My personal notes from the book Quantum Reality

---

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13

1.

Misc. thoughts: randomization collapsed the wave function.

Top

9. Four Quantum Realities

Intro (157)

• "Discoveries in physics cannot in themselves - so I believe - have the authority of forcing us to put an end to the habit of picturing the physical world as a reality." - Erwin Shrödinger
• Quantum theory works (explains the facts), but physicists don't know why.
• Quantum theory is like a tower:
  • middle: known and occupied
  • top: work is going on
  • bottom: structure is unknown, physicists shun it with superstition and dread
• reality crisis = no one can agree what's holding it up
• different theories of reality are from taking some features of quantum theory seriously and rejecting others

Quantum Reality #1: Copenhagen Interpretation I: There is no deep reality (158)

• Bohr and Heisenberg
• believe when an electron is not being measured, it has no definite dynamic attributes
• QR1 is not pragmatic
  • a pragmatist is concerned with results, not reality
  • theory is a mathematical engine for generating numbers which are then compared with experiment
• Heisenberg Uncertainty Principle (HUP) is central clue to nature of quantum theory, and HUP bound with process of measurement
• earlier on, the measurement dependent uncertainty was attributed to measurement
• but the shifting uncertainty of conjugate attributes is too systematic to be explained by measurement
• also, Renninger-style measurements - where you gain info because you do NOT detect something... same as when something DOES happen, something NOT happening collapses the wave function and increases uncertainty of conjugates
• in disturbance model, electron possesses attributes which are unpredictably changed by the measuring device
• in quantum measurement, attributes don't belong to electrons but are relations between it and measuring device and don't belong to either
• Bohr's "relational reality": since attributes in between, you can change measuring device and influence the attributes
• recall analyzing traffic into tuba, piano etc. waveforms - it's analogous to electron's position, momentum etc.
• ordinary world: an apple = one objective apple, though many subjective ones
• quantum world: not one comprehensive "thing" / picture of the world - atoms are not "things"; the quantum world is objective but objectless.. not subjective
• like a rainbow: no beginning / end, different for each observer, but it is objective, can be photographed
• for Bohr, search for deep reality is like looking for the end of the rainbow
• phosphor screen is made of electrons and opposite also true to Copenhagenists
• Bohr thought of ordinary objects like measuring devices, cats, etc. as following classical style of existence, different from electrons
• von Neumann's paradox of infinite regress: measure M1 with a measuring device M2, then measure M2 with another M3, etc. Roles change, classical to quantum
• i.e. privileged role for measuring devices, in terms of actualities not possibilities like everything else
• another difficulty with this reality / view is that measuring devices and measurement are both unanalyzable

QR #2: Reality is created by observation (164)

• stresses quantum meter option: observer's ability to choose what attribute to look at, i.e. choose which waveform alphabet to use - "observer-created reality of the first kind"
• by choosing what attributes to look for, you choose what attributes a system will seem to possess
• John Wheeler built Institute of Theoretical Physics in Austin into most important center for quantum reality research
• he's championed several QR's but none more than this QR#2
• Wheeler's delayed choice experiment: observer creates not only present attributes but ones which must have existed way back in time
• illustrated by his thought experiment, gravity-lens interferometer
  • a massive object bends spacetime and deflects light
  • a quasar = intense source of light, ignited shortly after birth of universe
  • how you measure now influences whether photon took one or the other, or both paths
  • seems to show that the past is not fixed but alters according to present decisions
  • Alan Watts, philosopher: some Eastern philosophies say this: "The moment of the world's creation is seen to lie not in some unthinkably remote past, but in the eternal now."
  • note limits: can choose whether one path or two paths, but not where or which path... "quantum random", i.e. can select attribute but not its value
• attributes of larger objects like apples? Wheeler implies they're real before they are observed. N David Mermin says they're not.
• what counts as an observation was also debated
  • Wheeler: making a record (Polaroid, Geiger counter)
  • some say not enough, need a conscious observation, i.e. "observer-created reality of the second kind". Before observers, universe was in an indefinite state with undetermined attributes and their values
  • Bishop Berkeley goes farthest to say that matter is not real until a mind perceives it (see QR#7, consciousness-created reality)

