Named after the ancient Roman goddess of beauty, Venus is known for its exceptional brightness. Find out about the volcanoes that dot Venus's surface, the storms that rage in its atmosphere, and the surprising feature that makes Venus outshine every planet or star in the night sky.

Sheldon knocks Leonard's door at night and tells him that he doesn't feel so good. He thinks it's a serious problem, but it turns out to be gas.

Penrose describes his black hole theory, which sparks an idea in Stephen's mind. Stephen reverses Penrose's theory and develops one of his own. Stephen suggests that the universe was born from a black hole exploding. The black hole has such strong space-time singularity that nothing can escape from it, even light. The black hole is triggered by the collapse of a star.

This song discusses Tarzan's fascination with the wider human world he has yet to see. During the song, he looks through a telescope and sees the Great Comet of 1882.

This clip takes us into the universe through a series of steps, with each step being 10x larger than the previous. It illustrates the vastness of the universe and that increasing the field of view by a power of 10 makes a dramatic change in what we see.