Under Construction Work in Progress
Fun In Da Mental Space?
Stuart Hameroff has coined the term "Funda-Mental Spacetime" alluding to the Penrose "spin networks" and invoking an analogy to earthquake faults. The "OR" self-gravity collapse is likened to a 3D fault only 10^-33 cm thick of at least mesoscopic 2D area, or perhaps a 3D volume since the "-time" is in his phrasing. In any case, it is never clear exactly what Hameroff is talking about in his oft-repeated canned speech on the subject cloned in many of his almost identical publications – is this evidence for David Deutsch’s "multiverse" in the approximation of the "parallel universes" of the cosmic quantum computer? J
I will attempt to put some meat, for the malnourished reader, on Hameroff’s bare-boned description of what is called "loop quantum gravity". Hameroff is actually pointing, but too vaguely for my taste, beating his Tin Drum, to something very important. To this end let us look at a review paper by Carlo Rovelli "Quantum spacetime: what do we know?" http://xxx.lanl.gov/abs/gr-qc/9903045
"a consistent picture of the physical world … has been lost with the advent of quantum mechanics and general relativity … The basic Cartesian-Newtonian notions such as matter, space, time, causality have been modified in depth. The new notions do not stay together. …"
Rovelli asks the perennial questions at the heart of theoretical physics, yesterday, today, tomorrow, here-now, there-then, elsewhere and beyond:
"What is matter?"
"What is causality?"
"What is the role of the observer in physics?"
"What is time?"
"What is the meaning of ‘being somewhere’?"
"What is the meaning of ‘now’?"
"What is the meaning of ‘moving’?"
"Is motion to be defined with respect to objects or with respect to space?"
Those readers interested in the widely spread mostly Eastern European and Russian claims of "Tesla super-weapons" of non-lethal "psychotronic warfare" of "mind-control" at-a-distance and all that, with something important missing in orthodox Maxwell electrodynamics that Tesla allegedly discovered in a practical way, should now pay close attention.
"First step. A new actor on the stage: the field … Faraday’s book includes … the discussion of whether the field … the ‘lines of force’ … is ‘real’ … in modern terms what Faraday is asking is whether there are independent degrees of freedom in the electric and magnetic fields. A degree of freedom is a quantity … whose value and whose time derivative I need to specify in order to be able to predict unequivocally the future evolution of the system."
Note the conceptual straight jacket of determinism and the retarded arrow of time built ad-hoc into this stipulative definition of the "independent field degrees of freedom". This is all classical field physics entirely restricted to the explicate order without any direct implicate quantum informational unconscious "mental" physical influences, either on the classical charges, that are sources of the classical fields, or the classical fields themselves.
"Thus Faraday is asking: If we have a system of interacting charges, and we know their positions and velocities, is this knowledge sufficient to predict the future motions of the charges? Or rather, in order to predict the future, we have to specify the instantaneous configuration of the field (the field’s degrees of freedom) as well? The answer is in Maxwell’s equations: the field has independent degrees of freedom."
This is in stark contrast to the 1940 Wheeler-Feynman version of classical electrodynamics in which "Everything is particles." (John Archibald Wheeler "Geons, Black Holes, and Quantum Foam") and the electromagnetic field does not have independent degrees of freedom. However, the price of renouncing the field degrees of freedom is that the future influences the present equally to the past influencing the present. It is the idea that the field is real that allows us to pretend that the future does not influence the present. That is, the faster-than-light (FTL) instantaneous field configuration in any relative "now" slice of spacetime is really a hidden cosmic code for advanced influences from the future. The direct action-at-a-distance between charged particles in the Wheeler-Feynman theory is actually "contiguous" in 4D spacetime along the classically well-defined lightlike world lines of zero length frame-invariant absolute proper time differences. In this sense, the different emitter and absorber electric charges are in "contact" at the higher 4D level even though they are far apart in the lower 3D level. One imagines a bundle of world lines of the charges connected by another bundle of both past and future light cones emanating from each point of every world line.
Let us now return to the orthodox "both field + particles & only past causes of present effects" picture away from this alternate unorthodox Wheeler-Feynman "only particles & both past and future causes of present effects" picture.
