"'39" is a song by British rock band Queen. Composed by lead guitarist Brian May, it is the fifth track on their fourth studio album A Night at the Opera. The song was also the B-side to "You're My Best Friend".
The song relates the tale of a group of space explorers who
embark on what is, from their perspective, a year-long voyage. Upon
their return, however, they realise that a hundred years have passed,
because of the time dilation effect in Einstein's special theory of relativity, and the loved ones they left behind are now all dead or aged.