How big is the Universe? | *THE* Great Debate in Physics
26:30
How did the Universe begin? | Great Debates in Physics (Cosmology)
12:07
The Crisis in Cosmology: We Don't Know How Big the Universe Is
19:43
Is light a wave or a particle? | Great debates in physics
14:02
Do ALIENS exist? | An astrophysicist's perspective
26:04
The Great Debate or How Big is the Universe?
12:46
The Speed of Light is NOT About Light
12:09
Where is the anti-matter?
18:31