QR#3: Reality is an undivided wholeness

• David Bohm and others
• related to Bohr's notion that quantum attributes reside in the "entire experimental arrangement"
• by extension this can implicate the whole universe
• basis is rooted in phase entanglement
  • when 2 quons meet, their proxy waves merge
  • on separation, their amplitudes come apart but their phases do not
  • phases become entangled such that interference effects of A depend instantaneously on disposition of B
  • ordinary waves do not become phase entangled
  • has to do with quantum waves living in "configuration space", not 3-D space
  • configuration space has 3 dimensions for each quon, i.e. 2 quons means 6 dimensions
  • this is why physicists consider wave function to be fictitious (many more dimensions then our own space)
• spooky action at a distance: first emphasized by Shrödinger
• so unusual to Shrödinger he called it THE chief feature of quantum theory
• this connection may not exist in "reality" though
  • quantum theory does not seem to permit any messages to be sent along this link
  • link may be like dotted lines on a star map
  • if wave function were real, waves shape would have to change drastically at faster than light speeds
  • Heisenberg suggested wave function represents our knowledge of a physical situation, not a real situation. Wave function collapse also not real but represents a change in our knowledge. Renninger style measurements too just increase our knowledge
  • analogy: 2 coins mailed to Tokyo and London. Opening Tokyo's does not mean faster than light communication to London, it is from "preestablished relation" - they're correlated, but not connected
  • implying that instantaneous phase connections exist in math but not real world
• remember that rainbow: it's a virtual image - it appears to be someplace that it is not. Alice's world on the other side of the mirror also.
• in optics, these things are real - can be photographed, magnified, reflected.
• gold / silver coin analogy may not be best comparison - but, knowledge of quantum world may not be of preexisting reality (Heisenberg)
• John Bell discovered "quantum correlations are too strong to be explained by ordinary knowledge models like the gold/silver coins"

QR#4: The many-worlds interpretation (172)

• first by Hugh Everett in 1957, under John Wheeler
• takes measurement problem seriously
  • measurement interactions can't really be special
  • Everett follows von Neumann's quantum theory and represents everything by proxy waves, but leaves out wave function collapse
  • each measurement split to waveforms = number of quantum systems = number of measuring devices
  • e.g. 5 possible waveforms, 5 quantum systems and 5 meas devices
  • since we don't see 5 M devices, Everett proposed the M device splits into 5 in 5 parallel universes
  • each human observer perceives only one universe
  • without all universes, ours wouldn't be the same
  • imagine a continually branching tree
• interactions in this "super-real world": 2 systems come together, get correlated and realize mutual possibilities. an M device is like any quantum entity except sensitive to a certain correlated atomic entity's attribute
• despite wild assumption, this reality is a favorite of many theoretical physicists because its the only one that solves the measurement problem without exalting measurement act
• there are no "measurements" in the world, only correlations
• the system does not impact the observer; the observer becomes correlated to the system
• Henry Stapp: infinitesimally small possibilities can happen with this reality, e.g. life on earth

Misc. thoughts: when two quotons meet, they become phrase entangled. Shrödinger's blanket.

Top

10. Quantum Realities: Four More

QR#5: Quantum Logic (177)

• the world obeys a non-human kind of reasoning
• 1936 John von Neumann and Garrett Birkhoff
• "logic" = how attributes combine to make new attributes
• classical world was Boolean logic
• vN and B: because quantum attributes represented by waveforms, "wave logic"

Logic Lattices

• lattices show at a glance all AND/OR relations between attributes
• ordered by inclusiveness, most inclusive on top
• classical (Boolean example: colors ... page 179 diagram)
  • primary RGB are basis of additive color mixtures
  • process (yellow, magenta, cyan) colors = subtractive - for color printing
  • AND = follow lines down and first / topmost one in common is result of AND
  • OR = follow lines down and first / bottommost is result
  • in diagram, white = all at top; black = null, all at bottom
  • cyan and magenta = blue. cyan filter (passes only cyan light) + magenta = filter that passes only blue light
  • OR = mixing 2 colored lights. cyan light + magenta light = white light... but it is bluish white light.
• nonclassical non-Boolean example: polarization lattice
• polarization P(¢) = quantum attribute defined for any direction ¢ in spaces which can take only 2 values
• P(0) and P(45): P(0) can only be H or V, P(45) can only be D or S
• H OR D = all: superpose H and D and can get all polarization attributes (if put in proper place)
• H AND D = null: no attributes in common i.e. no light beam will go through both an H and D filter
• distributive law in classical logic: A OR (B AND C) = (A OR B) AND (A OR C): loosely means that a combination attribute behaves like the sum of its parts
• quantum logic lattices follow all Boolean rules EXCEPT the distributive law: H OR (D AND S) = H OR N = H; (H OR D) AND (H OR S) = H AND A = A .... H IS NOT = A!
• sublattices HVNA or SDNNA are Boolean, however. these are compatible attributes, follow ordinary logic. you can only measure a certain set of compatible attributes at one time; they reflect the "surface ordinariness" of quantum fact.
• "isles of Boole" in a wave-logical ocean of non-Boolean relations
• since relations between isles don't satisfy Boolean logic, something is fishy about the connection between the whole and its parts
• most quantum logic work is a mathematical study of non-distributive lattices... exception: David Finkelstein: quons differ from classical objects:
  • in how their attributes combine to make new attributes, i.e. have classical attributes that follow a non-classical logic
  • a classical object has parts and assembly drawing; a quantum object does not have definite parts - can break up many ways, each division has classical style view but connection between them all by non-distributive lattice

