What's the difference between nothingness and existence?

There's no Yahoo! Answers in nothingness, although I hear they DO have a Starbucks!

Good luck!... ☺

If you think you already know the answer, then why do you ask? Nonetheless, here is my view.

Philosophically, you are asking about the difference between something and nothing. This seems simple enough until you ask whether nothingness itself is something. In the physical realm of things, wherein we regard "something" as having physical dimension, then nothingness has no dimension, yet as a concept or "state of being" it still exists. That in itself gives it existence.

Hmmm. It seems like we cannot help but contradict ourselves and the answer seemingly presents us with an insurmountable obstacle. However, we can find a solution if we take the observer (ourselves) out of the equation. Without an observer to conceptualize what nothingness is, it cannot exist even as a concept. To sum up, the difference between nothingness and existence is whether or not there is an observer to make the distinction.

There is a funny thing about "reality" that one discovers in the study of quantum mechanics, and that is the apparent fact that some states of sub-aromic particles cannot be predicted. Their quantum states can only be determined if they are observed. The observation itself necessarily dictates the outcome, which in itself dictates the state of other sub-atomic particles. In other words, the observed (existence, or reality) requires an observer. Nothingness requires the lack of an observer.

This can bring up some interesting questions in relation to the existence, or lack thereof, of "God", but I won't go there in this answer.

Without existence, nothingness wouldn't exist. Being as that, nothingness would have to be something to be a part of existence. Therefore, nothingness couldn't exist in the first place.

Nothing is something.

Something is everything.

There is no difference here because nothingness does not exist, as there is no duality in the universe. Non-duality means that there is only one principle operating in reality, not two or more, appearances to the contrary notwithstanding. It means that the subject and the objects are actually non-different, although they seem to be different. When we wake up to reality this world disappears. The world of thought and matter is a misreading of pure spirit and nothing more. It has a phenomenal or relative existence superimposed upon Absolute Reality by ignorance and remains superimposed until ignorance is destroyed by knowledge of reality, commonly called Spiritual Enlightenment. This Pure Consciousness is permanent existence, knowledge and bliss and is one with man’s inner self. There is no difference here because nothingness does not exist, as there is no duality in the universe.

Nothingness is a state of sleep without a dream. The existence is a state of awaken state with full consciousness.

Nothingness is eternal, existence isn't.

That's the same as just asking, "What is existence?" Which is possibly the hardest question anyone can ask. I'll be lucky if i can answer that by the time I die. At the moment I can't help you

Nothingness is our origin and our end, existence is only limited.

Zaphod's answer seems the most reasonable.

Consciousness