"To which physical entity do the degrees of freedom of the electromagnetic field refer? … The electromagnetic waves have aspects in common with water waves, or with sound waves, which describe vibrations of some material medium – for which the name "ether" [AKA "aether",JS] was chosen. … But a convincing dynamical theory of the ether compatible with the various experiments (for instance on the constancy of the speed of light in vacuum) could not be found. … Einstein believed Maxwell’s theory … and believed the Galilean insight that velocity is relative and inertial systems [frames of reference, JS] are equivalent. Merging the two he found special relativity … The idea of the ether is abandoned … the field has to be taken seriously as an elementary consituent of physical reality."
Note that J. P. Vigier has recently proposed a dramatic change in this picture in which the electromagnetic field has a tiny amount of rest mass with a new long-range "longitudinal polarization degree of freedom. When coupled to bare electric charges of finite spatial extent instead of the bare "point charges" of standard theory, he gets new physical effects that appear to agree with experiments. These new effects include a new "cold fusion" form of practical atomic energy, and a possible explanation for the anomalous acceleration of our apparently ever-expanding open universe. Vigier brings back the "ether" in the sense of both general relativity and quantum mechanics. So, we will return to Vigier’s ideas another time. Ref: "Possible Consequences of an Extended Charged Particle Model in Electromagnetic Theory", "Causality and Locality in Modern Physics", Kluwer, 1998.
Back to Rovelli:
"Second step. Dynamical entities have quantum properties. … Evolution is probabilistically determined only; some physical quantities q can take certain discrete values only … superposition principle … conjugate variables cannot be assumed to have [exact, JS] values at the same time … The empirical success of quantum mechanics is immense. Its physical obscurity is undeniable. Physicists do not yet agree on what quantum mechanics precisely says about the world (the difficulty … refers to the physical meaning of notions such as ‘measurement’, ‘history’, ‘hidden variable’. It is a bit like the Lorentz transformations before Einstein: correct, but what do they mean? … Quantum mechanics was first developed for [particle, JS] systems with a finite number of degrees of freedom … Faraday, Maxwell and Einstein … introduced the field, which has an infinite number of degrees of freedom [only because classical spacetime is a mathematical continuum, JS] … Dirac put the two ideas together … beyond their established domain of validity … Dirac derived the existence of the photon just from Maxwell’s theory and the basics of quantum mechanics. Furthermore, by just believing special relativity and believing quantum theory, namely by assuming their validity far beyond their empirically explored domain … he predicted the existence of antimatter."
This is also exactly what I do with Einstein’s principle of relativity, in the context of Bohm’s nonlocal quantum realism, that there are no absolute physical objects that act without direct back-reaction on them from what they are acting on. I lift Einstein’s principle out of its original home in the classical explicate local spacetime material "rocklike" (Stapp) physical order up into the quantum informational implicate nonlocal beyond spacetime nonmaterial "thoughtlike" (Stapp) physical order. The result is the physical generation of conscious experiences AKA "e-motions".
"Third step. The stage becomes an actor. … Descartes … gave a fully relational definition of localization (space) and motion … According to Descartes, there is no ‘empty space’. There are only objects, and it makes sense to say that an object A is contiguous to object B. The ‘location’ of an object A is the set of objects to with A is contiguous. ‘Motion’ is change in location. … Thus there is no ‘absolute’ motion. This is the same definition of space, location, and motion, that we find in Aristotle. Relationalism … should not be confused with Galilean relativity … that ‘rectilinear uniform motion’ is a priori indistinguishable from stasis [AKA rest JS] … that velocity (but just velocity!), is relative to other bodies. Relationalism holds that ANY motion (however zigzagging) [AKA accelerating, JS] is apriori indistinguishable from stasis. The very formulation of Galilean relativity requires a nonrelational definition of motion ) ‘rectilinear and uniform’ with respect to what?). … Newton took a different course … According to him, space exists. It exists even if there are no objects in it. … Newton argues that the notion of absolute motion is necessary for … his famous experiment of the rotating bucket in the Principia is one of the arguments to prove that motion is absolute [see also Foucault’s pendulum, JS] … the notion of absolute [uniform, JS] velocity is meaningless in Newton’s mechanics, but any other feature of motion is not relative: it is absolute. In particular acceleration is absolute. … it is acceleration that the bucket experiment is supposed to prove to be absolute, against Descartes… Newton overdid it a bit, introducing the notion of absolute position and velocity … The important point here is that Newton’s mechanics requires absolute acceleration, against Aristotle and against Descartes … Similarly, Newton introduced absolute time … Newtonian space and time… are like a stage over which the action of physics takes place, the various dynamical entities being the actors. … The key feature of this stage, Newtonian spacetime, is its metrical structure. Curves have length, surfaces have area … On this space there exist preferred coordinates [defining inertial frames, JS] in terms of which the metric is [diagonal, JS] … The metric determines lengths, areas, and volumes and defines what we mean by a straight line in space [AKA ‘geodesic’, JS] … If a particle deviates with respect to this straight line, it is, according to Newton, accelerating. It is not accelerating with respect to this or that dynamical object: it is accelerating in absolute terms. Special relativity changes this picture only marginally, loosening up the strict distinction between the ‘space’ and the ‘time’ components of spacetime. In Newtonian spacetime, space is given by fixed 3D planes. In special relativistic spacetime, which 3D plane you call space depends on your state of motion."
