Manifestation of powers: timing and continuity

Manifestation of powers: timing and continuity John Pemberton 21 November 2012

Manifestation of physical powers • Credible account of powers ↔ clear account of timing of manifestations of powers Change Compresence Resultant set of properties Property a Property b … Mutual manifestation partner 1 Property 1 Property 2 … Set of mutual manifestation partners • Ambiguity concerning manifestation – is it: • End state – i.e. a new set of properties (relational / causal profile account of powers) • A process of change (which brings about an end state featuring resultant set of properties) • Aristotle careful to make such distinctions concerning change • Nowadays less careful – e.g. use of term “event” • Let’s look at options for how change / timing might work

Option 1: Manifestation is (1) new state and (2) is not time extended • Now future history is some stepwise manifestations of powers • If finite number of powers in Universe: • Future history is not time extended • Even if countably infinite sequence of future manifestations (still has measure zero) • Perhaps Universe contains infinite number of powers and uncountably many future manifestations • Does not seem consistent with examples, e.g. fragility, solubility, power to heat

Option 2: Manifestation is (1) new state and (2) is time extended • What happens in between start and end? Can’t leave ontological gap • Perhaps there are intermediate steps: Mutual manifestation partner 1 Property 1 Property 2 . . Manifestation 1 Manifestation 2 Manifestation … • If temporal gaps between states, then same problem 1 level down • Need red arrows to have zero time extension • Perhaps compresence is time extended event – and (in limit) events are contiguous • Face Russell-type challenge: • Static time-extended events problematic – why does change occur now? • If exercising of power is not at end of change-event, then still lack contiguity • Power driven change at arrows – with other change during events? • Original power is e.g. not power of glass to smash – but power of glass to become stressed

Option 3: Manifestation is continuous process of change (resulting in new state) Mutual manifestation partner 1 Property 1 Property 2 . . Manifestation outcome Property a Property b Property c … Continuous path through property state space • But – need clarification: • Are all properties determinable? If not: what does continuity of property amount to? • May end with different number of things and properties • E.g. how can single, smooth, round object (e.g. glass) go through such continuous property change to produce lots of sharp, differently-shaped fragments • Need account of what continuity of change amounts to

Option 3 contd. • Power of original object sets trajectory through property state space, it seems • But how? • By assumption it is not stepwise process • Does control reach across time to guide through to end point? • Suppose just after glass hits ground and start to smash a strong wind suddenly starts • I suppose that how glass flies off is changed by wind • If so, manifestation of power is not “pre-programmed” absolutely – but only its “direction” is set (through to the end)

What can we learn from the practice of science? • How does (everyday) science model manifestations of physical powers? • Look at some typical examples • Scientific practice suggests that powers exhibit differing characteristics as to the timing and form of their manifestations • Draw rough characterisation of 2 types of manifestation which seem distinct: • Force-manifestations • Rearrangement-manifestations • Note some (prima facie) others types of manifestations

Force manifestations - examples • Pulling of object, e.g.: • Rope • Spring • Lifting rod • Pushing of object • Lever • Cog (on interlocking cog) • Gas pressure • Gravitational attraction • Electromagnetic attraction / repulsion

Two horses pulling a barge Horse 1 • See e.g. J. S. Mill, Cartwright, Molnar • Horses have the power to pull on rope • Manifestation of the pulling is a contribution • In this case contribution is a force • Force from horse 1: NE • Force from horse 2: SE • Manifestations is not a movement: • Barge is pulled E - the barge does not move NE or SE • (Manifestation = exercising) • Movement arises from combination of forces in the given arrangement Horse 2

Force-manifestations • Manifestation is a force • Force is a contribution to change • Given suitable machine arrangement (e.g. rigid bodies) forces combine by vector addition • Doesn’t seem to depend on what produces the force (e.g. gravity, electromagnetism, pulling from rope, gas pressure) • Manifesting is immediate and homogeneous – a directed pulling (or pushing) • Direction and strength can change continuously through time • Force must be time-extended • Science does not feature forces which exist for a single point in time • Eleatic Stranger’s principle for existence • (Force exists at each point in time during relevant time-period) • Force-powers are correlative • Power continues to exist throughout manifesting • Relativistic or QM modifications sometimes required to Newtonian story – here focus on mid-size slowish domain where accounts must agree closely

Rearrangement-manifestations • Manifestations which include movement of things from one place to another • And thus typically acceleration of things, changes in velocities, changes in orientation (i.e. rotation) • Rearrangement manifestations: • Take time (movement from one place to another is not instantaneous) • Non-homogeneous stages • Changes in other properties of things also typically occur during rearrangement manifestation, perhaps e.g.: • temperature, wear-and-tear, colour, etc.

