     drop ;
 
 : medium ( -- )
-    bubble-chamber new
+    <bubble-chamber>
     { 400 400 } >>size
-    randomize-collision-theta
-    dup start-bubble-chamber-thread
     dup "Bubble Chamber" open-window
 
     100 [ <muon>   add-particle ] times

    drop ;

: large ( -- )
    bubble-chamber new
    { 600 600 } >>size
    randomize-collision-theta
    dup start-bubble-chamber-thread
    dup "Bubble Chamber" open-window

    550 [ <muon>   add-particle ] times

: original-big-bang ( -- )
    <bubble-chamber>
    { 1000 1000 } >>size
    dup "Bubble Chamber" open-window

    1789 [ <muon>   add-particle ] times
