c = 10.;
v = \[Tau];
p1 = Table[
   Graphics[{Disk[{v \[Tau], 0}, 1], 
     Table[Circle[{v t, 0}, c (\[Tau] - t)], {t, 0, \[Tau], 0.5}]}, 
    PlotRange -> {{-50 + v \[Tau], 50 + v \[Tau]}, {-50, 50}}, 
    PlotLabel -> 
     Style[StringForm["v\!\(\*SubscriptBox[\(=\), \(``\)]\)c", 
       N[v/c, 3], \[Tau]], Medium, FontFamily -> "DejaVu Serif"], 
    LabelStyle -> {Black, Bold}]
   , {\[Tau], 0, 15, 0.04}];
ListAnimate[p1]

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This file, which was originally posted to https://twitter.com/j_bertolotti/status/1030470604418428929, was reviewed on 24 November 2018 by reviewer Ronhjones, who confirmed that it was available there under the stated license on that date.