The 3-Polarizer Paradox (182)

• polarizing filter lets only one kind (parallel to optic axis) of light through
• H and V filters together will block all light
• put a D filter in front of or in back of H and V, and light is still all blocked
• but, put D in between H and V and light shines through!
• H = D o+ S (note using o+ as symbol for circle with plus inside)
• D = H o+ V, S = H o+ V (difference in phase though with these two)
• i.e. D and S consist of half V light but combined, they have no V light. D's V light must interfere destructively with S's V light.
• H = D o+ S = (H o+ V) o+ (H o+ V) = H ... the V's are destructive
• when the D filter absorbs S light, the perfect destructive interference is destroyed and now uncanceled V light gets through the filter
• implies, by removing one member of a pair of interfering attributes, the D filter appears to create light out of nowhere!
• analogous to Sheldon Glashow's quark-mediated K-particle decay, where more is less: adding a second decay channel suppresses decay, whereas in 3-polarizer paradox, less is more
• quantum logicians describe this 3-polarizer paradox as a simple case of nondistributive logic

QR#6: Neorealism - world made of ordinary objects (185)

• generally dismissed by physicists as misguided and naive, as outmoded as a flat earth (Heisenberg: atoms are not things)
• von Neumann's proof too blasted it - proved atoms cannot resemble ordinary objects
• Quantum Monte (186): 3 card game analogy - 3rd card is conjugate attribute
• similarities of card game to quantum situation:

• element of chance
• unremarkable events (Cinderella effect)
• statistical pattern gives the game away
• definite restriction on measurement
• a choice to look at one aspect means not looking at something else

David Bohm's ordinary object model of the electron

• he was a Copenhagenist until conversations with Einstein influenced him
• the act of turning over one card changes the others
• or, the electron changes its colors depending on what you decide to measure, via the "pilot wave" field
• the pilot wave puts electron in instant contact with every other particle in the universe
• you can't trick the system (turn over two cards at the same time) - the communication is too instantaneous
• loophole in von Neumann's proof: "ordinary objects" is too restrictive
• Copenhagenists reject it on grounds: 1. "Objects" should not be in touch with everything in the universe, and 2. especially not faster than light
• Bohm's ideas were no return to an ordinary reality
• Bell showed these instant connections are necessary in any (neorealist?) object-based reality

QR#7: Consciousness creates reality

• first suggested by John von Neumann
• used logic to get there
• assumes quantum theory applies to everything including M devices
• proxy waves represent everything
• quantum measurement problem boils down to: where does the wave function collapse? where in the von Neumann chain?
• thinking that where the mystery of matter gives way to the mystery of mind is where quantum jump occurs
• because all other places are rather unremarkable
  • making a record implies an irreversible event
  • Renninger-style measurements still require possibility of an irreversible act
• consciousness created (#7) versus observer-created (#2) different in that:
  • observer kind: observer creates reality by choosing what kind of attributes a quon shall possess (observer creation of the first kind)
  • consciousness-created goes farther - consciousness selects which values actually become realized (observer creation of the second kind)
  \
  • i.e. .meter option chooses the game, consciousness deals the cards
• machines can't observe unless they have an awareness of their own (ghost in the machine)
• 18th century, Newton's mechanics led many to believe all phenomena can be explained as type of complex machinery
• George Berkeley of Ireland agreed and started "idealism" - existence belongs to minds alone, mind is not a form of matter but rather matter only exists as a perception of the mind
• QR#7 does not go this far - a quon and its static attributes don't need conscious observer, just its dynamic attributes need one
• the entities themselves do exist before consciousness

QR#8: the duplex world of Werner Heisenberg (193)

• foundation of empirical evidence via measurement
• analogy to King Midas: all he touched turned to gold. All we touch turns to matter!
• the majority of the universe, as unmeasured, is a mystery
• Heisenberg tried to describe this world in non-math terms
• takes Copenhagen interpretation literally: two worlds:
  • observed one of ordinary experience
  • the unobserved one is of possibilities, potentia: multitude of contradictions, not possible with actualized elements. In a sense it is more real because of this; it is ghostly, transitory and yet the foundation for everything around us

Quantum Reality Reprise (196)

• heated debates for 30 years, then
• in 1964, John Bell proved theorem and gave new insight

Top

11.

Top