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27. Natural Reality / C. Space / 6. Space-Time

[relative space and time, treated as one system]

16 ideas
Space alone, and time alone, will fade away, and only their union has an independent reality [Minkowski]
     Full Idea: Henceforth, space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.
     From: Hermann Minkowski (Space and Time [1908], Intro)
     A reaction: Notice the qualification that it is a 'kind of' union. Deep confusion arises from exaggerating the analogy between space and time. Craig Bourne remarks (2006:157) that this shows independence of measurement, not of reality
Space-time arises from the connection between measurements of space and of time [Einstein, by Farmelo]
     Full Idea: Einstein noted that the measurements of space and time are not independent but inextricably linked, leading to the idea of unified space-time (introduced by his former teacher Minkowski).
     From: report of Albert Einstein (works [1915]) by Graham Farmelo - The Strangest Man 03
     A reaction: Notice the instrumentalist assumptions behind this.
We can't think of space-time as empty and propertyless, and it seems to be a substratum [Martin,CB]
     Full Idea: It makes no sense in ontology or modern physics to think of space-time as empty and propertyless. Space-time nicely fulfils the condition of a substratum.
     From: C.B. Martin (The Mind in Nature [2008], 04.6)
     A reaction: At the very least, space-time seems to be 'curved', so it had better be something. Time has properties like being transitive. Space-time (or fields) might be a pure bundle of properties (the only pure bundle?), rather than a substratum.
Space-time is indeterminate foam over short distances [Close]
     Full Idea: At very short distances, space-time itself becomes some indeterminate foam.
     From: Frank Close (Theories of Everything [2017], 6 'Intro')
     A reaction: [see Close for a bit more detail of this weird idea]
We distinguish time from space, because it passes, and it has a unique present moment [Le Poidevin]
     Full Idea: The most characteristic features of time, which distinguish it from space, are the fact that time passes, and the fact that the present is in some sense unique
     From: Robin Le Poidevin (Travels in Four Dimensions [2003], 08 'Mystery')
     A reaction: The B-series view tries to avoid passing time and present moments. I suspect that modern proponents of the B-series mainly want to unifying their view of time with Einstein's, to give us a scientific space-time.
Time, as it appears in standard modern science, is bad verificationist metaphysics [Smith,Q, by Le Poidevin]
     Full Idea: Smith argues that the theories of time which appear in the Special and General Theories of Relativity and in orthodox quantum mechanics are false metaphysical theories, based on verificationist assumptions.
     From: report of Quentin Smith (Absolute Simultaneity and Infinity of Time [1998]) by Robin Le Poidevin - Intro to 'Questions of Time and Tense' 4
     A reaction: I wouldn't have to confidence to stand up to the panoply of modern scientists, but I am glad Quentin Smith is having a go. I love Shoemaker's three worlds example, which defies all physics.
Space is 3D and lacks a direction; time seems connected to causation [Sider]
     Full Idea: Unlike time, space has three dimensions and lacks a distinguishing direction; unlike space, time seems to be specially connected with causation.
     From: Theodore Sider (Four Dimensionalism [2001], 4.5)
     A reaction: These strike me as nice reasons to doubt (what I already prima facie doubt) that there is a single manifold that is 'space-time', for all that twentieth century physics tells us it is so. A century is a mere click of a clock where truth is concerned.
The central question in the philosophy of time is: How alike are time and space? [Sider]
     Full Idea: The central question in the philosophy of time is: How alike are time and space?
     From: Theodore Sider (Writing the Book of the World [2011], 11.1)
Modern metaphysicians tend to think space-time points are more fundamental than space-time regions [Hawthorne]
     Full Idea: Nowadays it is common for metaphysicians to hold both that space-time regions are less fundamental than the space-time points that compose them, and that facts about the regions are less fundamental than facts about the points and their arrangements.
     From: John Hawthorne (Three-Dimensionalism v Four-Dimensionalism [2008], 1)
     A reaction: I'm not quite sure what a physicist would make of this. It seems to be motivated by some a priori preference for atomism, and for system-building from minimal foundations.
Spacetime may well be emergent, rather than basic [Ladyman/Ross]
     Full Idea: Contemporary physics takes very seriously the idea that spacetime itself is emergent from some more fundamental structure.
     From: J Ladyman / D Ross (Every Thing Must Go [2007], 1.2.3)
If spacetime is substantial, what is the substance? [Ladyman/Ross]
     Full Idea: It is fair to ask: if spacetime is a substance, what is the substance in question?
     From: J Ladyman / D Ross (Every Thing Must Go [2007], 3.2)
     A reaction: Personally I love the question 'If it exists, what is it made of?', though physicists seem to think that this reveals a gormless misunderstanding. To my question Keith Hossack retorted 'What are the atoms made of?'
The universe expands, so space-time is enlarging [Bardon]
     Full Idea: More and more space-time is literally being created from nothing all the time as the universe expands.
     From: Adrian Bardon (Brief History of the Philosophy of Time [2013], 8 'Realism')
     A reaction: [He cites Paul Davies for this] Is the universe acquiring more space, or is the given space being stretched? Acquiring more time makes no sense, so what is more space-time?
Relativity makes time and space jointly basic; quantum theory splits them, and prioritises time [New Sci.]
     Full Idea: Relativity says space and time are on the same footing - together they are the fabric of reality. Quantum mechanics, on the other hand, treats time and space differently, with time occasionally seeming more fundamental.
     From: New Scientist writers (New Scientist articles [2013], 2013.06.15)
     A reaction: Interesting. When talking about time, people glibly cite relativistic space-time to tell you that time is just another dimension. Now I can reply 'Aaah, but what about time in quantum mechanics? Eh? Eh?'. Excellent.
Space-time may be a geometrical manifestation of quantum entanglement [New Sci.]
     Full Idea: A promising theory (based on the 'Maldacena duality' - that string equations for gravity are the same as quantum equations for surface area) is that space-time is really just geometrical manifestations of quantum entanglement.
     From: New Scientist writers (New Scientist articles [2013], 2015.11.07)
     A reaction: This is a speculation which might unite the incompatible quantum and general relativity theories.
Einstein's merging of time with space has left us confused about the nature of time [New Sci.]
     Full Idea: Our hunt for the most basic ingredients of reality has left us muddled about the status of time. One culprit for this was Einstein, whose theory of general relativity merged time with space.
     From: New Scientist writers (New Scientist articles [2013], 2017.02.04)
In relativity space and time depend on one's motion, but spacetime gives an invariant metric [Baron/Miller]
     Full Idea: While spatial and temporal distances in relativity depend on one's relative state of motion, spatiotemporal distances within Minkowski spacetime do not. It therefore provides an invariant metric for describing the distances between things.
     From: Baron,S/Miller,K (Intro to the Philosophy of Time [2019], 4.2)
     A reaction: I doubt whether this solves all the worries which philosophers have, about relativity giving an account of time which contradicts our concept of time in every other area of our understanding.