Wednesday, February 25, 2009

Quantum mechanics, uncertainty principle and the relativity of truth?

this is a very long passage from Scientific American, but i think it's worth reading, because think in the next few decades, people will start using this as scientific proof that truth is RELATIVE. if even the very nature of physical reality as we know it is ever changing and uncertain, then what grounds for absolute truth? and if there is no grounds for absolute truth... you know the rest of the story.

so here goes.

Was Einstein Wrong?: A Quantum Threat to Special Relativity
Our intuition, going back forever, is that to move, say, a rock, one has to touch that rock, or touch a stick that touches the rock, or give an order that travels via vibrations through the air to the ear of a man with a stick that can then push the rock—or some such sequence. This intuition, more generally, is that things can only directly affect other things that are right next to them. If A affects B without being right next to it, then the effect in question must be indirect—the effect in question must be something that gets transmitted by means of a chain of events in which each event brings about the next one directly, in a manner that smoothly spans the distance from A to B. Every time we think we can come up with an exception to this intuition—say, flipping a switch that turns on city street lights (but then we realize that this happens through wires) or listening to a BBC radio broadcast (but then we realize that radio waves propagate through the air)—it turns out that we have not, in fact, thought of an exception. Not, that is, in our everyday experience of the world.

We term this intuition "locality."

Quantum mechanics has upended many an intuition, but none deeper than this one. And this particular upending carries with it a threat, as yet unresolved, to special relativity—a foundation stone of our 21st-century physics.


Let's back up a bit. Prior to the advent of quantum mechanics, and indeed back to the very beginnings of scientific investigations of nature, scholars believed that a complete description of the physical world could in principle be had by describing, one by one, each of the world's smallest and most elementary physical constituents. The full story of the world could be expressed as the sum of the constituents' stories.

Quantum mechanics violates this belief.

Real, measurable, physical features of collections of particles can, in a perfectly concrete way, exceed or elude or have nothing to do with the sum of the features of the individual particles. For example, according to quantum mechanics one can arrange a pair of particles so that they are precisely two feet apart and yet neither particle on its own has a definite position. Furthermore, the standard approach to understanding quantum physics, the so-called Copenhagen interpretation—proclaimed by the great Danish physicist Niels Bohr early last century and handed down from professor to student for generations—insists that it is not that we do not know the facts about the individual particles' exact locations; it is that there simply aren't any such facts. To ask after the position of a single particle would be as meaningless as, say, asking after the marital status of the number five. The problem is not epistemological (about what we know) but ontological (about what is).

Radical Revisions of Reality
Albert Einstein had any number of worries about quantum mechanics. The overquoted concern about its chanciness ("God does not play dice") was just one. But the only objection he formally articulated, the only one he bothered to write a paper on, concerned the oddity of quantum-mechanical entanglement. This objection lies at the heart of what is now known as the EPR argument, named after its three authors, Einstein and his colleagues Boris Podolsky and Nathan Rosen. In their 1935 paper "Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?", they answer their own question with a tightly reasoned "no."

Their argument made pivotal use of one particular instruction in the quantum-mechanical recipe, or mathematical algorithm, for predicting the outcomes of experiments. Suppose that we measure the position of a particle that is quantum mechanically entangled with a second particle—so that neither individually has a precise position, as we mentioned above. Naturally, when we learn the outcome of the measurement, we change our description of the first particle because we now know where it was for a moment. But the algorithm also instructs us to alter our description of the second particle and to alter it instantaneously, no matter how far away it may be or what may lie between the two particles.

Entanglement was an uncontroversial fact of the picture of the world that quantum mechanics presented to physicists, but it was a fact whose implications no one prior to Einstein had thought much about. He saw in entanglement something not merely strange but dubious. It struck him as spooky. It seemed, in particular, nonlocal.

Nobody at that time was ready to entertain the possibility that there were genuine physical nonlocalities in the world—not Einstein, not Bohr, not anybody. Einstein, Podolsky and Rosen took it for granted in their paper that the apparent nonlocality of quantum mechanics must be apparent only, that it must be some kind of mathematical anomaly or notational infelicity or, at any rate, that it must be a disposable artifact of the algorithm—surely one could cook up quantum mechanics's predictions for experiments without needing any nonlocal steps.

And in their paper they presented an argument to the effect that if (as everybody supposed) no genuine physical nonlocality exists in the world and if the experimental predictions of quantum mechanics are correct, then quantum mechanics must leave aspects of the world out of its account. There must be parts of the world's story that it fails to mention.

