CanMan » July 24th, 2020, 10:33 pm wrote:The infinite universe is a "where", where all finite objects exist.
charon wrote:A dimension is something measured.
CanMan wrote:It boils down to this  if you believe Time is truly a dimension, then motion is a function of time (not the other way around).
Serpent wrote:And if I don't?
Positor wrote:Section 2 of the Stanford article on Time (Reductionism and Platonism with Respect to Time) is worth reading. It deals with the question of whether there could be time without any change/motion.
CanMan wrote: Zero dimensional point can't change/translate into a line without a 1st dimension.
 One dimensional line can't change/translate into a plane without a 2nd dimension.
 Two dimensional plane can't change/translate into a solid (object) without a 3rd dimension.
 Three dimensional object can't change/translate into motion without a 4th dimension.
The 4th dimension is called Time. Without Time, there could be no motion or change of 3D objects.
CanMan wrote:The infinite universe is a "where", where all finite objects exist.
DragonFly wrote:There are no infinities (Einstein's curved spacetime is finite but boundless.
That is one interpretation
CanMan » July 26th, 2020, 6:03 am wrote:DragonFly wrote:There are no infinities (Einstein's curved spacetime is finite but boundless.
"Finite but boundless" seems to be as selfcontradictory as the phrase "beginning of time".
It is not possible for a finite universe to exist nowhere.
CanMan wrote:That is one interpretation of the word (dimension). A "measurement" is one thing, and a "structural property of the universe" is quite another.
charon wrote:You know, I get very frustrated with conversations of this kind. You say 'one interpretation'. What does that mean…
common sense
Positor » July 26th, 2020, 7:09 am wrote:The problem with a 'common sense' view of time is that many scientific observations about time and movement are contrary to common sense. For example, the fact that the observed speed of light is constant, regardless of the motion of the observer. And the fact that the internal changes in an object (how fast it ages) depend on its speed – hence the twins paradox.
We need a sophisticated understanding of time, and its relation to space (spacetime), to explain such things.

CanMan wrote:"Finite but boundless" seems to be as selfcontradictory as the phrase "beginning of time".
Positor wrote:A 2D surface can be finite and boundless, e.g. the surface of a sphere. A finite but boundless 3D volume is more difficult to conceptualize, but the principle is the same, and I think physicists are agreed that it is at least a logical possibility. The basic idea, as I understand it, is that 3D space is 'curved' in a fourth spatial dimension, so that you can travel in a straight line and eventually come back to where you started (given a vast amount of time).
Positor wrote:Please see the Stanford article I linked, for the argument against the universe existing 'somewhere'.
CanMan » July 26th, 2020, 2:30 pm wrote:...either, but I believe Time is a true dimension of reality, for without it motion could not occur. Motion can't happen without a means to happen, no more than a line can transform into a plane without a means.
My point is that if Time is a real dimension of this universe, then Motion is a function of, and is dependent upon Time. And if Time is merely a human construct; a measurement made with a clock, then the reverse is true  Time is then dependent on motion and change.
charon wrote:But you've said previously, I believe, that there can be time without motion.
charon wrote:I've seen that idea before but I have to admit it sounds like a nonstatement to me since there's never been any point when there was no motion at all.
charon wrote:So are we agreeing that time and movement are the same?
charon wrote:As long as there is movement there must be time simply because it takes time for any movement to take place.
CanMan » July 26th, 2020, 3:34 pm wrote:Positor wrote:Please see the Stanford article I linked, for the argument against the universe existing 'somewhere'.
I could not find where this was discussed in this linked article.
Positor wrote:If the universe is 'somewhere', what thing contains it, and where is it located within that thing? Might it have been located somewhere else?
Positor wrote:On the question of boundaries: Where is the boundary of the surface of a sphere? Don't confuse it with the boundary of the volume of a sphere (the latter boundary is, of course, the surface as a whole).
If we view time as a true dimension, then this is the means by which 'motion' is possible (i.e the movement/change of 3D objects).
There are more places without motion than with motion. Motion is only possible with 3D objects (matter). Much of our universe is matterless.
Time and motion are not the same. Without time there can be no motion. But without motion, time still exists.
Our only glimpse at Time is through the measurements of the spatial change in 3D objects (aka "motion"). "Measurement of time" is not the "dimension of Time".
