I already said this is NOT Newton’s absolute space, but rather space substantivalism. The spacetime version is rejected by Einstein not because of logical positivism/verificationism, but rather the hole argument. A majority (but definitely not all) of physicists are convinced by the hole argument, and agree with Einstein that spacetime subtantivalism is false. I myself am not convinced one way or the other.
Regardless, this has nothing to do with Newton’s absolute space, which goes back to the problem in this entire discussion that you don’t even know what Newton’s absolute space even is…
That’s all I want to add. Next time maybe learn the subject first before arguing it with someone.
I’ve enjoyed following this exchange, mostly because I learn a lot from PdotdQ’s posts on physics so I appreciate how your posts have led to him saying more.
From reading your posts, I suspect you and he differ on an a basic assumption which I have not seen mentioned explicitly. It is this question:
How should our best physics constrain our metaphysics of space and time?
I think PdotdQ and almost all philosophers believe that our metaphysics must be consistent with our best science. With this in mind, Newton’s concept of absolute space cannot be used for an ontology of space. You are correct that there is no general agreement in philosophy about what the ontology of space is; but whatever it is, philosophers agree it must be consistent with what we have learned about reality from our best physics.
You seem to think that metaphysics proceeds independently of science. If so, that would be why you do not see the point of PdotdQ’s posts.
PdotdQ has explained absolute space using advanced mathematics; that math much too advanced for me. Instead, I have found the following helpful; they require much less mathematics. The Maudlin book is a very nice introduction to the philosophical issues and the related physics, should you want to invest more time in these.
I don’t plan to contribute further to this thread.
I’m a physics hobbyist, so I may get this wrong . . .
The speed of light seems to be an important thing to look at. From all experimentation we have looked at, the speed of light is the same in all frames of reference. If there was an absolute frame of reference that everything is compared to, then the speed of light should be different in all but one frame of reference.
This is why I asked you before if there were experiments that we could run on a spaceship to tell us if the spaceship was moving or not. If the spaceship was the only thing in the universe, how would you determine its velocity if you have no knowledge of any past acceleration that has acted on the spaceship? If you measured the speed of light on that spaceship it would be the standard 3E8 m/s, would it not? In fact, the speed of light will not change even after you accelerate the ship and start coasting through space.
Now let’s add another spaceship in our empty universe. You wake up and look out the window of the spaceship. You see a spaceship hurtling towards you. A passenger in the other spaceship observes the very same thing. So who is moving? Are you both moving? You shoot a 588 nm laser out the window and the passenger in the other spacship measures it as 500 nm. Who is right? Is the wavelength of the laser 588 or 500 nm? You both measure the speed of the laser light at 3E8 m/s, but the spaceships are moving towards one another. How does that work?
I could be wrong, but if I’ve understood correctly substantivalism seems to be a term that was coined along with relationalism to represent the ontology of Newton’s views of space and time as opposed to Leibniz’s views.
The confusion may be over (Newtonian?) space substantivalism vs (Galilean?) space-time substantivalism which I believe represent differing mechanistic formulations from the same conceptual framework of the absoluteness of space and time.
But as I’ve already mentioned, I’m not concerned with the mechanics, but rather with the ontology. So as far as I can tell, my points in regards to the ontological issues seem to still be valid.
The notion of substance has played a leading role in the ongoing debate about the nature of space and time. Although neither Isaac Newton nor Samuel Clarke claimed that space is a substance, the positions taken in the famous debate between Leibniz and Clarke have come to be known, respectively, as relationism and substantivalism. Various philosophical views asserting and denying that space and time are real entities distinct from physical objects have been refined, and the pendulum swings between them have [sic] often been guided by technical results of current physical theory.
In discussions about space and time, the name relationalism (or relationism) refers to Leibniz’s relationist notion of space and time as against Newton’s substantivalist views.[4][5][6] According to Newton’s substantivalism, space and time are entities in their own right, existing independently of things. Leibniz’s relationism, on the other hand, describes space and time as systems of relations that exist between objects.
