I am small as an ant and big as a whale,
I can soar through the air like a bird with a tail.
I can be seen by day and not by night,
I can be seen with a big flash of light.
I follow whoever controls me by the sun,
but I fade away when dark fell like a ton.
What am I?
If 7 is transformed into 13 and 11 is changed to 21 then what does 16 become?