Bohr responded to the EPR paper practically overnight. His feverishly composed letter of refutation engaged none of the paper's concrete scientific arguments but instead took issue—in an opaque and sometimes downright oracular fashion—with its use of the word "reality" and its definition of "elements of physical reality." He talked at length about the distinction between subject and object, about the conditions under which it makes sense to ask questions and about the nature of human language. What science needed, according to Bohr, was a "radical revision of our attitude as regards physical reality."

Bohr did go out of his way to agree with the EPR paper on one point: that of course there can be no question of a genuine physical nonlocality. The apparent nonlocality, he argued, was just one more reason why we must abandon the quaint and outdated aspiration, so manifest in the EPR paper, of being able to read from the equations of quantum mechanics a realistic picture of the world—a picture of what actually exists before us from moment to moment. Bohr insisted, in effect, that not only do we see the world through a glass darkly but that this shadowy and indefinite view is as real as anything gets.

I was reading this article on the phenomenon of non-locality as described by quantum mechanics, and a rather disturbing thought occurred to me. if the universe itself - physical reality as we see it and know it - is literally and visibily proven to be non-local... then perhaps God really did play dice with the universe, to contradict even Albert Einstein himself?

and if God really does play dice with the universe, then what hope do we who proclaim absolute truth have - that we have rested all our hopes onto an immovable and immutable Creator and Mover... only to find that our God is a chancy God? A God who takes chances with his creation?

what then, for absolute truth, and even for the very nature and foundation of logic - the law of non-contradiction?

if non-locality has been proved empirically visible, in short, then it must prove Hegel has prophesised true - that the thesis and the antithesis really did meet together in a synthesis.

in short - post-modernism has laid its feet upon absolute truth, not only metaphorically, but physically too.

in fact, one friend did think about this - i had brought him to Christ last time - but his studying of quantum physics led him to pretty much the same disturbing conclusion. and as a result, he stopped believing in God, and turned back to atheism.

now, allow me to present an apologetic for the existence of absolute truth, even in a world that is itself physically uncertain, where the uncertainty principle holds sway.

first, i want to debunk the notion that the physical world and its uncertainty must necessarily determines the foundation of truth. just because the uncertainty principle exists and is true for the physical world and its dimensions as we humans can perceive it, doesn't mean that it must therefore apply to the very nature of truth itself.

for truth is far more than jus what is seen. in fact, the Scriptures say that we know that the world was not made out of what is seen. "...we understand that the universe was formed at God's command, so that what is seen was not made out of what was visible." dark matter, space-time expansion, DNA, information theory and all these wonders of nature are simply declaring the glory of God.

"the heavens declare the glory of God
the skies proclaim the works of his hands
day after day they pour forth speech
night after night they display knowledge..."

in fact, did you realise the uncertainty principle is itself very certain. and in order to prove the uncertainty principle, Heisenberg, Bohr and other quantum physicists had to use a most-decidedly antithetical line of reasoning in order to prove the certainty of the uncertainty principle. so much then for Hegel and his gang of post-modernists. synthesis FAIL.

(disclaimer: now, pls don't hammer me on my overuse of the uncertainty principle as an example. i'm just using it as an illustrative (and convenient) shorthand... so forgive me for oversimplifying my arguments... :P)

so then, let's be careful in our interpretations and what certain half-informed pple may have said about what they _think_ they understand about quantum mechanics and uncertainty and all that... Whatever the non-locality principle says - one thing it does NOT say is that a fact is uncertain, and therefore relative.

else we risk falling into Sokal's trap.
1 Corinthians 3:19b
"He catches the wise in their craftiness"

it simply means that the fact doesn't exist in the first place. like asking what's the marital status of 5. or what a square circle looks like. thus the same applies for the position of a single particle.

it simply means that we can never know the world fully. we can't even predict with absolute certainty. all it does show us is our helplessness and ignorance.


now, i'll move into the reams and realms of Scriptures. the next section is for Christians.

Firstly, i'm thinking then. why did God create the uncertainty principle in the first place? To that, I think God will simply ask us the same questions as He asked Job thousands of years ago in Job 38:
"Who is this that darkens my counsel
with words without knowledge?

3 Brace yourself like a man;
I will question you,
and you shall answer me.

4 "Where were you when I laid the earth's foundation?
Tell me, if you understand.