Isaac Newton founded classical mechanics on the view that space is distinct from body and that time passes uniformly without regard to whether anything happens in the world. For this reason he spoke of absolute space and absolute time, so as to distinguish these entities from the various ways by which we measure them (which he called relative spaces and relative times).
Substantivalism is the view that space exists in addition to any material bodies situated within it. Relationalism is the opposing view that there is no such thing as space; there are just material bodies, spatially related to one another.
The Galilean substantivalist usually sees himself as adopting a more sophisticated geometry than Newton but sharing his substantivalism (though there is room for debate on Newton’s exact ontological views; see DiSalle, 2002).
I think this excerpt from above is key to the point I’m making.
Newton spoke of absolute space and absolute time, so as to distinguish these entities from the various ways by which we measure them (which he called relative spaces and relative times).
So it seems pretty clear to me that Einstein’s rejection of Newton’s absolute space and time was to assume that their existence was dependent on the act of measurement. In other words, it doesn’t exist until it’s been measured, or at least unless it can conceivably be measured. And since there’s no way that absolute space can be measured in human terms, therefore it doesn’t exist.
That’s a classic verificationist/logical positivist view, similar to how various interpretations of QM claim how particles don’t really exist until being measured. But a measurement implies an observation of the measurement, and that implies an observer.
So basically that implies that space, time, and matter are observer dependent which would imply that there is no objective reality. But what compelling evidence is there to cause us to deny everything our experience of observable reality is intuitively telling us?
Now I’m not saying that such a reality isn’t possible. I’m aware of the idealist philosophy that suggests that everything is mind dependent. Personally I just don’t find it very persuasive since there isn’t compelling enough evidence or reasoning that I can see to deny what observation and experience tell us.
And I don’t see how mathematical equations qualify as evidence either. They are just abstractions of observations, not, in and of themselves, actual observations. Nor does the ontology from which the conceptual framework of a mechanistic description is derived provide any epistemic value, that I can see, in establishing the truth of that ontology. Otherwise, based on empirically equivalent equations, there would be several true ontologies for one true reality, which seems absurd.
Regardless of the conceptual framework, as long as the mechanics is shown to be accurate that’s all that really matters as far as the usefulness of the equations are concerned. But the mechanics of physics don’t determine reality, they are simply useful abstract tools for describing the reality that we have empirical access to of how matter behaves.
So I don’t see how they can provide any epistemic value when it comes to the question of existence that is beyond empirical access because of human limitations. Again, that’s a job for observation and reason to sort out, not mathematical equations.
As far as I can tell, the hole argument has to do with mechanics, not ontology. And if I’m not mistaken, spacetime substantivalism was developed after Einstein developed the hole argument, which he originally developed for a different purpose. I believe his argument was later modified by other philosophers for use as an argument against spacetime substantivalism in the second half of the 20th century.
Yes, that’s the question I’m raising. My contention is that ontology should be based on observations and reason, not on mechanics which, in my opinion, don’t provide any epistemic value to ontology. And until someone can offer a valid argument as to why I’m wrong, I believe I’m warranted to take such a position.
Not exactly. Science provides the evidence through the observations it makes. And thanks for the links you provided.
OK. But what is the point you’re making? That’s not clear to me. Would you mind to clarify that?
I’m pretty doubtful that ontology can be defined mathematically. I think any mathematical definition of absolute space is simply going to be a mechanical definition, not an ontological definition. But I’m sure you won’t agree with me so I guess we’re back to agreeing to disagree.
You misunderstood me. I don’t need you to write:
“Absolute space is ontologically real”
in mathematics, just what is “absolute space” itself.
At this point, I don’t even know what you claim to be ontologically real. You might as well said:
“Gorblasch is ontologically real”
but never defined what a Gorblasch is.
This is not an impossible task. Indeed, now knowing that you are just talking about space substantivalism, I know how to write it mathematically myself. I just want to have your definition, as from speaking to you, it’s apparent that your definition of absolute space requires ridiculous, non-standard things like “human observers”.
I could be wrong ( ) , but it seems to me we are talking past each other again. You seem to want to define absolute space “itself” as a mathematical entity. But that’s not where I’m coming from at all. My concern it with how it’s being used in an ontological sense of what is its nature.
