Sept 17: Space and Time
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To do for next class - 1) Read chps 7-9; 2) List all of the assumptions you notice that Taylor makes in his arguments for the nature of space and time. |
To do for next class - 1) Read chps 10 and 11; 2) Come up with your own few line definition of 'A caused B' |
Space and time
What are some of the motivating questions for examining space and time in metaphysics? None is there ontological status. If all things which exist must exist in space and in time then what shall we say of the existence of space and time? When we speak of time we often speak of something which moves (e.g. a river). However, movement presupposes time and thus it makes no sense to speak of time itself as moving. We must be careful of the sorts of analogies we use when speaking of space and time. It is common to refer to them as containers in which things exist (or space as a container and time as a river). However, we then have no answer for what contains those containers (or contains space, or what time is flowing with respect to... i.e. you can't define a container without space or a flow without time).
Of particular interest to Taylor is the relationship between spatial and temporal concepts. In essence, this seems to be an interest in the similarities of things we call dimensions. What sorts of similarities this Taylor find most obvious?
Notably, if we use these similarities as a basis for further exploration of the similarities of space and time, and don't speak of space and time as containers (e.g. the University campus takes up a mile of space; this class occurs at a certain point in time) they come to have many of the same sorts of characteristics.
What sorts of differences can you think of between space and time?
How does Taylor reject each of these claims? Did you find his explanations satisfactory?
1. That objects can be in two times at one place means that the object exist at each of the times and all the times in between. However, it is also the case that an object can be in two places by existing at each of those two places and all of the places in between. In neither the case of time nor space can object exist in two places and not be at the places in between.
2. What do we mean by an object moving back and forth in space? We mean and object is at its original place at a certain time and comes back to that place at a later time. If we slavishly replaced times and places in such a sentence, we obtain: an object is at its original time at a certain place and comes back to that time at a later place. This kind of sentence does not so the problem because we have assumed and use temporal words like 'coming back' and 'original'. In we leave aside such words, we can say the object is at place1 at time1 and at place1 at time2. Now the dual sentence becomes: the object is at time1 at place1 and at time1 at place2. The previous point can provide a consistent interpretation of these two sentences. Of course, we must provide the corollary that at intervening times or places it is at other times or places. Can you see a problem with Taylor's formulation? It seems to me to that in the case of moving back and forth in space, and object could either move back and forth or stay at the same place between times when into. However, in the case of time, and object has to be at all places between place 1 and place 2 at time 1 as well as being at other times. Nevertheless, it is interesting when Taylor describes what time travel amounts to in its spatial equivalent. Time travel means that an object can be at the same point in space at two different points in time and not in between. Analogously, and object would have to be into points in space at the same time and not in between. When thought of this way, it is not surprising that time travel is as difficult to conceive of as it is.
3. What you think of his case for change? I think Taylor's point might be more sound in the case of change. It does seem somewhat arbitrary whether we report our gas mileage as mpg or as liters per hundred kilometers. Dx by dt and dt by dx will give us the same slope if the axes are changed accordingly. What about changing other properties?
4. What you think of his claims about the fixity of spatial positions? He says that changing your positions and time is no more strange than your being two places at one place. Also, saying that something is always future to another thing is like saying something is always east of me. It is there a way of restating this sentence to make it not as obviously acceptable? How about: something is always future to another thing at every place. Then we get the dual of: something is always east of me at every time. This is only true if place stays fixed, which it need not. However, time must stay fixed in the examples of birth which he provides. This goes to show that we simply cannot treat events like objects. If we consistently talk of objects, or events perhaps we can make his point clearer. An event is always future/past or north/south of another event at every time/place. However it is not the case that an object is either always future/past or north/south of another object at every time/place. When cashed out more carefully like this, we still end up with Taylor's conclusion. With this realization, we can then understand better perhaps what he means with his hurricane example. Did anyone think of a way of doing the changing of places and changing of times and approaching and receding as suggested by Taylor at the bottom of p. 75?
Relativity of time and space
Space and time, it seems, are relationships not things. It is a category mistake to call them things and from this mistake much confusion is likely to arise. We try to make time for example, less like a relationship by agreeing upon a first-year. This gives us a fixed point of reference, making it seemed like time is not simply relative but rather absolute. However, 0 CE is an arbitrary choice. We are often under the impression that we can pinpoint a specific moment in time or space. However, try to pinpoint a place, and you'll find that at place only exists relative to other places denoted by objects. Relative to the position of the sun, here is no longer here for any here designating a physical object on Earth's surface. The same is true of now. It is this property which makes both space and time relative.
Taylor also talks of the direction of time. To agree with him that there's nothing metaphysical about the direction of time? What about the second law of Thermodynamics? Taylor points out that some temporal processes are reversible. Even if we generously grant him that, isn't it the case that all spatial processes are reversible? Can you think of any that aren't?
Temporal passage
Taylor notes that one way of conceiving the time and space relationship is to think of time as another dimension of space. We often here of time referred to as the fourth dimension. If all of time was laid out as we think of spatial dimensions being laid out, we can understand what Plato means in saying that time is the moving image of eternity. Consider analogously a two-dimensional world, called flat land, which is moving through time as its third dimension. From a God's eye view, temporal and spatial relationships are identical and ever fixed.
Taylor is not satisfied with this view because he is not certain in accounts for the data. In this case the data is that things in time seem to pass into through and out of existence. Taylor uses the term "pure becoming" to designate the fact that things become older, no matter what other changes they may undergo. does this turned make sense to you? Note: I'm not so sure how much sense it makes to talk of things ceasing to exist as Taylor seems happy to do on page 83. Do you find the idea of pure becoming extremely odd? Why does Taylor think it is odd?
These considerations lead Taylor to think that we might want to reject our data. However he then mounts a strong argument in favor of our intuitions. Note, that this is strange, given his complete disregard for intuitions in the section on fate.
The present
In this final section, Taylor pays for us the picture which is provided by Plato. The one we see analogously in flat land. Of course, given a God's eye view and certain assumptions about the reversibility of processes we end up at Taylor's favorite position, namely, fatalism. It is interesting that Taylor concludes by noting a disanalogy between time and space. Namely that at spatial relationships can be reduced to relationships between objects whereas temporal relationships can not. Why, precisely, is temporal passage so mysterious?
To do for next class
1) Read chps 10 and 11; 2) Come up with your own few line definition of 'A caused B'