It is this renunciation of Newton’s absolute simultaneity that leads to the observed slowing down of the rate of fast moving clocks and to the equivalence of mass to energy "E = mc^2" that we see confirmed in the release of a small fraction of the total rest mass of the uranium (U) and plutonium nuclei in the repulsive electrostatic Coulombic near-field atomic energy in the nuclear fission bomb of less than 0.2% conversion of rest mass into explosive energy, i.e. 200 mev released from the bit less than 100 (92 for U) protons each of 1000 mev rest mass. Therefore, approximately 200/100 x 1000 = 2x10^-3 = 0.2%. In modern terms, the energy of the nuclear fission explosion is from the virtual photons of longitudinal and scalar polarizations. These virtual photons combine the non-radiative "near field" part of the classical electromagnetic field with the unconscious quantum mental wave properties of the nucleonic electrical charges on the protons.
"again [in special relativity, JS] there are preferred coordinates [defining inertial frames, JS] … This [special relativity metric] tensor enters all physical equations, representing the … influence of the stage … on the motion of anything."
Therefore, the special relativity metric geometry tensor is an absolute physical object in the classical explicate order that universally acts on the motion of anything without any direct back-reaction of anything on it! Note a "tensor" is an object that transforms in a special "multi-linear" way in a change of frame of reference. A "spinor" is the "square root" of a tensor. Penrose, prefers to use the more fundamental "spinors". Penrose’s "twistors" are a generalization of the "spinor" from a real spacetime to a complex spacetime. The spinor is really a quantum informational thing from the implicate order in contrast to the tensor from the explicate order. Therefore, in a sense, part of the implicate order is a kind of square root of the explicate order. One spinor enfolds (encodes) and its conjugate partner in the product unfolds (decodes) to form the classical tensor in a kind of Shiva dance of implication and explication. The spinors have different ranks corresponding to the entanglement number N in my back-reaction consciousness-in-time generating equation
T(Orch) = 1/HN
H = Hubble’s constant in the expanding co-moving space of our apparently open universe.
The expansion of 3D space in general relativity is Henry Adams’s "dynamo" of all "low-energy" order in the universe in which time, like Botticelli’s "Venus Arising From The Sea" is emergent out of the timeless pre-geometry of Dante’s "Paradiso".
" with special relativity … the ‘dynamical objects’ or ‘bodies’ … now include the fields … a violent burst of electromagnetic waves coming from a distant supernova has traveled across space … the Newtonian construct of a fixed background stage over which physics happens is not altered by special relativity …
The profound change comes with general relativity (GR). The central discovery of GR, can be enunciated in three points … First, the gravitational force is mediated by a field, very much like the electromagnetic field … Second, Newton’s spacetime … and the gravitational field, are the same thing. Third, the dynamics of the gravitational field, of the other fields such as the electromagnetic field, and any other dynamical object, is fully relational, in the Aristotelian-Cartesian sense … The gravitational field has independent degrees of freedom … The stage is promoted to be one of the actors."
Relationalism is the core of Einstein’s principle that there are no absolute physical (dynamical) objects. Newton’s spacetime, now the gravitational field, not only acts to make matter move, but it experiences back-reaction from the matter in motion to make the space-time curve. Similarly, the quantum information field from the implicate order will act on the gravitational field and also on matter. The direct back-reaction of the gravitational field and of matter on the quantum information field generates the conscious experiences or sentient excitations of that information field.
gravity <-> matter
consciousness <-> matter
consciousness <-> gravity
form the three sides of a conceptual triangle whose vertices are "gravity", "matter", and "consciousness". The two-way arrow <-> is
<-> = -> + <-
-> = quantum action of mind on either matter or gravity
<- = post-quantum back-reaction of either matter or gravity on mind to generate consciousness
-> >> <- when N -> 1 and n >> 1 (orthodox QM)
-> = <- when N >> 1 and n -> 1
N = entanglement number measures magnitude of nonlocal quantum gluing together of separate pieces (dynamical degrees of freedom) into an undivided coherent non-mechanical whole.
n = statistical ensemble number
"GR describes the world as a set of interacting fields and, possibly, other objects."