CanMan » July 26th, 2020, 12:16 pm wrote: The universe is structured by its 4 infinite dimensions
[ P  Where is the boundary of the surface of a sphere?]
If the sphere is finite, then that which gives it its finiteness is its boundary.
charon wrote:How can time possibly exist without duration?
charon wrote:Our only glimpse of time is via motion. Obviously! Measurement of time is not the dimension of time. Obviously not. We invented the measurement!
charon wrote:This is why these arguments (not in the personal sense) get nowhere. We can't just posit stuff which may suit the purpose but doesn't exist. Come on, CanMan!
CanMan wrote:The universe is structured by its 4 infinite dimensions.
Serpent wrote:So you keep stating. Others say it's 10 dimensions, or n dimensions. How could we possibly know the limits of dimensionality?
CanMan wrote:If the sphere is finite, then that which gives it its finiteness is its boundary.
Serpent wrote:Now there is your classic tautology! The sphereness of a sphere guarantees (not gives) a shpere its finitness. Doesn't imbue it with the property of finiteness, but means that in order to be identified as a distinct object, it must first be finished. But that does not impose a limit on its surface, which is continuous. You can make an arbitrary mark anywhere and draw a finite line on the surface all around the sphere and back to that point, but the surface doesn't begin where you start or end where you stop; all you've done is measure one circumference of the sphere. OTH, a surface is not an object in its own right, but merely an aspect or attribute of an object, and thus limited in size and shape by the object it covers. If a surface is shaved off, the object still has a surface, but the removed surface no longer has an identity. If it was the surface of an actual sphere, made of solid material, then the shavedoff surface becomes a little pile of threedimensional matter, like clay or wool, with obvious limits. If it was the surface of an imaginary or holographic sphere, the shavedoff surface becomes nothing at all, which has no limits.
CanMan » July 26th, 2020, 1:54 pm wrote:I'm not disputing the number of dimensions. Who knows, maybe there are thousands of dimensions.
I'm just saying we need dimensions for change to happen.
A zero dimensional point can't change into a line without a 1st dimension. A one dimensional line can't change into a plane without a 2nd dimension. ...and we certainly can't get 3D objects to move (change into motion) without a 4th dimension (called Time).
My point is that if we call something "finite", we do so for some reason.
We do so because it has a boundary; a border; limits of some sort.
So if we call a sphere "finite" then it is specifically because it has a boundary.
If we identify that boundary as it's spherical shape,
That which gives it its 'finiteness' is that which gives it boundary.
"Finite" and "boundary" are therefore inseparable. Claiming something as "Finite and boundaryless" is a self contradicting oxymoron.

CanMan wrote:A zero dimensional point can't change into a line without a 1st dimension [i.e. without a space to move into].
Serpent wrote:Alternatively: When a zero dimensional point changes into a line, it creates the 1st dimension.
Serpent wrote:When 3D objects acquire the ability to move, a 4th dimension comes into effect and we may arbitrarily call this dimension Time  or Process or Change  or even use each of those words to describe activity in the 3dimensional universe.
CanMan wrote:"Finite" and "boundary" are therefore inseparable. Claiming something as "Finite and boundaryless" is a self contradicting oxymoron.
Serpent wrote:Stated, reiterated, still unproven.
CanMan » July 26th, 2020, 4:00 pm wrote:How can a 0D point move into a 1D space to change into a line, if a 1D space does not yet exist?
How do 3D objects acquire the ability to move into 4D motion if the 4th dimension does not yet exist?
Something cannot be both X and ~X.
Serpent » July 26th, 2020, 8:51 pm wrote:You can know the limit of a sphere, but you cannot find the borders of its surface. At least, that's how I understood Positor's example, which you didn't address, except to conflate the surface with the sphere itself, as you are doing now.
Positor » July 26th, 2020, 7:54 pm wrote:Yes.
Contrast this with a cube,
the 2D sides of which have boundaries; you can reach the edges of the sides. We are talking here about the boundaries between one side (surface) and another side (surface), not between the interior and exterior of the sphere.
There are no equivalent boundaries on the 2D surface of a sphere; there is only the boundary between the interior and exterior of the sphere, which is not the point at issue.
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