Guarding the Wall: tunnels, bridges and tendrils

Mon Apr 22 05:00:25 CDT 2013

If y'all'll allow me the dubious honour of a triple post, let
me preemptively clarify what I meant about "the relationship between the
arrows". You might and therefore should ask: "How can I tell the
`relationship' at the start from that at the end? Or, stated differently,
is there a way to make precise the notion of `random' w.r.t. the bunch of
arrows?". Good question, whomever. Think of a game of chess. If I give you
a chessboard with an arrangement of pieces, with a little wikipedia you
should be able to tell me whether the configuration is legal. In QM, there
are similar rules defining how a quantum system (the bunch of arrows) can
change in magnitude and direction while still retaining coherence, their
"relationship". So when I get the chessboard I check for legality: based
on successive measurements, I can probe the "evolution" of the arrows, and
find out whether they've stayed kosher. It is usually possible to work this
out given details of the environment system, however.

P.

On 22 April 2013 19:44, Prashant Kumar <siva.prashant.kumar at gmail.com>wrote:

> And in the spirit of intuitive presentation I want to try to explain
> quantum coherence: Keith asked and I totally glossed over it. Imagine that
> you're sitting in a room with a pendulum hanging from the ceiling. This
> pendulum is oscillating at some frequency, in one dimension (back and forth
> only, none of this crazy elliptical shit). There is no air in the room, so
> we have to be quick. What happens if my neighbour upstairs starts playing
> music? The vibrations will kick my pendulum off course. Does it matter if
> it's speed metal or classic rock? Well, the bass will have some vibration
> frequency, and when this is close to that of the pendulum you get the
> strongest "coupling" between the two systems. This is a thermodynamic
> thing; there is energy transfer as per the 2nd going on. In practice music
> has a fairly wide band of frequencies, so you'll get coupling with either
> genre, but if instead of music we considered, say, a truck then the
> frequency of the engine noise matters.
>
> Now, what does this have to do with quantum anything? Any time you want to
> get information out of a quantum system you have to measure it. This
> entails getting a whole load of fat classical apparatus and coupling it to
> the QM system. I want you to think of this QM system as a bunch of arrows
> in 3D space. Each starts at the origin, and has a defined direction and
> total length (or magnitude). The dimensions aren't spatial, however. You
> can think of each dimension as a number which indicates "the extent to
> which the system is state-{1,2,3}"; these are components which sum with
> direction to give the total state -- think back to adding vectors, or
> finding the hypotenuse given the two sides: this is a similar thing. Each
> number is the probability of finding the system in a given state upon
> measurement. This probabilistic construct is called a superposition state,
> and is uniquely quantum thing. *Quantum coherence* is the relationship
> that exists between all your arrows, before you couple it to some other
> system -- I'll call this latter "the environment". What happens upon
> coupling is that your 3D space becomes a lot larger -- the extra
> "dimensions" correspond to states in the environment. Let's for
> concreteness say we have 2, so (3+2)D.
>
> Now things happen just like with the pendulum and the truck. Energy flows
> from the environment into our QM system, and the effect it has is to rotate
> our bunch of arrows, each independently of the other. To extend the
> classical analogy, what we have is a collection of pendulums each with a
> different oscillation frequency. So the music will cause them each to move
> differently. Then, when we go to measure our system -- to try to find out
> the values of the numbers belonging to the three state dimensions -- we
> have a problem. Our arrows now have 2 extra dimensions in which to play
> about in, but the same magnitude. This, as well as energy flowing into the
> QM system from the environment will have changed the values of the
> state-numbers. So if we measure, we don't see the same state we started out
> with: our initial quantum superposition has become a different one. The
> effect of this process over time is to destroy in its entirety the
> relationship between the arrows, to make the arrows point in random
> directions. This, my friends, is entropy at the quantum level.
>