Include the quantum information fields from the implicate mental order in that category of "other objects".
"One of these interacting fields is [the gravitational curved metric, JS] guv(x). Motion can be defined only as positioning and displacements of these dynamical objects relative to each other."
There are no absolute dynamical objects, in either the explicate material, or the implicate mental physical orders, that touch without being touched.
"Newton’s motion with respect to space is indeed motion with respect to a dynamical object: the gravitational field. All of this is coded in the active diffeomorphism invariance (diff invariance) of GR.
Active diff invariance should not be confused with passive diff invariance … under change of coordinates. Passive diff invariance is a property of a formulation of a dynamical theory, while active diff invariance is a property of the theory itself. … Passive diff invariance … re-expresses ALL the geometric quantities (dynamical and NON-DYNAMICAL) … and the form of the equations of motion does not change. A theory is invariant under ACTIVE DIFF, when a smooth displacement of the … DYNAMICAL FIELDS ALONE over the manifold, sends solutions of the equations of motion into solutions of the equations of motion. Distinguishing a truly dynamical field, namely a field with independent degrees of freedom, from a non-dynamical field disguised as a dynamical one … require a detailed analysis."
So the technical difficulty is to separate the dynamical from the non-dynamical.
"The basic dynamical variables … are fully independent from the points of the manifold … Newton introduced … a spacetime manifold, and its non-dynamical metric …. GR gets rid of the non-dynamical metric, by replacing it with the gravitational field. … it gets rid of the manifold, by means of active diff invariance. … single out the gravitational field as ‘the more equal among equals’ … declaring that location is absolute in GR, because it can be defined with respect to it … this can be done within any relationalism … this attitude … fully misses the great Einsteinian insight: that Newtonian spacetime is just one field among the others … this … sends us into a nightmare when we have to deal with the motion of the gravitational field itself … we are spending millions for constructing gravity wave detectors … the dynamical fields move with respect to each other …"
Remember, all of the above is strictly classical in the explicate order.
"the third step was not easy for Einstein, and came later than the previous two … With his famous ‘hole argument’ he had convinced himself that …. active diffeomorphism invariance would imply a truly dramatic revolution with respect to Newtonian notions of space and time …
in terms of [quantum, JS] states in a Hilbert space … these states [for quantum gravity] cannot represent quantum excitations localized in space … They must define space themselves."
Rovelli is hampered here in his conceptualization by the incompleteness of the orthodox quantum picture that eschews the Bohm point P, in this case a classical 3D sub-geometry "hidden variable".
"They must be quantum excitations ‘of’ space, not ‘in’ space. Physical quantities in GR … are invariant under active diff … Examples of diff-invariant geometric quantities are lengths, areas, volumes, [proper, JS] time intervals, of regions determined by dynamical physical objects … we should expect a discrete geometry … a generic state of spacetime will be a continuous quantum superposition of states whose geometry has discrete features, not a collection of elementary discrete objects … In loop quantum gravity, the quantum states … [are, JS] … linear combinations of SPIN NETWORKS … A spin network is an abstract graph with links labeled by half-integers … each node of the graph as an elementary ‘quantum chunk of space’. The links represent (transverse) surfaces separating the quanta of space. The half-integers associated to the links determine the (quantized) area of these surface."
Remember the Bekenstein information as the area of a blackhole event horizon. So these areas are c-bits of Shannon information superposed to form qu-bits of unconscious quantum mental information that can become conscious if there is back-reaction of some kind. Remember Joe Campbell’s "The Hero’s Journey" and "Myths to Live By" lying on a pillow at Esalen in Big Sur in 1975 listening to Joe talk. Thus, like Parsifal in quest of Das Graal, we boldly approach The Conscious Mind of God! Think of Plato’s Allegory of The Cave in Book Seven of The Republic, the first book I read as a Cornell freshman in 1956 in Philosophy 101 far above Cayuga’s waters. Remember the fellow who escapes The Cave and sees The Source of The Quantum Wave Function of The Multiverse, symbolized, of course, by The Sun God – the Source of That Spiritual Nile from the Fountain of Eternal Youth in The Temple of Immortality where our Star Ship is heading.
"The spin networks represent relational quantum states. They are not located in space."
