Your fingers aren't what you think they are - if they were what you think they are, that is, objects extended in space, then they would have to pass through an actual infinity of postions in order to move. So they're not objects extended in space. — Bartricks
Please explain what my fingers are if they are not 'objects extended in space'...
Time is not stuff - not a substance - for the reasons outlined, namely that if it were a stuff there would be no intrinsic difference between future, present and past and because if it was a stuff it would have to extend infinitely — Bartricks
That's not true, under the moving spotlight theory of time, 'now' is a cursor that moves down a line (or around a circle maybe), so time can be a substance and we can still differentiate between past, present and future.
I mean, try and imagine a portion of space that isn't divisible - it's impossible. — Bartricks
To divide something, you have to insert a piece of matter in-between the two parts. If space is made up of some sort of discrete mesh/grid, then it would be impossible to divide a mesh/grid node into two - the particle of matter exactly occupies one node of the mesh/grid at any time.
How many natural numbers are there? Infinite yes? Is that a problem? No. Why? Because it doesn't lead to an infinite task. — TheMadFool
There are an unlimited number of natural numbers - they go on forever in our minds - which is different from infinity - no matter how many times you add 1, you never get to a number called infinity. Only in our minds is it possible for something to 'go on forever' - if this occurred in reality, it would be akin to magic.
How many points are there on a line? Infinite yes? Is that a problem? Yes. Why? As Zeno showed Achilles can't catch up with tortoise. An infinite task.
A point has length 0, say the line segment is length 1, then the number of points on it is 1/0=UNDEFINED. It is not infinite or unbounded, it is just UNDEFINED. It's not surprising considering a point is defined to have length 0 - so cannot exist - something with all dimensions set to zero clearly does not exist - so the question can be rephrased as 'how many non-existent things can you fit on a line segment' - an answer of UNDEFINED is exactly what you'd expect.
This tells us that any ‘point-like’ particle that exists in reality must in fact have a non-zero extension in space. So any real life line segment made up of real life points must have a finite number of points on it.
I see no such problems in infinite space. What other alternative do we have if space is not infinite? Finite space, right? And the next question would be what lies beyond space? In fact infinite regress seems to be in favor of space being infinite rather than finite. — TheMadFool
The BB suggests that space maybe finite - space has been expanding at a finite rate for a finite time since the BB - so that suggests finite space (finite spacetime too). What lies beyond is pure nothing - there is no space and no time beyond the boundaries so nothing can exist.
Given that time is just a spatial dimension we have limited access to, there should be no problem in imagining time too to be infinite. — TheMadFool
But nothing can exist forever in time, so it must have a start. See for example the argument I gave in this OP:
https://thephilosophyforum.com/discussion/6218/the-universe-cannot-have-existed-forever/p1
Time - time - is not a stuff, not a dimension. Why? Because thinking of it that way means it would instantiate actual infinities. That's sufficient to establish that it is not a stuff, not a dimension. — Bartricks
If time was finite in extent and discrete, then it would be a dimension without any actual infinities. Same applies for space.
Limits, in mathematics, are calculations - tasks - that are infinite; they involve infinite steps. — Banno
Limits involve imagining an infinite number of steps which is distinct from actually performing infinite steps - actual infinity is unconstructable. See for example Thompson's Lamp paradox for the sort of nonsense results we get when performing the limit procedure out to actual infinity.