Terrapin Station wrote: ↑Wed Sep 01, 2021 12:29 pm
RCSaunders wrote: ↑Tue Aug 31, 2021 1:13 pm
Actually that makes it clear what you seem to mean. I cannot agree with it, but I see no good reason to debate it.
I do have one question, because it nags me. If there is some entity with a specific attribute, a certain mass, for example, are you saying that the mass is not the same mass a moment later? If that is what you are saying, did the first mass go away and become replaced by a new mass. If the mass is not the same, "identical," mass, it must be a different mass. What changed and how did it change?
Now that may not be what you are saying, I understand. But I think you can understand what nags me. I'm also not quite sure what you mean by the word, "identical." That may be what I'm not understanding.
So mass is tricky, because it's difficult to construe mass as something without a mathematical aspect. For example, mass is often said to be the "
amount of matter" that something has, or the more typical physics definition is that it's a
quantitative measure of inertia. So if we're saying that mass is an objective property, and we're going with one of those mathematics-oriented definitions, then all of a sudden we're positing objective mathematical properties/objects, etc., which is a mess; and in general I don't buy that mathematics is objective.
On the other hand, I do agree that there is objective matter and that there are objective properties that amount to inertia. And in my view there are objective relations, and some of those form the ideational basis of mathematics (without literally being mathematics). So the question is in what way, if any, can something's matter or inertia can remain the same over time.
What I'm referring to above in talking about something being the same, especially in an ontological sense, is whether it's literally what we'd call "one item" (so "numerically identical") that's somehow multiply instantiated. That "one item" is both here and there, spatially or temporally, so that two occurrences are somehow just a single thing. Spatially, I think that's incoherent, but temporally, there's one way that it can be coherent, and maybe this can apply to (amount of) matter or inertia.
It's important for this to remember that all that time is is change, including motion (motion is a type of change). So the one way it can make sense to talk about identity through time is if we're talking about changes to
other things, but not to the thing in question. For example, we're saying that x is "identical through time," based on x not changing (so in a sense there's no time for x, or time doesn't pass for x) but y and z change as a relative reference point for time passing.
However, a problem with this is that at least x's relations to y and z have changed if y and z have changed (so in that sense time
does pass for x), and especially given that mass seems to be a relational property (again, this is a fairly standard view in physics--mass is thought to obtain in the first place via interaction with the Higgs field, mass changes with relative velocity, etc.), then mass probably doesn't stay the same through time, even if the idea isn't completely incoherent (as I believe multiple
spatial instantiations of a single thing is). Does this mean that we'll measure different weights (we measure mass via weight while understanding that the two are not the same thing, they're just correlated) for what we consider the "same thing" at different times? No. But any device fine-grained enough to measure the differences that obtain would at the same time interfere with the object in question to an extent that the measurement device would "become part of the measurement" effectively, and the measurement wouldn't be accurate.
Thank you for that thoughtful explanation. I understand why you question identity in the ontological sense. It does not convince me, but I do understand why you have the view you have.
There are two things you said, I cannot have the same view of, however. I'll only explain why because you might like to consider them, not to convince you.
The first is this statement:
It's important for this to remember that all that time is is change, including motion (motion is a type of change).
Conceptually, the three primary attibutes of ontological existence are
position,
motion (change of position) and
acceleration (change in motion). Every single physics principle can be reduced to these three characteristics.
All three are relationships and have no meaning except as relationships. Anything that exists only has a position relative to other existents. All positions can be identified by the two metrics direction and distance. A thing's position is determined by it direction and distance relative to other existents.
In a static universe, positional relationships would be the only attributes there are, but of course we live in a dynamic universe, which means there is, "change." Change in position is motion. Motion is nothing more than the change in position of an existent relative to another existent, that is, a change in one existent's direction, distance, or both relative to another existent.
All motion can be identified by the two metrics,
time and
velocity. A things motion is determined by its amount of change relative to the amount of change of aother motion. Time is the amount of motion of one thing (how much its distance and direction changes) relative to a specific motion of another thing (a specific change in its direction or distance). Velocity is the amount change in direction or distance of one motion relative to a aother motion's change.
Acceleration is just another change, a change in motion, either its direction, velocity, or both, which I'll not discuss here.
Since direction, distance, time, velocity, and rate of acceleration are only metrics, that is, arbitrary ways of measuring the relationships between the positions, motions, and accelerations, they only exist epistemologically. The relationship are certainly real ontological phenomena, that is, the relationships between motions identified as time and velocity are real, but they are not independent ontological existents. There is no thing, "time," and there is no thing, "velocity."
The other thing I cannot quite view in the same way you do is:
What I'm referring to above in talking about something being the same, especially in an ontological sense, is whether it's literally what we'd call "one item"
The reason this does not make sense to me is unless something simply is what it is, there can be no motion, and no such thing as time or velocity. If a thing cannot change position (which it couldn't if it is not the same thing) it cannot move.
* The problem seems to be trying to view things as, "existing in time," because our own consciousness covers a lot of change (which we call time) but time is not a thing or place. (The same mistake is made about space which is nothing more than the fact that positions must all be different.)
*[One might picture things as an infinite string of infinitesimally enduring different things in time, I suppose, but don't see how that is not just a different way of picturing things remaining the same.]