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**These are excerpts and elaborations from my book "The Nature of Consciousness"**

Since we started
with the assumption that our Physics is inadequate to explain at least one
natural phenomenon, consciousness, and therefore cannot be "right"
(or, at least, complete), it is worth taking a quick look at what Physics has
to say about the universe that our consciousness inhabits. Our view of the
world we live in has undergone a dramatic change over the course of this
century. Quantum Theory and Relativity Theory have changed the very essence of
Physics, painting in front of us a completely different picture of how things
happen and why they happen. Let’s first recapitulate the key concepts of
classical Physics. Galileo laid them down in the 16th century. First of
all, a body in free motion does not need any force to continue moving. Second,
if a force is applied, then what will change is the acceleration, not the
velocity (velocity will change as a consequence of acceleration changing).
Third, all bodies fall with the same acceleration. A century later, Newton expressed these findings in the elegant form of differential
calculus and immersed them in the elegant setting of Euclid's geometry. Three
fundamental laws explain all of nature (at least, all that was known of nature
at the time). The first one states that
the acceleration of a body due to a force is inversely proportional to the
body’s “inertial” mass. The second one states that the gravitational attraction
that a body is subject to is proportional to its “gravitational” mass. The
third one indirectly states the conservation of energy: to every action there
is always an equal reaction. They are mostly
rehashing of Galileo’s ideas, but
they state the exact mathematical relationships and assign numerical values to
constants. They lent themselves to
formal calculations because they were based on calculus and on geometry, both
formal systems that allowed for exact deduction. By applying Newton’s laws, one can derive the
dynamic equation that mathematically describes the motion of a system: given
the position and velocity at one time, the equations can determine the position
and velocity at any later time. Newton’s world was a deterministic machine,
whose state at any time was a direct consequence of its state at a previous time.
Two conservation laws were particularly effective in constraining the motion of
systems: the conservation of momentum (momentum being velocity times mass) and
the conservation of energy. No physical event can alter the overall value of,
say, the energy: energy can change form, but ultimately it will always be there
in the same amount. In 1833 the
Irish mathematician William Hamilton, building on the 1788 work of
the Italian mathematician Luigi Lagrange (the trajectory of an object can be derived by finding the path
which minimizes the “action”, such action being basically the difference
between the kinetic energy and the potential energy), realized something that
Newton had only implied: that velocity, as well as
position, determines the state of a system. He also realized that the key
quantity is the overall energy of the system.
By combining these intuitions, Hamilton redefined Newton’s dynamic equation with two equations that
derived from just one quantity (the Hamiltonian function, a measure of the
total energy of the system), that replaced acceleration (a second-order
derivative) with the first-order derivative of velocity, and that were
symmetrical (once velocity was replaced by momentum). The bottom line was that
position and velocity played the same role and therefore the state of the
system could be viewed as described by six coordinates, the three coordinates
of position plus the three coordinates of momentum. At every point in time one
could compute the set of six coordinates and the sequence of such sets would be
the history of the system in the world. One could then visualize the evolution
of the system in a six-dimensional space, the “phase” space. In the Nineteenth
century two phenomena posed increasing problems for the Newtonian picture:
gases and electromagnetism. Gases had been studied as collections of particles,
but, a gas being made of many minuscule particles in very fast motion and in
continuous interaction, this model soon revealed to be a gross approximation.
The classical approach was quickly abandoned in favor of a stochastic approach,
whereby what matters is the average behavior of a particle and all quantities
that matter (from temperature to heat) are statistical quantities. In the meantime,
growing evidence was accumulating that electric bodies radiated invisible waves
of energy through space, thereby creating electromagnetic fields that could
interact with each other, and that light itself was but a particular case of an
electromagnetic field. In the 1860s the British physicist James Maxwell expressed the properties of electromagnetic fields in a set of
equations. These equations resemble the Hamiltonian equations in that they deal
with first-order derivatives of the electric and magnetic intensities. Given
the distribution of electric and magnetic charges at a time, Maxwell’s equation can determine the
distribution at any later time. The difference is that electric and magnetic
intensities refer to waves, whereas position and momentum refer to particles.
The number of coordinates needed to determine a wave is infinite, not six... As
a by-product of his equations, Maxwell also discovered that light is an
electromagnetic wave. Basically, Michael Faraday had shown that changes in magnetic fields produce electric fields;
Maxwell realized that the opposite is also true: changes in electric fields
cause magnetic fields. His equations describe this endless dance between
electric and magnetic fields. By then, it was
already clear that Science was faced with a dilemma, one which was bound to
become the theme of the rest of the century: there are electromagnetic forces
that hold together particles in objects and there are gravitational forces that
hold together objects in the universe, and these two forces are both inverse
square forces (the intensity of the force is inversely proportional to the
square of the distance), but the two quantities they act upon (electric charge
and mass) behave in a completely different way, thereby leading to two
completely different descriptions of the universe. The inverse
square law indirectly also implied that the “vacuum” has a role: the attraction
decreases exponentially with distance; hence there is a relationship between a
force and space. These two forces act at a distance, but somehow their
"strength" depends on the distance, as if the "nothing" in
between two bodies contributed to the measured strength at each side. Newton's laws of motion apply to
inertial frames and those laws are the same for all inertial frames. However,
Maxwell noticed that an electric phenomenon in one
inertial frame was a magnetic phenomenon in another. An electric phenomenon in
movement gives rise to a magnetic phenomenon, and viceversa, but the
"movement" depends on who is observing: if you observe the electric
phenomenon while it is moving in front of you, you perceive a magnetic
phenomenon; if you "ride" on the electrical phenomenon (which is
therefore at rest from your viewpoint), you perceive instead only an electrical
phenomenon. Maxwell's equations showed that the electromagnetic phenomenon
"oscillates" like a wave and all such waves travel at 300 thousand
kms/hour (in the vacuum). Light is one particular electromagnetic wave, hence
that speed is now known as "the speed of light". What we perceive as
different colors of light correspond to different frequencies, not velocities.
And some frequencies of electromagnetic waves we can't perceive at all. The
interaction between distant bodies does not happen instantaneously as Newton
thought but is mediated by a "field". Another catch
hidden in all of these equations was that the beautiful and imposing architecture
of Physics could not distinguish the past from the future, something that is
obvious to all of us. All of Physics' equations were symmetrical in time. There
is nothing in Newton's laws, in
Hamilton's laws, in
Maxwell's laws or even
in Einstein's laws that can
discriminate past from future. Physics was reversible in time, something that
goes against our perception of the absolute and (alas) irrevocable flow of
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