Combining Texts

Ideas for 'On Liberty', '25: Third Epistle of John' and 'Travels in Four Dimensions'

unexpand these ideas     |    start again     |     choose another area for these texts

display all the ideas for this combination of texts

---

5 ideas

27. Natural Reality / C. Space / 3. Points in Space

22922	We can identify unoccupied points in space, so they must exist [Le Poidevin]
	Full Idea: If the midpoint on a line between the chair and the window is five feet from the end of the bookcase. This can be true, but if no object occupies that midpoint, then unoccupied points exist
	From: Robin Le Poidevin (Travels in Four Dimensions [2003], 03 'Lessons')
	A reaction: We can also locate perfect circles (running through fairy rings, or the rings of Saturn), so they must also exist. But then we can also locate the Loch Ness monster. Hm.

22924	If spatial points exist, then they must be stationary, by definition [Le Poidevin]
	Full Idea: If there are such things as points in space, independently of any other object, then these points are by definition stationary (since to be stationary is to stay in the same place, and a point is a place).
	From: Robin Le Poidevin (Travels in Four Dimensions [2003], 03 'Search')
	A reaction: So what happens if the whole universe moves ten metres to the left? Is the universe defined by the objects in it (which vary), or by the space that contains them? Why can't a location move, even if that is by definition undetectable?

27. Natural Reality / C. Space / 4. Substantival Space

22923	Absolute space explains actual and potential positions, and geometrical truths [Le Poidevin]
	Full Idea: Absolutists say space plays a number of roles. It is what we refer to when we talk of positions. It makes other things possible (by moving into unoccupied positions). And it explains geometrical truths.
	From: Robin Le Poidevin (Travels in Four Dimensions [2003], 03 'Redundancy')
	A reaction: I am persuaded by these, and am happy to treat space (and time) as a primitive of metaphysics.

27. Natural Reality / C. Space / 5. Relational Space

22928	For relationists moving an object beyond the edge of space creates new space [Le Poidevin]
	Full Idea: For the relationist, if Archytas goes to the edge of space and extends his arm, he is creating a new spatial relation between objects, and thus extending space, which is, after all, just the collection of thos relations.
	From: Robin Le Poidevin (Travels in Four Dimensions [2003], 05 'beyond')
	A reaction: The obvious point is what are you moving your arm into? And how can some movements be in space, while others create new space? It's a bad theory.

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

22931	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.