At least when it comes to physical reality, which I define here as that which exists in the cosmos, there is no such thing as complete emptiness.
Quite the opposite, it seems that the more we learn about nature, the busier space becomes. We can, of course, contemplate the idea of a metaphysical emptiness, a complete void where there is nothing, what some people like to call absolute nothingness. But these are concepts we make up, not necessarily things that exist. In fact, calling nothingness a "thing" automatically makes it into a something, a curious paradox.