New book documents UFO sightings - are we alone in the universe?

What can we conclude from existing UFO sightings?

A new book published by Haynes - a company involved in the publication of car manuals since 1956 - looks at a much less down-to-earth type of vehicle than they're usually involved with. The 'Haynes UFO Investigation Manual' looks into thousands of reported UFO sightings, and painstakingly documents even the most unlikely. The book also looks at Ministry of Defence information and attempts to understand all that we know for sure about the subject matter.

The concept of men from Mars and alien life forms from other planets travelling through the universe at tremendous light speeds to visit our planet has been the subject of science-fiction and speculation for many decades now. So as this new documentation of UFO sightings is released, can we consider any of the sightings to be credible? Have we really been visited on Earth by little green men? Or is it all a load of nonsense?

The first thing to say about this matter is that it would be extremely naive, and indeed arrogant, to suggest that we understand everything in the universe, or indeed even that we're capable of perceiving everything that exists with our senses. Mainstream science would tell us quite clearly that both of these assertions are entirely erroneous. Dark matter, for example, exists beyond the parameters of human eyesight, while anyone with a pet dog will know that they can hear many things that we cannot.

Therefore, the boundaries of the possible are beyond what we often perceive them to be, and in an infinite universe, there must be a great deal of possible life forms. It is frequently asserted that such an unfathomably immense universe would obviously be capable of supporting a variety of intelligent life, some of which could presumably be more intelligent than human-beings. Although some scientific efforts have been made to debunk this, it would seem to be simply self-evident according to the law of averages, if we assume for the sake of argument that the universe is infinite.

However, it is reasonable to assert the vast majority of UFO sightings are not alien spacecraft. If they were, then one would really expect to have seen something a bit more solid by now than lights in the sky, and so forth. In fact, the lack of solid evidence of anything actually resembling a physical part of an alien spacecraft or the physical body of an intergalactic being, would be the biggest piece of evidence that would be cited by sceptics.

Nonetheless, it is incorrect to assert that every UFO phenomenon that has been reported has been satisfactorily accounted for. This would seem to be impossible for human-beings, beyond the scope of our intellect and limited senses. It is at this point that I'd like to remind readers what the term UFO actually stands for - Unidentified Flying Object. The implication is often that UFO literally means alien spacecraft, which of course it does not. All it means is something moving in the sky which cannot be identified.

In the most accurate sense of the term, we have witnessed thousands of UFOs, because there are thousands of strange phenomena that have been witnessed by people which have never been definitively explained. In some cases, people have put explanations forward, but the fact that many of these explanations differ indicates our lack of certainty on the subject.

In a world in which in universal terms, humans are as blind as bats, and even the immense force of nature which is our collective brain power struggles to comprehend the concept of an infinite universe let alone the implications, there will always be occurrences and events that defy convincing explanation. It would be extremely stupid to assume that aliens exist without solid evidence, but equally arrogant to scoff at the possibility until human understanding can definitively rule it out.

Christopher Morris is a regular contributor to Yahoo on television, cinema, video games, technology and politics.

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