Is it possible to prove that something DOESN'T exist?

Answer 1

The word 'proof' is a slippery one. There isn't really any way to prove ANYTHING beyond any concievable doubt (try to prove that the sun is going to come up tomorrow, or that I exist). Ask your typical solipsist.

On the other hand, it IS quite possible to prove any number of things to a reasonable degree of certainty. You can even prove that some things don't exist to a reasonable degree of certainty, such as things that violate physical laws as we know them (I am reasonably certain that there are no elephants in my pants).

But absolute proof lies only in the realm of the imagination. The real world is just too messy.

Answer 2

Well, there are some things that are relatively easy to prove don't exist: simple logical contradictions. For example, I could prove that there are no married bachelors, or that there are no round squares. Arguably, you could empirically prove that there are no 1000 foot tall gorillas on Earth (and, more arguably, anyplace else, since a 1000-foot gorilla-like creature in Alpha Centauri would not bear a sufficient causal connection to our use of the word "gorilla" to count as one).

Also, you have to be careful about what you mean by "prove": if you mean something like having absolute and mathematical certainty, then you will be unable to prove the existence or non-existence of almost anything: that thing you think is your couch may be an alien disguised as a couch, a figment of your imagination, a product of a diseased mind, or a deception created by an evil demon.

If, however, by "proof" you mean something more reasonable, like "highly confirmed" or "highly likely", then you can "prove" the non-existence of a number of things. It's generally much easier, under this definition of proof, to prove that things exist rather than that they don't. But I think that the proposition "there are no living dinosaurs" has been proven, at least to my satisfaction.

Answer 3

If you identify the particular construct and prove that the construct cannot exist then it is possible to prove something doesn't exist.

For example, is it possible to prove the World Trade Center doesn't exist? Go to the former location and point at the missing buildings.

Otherwise, you can only 'prove' something doesn't exist by proving the impossibility of its existence. For example, can you prove there has never been a 6,000 foot tall steel office building no larger than a city block? Well, it can be shown with exactitude that for a building of that size steel can't be raised that high - the steel would collapse upon itself because of the weight - thus it is possible to prove such a condition.

In all of these cases though, we are only 'proving' nonexistence of something based upon the existence of something else, e.g. a fact which makes the particular proof of the existence of the item in question impossible. Without this condition - something else proving impossibility - it's generally not possible to prove something doesn't exist.

However, be advised that just because someone can't prove something does not exist does not necessarily prove it does exist. Nor does it fail to 'prove' it does not exist. When someone makes the proposition of the existence of something, it is beholden upon them to prove the existence of the thing in question, not for someone to prove it can't exist.

This is why when people make the argument in favor of the existence of God, it is their responsibility to provide proof she exists, not for the person who disagrees to prove that she doesn't.

Answer 4

No, you cannot prove anything with absolute certainty.
There is a huge gulf between certainty and beyond any reasonable doubt. So the question is... what level of doubt are you prepared to accept?
Try it for yourself... try to prove the non existence of unicorns, fairies or leprechauns. By the laws of logic it is impossible to prove the non-existence of anything. You have not been everywhere in the universe at every time that has been (unless you happen to be God... and I'm making the rash assumption that you are a mere mortal).

Oh, If you are God do I have a bunch of questions for you!

Answer 5

To who? Nothing can be proved to anyone. You either keep a current belief or change to another. Nothing is proved. You can't even define existence much less force another to believe something about how 'things' operate in that undefined environment. You are only talking about argument and persuasion. If enough people believe in either direction then it becomes the norm. Persuade enough people to believe a 'something' doesn't exist and it will be considered proved.

Answer 6

I have found (as well as other people throughout history) that in many cases, in proving that something does not exist, one will actually prove that that said issue or thing or being does exist.

Good luck, though, in finding out whatever it is you want to exist.

Answer 7

It is impossible to prove that something does not exist.
The human mind cannot grasp the concept of nothingness. Furthermore, the human mind cannot look at the world without time.
In order to prove something does not exist the human mind must conceptualize this or that thing to either be nothing or to not be without time which it cannot!

Answer 8

You can never prove the null case.

To do so would mean having examined every bit of time and space, which so far as we know are infinite.

For that reasons maintenance, safety etc. are often neglected until harm is done.

Politicians are adept at using the flip side of the coin, taking credit for things that do not happen, because you cannot prove that they would not have happened in an event.

Answer 9

I would say yes, depending on what it is. For certain things its just someone's opinion on whether or not somethings does exist or not. No matter what there's always going to be people who will believe in certain things that really don't exist. This is actually a very tough question to answer since I don't have a specific topic to say for myself whether "it" exists or not. No matter what you are trying to disprove there will always be people trying to prove that to you.

Answer 10

Yes, you can. If something can't exist because something else exists, and if the second thing DOES exist, you've proven that the first one DOESN'T exist. Other than that, I don't think you can prove your point.
Hope this helps,
-Matt