Emptiness is not nothingness

"While the Buddha did teach that the nature of the mind—in fact, the nature of all phenomena—is emptiness, he didn't mean that their nature was truly EMPTY, like a vacuum. He said it was emptiNESS, which in the Tibetan language is made up of two words: tongpa-nyi. The word tongpa means "empty," but only in the sense of something beyond our ability to perceive with our senses and our capacity to conceptualize. Maybe a better translation would be "inconceivable" or "unnamable." The word nyi, meanwhile, doesn't have any particular meaning in everyday Tibetan conversation. But when added to another word it conveys a sense of "possibility"—a sense that anything can arise, anything can happen. So when Buddhists talk about emptiness, we don't mean nothingness, but rather an unlimited potential for anything to appear, change, or disappear."

–Yongey Mingyur RInpoche, "The Joy of Living," Chapter Four: Emptiness: The Reality beyond Reality