It&#x27;s not a typo. When two ships are moving fast relative to each other, they <i>both</i> determine the other&#x27;s clocks to be ticking slower.<p><a href="http:&#x2F;&#x2F;casa.colorado.edu&#x2F;~ajsh&#x2F;sr&#x2F;paradox.html" rel="nofollow">http:&#x2F;&#x2F;casa.colorado.edu&#x2F;~ajsh&#x2F;sr&#x2F;paradox.html</a>