> So, what I was saying re quantum mechanics in the brain is that, at brain
> temperatures, this *quantum decoherence* (is the name for the loss of
> coherence via entropic action) will take almost no time to destroy any
> quantum superposition: the arrows will fly away from each other in some
> infinitesimal time. To retain quantum coherence in most systems you need to
> be at milliKelvin temperatures.
>
> P.
>
>
> On 22 April 2013 05:40, Keith Davis <kbob42 at gmail.com> wrote:
>
>> Prashant,
>>
>> I really wish I could understand what you're saying here. Can you point
>> me to something that helps to explain "quantum coherence"? I'm not even
>> sure I understand this whole thread, but I'm interested.
>>
>> kd
>>
>>
>> On Sun, Apr 21, 2013 at 7:55 AM, Prashant Kumar <
>> siva.prashant.kumar at gmail.com> wrote:
>>
>>> My take on it is this: what DC and others does is manipulative (in that
>>> it does prey on people who must necessarily "trust the experts") and shits
>>> all over a nascent field; applications of quantum mechanics in the life
>>> sciences is only slowly being studied for all the damage new agers have
>>> done (academic jobs being the way they are, no newly minted PhD wants to
>>> risk his or her reputation on something so fringe. It's unreasonable to
>>> expect people to live as tortured maybe-geniuses). It's a technique of the
>>> right: teach the controversy. DC et al. in this article are attempting to
>>> blur the line (and there is one) between his horseshit and actual
>>> speculative science which exists outside the norm.
>>>
>>> Quantum consciousness is a prime example: there is no way to maintain
>>> quantum coherence at the energy scale at which the brain operates.<http://arxiv.org/abs/quant-ph/9907009> Now,
>>> this doesn't mean that quantum physics has no role in biology. Here<http://www.nature.com/nphys/journal/v9/n1/abs/nphys2474.html>is a wonderful review article detailing various applications. Turns out,
>>> magnetoception in pigeons *may *be quantum mechanical in nature! This
>>> is the kind of research which we don't hear about, thanks to these
>>> arseholes. I'm willing to bet reality is more interesting than anything
>>> Chopra could come up with.
>>>
>>> P.
>>>
>>>
>>> On 21 April 2013 21:28, <bandwraith at aol.com> wrote:
>>>
>>>>  You mean... It's just another rope trick?  : )
>>>>
>>>> Thinking about it in general terms, I guess there're lots of "cracked
>>>> pots"- scientific, religious, artistic, etc. Some are endearing, some more
>>>> consciously manipulative and willing to prey on people's niavete. But I
>>>> maintain that - if I can be excused the royal "we" here- we are all a
>>>> little cracked in our own way, and its probably okay to embrace our inner
>>>> crack-pot, just not too vehemently, lest we seal the cracks and it becomes
>>>> a pressure cooker- just enough to foster a little empathy.
>>>>
>>>> I was going to say something about the Liberty Bell, but I'm uncertain
>>>> now. It's Sunday here. I'll go meditate on it for awhile.
>>>>
>>>>
>>>>  -----Original Message-----
>>>> From: Prashant Kumar <siva.prashant.kumar at gmail.com>
>>>> To: bandwraith <bandwraith at aol.com>; pynchon -l <pynchon-l at waste.org>
>>>> Sent: Sun, Apr 21, 2013 5:31 am
>>>> Subject: Re: Guarding the Wall: tunnels, bridges and tendrils
>>>>
>>>> This guy and his quantum mechanical snake oil...in the language of my
>>>> people: "madarchod".
>>>>
>>>>  P.
>>>>
>>>> On Saturday, April 20, 2013, wrote:
>>>>
>>>>> "...On the other side of the wall are lethal enemies and malefic
>>>>> magic. For centuries, no one has seen the zombie-like White Walkers who
>>>>> live on the other side of the wall, nor the dragons that once ravaged
>>>>> Westeros
>>>>> .
>>>>> Even so, after magic and zombies fell into disbelief, a hereditary
>>>>> band of guardians swore an oath to keep watch at the wall, generation after
>>>>> generation. TED has put itself in rather the same position. What the
>>>>> militant atheists and self-described skeptics hate is a certain brand of
>>>>> magical thinking that endangers science. In particular, there is the
>>>>> bugaboo of "non-local consciousness," which causes the hair on the back of
>>>>> their necks to stand on end. A layman would be forgiven for not grasping
>>>>> why such an innocent-sounding phrase could spell danger to "good science."
>>>>>
>>>>>
>>>>> http://www.huffingtonpost.com/deepak-chopra/dear-ted-is-it-bad-scienc_b_3104049.html
>>>>>
>>>>
>>>
>>
>>
>> --
>> www.innergroovemusic.com
>>
>
>
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