The Uncertainty Principle - is it real?

First of all, howdy folks! I've been browsing this board for a few months now and I'm really enjoying it. This is my first post on the board so I hope I'm not doing anything wrong. Okay, let's get into it.I'll start by saying that I'm currently not a physics student (I'm studying prep courses so I can study at university next year). However on top of the boring stuff I have to study for that, I have also spent the last couple of weeks reading Brian Greene's The Elegant Universe and Fabric of the Cosmos and just got started on Richard P. Feynman's QED.In Greene's books the uncertainty principle is very important in string theory and inflationary cosmology and is a part of the quantum physics that remains intact throughout pretty much the entire book. However, in QED there is an endnote on page 55 that says (I'll paraphrse);

quote:

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"I would like to put the uncertainty principle in its historic place: When the revolutionary ideas of quantum physics were first coming out, people still tried to understand them in terms of old-fashioned ideas... if you get rid of the all the old fashioned ideas and instead use the ideas that I'm explaining in these lectures - adding arrows for all the ways events can happen - there is no need for an uncertaintly principle!"

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My question is this - is the uncertainty principle real? This one endnote has me pretty confused so I was hoping some of the very intelligent people on this forum could help me.I would also appreciate it if someone could explain to me the experiments that have been performed that have shown us that the uncertainty principle is, in fact, real (if any). I would expect this topic (if accepted) would belong in the Big Bang/Cosmology section of the science forum.

It's not a direct quote, I omitted a bit in the middle of the endnote which I considered reasonably irrelevant

I'd be lying if I told you I fully understood all of what you said, but give me a bit more time and I'm sure I can digest the bulk of it - of course if you find you have the time I would very much appreciate it if you could give me the "long version."

I have a follow up question which I seem to recall was covered briefly in Fabric of the Cosmos, but which I would love to hear your opinions on.Do you think the uncertainty principle is a consequence of the limits of our technology and/or methods involved in measuring particles, or an intrinsic property of nature at an ultramicroscopic level?