I believe in the power of the unknown. I believe that asenseof the   (1)   inspires us in all of our creative activities, from  (2)  to art.

When I was a child, after bedtime I would often  (3)  my bed in my sleeping clothes, go to the  (4)  and stare at the stars. I had so many questions. How far away were those tiny points of light? Didspace go on_  (5)  and ever, or was there some end to space, some giant edge? And if so, what  (6)  beyond the edge?

  (7)  of my childhood questions: Did  (8)  go on forever? I looked at pictures of my parents and grandparents and tried to  (9)  their parents, and so on, back through the generations, back and back through time. Looking out of my bedroom window  (10)  _the endlessness of space, time seemed to spread forward and backward  (11)  , swallowing me, swallowing my parents and great-grandparents, the whole  (12)  of earth. Does time go on forever? Or is there some  (13)  of time? And if so, what came before?

When I  (14)  , I became a professional astrophysicist.  (15)  I never answered any of these questions, they continued to  (16)  me, to affect me, to drive me in my scientific research, to cause me to live on just fish and no sleep for  (17)  at a time while I was  (18)  a science problem. These  (19)  questions, and questions like them, challenge and never leave the leading__  (20)  of today.