It is not the burden of the disbeliever to prove or disprove anything. After all, if I believed on leprechauns, and you didn’t, then how would you prove that they do not exist?
Would you say the reason is that you have never seen one? Because there is no evidence? Quantifiable, scientifically measureable evidence? Because the concept is plain silly? What if I present you with a series of credible eye witnesses that believe that they have seen a leprechaun (there must be a few of those available this weekend… ) Would you say that you have to believe then? Maybe if I had a video of a small man in Irish garbs jumping with a pot o' gold?
I do not believe in Extra-Terrestrial visitations, not because I refuse, or because I think Alien life is impossible, but because there is no scientific hard evidence that supports any of it.
I don’t doubt the account of most honest people about it. I do think they believe they saw what they saw. But there is certainly a factor of sudden observation of unknown phenomena, then drawing a conclusion about it just based on a gut feeling that really puts them in the same category as believing the Earth is flat, because that is what you see… and you KNOW what flat looks like. There are indeed many unexplained things… but of the millions of things that do get explained with time, how many have been definitively explained by reason of being caused by ghosts, aliens, leprechauns, etc…??
Then there’s the science. Whenever something needs to recur to declaring science principles and the scientific method flawed because it doesn’t fit the observation, then we fall on the same trap the Church fell when condemning Galileo… because his findings contradicted the Bible.
It really puzzles me when the most simple explanation is ignored, just because it does not fit the observer’s conclusions. Out of an event that may have a much greater probability of being caused by technology developed in this planet, vs. something from another galaxy that, just the fact of traveling the distance between such galaxies would be an practical impossibility based on solid physics laws, we choose the extraterrestrial explanation? Really?
And there the lack of evidence… Video? Photographs? Why would anyone fake those, right? It’s not like a newspaper or magazine would pay anything to publish those… And we know faking them has never happened before and… ok, I’ll stop with the irony here.
Then there’s the conspiracy part of it. There have been many far worse things that governments would not like you to know about, and they come to light (Watergate anyone?, Soviet Union massacres during WWII?). But of course, since the evidence of all those crashes and alien bodies seem to escape everyone else every single time, they must be focusing in doing a great cleanup job ONLY on the Extraterrestrial ship crashes…and Bigfoot…the cleanup after Bigfoot dung is a massive government enterprise.
So believers… just present the simplest measurable (by independent entity), repeatable, solid piece of evidence (not circumstantial, or anecdotal), and I will believe too.
Finally, a little philosophical discussion on the apparent proof or disproof of something based on not having evidence about it:http://en.wikipedia.org/wiki/Argument_from_ignorance