In his book Demon Haunted World, Carl Sagan uses an analogy of a friend who says he has a dragon in his garage to illustrate how assertions that cannot be tested are worthless

I have been a research scientist in industry and academia for over 40-years. My speciality is clinical pharmacology with an emphasis on the use of radio-isotopic tracers to study how the body handles foreign chemicals (technically known as xenobiotics). My scientific journey has wandered through physics, biology and chemistry and even, to a small extent, archeology and geology.

I am now largely retired and spending my time writing in the public understanding of science.  I am also a Visiting Professor at the University of Lincoln in the UK, where I have a PhD student.

Over the years I had the privilege of meeting many great scientists, from those at the bench just enthralled with the subject, through to Nobel Prize winners. I have also met those with a severe case of the Dunning-Kruger effect and those that believe in all sorts of pseudoscientific nonsense, from a flat Earth, to intelligent design, to homeopathy. These views are not to be dismissed lightly as they dilute the wonder of science and confuse those that otherwise crave to understand more. Once you've seen the wonder of the true nature of science, then you really don't need to invent any other reality. 

The meaning of science itself is sometimes misunderstood, or occasionally wilfully misrepresented. The interview between Richard Dawkins and the Young Earth Creationist John Mackay is one such example. Mackay proclaims to Dawkins, "don't call evolution science, you weren't there, you didn't see it." For whatever reason, Mackay misunderstands (or misrepresents, it's hard to tell) the scientific method.  He takes as literal interpretation of the meaning of "observation" as he does the meaning of Genesis that God made the Universe in 7-days. The meaning of "observation", as indeed the meaning of "theory" in science does not have the same connotations as it might in everyday speech.  Have a look at the video on the right on the scientific method and then go to the link for the Dawkins / Mackay interview and spot where Mackay went wrong.