Bohmian Quantum Gravity
Re: http://xxx.lanl.gov/quant-ph/9902018
"Quantum Spacetime without Observers: Ontological Clarity and the Conceptual Foundations of Quantum Gravity" by Sheldon Goldstein and Stefan Teufel
This paper exposes the limits of conceptualization of mainstream quantum gravity and superstring theory that is trapped in Bohr’s "greatest mistake" of renouncing the classical world in quantum reality. Misner, Thorne, and Wheeler make this mistake in their remark:
"One cannot give both a dynamic variable and its time rate of change … complementarity forbids … Given the precise 3-geometry at one instant, one cannot also know at that instant the time rate of change of the 3-geometry … No prediction of spacetime, therefore no meaning for spacetime, is the verdict of the quantum principle."
"The major conceptual problems of canonical quantum gravity are the problem of time and the problem of diffeomorphism invariant observables. … these problems are artifacts of the subjectivity and vagueness inherent in the framework of orthodox quantum theory."
This explains why Stapp’s attempt at an orthodox quantum theory of consciousness leaves me with an empty feeling that I have not increased my understanding of the enigma of existence from his theory.
"When we insist upon ontological clarity – the distinguishing characteristic of a Bohmian approach – these conceptual problems vanish."
Stapp’s attempt at a theory of consciousness, like all the attempts at quantum gravity and superstring theory, have "the subjectivity and the ontological vagueness inherent in the very framework of orthodox quantum theory … most, and perhaps all, of the conceptual problems of canonical quantum gravity vanish if we insist upon formulating our cosmological theories in such a manner that it is reasonably clear what they are about … and … avoid any reference to such vague notions as measurement, observers and observables"
Canonical ADM math formulation of classical general relativity CGR.
GR as a Hamiltonian dynamical theory in phase space. The material Bohm point "P" is now the 3D Deutsch "snapshot" ("The Fabric of Reality") technically called the "3-geometry" gij(x) of signature +++ by Misner, Thorne and Wheeler. The symbol x is a point in the manifold. The Latin subscripts i,j domains are the three inflated space dimensions 1,2,3. There is no Calabi-Yau space of curled up extra space dimensions of scale R (a millimeter?) in Einstein’s classical theory of gravitation (1915). So the 3-metric (on a spacelike 3D hypersurface Sigma) i.e., gij(x) is like the position of the particle in elementary Bohm quantum "non-mechanics" (Hiley). So, the Bohm point of quantum gravity is a field spread over the entire "3Dspace" of the universe split off from "time". The conjugate "momentum" "pi" (not 3.14 etc) needed to form the phase space is the extrinsic curvature of the spacelike 3D hypersurface Sigma.
"The real time parameter of usual Hamiltonian systems is replaced by a ‘multifingered time’ corresponding to arbitrary deformations dSigma of the 3D spacelike hypersurface."
The deformation dSigma splits into two types. One is tangential or "transverse", AKA spatial diffeomorphisms, inside the 3D hypersurface infinitesimally generated by Hi(g,pi). The other is normal to the 3D hypersurface infinitesimally generated by H(g,pi). The "dynamics" is therefore only from the normal deformations generated by H(g,pi). This is a normal vector flow field.
Define the arbitrary lapse function i.e., a field N(x) "that determines how far, in terms of proper length, one moves the spacelike hypersurface at the point x along its normal vector: this distance is N(x)dtau, where tau is a parameter labeling the successive hypersurfaces arrived at under the deformation …. H(N) is an integral over Sigma of the product of [lapse field] N with a Hamiltonian density H(g,pi,x)." Use "g" and "pi" suppressing subscripts, the local classical Hamilton ADM equations of motion for Einstein’s general relativity are then
Dg(x)/dtau = DH(N)/Dpi(x)
(1)
Dpi(x)/dtau = -DH(N)/Dg(x)
where D denotes functional differentiation in a region around manifold point x. Note, however, that H(N) is global not local. This is all in the explicate material order. There are no unconscious quantum information mental effects at this initial stage. Also "the theory can be formulated completely in terms of geometrical objects on a three dimensional manifold, with no a priori need to refer to its embedding into a space-time."
This is like the people in Flatland who have no experience of the third dimension of our space. We are like the Flatlanders compared to the hypothetical "Extra-Dimensional Intelligences" (EDI) in the superstring Calabi-Yau space of enormous latent energy described in Brian Greene’s "The Elegant Universe" (on perhaps the millimeter scale) that UFO astronomer, Jacques Vallee (played by Francois Truffaut in Spielberg’s Close Encounters of the Third Kind) speculates about and that the late Sakharov’s student, George Ryazanov, calls "Angels".
