Kate Mulgrew

Narrator

Michio Kaku

Himself

Lawrence Krauss

Himself

Charissa Saverio

Hologram

Julian Barbour

Himself

Robert J. Bennett

Himself

John Byl

Himself

Bernard J. Carr

Himself

George F.R. Ellis

Himself

John Hartnett

Himself

Ron Hatch

Himself

Martin Selbrede

Himself