5 Who marked off its dimensions? Surely you know!
Who stretched a measuring line across it?

6 On what were its footings set,
or who laid its cornerstone-

7 while the morning stars sang together
and all the angels shouted for joy?"
only the immeasurable God is able to fully measure an immeasurable universe. only the Absolute One is capable of fixing both the position and velocity of a single particle perfectly. think about it. if we can't even measure a single particle perfectly... nor can we predict the motions of a trillion stars in a trillion galaxies... =)

and to borrow Bohr's insistence that we can only see the world as "through a glass darkly", and that this shadow world is as real as it gets...

absolutely so. for the Scriptures say in the epistle of Hebrews that this present world is only a shadow of the good things that are to come.

and to describe it more visually... i'll paraphrase CS Lewis from his Narnia book, "The Last Battle". In that book, the Narnian boy-king fought to the very bitter end, when he fell into the wooden shed, and suddenly, got transported into another land.

and he was so surprised to find that this land seemed so familiar. and yet so different.

and that the colours were more real than anything he'd ever seen.

then one of the Narnians (i think it was an eagle) flew up into the sky, and reported back - this IS Narnia. the new Narnia. the old Narnia is no more, and the new Narnia has come.

and to cut a (beautiful) story short, CS Lewis described this new Narnia as an allegory of the real world that is to come. for this current world, is but a fallen shadow of the world that was, and is meant to be.

the physical realities that we see right now, are only a shadow of the good things that are yet to come. heaven isn't a big cloud... it's a place far more real, more brilliant, more glorious, more wonderful than anything we can ever imagine on earth.

we don't become ethereal forms floating around. no, scripture declares that we will have brand-new physical bodies... (i reckon it'll look the same as now - except a whole lot better haha.) "for the perishable must clothe itself with the imperishable, and the mortal with immortality..." after all, Christ was physically resurrected. not metaphorically!

Secondly, I think God wants us to remember that this current heavens and earth is already so uncertain. thus, quantum mechanics simply testifies that this physical world that looks so certain is absolutely uncertain. (yes, i meant that to be an oxymoron.) He wants us to not place our faith in uncertain things, but only in His Word that is certain and true.

"Heaven and earth will pass away, but my words will never pass away."
"Therefore, since we are receiving a kingdom that cannot be shaken, let us be thankful, and so worship God acceptably with reverence and awe..."

but i must clarify - i don't mean that we should go the way of Kierkegaard and make a leap into the unknown. that's just S-T-U-P-I-D.

'cos the world is not totally random. correct? our senses, though not perfect, are a reasonable witness to reality. "Touch and see... stop doubting and believe," Jesus told Thomas.

i tink this is reasonable common-sense. physical realities are meant to be a pointer to the Great I AM.

So put your hope in the Lord, both now and forever, for He is the eternal unchanging God, the Tower of Refuge, the Way and the Truth and the Life - the One who speaks with utter confidence, "I AM WHO I AM." in a universe that is shakily uncertain.


ellson said...

wah, your post is like sermon like that! haha

YA, do correct me if i am wrong...
below is my 1 cent's worth

is the article trying to say that the fact that particles at atomic level are always on the go and we are unable to predict the actual location instantaneously means that God "bo heng sui" in creation? (taking a chance in creation)?

i believe God has a reason for creating atomic particles in this way... perhaps it is for stability? not sure...

just because we don't understand something, doesn't mean that thing is created wrongly or with flaws

a parallel question to ask is...
if humans are made in God's image, then we should be perfect. if we are perfect, then we shouldn't sin... and if we sin (and we did), then we are not perfect. can we still believe in a God with imperfect creations of his own image?

if we stop the series of questions at this point, of course we will arrive at the conclusion that God is not that powerful after all... perhaps there is no God at all...

but i believe the reason why we have the capacity to sin is because of free will... God loves us and want us to love him back with our free will... programmed love is not love at all

and YA (name), ya (ya lor), i agree with you... let us put our hope on God... after all, the whole world we know is wasting away and it is nothing but a tent... we have a building in heaven waiting for us.

yeu@nn said...

hey ellson! gosh, long comment... haha... i try to give long answer...

"is the article trying to say that the fact that particles at atomic level are always on the go and we are unable to predict the actual location instantaneously means that God "bo heng sui" in creation? (taking a chance in creation)?"

Nope. Doesn't mean that. My entire post was birthed out of a friend's comment that quantum mechanics has shown that even physical reality can't be relied upon to be absolute... so how can we be even sure of what we see and hear?

and he went on to ask about what if multiple universes really did exist? what room then for a Creator?

so that's why i wrote the post as a belated apologetic. but haha, i think ppl won't understand it 'cos my writing very long-long leh...

"i believe God has a reason for creating atomic particles in this way... perhaps it is for stability? not sure...

just because we don't understand something, doesn't mean that thing is created wrongly or with flaws"

of course. but i wasn't writing about that topic at all, actually. totally different issue.