Four episodes in, and ‘Cosmos’ continues to amaze with the quality of its insights, and its simple way of explaining the mysteries of the universe. The narrative is as poetic as it is scientific, and it in this episode, it was nothing short of awe-inspiring.

“A Sky Full of Ghosts” begins by focusing on the idea that the light we see from stars is old light, traveling to us from over centuries, and indeed hundreds of thousands of millennium. The telescope, Neil Degrasse Tyson explains, is much like a time machine. From there, he talks about the speed of light, and gravity, and then launches into the most flawless layman’s explanation of the Theory of Relativity anyone could ever need. High school science teachers should take note.

For someone who has struggled with trying to understand the concept, the simple five minute segment of Tyson on a bike explaining how speed is measured only relative to other objects, with the universal constant being light, opened a part of a physics that had always been a little closed and obscured to me. This is why this series keeps impressing me.

And if all that science goodness wasn’t enough, Sir Patrick Stewart voiced the famed scientist, William Herschel in this episode.

Anyway, the show keeps in line the theme of its previous three episode by continuing with the idea that inspiration is the key source of science. He talks of who stood on whose shoulders and how ideas came about (like the Theory of Relativity)in a clear attempt to reach out to the next generation of possible scientists.

In short, each episode gets better and more thought provoking. The series, and especially this episode, are well worth the watch.