"A solution of (1) is a family of 3-metrics g(tau) that can be [classically] glued together to build up a 4-metric using the lapse function N to determine the transverse geometry … the spacetime metric emerges dynamically when one evolves the canonical variables with respect to multi-fingered time."
"Multi-fingered time" means each element inside g at x has its own local time. If we were to think of N point particles instead, then we are in a 4N dimensional configuration space with N local times attached to each particle considered as a clock, rather than a 3N + 1 dimensional one with Newton’s absolute time.
Of Super-Human Bondage
"However, the initial canonical data cannot be chosen arbitrarily, but must obey certain constraints: Only for initial conditions that lie in the submanifold of phase space on which Hi and H vanish do the solutions (spacetime metrics guv(x) also satisfy Einstein’s equations."
This means that the extremums of the action of the pure gravitational field, corresponding to constructive interference of the timeless implicate unconscious mental quantum informational amplitudes and phases for given spacetime histories require these constraints of vanishing transverse and normal infinitesimal Hamiltonian generators acting on the Bohm points (3-geometries) making them evolve i.e. generating time in the explicate order. The implicate order in quantum gravity is timeless like Dante’s Paradiso and like St Augustine’s theory, only the explicate order of the moving Bohm point, eschewed by all the mainstream quantum gravity theorists today has time. This is not yet the time of our conscious experience however, because even Bohmian quantum gravity has no back-reaction of the Bohm point 3-geometry on its timeless quantum information field that obeys the Wheeler-DeWitt equation.
To be continued.
Appendix
Murray Gell-Mann, without Bohm’s insights,
http://www.itp.ucsb.edu/online/hartle_c99/gellmann/
says about the limits of Stapp’s preferred orthodox quantum theory, his ontologization of Bohr’s "Copenhagen Interpretation"
"It is not wrong, …. but it’s far too special… it requires an outside observer making repeated measurements that’s not a universal situation, we don’t always deal with reproducible situations. What about individual objects and specific incidents in history… What about all those billions of years before there were complex adaptive systems? What about quantum cosmology where is the physicist outside it …. It insults our intelligence … how the classical world around us emerges from quantum mechanics … we are not finished … we know how to calculate probabilities … we will not make new predictions … we wish to explain convincingly … on the frontier between science and philosophy … conflict between poorly thought out concepts … personal attacks are not rare … we cannot appeal to observations … it is like the humanities …. How does quantum mechanics give rise to what we see around us … Early physicists had no doubts about classical world …. Two kinds of laws … classical and quantum … didn’t matter where line was drawn .. this dualistic view implicit made explicit by Landau and Lifshitz .. how 19th century physics emerges from 20th century physics …. [Gell-Mann assumes probability as fundamental] … History of universe is not fully determined by TOE of superstrings … need initial condition and results of accidents … many physicists fail to understand importance of the initial condition - second law of thermodynamics depends on the initial condition of the universe … initial condition was far from thermal equilibrium … any explanation that does not include initial conditions and accidents of history in the past [Gell Mann does not accept future causation]…. Only the whole of a closed system has a pure wave function … Avoid pure states for parts of the universe … use Heisenberg picture time-independent state with time dependent operators …. Wave function of the universe initial condition calculated in Lagrangian form (Hawking and Hartle) history still needs the accidents … competing is Linde, and if M theory then no Lagrangian … our work related to Hugh Everett III many-worlds … Zurek uses "environment" different from Gell-Mann … do not always sum over environment … Griffiths & Omness use "consistent histories" … not same as "decoherent histories" … "fine grained histories are not decoherent" , probabilities are only for coarse-grained decoherent histories … impossible to define sequence of spacelike surfaces from topology fluctuations …. Can still do sum over histories … decoherent histories are bundles of fine-grained histories … ignore general relativity …. Take discrete times with mutually exclusive infinite dim projection operators … set of projections depend on earlier history [memory] … path dependence of the projections … total probability always conserved … chain operator is product of the projections … i.e. different accidents of history are in the chain operator … no such thing as probability without a single decoherent set with no interference terms … Pa only relative to that particular decoherent set … different strengths of decoherence … weak minimal for consistency … weak …. medium … strong decoherence persistence of the past … you cannot disrupt past decoherence (Oh really? JS)