I am watching right now a documentary of BBC about the nature of Nothingness. Well you it seems that you can create nothing or vacuum or as it typically called EMPTY SPACE, by using Mercury ( the one in the thermometer not the singer) . Well we know that Brian who wrote the lyric is a lot into physics and of course the song was dedicated to Mercury( the singer this time) .So could that lyric be a smart reference or i am just reading wayyyy too much. Or maybe bouth.
The documentary by the way is on you tube. Or here link ( after 5:50 is the Mercury-Empty Space experiment)
I think the lyric "empty spaces" is a Pink Floyd reference. The title of the song is the same as the title of a song of Pink Floyd's album "The Wall", and another song on that album is titled "Empty Spaces", which I believe is no coincident.
There was also a song on The Wall called The Show Must Go On, which was notable for having Queen-like harmonies not typical of Pink Floyd compositions at the time! Plus, Brian and David Gilmour are good friends, and since Brian was the main composer of TSMGO there was probably quite a few deliberate nods towards the Floyd :-)
In the first clause of my second sentence in my previous post, I was referring to the song "The Show Must Go On".
Anyway, I believe that the entire Innuendo album is quite Pink Floyd inspired, or at least a tribute to progressive rock.