Is it possible that time is not a 'time-like' dimension, but a proper spatial dimension just like the others but we only have access to a 3D cross-section of it?
I did some research about the internet if there is some discussion about this but I haven't found anything related. I am sure that people have already thought about this and probably it is just wrong, in ways that I can't see due to my lack of knowledge. So forgive me if this is trivial or has been asked and answered before.
So let me elaborate my hypothesis. GR treats the universe as a 4D Minkowski spacetime, of which the 3 dimensions are space-like or spatial and the 4th is a special dimension (time) which is time-like or temporal. What if this 4D structure was actually all composed of 4 space-like dimensions instead where, for some unknown reason, we only have access to a 3D cross section of this 4D structure, which is moving along with a particular direction (4D vector) and a particular momentum (having constant velocity due to inertia). Would that be compatible with the observations and data that we have?
I am thinking about it these past few days and it makes sense to me and I try to find ways to differentiate the 4D spacetime of GR with this hypothesis of mine, but I haven't yet found something convincing.
This hypothesis is actually based on the plain old block universe hypothesis but in addition it describes the time dimension as spatial, using well known and established laws and terms about moving through spatial dimensions (space). And, most importantly, it also explains why there's an arrow of time, why time "passes" and why it pass at a particular rate. Therefore it radically changes what we think time is.
I will give here a thorough example, (without any equations as I am not proficient at physics) describing this hypothesis. So, as it is impossible to imagine a 4D structure, let alone imagining moving through it, I will simply use fewer dimensions to provide the example, that will hopefully be equivalent in higher dimensions (4D space), and how this hypothesis can be true.
Lets imagine that we have a 2D space, instead of 3D, and time is just the 3rd dimension, which we do have access and can clearly imagine and see it thoroughly. Lets imagine a simple 2D world, one prime example would be a 2D game like Pacman. Pacman can move up and down and left and right, e.g. it has 2 freedoms of movement, but not in or out (the 3d dimension). Therefore we can safely say that the "world" of Pacman is a 2D slice (cross section) of a 3D spacetime. Lets imagine one game round of Pacman that is one minute long. This would essentially consist of just a series of 2D frames that are displayed on a monitor at a rate of 60Hz or 60 frames per second. Lets also imagine that this game round has been already been played and has been recorded (so the round is pre-determined). At the rate of 60Hz the total frames would be recorded would be 60 secs * 60 frames = 3600. We established up until now, that we can have all these 3600 frames already created. Lets say that we have recorded that game particularly in film with 60HZ rate. Therefore we can run and project the film, with a film projector, on a 2D screen at the same rate. The screen would be the 2D accessible slice of the film (that exists wholesome in the 3rd dimension). The same game round of Pacman will be replayed exactly as if it was the first time.
Now, lets say that instead of film we have printed the frames on paper, one paper per frame, and we have put all those papers on top of each other in order, forming a stack, just like a book. In this case we can say that we have a 3D block of 2D slices.
And lastly lets imagine that we have a scanner that is like a frame of a window, or an MRI scanner, that can somehow read 1 slice when that paper/slice is exactly in the center of it and projects it to a 2D screen. Then we can move this "book" (block of 2D slices) through that scanner at a steady speed by just pushing it, with a steady speed that crosses the scanner at 60 papers per second, and the scanner will project each paper on the screen at the same rate. That will essentially replay the whole recorded game round of Pacman at that screen and will last for 1 minute.
Here is a video which I found yesterday that is relevant to what I'm talking about.
So at this point in the example, we have established a world of 2D space, moving through the 3rd dimension in a constant velocity with constant momentum, which essentially resembles the time dimension that we are familiar with.
And now here are the conclusions and the profoundly sufficient explanations and answers to some of the most fundamental questions about time (always in the context of the above example):
NOTE: The following answers are only valid under the context of the above 2D + 1D time spacetime example.
What is time? Answer: Time is the successive projection of 2D slices of a 3D structure (the book), where pacman exists and has access to (only in the projected 2D screen).
Why time moves in one particular direction only? Answer: Because the 2D slice that pacman lives in is moving through the 3rd dimension at a particular direction. e.g. it moves in the direction which is exactly parallel to the book from page 1 to the last page. It doesn't matter the exact orientation and direction in the 3rd dimension, as long as it is the same as the orientation and direction of the book.
Why time moves in a particular and constant rate and doesn't slow down, speed up or stop completely? Answer: Because for some unknown reason, the 2D slice that is projected, along with a particular direction it also has a particular momentum (lets say that someone gave it a push), therefore it is moving with a velocity and because there are no other forces to act upon it in the 3rd dimension (e.g. no friction, no gravity etc) the velocity due to inertia it remains constant. As our known physical laws describe.
Why time doesn't move backwards? Answer: It can't, because it already has a direction and a momentum, and there is force to stop it and push it backwards
Why Pacman doesn't have access (freedom of movement) to the dimension of time? Answer: Because the "world" is just a 2D cross section of an existing unmutable 3D structure (book), motion is just the slice moving through that 3D structure.
I tried my best to explain my hypothesis, however if there's something missing or needs more clarification please let me know and I'll add to it.