are used to. The correct formula to apply involves dividing the sum by one plus the product of the velocities (as fractions of c). -- I'm not afraid of dying Ethan Vishniac, Dept of Astronomy, Univ. of Texas I just don't want to be {charm,ut-sally,ut-emx,noao}!utastro!ethan there when it happens. (arpanet) ethan@astro.AS.UTEXAS.EDU - Woody Allen (bitnet) ethan%astro.as.utexas.edu@CUNYVM.CUNY.EDU These must be my opinions. Who else would bother?