There are some good replies to this already, but I'd like to add another, essentially of my own. As a professor friend of mine once explained, for some reason p

There are some good replies to this already, but I'd like to add another, essentially of my own. As a professor friend of mine once explained, for some reason people seem to want to accept extraordinary explanations over ordinary ones (just look at many commonly held unfounded beliefs). This might be some innate primordial mechanism of the human brain. I don't know, but if there is any truth to it then we must carefully guard against our own bias to make sure we are not unwittingly seeing the results we want to see, hence the need for extraordinary evidence to back up extraordinary claims.