You have a quiet though dreary and damp Saturday
morning. Carol is talking to Gayle on the phone and Jadah is readying herself
for a nap. Spooky is presently unseen. Library quiet otherwise. – Amorella
0954
hours. “It is an ancient mariner, he stoppeth one in three . By thy long grey
beard and glittering eye, Now wherefore stopp’st thou me?”
I drift to the contents of Coleridge, Melville and Hawthorne. Such great and wonderful worlds are found within.
“And Heaven have mercy on us all – Presbyterians and Pagans alike – for we are all somehow dreadfully cracked about the head, and sadly need mending.”
This leaves Hawthorne to turn the corner up –
“Happiness is a butterfly, which when pursued, is always just beyond your grasp, but which, if you will sit down quietly, may alight upon you.”
The Romantics bound in on such a gray late November day and I am one and at peace with my old literary friends’ words.
I drift to the contents of Coleridge, Melville and Hawthorne. Such great and wonderful worlds are found within.
“And Heaven have mercy on us all – Presbyterians and Pagans alike – for we are all somehow dreadfully cracked about the head, and sadly need mending.”
This leaves Hawthorne to turn the corner up –
“Happiness is a butterfly, which when pursued, is always just beyond your grasp, but which, if you will sit down quietly, may alight upon you.”
The Romantics bound in on such a gray late November day and I am one and at peace with my old literary friends’ words.
This
has been a relaxing mostly do-nothing day for both of you. You did watch NBC
News this evening on the DVR as well as “Blindspot” (the last episode until
February) and “NCIS.LA”. Individual snack-suppers for you both; you had baked
beans and wieners – one of your favorites. – Amorella
2047
hours. I was just looking at Quora and a question came up relating to the 1989
book The Emperor's New Mind: Concerning Computers, Minds
and The Laws of Physics so I checked out
Wikipedia.
** **
Shadows of the Mind: A Search for the Missing Science of
Consciousness is a 1994 book by mathematical
physicist Roger Penrose, and serves as a followup to his 1989 book The Emperor’s New Mind: Concerning
Computers, Minds and The Laws of Physics.
Penrose
hypothesizes that:
Human consciousness is
non-algorithmic, and thus is not capable of being modelled by a conventional
Turing machine-type of digital computer.
Quantum mechanics plays an
essential role in the understanding of human consciousness, specifically, he
believes that microtubules within neurons support quantum superpositions.
The objective collapse of the
quantum wavefunction of the microtubules is critical for consciousness.
The collapse in question is
physical behaviour that is non-algorithmic and transcends the limits of
computability.
The human mind has abilities that no Turing machine could
possess because of this mechanism of non-computable physics.
Mathematical thought
In 1931, the mathematician and logician Kurt Gödel proved
his incompleteness theorems, showing that any effectively generated theory
capable of expressing elementary arithmetic cannot be both consistent and
complete. Further to that, for any consistent formal theory that proves certain
basic arithmetic truths, there is an arithmetical statement that is true, but
not provable in the theory. The essence of Penrose's argument is that while a
formal proof system cannot, because of the theorem, prove its own
incompleteness, Gödel-type results are provable by human mathematicians. He
takes this disparity to mean that human mathematicians are not describable as
formal proof systems and are not running an algorithm, so that the
computational theory of mind is false, and computational approaches to
artificial general intelligence are unfounded. (The argument was first given by
Penrose in The Emperor’s New Mind (1989)
and is developed further in Shadows of The Mind. An earlier version of
the argument was given by J. R. Lucas in 1959. For this reason, the argument is
sometimes called the Penrose-Lucas argument).
Objective reduction
Penrose's
theory of Objective Reduction is a prediction of Sir Roger Penrose about the
relationship between quantum mechanics and general relativity. Penrose proposes
that a quantum state remains in superposition until the difference in
space-time curvature reaches a significant level. This idea is
inspired by quantum gravity, because it uses both the physical constants. It is
an alternative to the Copenhagen interpretation, which posits that
superposition fails under observation, and the many-worlds hypothesis, which
states that each alternative outcome of a superposition becomes real in a
separate world.
Penrose's
idea is a type of objective collapse theory. In these theories the wavefunction
is a physical wave, which undergoes wave function collapse as a physical
process, with observers playing no special role. Penrose theorises that the
wave function cannot be sustained in superposition beyond a certain energy
difference between the quantum states. He gives an approximate value for this
difference: a Planck mass worth of matter, which he calls the
"'one-graviton' level". He then hypothesizes that this energy
difference causes the wave function to collapse to a single state, with a
probability based on its amplitude in the original wave function, a procedure
taken from standard quantum mechanics.
