Could space be just our perceived reality instead of the true nature of the universe? [duplicate]

Question

We've proven that color is a subjective experience. So we know that the outside world does not look like anything at all. All the events happening in the outside world do not look like anything.

But space could be, in the same way, a representation of the actual universe, evolved over time in complex organisms .

What is the true nature of the universe? Is it just supposed to be abstract information?

If we, say, program sentient beings in a video game, they'll perceive a bunch of abstract information as space.

If there's no living thing to observe space, could we say that the universe is still a bunch of particles moving inside this stage called 'space'?

There's also the thing that all reference frames or 'point-of-views' in the universe are equivalent. This also kind-of pushes forward the idea that each reference frame is a stationary piece of information getting affected by the outside world, which is also a piece of information.

And the nature of this abstract information called 'universe' can't be such that the info is evolving as a function of time, because that would imply that time is absolute. Since time and space are interconnected, so if space is just a bunch of info, then time also has to be just laid out info or something like that.

If this is true, is it possible for information to exist if there's no such thing as space? I mean...where or how would the information exist?

Answer 1

There are many kinds of space. Hilbert space, phase space, Minkowski space, twistor space. Spaces are models.

Noether's theorem shows us that symmetries under transformation and conservation laws are the same thing stated different ways. So in this view space and time are sets of symmetries. Space is a pattern in what is local to what, in how properties are conserved or not under transformation (or iteration of the wavefunction).

Sean Carroll is looking at gravity and space-time emerging from quantum mechanics. Carlo Rovelli is also working on space-time as emergent from spin networks, the propagation of quantum information. Antony Lisi has presented the idea the fundamental particles are nodes on a hyper dimensional symmetry-structure called E8.

Archibald Wheeler suggested the 'it-from-bit' doctrine, the idea that all of physics could be reduced to a series of yes & no answers. There are many who question what this adds to physics as it is not frameable as a theory, and many physicists criticise it. But none-the-less it is influential. The programme of reductionism and finding the simplest constituents, has a long record of success in unifying different phenomena and models into a single language.

Nancy Cartwright argues in How The Laws Of Physics Lie that we make simplifying assumptions to make tractable models, which are always a 'lie', and can only be as good as the assumptions they are based on are sound. This is similar to Hume's 'problem of induction', we can observe patterns but reality always has the last word. All of science is only what has not been falsified yet, it has to be noted that all scientific truths are fundamentally tentative.

Time as a dimension, and time's arrow, are not reconciled. It could be that we exist as a pattern in 4D that is already complete, but our brains require limiting ourselves to one moment, one slice. It could also be that our universe is a 4D surface in a 5D space, like may be suggested by the holographic principle. And in the higher dimensions still of string theory, we can picture a space with every quantum outcome, every set of initial conditions, and every set of fundamental constants to physics, and alternative physics

Answer 2

The first significant philosopher to speculate on the nature of information in this way was Plato. He proposed an Ideal realm where ideas existed in archetype form and when we think about them we reference the ideal prototype.

Probably not so long before him, the Buddha taught in India and early Daoists (Laotzi if he existed) in China that perceived reality is illusion cooked up by our senses and conscious experience is just a stream of these illusions. The true nature of oneself was inexpressible but the Buddha described it as your dharma or "buddha nature" and the daoists as being "one with the Dao" (the dao or Tao being eternal but also ever-changing).

Since then Penrose has introduced us to twistor space. Loosely speaking a point in twistor space is a photon of light. It corresponds to the path of that photon in ordinary space. Conversely, a single point in ordinary spacetime is spread in twistor space across every photon which passes through it. (Mathematically it is analogous to the transformation between the sound wave of a vibrating loudspeaker and its frequency spectrum). Twistor space is pretty unintuitive but it does make some traditionally fiendish calculations in particle physics remarkably elegant and simple, so it must reflect some aspect of reality.

Others have speculated that the visible world might be two dimensional and we are holograms each spread across a large area and being fooled into thinking we are compact and three-dimensional. Their maths is sound but their interpretation of it is questionable.

Mathematics certainly has an "unreasonable effectiveness" in describing nature. But maths often offers multiple transformations of a given construct into different forms and says nothing about which is the "real" one. Whether understood as a waveform or a spectrum, the sound of a violin is still the sound of a violin; the air transmits the wave, the cilia in our ear canals perceive the spectrum, our brains create an illusory sound quality. Ultimately, twistors and holograms and the like tease but do little to elucidate.

Other than that, we are really no wiser than the sages of ancient times.

Answer 3

Colour isn't just a subjective experience but an inter-subjective experience. Which is why when I say the colour red everyone knows what I'm talking about.

Aristotle already asked questions such as whether space itself occupies space, whether it was ponderable and then 'given all these difficulties whether there was such a thing as space'.

This may be one reason why he considered that space was something that was designated not by volume but by boundaries.

This notion was understood generally as being rather at odds with our intuitive understanding of space but it comes into its own when we understand space as its understood in one possible incarnation of quantum gravity. That is loop quantum gravity where volume operators are given by the intersection of spin networks with surfaces, that is boundaries.

Its also worth pointing out that the understanding of space is manifold. When physicists talk about the fundamental nature of space they are merely focusing their attention on one aspect of it.