Q:  What is the number represented by the sequence of vertical (1)
           and horizontal (0) dashes for the line marked with "A"?


             in binary:   1011 0010 0110 0010 1011 1011 0111 1

             in decimal:  374101871



  Q:  The wavelength of the 21-cm hydrogen transition is 21.106 cm.
           Can you figure out the PERIOD of that transition?

                                  c           2.99792458 x 10^(8) m/s
          frequency f21    =  ----------  =  -------------------------
                              wavelength            0.21106 m

  
                           =   1.4204 x 10^(9)  Hz


                                 1
           period  P21     =   -----  =  7.04020 x 10^(-10)  seconds
                                 f


  Q:   What is the period of the pulsar indicated by the line
           marked with "A", in seconds?


             pulsar period  P  =  P21  *  374101871
       
                               =  7.04020 x 10^(-10) s  *  374101871

                               =  0.26338 seconds