Can we know the fundamental nature of space and time?

Question

Can you please point me to an argument by a notable contemporary philosopher arguing why we may know the fundamental (metaphysical) nature of space and time?

In a recent answer to a question I wrote that we cannot, to which @modalmilk commented "there are plenty of professional philosophers who ... think we can know the nature of space and time".

There seems to be plenty of discussion about the metaphysics of space and time, but I was surprised that I did not find anything corresponding to why in principle we may or may not someday know the fundamental nature of space and time.

Here is my take on this:

One might suppose that we may someday come to know the fundamental nature of space and time through physics, but I have a problem with that.

In chapter 12 of The Feynman Lectures on Physics Richard Feynman says:

in order to understand physical laws you must understand that they are all some kind of approximation.

And earlier in the very first chapter he says:

most interesting, philosophically we are completely wrong with the approximate law. Our entire picture of the world has to be altered even though the mass changes only by a little bit. This is a very peculiar thing about the philosophy, or the ideas, behind the laws. Even a very small effect sometimes requires profound changes in our ideas.

for example, in Newtonian physics one could imagine a snapshot of the state of the entire universe in a single moment in time (a plane of simultaneity) but the small changes of special relativity to the approximate laws of Newton, made that impossible - today we believe it is meaningless to ask what is happening now somewhere else:

Alpha Centauri “now” is an idea or concept of our mind; it is not something that is really definable physically at the moment.

So if Feynman is correct, physics is out of the window; what next? maybe direct experience? after all we seem to have an experience and an intuition of space and time.

here the problem seems to double; now we need to answer both what is the fundamental nature of our experience of space and time, and what is the fundamental nature of the elements of reality these experiences correspond to.

Take for example the color blue; we can ask what is the fundamental nature of the experience of blue - and since we know that blue corresponds to a particular frequency of light, we need to also ask what is the fundamental nature of light; but what can we say about the fundamental nature of blue color, except maybe in the spirit of Zaphod Beeblebrox, blue's just this color, you know?

then, we can also ask what we can expect to learn from our experience of space and time about the elements of reality they correspond to; why should our experience of space correspond to real space any more than blue corresponds to a bombardment of photons?

on the other hand, there seems to be something in the nature of our experience of time that makes physicists and philosophers try to dispose of it as an illusion; one example is eternalism and another is that of Julian Barbour who advocates the view that "time, as we perceive it, does not exist as anything other than an illusion".

However, when it comes to our experience, time actually seems to be more persistent than space; all we need to do to make the experience of space disappear is close our eyes; and we have several kinds of experiences which do not seem to involve location, such as anger or smell, and just as we can experience blue without light, in a dream, we can experience space without real space, as an illusion; but can we similarly have an illusion of time? wouldn't the dreamworld illusion of the flow of time require real time to flow? this reminds me of the omnipotent being failing to deceive Descartes into believing he does not exist.

In fact, Stephen LaBerge showed dream time flows at the usual rate: "time perception while counting during a lucid dream is about the same as during waking life".

so, in general, it seems that our experience of space and time is not a promising avenue to knowing the true fundamental nature of the corresponding elements of reality.

but what does it even mean to know the fundamental nature of space and time? the experience of colors is literally in our face, and yet philosophers cannot say much about their mysterious phenomenal existence; is this because of a limitation of language? or of our ability to comprehend? is this possibly what Wittgenstein meant by:

Whereof one cannot speak, thereof one must be silent.

If this is so for direct phenomenal experience, why should we expect the fundamental nature of space and time, or matter, or existence itself, to be any more comprehendible to human intellect? isn't that pure vanity?

we can hardly even fathom the physical facts we discovered, such as the incredible size of the universe, or quantum mechanics; as Richard Feynman put it:

If you think you understand quantum mechanics, you don't understand quantum mechanics.

Answer 1

You did not find any answer to this question in the literature precisely because it does not concern space-time only, but metaphysical knowledge in general. Philosophers who discuss the fundamental nature of space-time generally assume that metaphysics is open to rational inquiry, while philosophers who think it's not simply don't discuss this specific issue.

As for the general debate on metaphysical knowledge: there has always been, throughout history, anti-metaphysical movements: skeptics, quietists, and notably empiricists. Hume's empiricism was anti-metaphysics. Carnap's logical empiricism too. A general argument against metaphysics is underdetermination: if experience cannot tell us which metaphysical package is true because all observable consequences are the same, then how would we know? However the lesson from 20th century and the collapse of logical empiricism is that the problem concerns not only metaphysics but scientific knowledge too. There is no science without metaphysical assumptions, and there is a continuity between metaphysics and fundamental scientific principles. Yet it seems that we can gain scientific knowledge based on other rational principles than experience alone: parsimony, fruitfulness, unification, explanatory power... From then (the 70's) philosophers started doing metaphysics again.

There has been crtiticism of this new analytic metaphysics, sometimes dubbed "neo-scholastic" and there are proponents of naturalized metaphysics (you can read Ladyman's "everything must go" on the subject). These authors say that metaphysics should be read from scientific theories and have a role of unifying diverse branches of science and our everyday experience and perhaps common sense intuitions into a coherent picture of the world, and nothing else. It shouldn't be an autonomous discipline that would try to domesticate science.