And I think the definitions that I quoted were clear enough to get the sense of what its nature is. Granted, there are discussions about specific aspects of it that philosophers go back and forth on. But, I think it’s pretty obvious that the existence of space that’s dependent on relativity is the opposite of its nature being absolute and independent of measureability.
(Edit) And I’m not talking about space subtantivalism, I’m talking about substantivalism. There is a difference from what I can tell from the quotes I provided in my last comment.
I don’t think it’s clear at all, especially because the previous definitions you gave requires things like “human observers”, which are different from “definitions” that you quoted.
Right now, you are really just saying “Gorblasch is ontologically real” to me. I don’t know what you are claiming is ontologically real.
I am curious of your use of the word “relativity”. Do you think that Einstein’s theory of relativity or general relativity refers to spactime being “relative” in the sense that its existence depends on matter? What would you say if I said that that is not the “relative” that Einstein meant at all?
Finally what about your lofty goal of creating a theory of everything? Do you think that you can combine quantum mechanics and gravity, two theories that are incompatible at the mechanistic level by adopting an attitude that according to yourself does not change the mechanism? Or have you given up on that ambition?
The observers are implied from the definition. And those definitions are how professional philosophers define it. That’s the best I can do. If that’s not good enough, I would agree with you that there’s not much point in discussing this any further.
I think we’re talking about whether or not space is real, aren’t we?
This whole discussion has helped me see a lot of things I didn’t realize when I first posted the op. I now am of the opinion that there just is no conflict between quantum mechanics and relativistic mechanics, at least as far as their ability to describe empirically accessible observations of how matter behaves.
That’s really all that matters as far as I can tell. There’s the side issue that remains of the ontologies used for their conceptual frameworks not being compatible. But big deal. As long as they work that’s really all that matters.
The only real issue that needs to be settled is which ontology is true, which in my opinion is totally separate from the mechanical issues. But regardless of which ontology is decided upon, I don’t see how it wouldn’t affect the accuracy, and therefore the validity, of any of the empirically verified mechanics used in physics.
My point is that all experiments give the same results in all non-accelerating frames of reference. That doesn’t seem consistent with absolute space. If there was an absolute frame of reference, then you should be able to tell us what our velocity is with respect to that frame, but all we can do is give our velocity relative to another object.
Not sure I’m following you here. If space exists in an absolute sense it exists regardless of whether or not it can be measured. If it exists in a relative sense, it exists only if it can be measured. Measurement necessarily requires observation. Observation necessarily requires an observer.
So it follows necessarily that if space is dependent on measurement it is observer dependent. If not, then it isn’t observer dependent. As far as I can tell that makes perfect sense. Am I missing something?
As quoted from my previous comment:
Isaac Newton founded classical mechanics on the view that space is distinct from body and that time passes uniformly without regard to whether anything happens in the world.
Also:
Substantivalism* is the view that space exists in addition to any material bodies situated within it. Relationalism is the opposing view that there is no such thing as space; there are just material bodies, spatially related to one another.
*Not to be confused with space, or space-time subtantivalism which are mechanical applications of the ontology of substantivalism.
What I mean by space is whatever it is that the material bodies we observe inhere and move in.
What I’m referring to is absolute in the sense that its existence is independent of human measurement.
The specific issue I’m addressing is analogous to being in a forest where we can see the trees around us, but we don’t know exactly where we are in relation to the forest as a whole. If we want, we can measure the distances between the trees. But if we want to know exactly where each tree is located relative to the whole forest, we have to measure the forest as a whole.
Similarly, we can measure the distances in space relative to the bodies we observe around us. But since we can’t measure the whole of space we can never know exactly where each of the bodies we observe in space is located relative to the whole of space itself, or even if there is such a thing as the whole of space, which is kind of what the question of absolute space is about.
Absolute space, as I understand it, is among other things, the notion that even though we can’t know exact locations of observed bodies relative to the totality of space, we can still logically assume that whatever space is, even if infinite, there is a totality of space and an exact location relative to the totality of space in which those observed bodies exist.
