: Really, is this so absurd? Is it so strange to think of a
: world where we can't see what's really going on? After
: all, you can't perceive an electron, or an atom...you
: can only perceive an image produced by a brain state
: produced by a retinal impulse produced by a photon
: emitted by that electron or atom. We could never hope
: to perceive any system (other than our own thoughts
: and sensory perceptions) directly, unless we're God.
It's funny (in that weird ironic way) to read this from a berkeley.edu IP, since it's the view of Bishop Berkeley himself, wittly expressed in the famous pair of limericks:
There once was a man who said 'God
Must think it exceedingly odd
To find that this tree
Continues to be
When no one's about in the quad.'
'Dear Sir, your astonishment's odd
I am always about in the quad
And that's why the tree
Will continue to be
Since observed by Yours Faithfully, God.'
It's a fantastic philosophical puzzle that everybody (who enjoys such things) should get into and enjoy. Is it (perception, the world) all just in your head? Berkeley argues convincingly (to a degree) that since the perceptions exist in your head (where else?) all the perceptible qualities of objects really just existed in your head. And we have no evidence of any objects beyond its perceptible qualities. [Stop and run over this a couple times. It's fun, isn't it?]
All of our intuitions about the world run counter to this, but getting a firm handle on why and to what degree the world is mind-independent really gives you a solid resting ground to attack questions like QM and uncertainty. I'd venture you can't really address QM without addressing that first question.
: And is it strange to think that you always affect a
: system by observing it? What sense *doesn't* work that
: way? Can't see something without bouncing light off
: it...can't hear it without bathing it in gas and
: making it vibrate...can't smell it without pulling
: molecules off it and sending them into the air. Even
: the most abstract types of perception--such as feeling
: its gravitational pull--require, by Newton's 3rd law,
: that the object get pushed too. QM doesn't add much
: new to this.
And this is the difference between actual human perception and ideal, God-like perception (a simple knowing-of-all-things-in-what-state-they-are, without touching it or interacting with it). Human perception, by definition, by its nature, is an intrusive, interruptive process, especially on the finely microscopic level where QM lives. But is human perception indicative of what's really out there or just of what we know about what's out there? Is ideal, God-like perception logically impossible, or just humanly impossible? Just because we can't know what state something's in with absolute certainty, does that mean there's not a fact of the matter? This is where the limerick pair comes in again.
Which gets to the fundamental question of QM and uncertainty, which is: Given that the theory works, what does it mean? I've often been reminded of The Hitchhiker's Guide to the Galaxy when thinking about this sort of thing. Remember how the answer to Life, the Universe and Everything turned out to be 42? We may have a system that works and delivers the right answer every time, and still not know what we're doing.
I think we need to ask ourselves seriously whether we are learning about the world with QM and related interpretations or learning about _the way we learn about the world_. Can objects really go into these bizarre superposition states--being neither alive nor dead, neither exploded nor not, neither decomposed or not--or is it simply our _knowledge_ of them that is undetermined and undeterminable?
If everything's a wave, then many of these bizarre conclusions follow, at least for the epistemological (how I know about it) question, and maybe for the ontological (what's really there) question. But why should I think EVERYTHING'S a wave? It's not enough to have examples of several things that I thought weren't waves acting like waves. I'm perfectly prepared to think many things are really waves even though they don't appear to be on everyday macro-level perception. That doesn't lead me to everything's a wave.
But suppose I do accept the conclusion that everything's a wave. Maybe that's like accepting that the answer to Life, the Universe and Everything is 42. I can know the words 'everything's a wave', and have no idea how that translate into a difference in the world, even though I know what the words mean. We all know what 42 means, right? But do we have any idea what it means that 42 is the answer to Life, the Universe and Everything?