Orchestrated objective reduction
When he
wrote his first consciousness book, The Emperor's New Mind in 1989,
Penrose lacked a detailed proposal for how such quantum processes could be
implemented in the brain. Subsequently, Hameroff read The Emperor's New Mind
and suggested to Penrose that certain structures within brain cells (neurons) were
suitable candidate sites for quantum processing and ultimately for
consciousness. The Orch-OR theory arose from the co-operation of these two
scientists and was developed in Penrose's second consciousness book Shadows
of the Mind (1994).
Hameroff's contribution to the theory derived from
studying brain cells (neurons). His interest centred on the cytoskeleton, which
provides an internal supportive structure for neurons, and particularly on the
microtubules, which are the important component of the cytoskeleton. As
neuroscience has progressed, the role of the cytoskeleton and microtubules has
assumed greater importance. In addition to providing a supportive structure for
the cell, the known functions of the microtubules include transport of
molecules, including neurotransmitter molecules bound for the synapses, and
control of the cell's movement, growth and shape.
Criticism
Gödelian
argument and nature of human thought
Penrose's
views on the human thought process are not widely accepted in scientific
circles (Drew McDermott, David Chalmers and others). According to Marvin Minsky,
because people can construe false ideas to be factual, the process of thinking
is not limited to formal logic. Further, Al programs can also conclude that false statements are true, so error is not
unique to humans. Another dissenter, Charles Seife, has said: "Penrose,
the Oxford mathematician famous for his work on tiling the plane with various
shapes, is one of a handful of scientists who believe that the ephemeral nature
of consciousness suggests a quantum process."
In
May 1995, Stanford mathematician Solomon Feferman attacked Penrose's approach
on multiple grounds, including the mathematical validity of his Gödelian
argument and theoretical background. In 1996, Penrose offered a consolidated
reply to many of the criticisms of "Shadows".
John
Searle criticises Penrose's appeal to Gödel as resting on the fallacy that all
computational algorithms must be capable of mathematical description. As a
counter-example, Searle cites the assignment of license plate numbers to
specific vehicle identification numbers, to register a vehicle. According to
Searle, no mathematical function can be used to connect a known VIN with its
LPN, but the process of assignment is quite simple—namely, "first come,
first served"—and can be performed entirely by a computer.
Microtubule
hypothesis
Penrose
and Stuart Hameroff have constructed the Orch-OR theory in which human
consciousness is the result of quantum gravity effects in microtubules.
However, in 2000, Max Tegmark calculated in an article he published in Physical
Review E that the time scale of neuron firing and excitations in
microtubules is slower than the decoherence time by a factor of at least 10.
Tegmark's article has been widely cited by critics of the Penrose-Hameroff
hypothesis. The reception of the article is summed up by this statement in his
support: "Physicists outside the fray, such as IBM's John Smolin, say the
calculations confirm what they had suspected all along. 'We're not working with
a brain that's near absolute zero. It's reasonably unlikely that the brain
evolved quantum behavior', he says."
However, in 2007, Gregory S. Engel claimed that all arguments
concerning the brain being "too warm and wet" have been dispelled, as
multiple "warm and wet" quantum processes have been discovered.
Selected
and edited from Wikipedia – Shadows of the Mind
** **
2123
hours. This is good stuff. I particularly love the criticism above:
** **
Gödelian
argument and nature of human thought
Penrose's
views on the human thought process are not widely accepted in scientific
circles (Drew McDermott, David Chalmers and others). According to Marvin Minsky,
because people can construe false ideas to be factual, the process of thinking
is not limited to formal logic. Further, Al programs can also conclude that false statements are true, so error is not
unique to humans. Another dissenter, Charles Seife, has said: "Penrose,
the Oxford mathematician famous for his work on tiling the plane with various
shapes, is one of a handful of scientists who believe that the ephemeral nature
of consciousness suggests a quantum process."
In
May 1995, Stanford mathematician Solomon Feferman attacked Penrose's approach
on multiple grounds, including the mathematical validity of his Gödelian
argument and theoretical background. In 1996, Penrose offered a consolidated
reply to many of the criticisms of "Shadows".
John Searle criticises Penrose's
appeal to Gödel as resting on the fallacy that all computational algorithms
must be capable of mathematical description. As a counter-example, Searle cites
the assignment of license plate numbers to specific vehicle identification
numbers, to register a vehicle. According to Searle, no mathematical function
can be used to connect a known VIN with its LPN, but the process of assignment
is quite simple—namely, "first come, first served"—and can be
performed entirely by a computer.
** **
2131
hours. This appears reasonable.
Your problem, orndorff, is that even though
an argument can appear reasonable it may be false, as you well know. – Amorella
2133
hours. You are right, Amorella. It is always better to doubt even when there is
no shadow of one, that’s my thinking, which serves to bring up the point. The
above is the stone onto which one might build a foundation only to find it
crumbling a generation later. Dark humor cements the stone and allows one a
smile even if she or he is wrong in her or his thinking.
Post. - Amorella
No comments:
Post a Comment