Hi Raoul.

There are a lot of reliable sightings that have not been explained.

I think that most of us that post here on HZ have seen something flying around that we could not identify.
There are many possible reasons why such flying objects could not have been identified, usually it is simply due to the lack of information about the object.

Personally I do not care if the sighted objects are ordinary things like airplanes, balloons, meteors, or something unusual such as extraterrestrial space craft, or simply imagination.
I simply like the idea that these purported UFO's represent.

They are said to be able to fly at incredible speeds in the air and do turns that are impossible to do with the most modern fighter planes, also they are said to be able to travel in space.

Whether these stories are true or false makes no difference as far as I am concerned, what I am interested in knowing is: What is preventing us from constructing machines that could do the above mentioned things?

Does it go beyond the laws of physics to construct such things, or is it simply that we do not know the methods required to construct such craft?