Full Idea
It would be impossible to verify directly that the rotation of the earth would continue if everyone in the universe were sound asleep, yet it is clearly possible that everyone in the universe should at some time be sound asleep.
Gist of Idea
We couldn't verify the earth's rotation if everyone simultaneously fell asleep
Source
Sydney Shoemaker (Time Without Change [1969], p.59)
Book Reference
Shoemaker,Sydney: 'Identity, Cause and Mind' [OUP 2003], p.59
A Reaction
Another beautifully simple argument from Shoemaker against anti-realism (cf. Ideas 8595, 8956). This one is nice because it is so obviously possible, given that everyone able to know of the earth's rotation also seems to need sleep.
Related Ideas
Idea 8595 If three regions freeze every 3rd, 4th and 5th year, they all freeze together every 60 years [Shoemaker]
Idea 8596 Inability to measure equality doesn't make all lengths unequal [Shoemaker]