Gainesbourg, most recently seen in Michel Gondry's The Science of Sleep, infuses the song with qualities of Gondry's sad, surrealist love story.

NPR: Lamenting a Love That Gets Under the Skin

As with most things in life, when it comes to babies and the science of sleep, the only certainty is that there is no certainty.

CNN: Should babies be allowed to 'cry it out'?

And Prof Horne, the author of Sleepfaring: A journey through the science of sleep, says the idea that Victorians got lots of sleep and had a better work-life balance is a myth.

BBC: NEWS | UK | Magazine | Why should we have eight hours' sleep?

You could monitor your sleep using the science of actigraphy but, as we've learned, accelerometers don't always make for the best slumber trackers.

ENGADGET: Sony patent application puts electrodes in a pillow, eases you out of slumber

While the science is in the early stages, one hypothesis suggests that by promoting feelings of safety and security, shared sleep in healthy relationships may lower levels of cortisol, a stress hormone.

WSJ: Who Sleeps Better at Night?