sambhava: If you're Danish then you should read Martinus "kosomolgi". It will explain everything.
Many of the so-called UFOs sighted around the world are craft being tested by the military, but those sightings that are not are a completely different phenomenon. It is impossible to explain this phenomenon without first having a basic understanding of the laws of physics. Space and time are not separate from consciousness, but are generated by it. The UFOs that certain people witness at certain times are apparitions from the "future" manifesting themselves in our "past" which we mistakenly interpret as the "present". Because of the relatively slow light speed activity of our brains we are unable to witness anything in the "real present". What we do witness everyday of our lives is the conceptual past insofar as everything we experience is first registered through the time interval of our brain synapses functioning at roughly the relatively slow speed of light. The objects we see are illuminated by the sunlight that takes roughly 8 minutes to reach them, and these objects all have a "conceptual past history" in themselves. In other words everything we experience through sight, sound, sensation etc. - is always a split second away from the "real present" - or in other words the very source of reality. For an "object of the future" such as a UFO to manifest in our consciousness which experiences everything in the past, it has to enter into this "past time dimension" in order to be experienced by us (or at least some of us). The only way anyone is able to fully realize the nature of reality is through "direct perception" and not through the snail's pace light speed operation of the brain. That's why only certain people experience the phenomena of UFOs and any other "psychic apparitions". You're not really experiencing them through your "ordinary" physical senses at the time. (If that can be of any help...) And would you believe, I almost forgot to mention who the inhabitants of UFO's actually are... They are US coming from the "future" witnessing ourselves in the "past" in the "real present". And do me a favour, don't ask any more questions like this, pleeeeez...!
And you believe the military has nothing to hide?