So there are at least two approaches to metaphysical knowledge: either metaphysics as an autonomous rational inquiry, or naturalized metaphysics as an induction from scientific theories (just as science works by induction on experiments). Metaphysics can also be seen as guiding future scientific inquiry (it seems that it was the case in the past, where Einstein had a relationalist conception of space-time when he developed his theory. Boltzman's atomism is another example. However contemporary scientists are much less philosophically educated).

Concerning space-time, the point is that precisely physics informs the debates. With relativity theory it is more difficult to defend space substantialism and presentism than before (see the hole argument for example). The success of one theory or the other seem to pull in one metaphysical direction or the other. This seems to show that at least naturalized metaphysics is possible.

Concerning our conscious experience: the debate between physicalism, dual aspect theories or neutral monism is pure metaphysics today but maybe neuroscience informed by the philosophy of mind will pull toward one direction or the other?

Answer 2

The fundamental nature of the universe is a complicated topic for many; indeed it often borders right on the edge of religion. However, I do believe there is an alternate reading which resonates with your line "is this because of a limitation of language?"

Space and Time are words, bound by the rules of linguistics. Obviously there is a goal that those words reflect something of the "real world," but they don't necessarily have to reflect it all.

I do not think it unreasonable to assume that, at some point, we will discover something about the world around us which is not well modeled by the behaviors of the words "space" and "time." We will need to coin a new word to describe this behavior. Eventually I think it is totally reasonable to assume that we will understand the fundamental nature of "space" and "time," just like mathematics pins down the fundamental nature of integers in many ways. However, I have reason to believe that won't mean we understand everything, it just means we will have bundled all of our unknowns into a new bucket.

Answer 3

Why not follow down the idea these are illusions?

From a Kantian point of view it may be that all we can know of things like space and time and color is their fundamental nature. We may never know all the ways nature interacts with or causes us to experience those things, but the fundamental nature of those things is an aspect of ourselves and not of nature.

The problem that makes quantum mechanics so awkward for us, then, is not that space and time are so odd, but that matter does not inhabit what we call space and time, but only indirectly affects it. We are looking at the genuine nature of matter "in a glass, darkly". We are fitting notions natural to us over nature, which does not actually have corresponding aspects.

From a more materialist para-Kantian point of view, space, time, color and other mathematical and perceptual models are our evolved approximations to reality, they are not real, beyond their effects upon us. They do not reflect the essential nature of the matter behind them, but they are themselves essentially and totally ours, and we can fully understand them.

This perspective suggests that our notions of space, time, color, etc. may need to evolve, perhaps in a literal and biological sense, before we can understand some of the deeper conundrums of physics.

It also makes the real nature of space its mathematics, which is an aspect of our psychology, something we can expect eventually to perfectly express, even if we will never run out of ways to be surprised by physics.

Answer 4

There's a useful discussion of these issues in Bohms Wholeness and the Implicate Order; the discussion below is derived from this as well as other sources.

Aristotle identified four causes in his Metaphysics (this word shouldn't be understood here as a kind of 'mystic' word, but as arguing from first principles); and which are:

1. Formal

2. Material

3. Efficient

4. Final

The formal cause of a tree is not its form, or shape; but it's inner law of development as it grows from seed to sapling to tree; the material cause is all the matter - the seed, oxygen, rain, sunlight; efficient is what caused it occur - I planted a seed in the ground; and final cause is its purpose - to live and flourish as a tree.

Now we can ask the same questions about the discipline of physics; and this with respect to the physical universe.

First, by supposition, there is no efficient cause; the big-bang in a sense 'caused' the universe; but we can ask the same question about the big-bang.

Similarly, and again by supposition, there is no final cause; when one looks in main-stream physics or cosmological textbooks there is no discussion of this - even if they discuss what the universe may look like in 10 Billion years.

It is by these two suppositions, and not otherwise that Hawking, amongst others can say the Universe is self-contained.

Now, it seems plausible that physics being a theory of physical things it must be a material cause; but this isn't true: given the laws of physics and no matter we couldn't get the universe underway. So physics does not, contra to naive expectations identify material cause.

What Physics as a discipline is - is the formal cause of the universe; by it we grasp the inner law of development of the universe and hence it's parts too: thus from the Big Bang to how an electron spins.

This places into context ie in Philosophical Language the observation in Feynmans The Character of Physical Law that Physics doesn't tell you what something is - it's thisness (material cause) but how it behaves (formal cause).

Answer 5

Contemporary notable philosophers? Nope.

But Barbour is certainly the closest.

Leibniz, Kant, Newton, Spinoza, Einstein, Schopenhauer, and many others certainly had a far more complete view than the notable philosphers today do.

They all had notions of relative time existing because of absolute time.

Here again is Newton's definitions:

http://plato.stanford.edu/entries/newton-stm/scholium.html

Today we argue whether time is this or that. Fundamental understanding is about why this and that (at two different levels of reality).