Pendulum: power to oscillate / swing Start-arrangement End-arrangement • Manifestation: • Bob exercises power to attract / be attracted by the Earth; • String exercises power to pull bob towards the pivot • Bob moves around arc • Forces combine in this arrangement to produce the swing of the bob • Which is the manifestation of the pendulum’s power to swing in this case • Arrangement matters: Parts must be positioned and connected in the right way, e.g. string must be tied to bob and other end to the pivot • Parts have distinct properties: bob is dense mass; string is sufficiently strong; pivot is fixed • Example typical of many other rigid body dynamic cases

Rearrangement manifestation involving movement of fluid: cistern flush • Cistern has power to flush When the handle is turned, the lever (which has the power to pull up the lift rod) pulls up the lift rod (which has the power to open the outlet valve) which opens the outlet valve (which has the power to release water from the cistern), which releases water from the cistern, which lowers the ball-cock, which opens the inlet valve,… • Manifestation involves nicely sequenced exercising of powers of parts • Powers of each component combine together in the machine arrangement to produce a manifestation of the power to flush • i.e. release of flush and refill of cistern • Manifestation of power is a rearrangement which involves movement of fluid

Chemical rearrangement: hydrogen-oxygen explosion O H H H H Start-arrangement H End-arrangement H O O O H H • Hydrogen gas has power to explode (with oxygen) to produce water • Manifestation: • H² and O² have power to separate in to atoms when sparked • The hydrogen and oxygen atoms have power to bond as H²O, and give out energy (which may separate more H² and O²) • Change process is explosion • Manifestation is a rearrangement: • Occurs quickly – but not instantaneously • Involves breaking and forming of (atomic) bonds • Involves subatomic forces / energy release • Other examples: solubility

Example: synaptic transmission

Smashing of glass • Manifestation is rearrangement • Involves breaking of microstructural (chemical) bonds • One thing → many things

Rearrangement manifestations • Time extended • Arrangement (structure) of things is central: • It fixes locations of powers – and thus what they do in this context • It is what changes when things move from one place to another • Thing with rearrangement power may or may not survive manifestation • A story we can sometimes tell about rearrangement manifestation is (roughly): • Structure coordinates forces to produce rearrangement • This story is incomplete, e.g.: • Fluid flow • Chemical rearrangement • Breaking and forming of bindings • Strong and weak forces • Relativistic / QM considerations • …but it does seem to be an important part of the story • To the extent we can tell this story, we have a nice account of how continuous process manifestations come about

Smashing glass + wind • Structure-coordinating-forces story also provides nice account of this case • Wind is an additional force which starts to operate during the unfolding rearrangement • Forces combine in the given arrangement at each stage: • Forces in glass (and pieces of glass) from smashing • Forces due to wind

Some other types of powers • Generic powers • E.g. to walk, fly, bark, solubility, fragility, etc. • Can these be equated with rearrangement powers? • Change to properties (other than structure) • E.g. (perhaps) power to make red • Animal powers • Human powers • Power of God

Metaphysics of power manifestations • What implications, if any, do these scientific considerations have for metaphysical account of power manifestations? • Metaphysics should be adequate basis for basic science • Let’s suppose that the world includes force-powers and rearrangement-powers (roughly as characterised) – what then?

Metaphysical implications • Force-powers: • When forces give rise to change, this change involves acceleration and movement which is continuous through time • Consistent with powers giving rise to continuous processes of change • Power persists through manifestation • Rearrangement-powers: • Involve movement from one place to another • Difficult to regard this movement of a thing as a property (E J Lowe) • (Velocity may be property) • This movement is continuous process • Favours view that: manifestations are processes not state-changes • But perhaps others might argue: • No force-powers and/or rearrangement-powers (in ontology) • Science is deceived – force & rearrangement manifestations are state-changes • Only some manifestations are processes • Other

Favours view that arrangement / structure matters • Position of powers affects: • how they manifest • how manifestations combine • Change in the arrangement is often a central part of the manifestation • i.e. move of part from one place (or orientation) to another • The structure-composes-force story: • Scientifically compelling • Suggests way we might integrate the metaphysical accounts of force-powers and rearrangement-powers - appeals to parsimony • Offers (remarkably nice) solution to the problem of manifestation timing • Interplay of force-manifestations, accelerations, velocities, ∆position through time, arrangement • Perhaps familiarity with Newtonian mechanics makes us overlook • Seems to be the only solution currently on the table • We need robust account of structure

Need for robust structure Property 1 Property 2 … • Seem to need structure which allows for: • Separate (potential) parts • Each part has its own: • Position • Properties / powers • Bindings link specific parts Prop 1 Prop 2 … Property 1 Property 2 …

List of properties does not seem adequate Property 1 Property 2 … Position prpty 1 Position prpty 2 … Binding type 1 … Property 1 Property 2 … • Need position properties to be associated with subset of properties / powers of list • Bindings • Link specific parts: need to be cross-referenced to these parts • Not just another compresent entity • Not clear that we can derive arrangement/structure of parts from property lists • So that e.g. butane and iso-butane are distinct Prop 1 Prop 2 … Property 1 Property 2 …

Molnar • Molnar argues that positions are non-powers • What is the manifestation of a position? • Positions central to how powers operate • Position of powers matter - not just another item on the property/power list • Points towards need for structure

Aristotle • Powers in modern science are Aristotelian: • Cartwright & Pemberton • Correlative, persist through change, arrangement matters, give rise to continuous change • Provisional view: things in modern science are Aristotelian • Changing material • Substantial forms are more than list of properties • Seems to include (some sort of) structure • Restricted mereology • heaps, bundles, artefacts, substances • Admits bindings: heap → bundle • Tyings, boltings, nailings, gluings, hookings, shape interlockings, chemical bondings, etc. • Arise from (juxtapositional) arrangement of things • In science bindings are often a mereological principle • Questions: • Can Aristotelian bindings do: parts → artefact? • Does Aristotle allow that artefacts have substantial (or other) forms

Summary • Manifestation timing and continuity: • How is this supposed to work? • Modern science suggests: • (Many) manifestations are continuous processes • Structure is often central to the manifestation • For a metaphysics in which powers give rise to processes of change, we seem to need structure • What is account of powers without structure? • Aristotle’s things and powers seem promising basis for modern science

Manifestation of powers: timing and continuity