Philosophy
The Metaphysics of the Void and the Nature of Nothingness
Quick fact
In ancient Greek philosophy, Parmenides argued that 'nothing' cannot be thought or spoken of because thinking and speaking require something to think about and refer to—so in a strong sense, nothingness is impossible and the universe must have always existed.
Why this is interesting
You can imagine an empty room, but can you imagine a truly empty universe—one with no space, no time, no matter, and no laws? What would it even mean for 'nothing' to exist?