The cosmos as revealed by science is stranger than we ever could have imagined. Light, time and gravity combine to distort our perceptions of the universe. In Sunday night’s brand new episode of Cosmos: A Spacetime Odyssey we eavesdrop on a conversation between William Hershel and his son in the year 1809.
Hershel was the first person to see a telescope for what it really is; a time machine. As we look up into space we can see the light from stars that no longer exist, it truly is a sky full of ghosts. In one second light travels 186,000 miles, that is nearly the distance between the earth and the moon. The moon is therefore around 1 light second away, so when you next look at the moon, remember that you are looking one second into the past.
With this knowledge, John Hershel grew up to make some rather profound discoveries of his own including photography, preserving the past for future viewing.
Tune into Cosmos: A Spacetime Odyssey ‘A Sky Full of Ghosts’ on Sunday 6th April at 7pm on National Geographic Channel.