I agree with you that all we can do is give our velocity relative to another object. But we can’t know what the absolute reference frame is, at least not in an exact sense. So it’s not surprising that mechanically it doesn’t work, at least not in a more precise sense. But my point is, to say it doesn’t work mechanically and that it doesn’t exist ontologically are two different things.
We can only measure space using relative objects because, whether or not the existence of space is absolute, either way we can’t know exactly where things are located in space relative to its entirety. But the ontology isn’t about making measurements involving absolute space. It’s about whether or not there is an absolute space, and therefore the existence within it of actual exact locations regardless of not being able to know precisely what they are.
So just as your example can be used to demonstrate that all we can do is give our velocity relative to another object, it can also be used to demonstrate that it makes no sense to say that absolute space doesn’t exist. Because if we say it doesn’t exist how do we explain the existence of two conflicting measurements?
Either we have to arbitrarily chose one over the other, or we have to say that there is more than one reality. But neither of those explanations seem satisfactory. The explanation that makes the most sense, at least to me, is that there is an absolute space, even though we don’t have access to precisely where things are located in it, and that there is one real exact measurement that we don’t have access to. And the fact that we can’t know what it is, at least not precisely, we have to rely on the relative measurements, which are generally good enough for what we require them for.
Observation, in the sense used in philosophy and physics, does not necessarily requires an observer, let alone a human observer. I suppose you introduce human observers to contrast with some sort of “godly” observer that you really want to exist… Regardless, the existence of an observer, let alone a human observer is not implied by any definition of absolute space in philosophy or physics.
No, space-time subtantivalism is an ontological statement, not a mechanical statement. Just because it is written with math does not suddenly mean it’s mechanical. Math is just a language. People who think math is just for describing mechanisms are just people who don’t know math.
Sigh… do you not see how this statement is filled with terms that are undefined? You did not rigorously define what it means for material bodies to “inhere” or “move in” a space. You did not rigorously define what “material bodies” are. You did not rigorously define what “we observe” mean in this sentence. All these terms have philosophical and linguistic baggage that you did not specify.
Probably it’s not possible to define these with the vocabulary in English, which is why I kept asking you to use the language of mathematics, which again, is JUST A LANGUAGE. Using math does not mean that you switch to speaking about mechanistic description.
Again, not-rigorously defined, e.g. what is a measurement? What is a human measurement?
I think we’re done here. Your inability to engage in a level of rigor that I am accustomed to makes this conversation pointless.
I disagree. There are real world consequences of absolute spacetime that should show up in the experiments we have done, but that evidence isn’t there. For example, the speed of light is the same in all frames of reference which, if I understand it correctly, should not happen if absolute spacetime is real.
To circle back to one thing I’ve been getting at, I don’t see how it’s possible to use a description as an explanation. Because description is pertaining to what can be observed, whereas explanation is pertaining to what cannot be observed, and therefore depends solely on what can be inferred from relevant observations.
They’re two totally distinct activities. To me, trying to use description to explain something is like giving a carpenter a mechanic’s toolbox and asking him to build a house with the tools in that toolbox. Both seem like pretty unrealistic propositions to me.
Ontology is philosophy so physics doesn’t seem relevant here other than providing any observational evidence. And if the existence of space hinges on being able to be measured, as relativity seems to be saying, then as I’ve pointed out, an observer is arguably implied.
Without an observer being implied, I don’t see how measurement makes any sense. What kind of measurement could there be that doesn’t necessarily require agency in some form or another for it to ever be actualized?
And I think the only two kinds of observers that would be referred to here would be either human or divine. And human observers would be the only kind that scientists who hold to methodological naturalism would be able to refer to.
From what I’ve read, of which I’ve previously provided the relevant quotes from, this doesn’t seem to be the case. The only thing I can figure, although I’ve yet to come across any, is that there are alternative ways of defining these terms among scientists.
From what I can tell, this does seem to be the case from time to time, as well as with other scientific terms. Nonetheless, " space is distinct from body" and “space exists in addition to any material bodies situated within it,” to my mind, seem to be two similar definitions about one and the same thing.
What do you mean by “rigorous?”" What do you mean by “philosophical and linguistic baggage?” What to you mean by “specify?” Can you explain those terms mathematically? How rigorously defined can terms in philosophical discussions about things as difficult to define as consciousness, aboutness, qualia, etc., be? There’s a limit on how rigorously something that is invisible that can’t even be agreed upon whether or not it even exist can be defined. Ontology is not an exercise in physics, but philosophy.
What I recognize can be done is to narrow the question down as much as possible. And that is what I’m trying to do by asking the question, is the existence of space absolute or relative? If it’s absolute it exists independent of measurement. If it’s relative its existence is dependent on measurement. And from there it’s a matter of asking what makes the most sense of what we experience and observe.
Let’s return to the discussion about using math to explain something, as I’m not convinced at all that it’s even possible. As far as I can tell, mathematics is solely a descriptive language. I don’t see how it can express explanation. To my mind, it’s just not structured in such a way as to accommodate for it. I’ve yet to come across an explanation in philosophy expressed in mathematical terms.
Probabilities? OK. Logic in terms of it’s structure? OK. But explanation? So to insist on using a descriptive language to express an explanation seems unprecedented to me. To say the earth is flat is really more of a description than an explanation. But let’s try with something that is much more clearly an example of explanation. For example, how would consciousness be explained in mathematical terms?
Sorry, but it’s hard to make any sense of what you’re saying here. Are you saying that measurement as defined in English is unintelligible? And if you’re looking for what kind of measurement, that would make sense if the discussion were about physics, but not when discussing ontology.
Yes, there are real world consequences for mechanical descriptions. But I’m not talking about mechanically defined absolute spacetime. Yes, as it is a description of what should be observed then it would be observed if the equations were correct. So obviously as formulated in mechanical terms it doesn’t work.
But it’s the ontology that I’m concerned with. And as I’ve said above, and numerous other times, mechanism has no relevance to the question of ontology. The question being asked is not if it can be described mechanically, but rather what the nature of it is. Does it exist independently of measurement, or is it dependent on it?
There’s no way to solve the problem through observation alone as is the case with description. It’s something that ultimately has to be resolved by looking at all the actual observed evidence that’s relevant to the discussion, contemplating on what reasonable inferences can be drawn from it, and then judging which best explains the evidence in a way that is coherent with and corresponds to our shared experience of reality.
To use an analogy, your logic seems similar to arguing that the Earth is flat in an ontological sense even if all of our measurements are consistent with a round Earth.
From what I can see, the lack of absolute spacetime best describes the observations.
OK. @PdotdQ I think I provided reasonable responses to your concerns so I guess we’ll have to leave it at that. Nothing wrong with agreeing to disagree. Thanks for the discussion.
I’m not even sure there is an ontological element here. But no, if there is an ontological element, if the measurements are consistent with a round Earth, then based not on the formulas, but on the evidence of the actual measurements, and any other evidence, the ontological conclusion would be a round Earth, if that’s what is the best inference from the observable evidence.
But I hesitate to use this as analogous with what we’re discussing as it’s got additional elements to it that are not present in the question we’re asking about space. For example, it’s about shape, which is more of a descriptive element, and it’s about the earth which we can objectively say exists.
Whereas with space we’re not asking about its shape, but the nature of its existence. And we can’t even objectively say whether or not it even exists. So I don’t think a flat or round earth analogy is a good application to what we’re discussing.
I think there’s two separate questions going on here depending on what’s being addressed. When addressing mechanics the question is, “Does the mechanical formulation of absolute spacetime accurately describe what’s observed?” And the answer to that question seems to be no. (Although I would question why it’s even being attempted in the first place since absolute space is by definition immeasurable?)
But when addressing ontology the question becomes, “What makes more sense of the reality we observe and experience, space “existing” only if measurable and therefore dependent on spatial relationships, or space existing regardless of measurement, and therefore independent of spatial relationships?”
Don’t see how the former makes sense of reality at all. How would you make sense of it?
) , but it seems to me we are talking past each other again. You seem to want to define absolute space “itself” as a mathematical entity. But that’s not where I’m coming from at all. My concern it with how it’s being used in an ontological sense of what is its nature.