What makes 7th and 8th Dimension Unique?

Here's an excellent question that was passed on to me from "Sevireth" via YouTube's messaging system. With Sevireth's permission, I'm publishing their question and my response.

I am trying to propagate your system of visualizing the higher dimensions to other people, but due to limited time and attention provided by a conversation (and everybody having ADD nowadays, especially on the internet) I have to come up with laconic ways of describing each dimension. In this way I come up with easy to present and understand concepts of what moving in each dimension makes a quantum observer observe changing around them.
It goes as follows: movements in first three dimensions usually need no explanation, so there's little to that.
Movement along the line of 4th dimension will make an observer see the universe around them change — turn younger or older depending of direction within the dimension. Actually -seeing- is only allowed in space-time, not just space, due to light taking its sweet time there's all that too.
Movement in the 5th dimension will allow the observer to choose a 4D path among all of the possible ones, will allow them to see the twists and turns of the 4D line caused by choice, chance and choice of others.
Movement in the 6th dimension is not principally different from movement in the 5th, it's still changing the same universe, but here the observer is not hindered by cause-and-effect relations, and is capable of freely choosing to observe any possible state of the given universe.
Movement (of a 6D universe at this point) along a line in the 7th dimension will change the universe itself — to a different one, with different physical constants. If a universe were to move too far in the 7th dimension, it would break apart, as at a certain point physical laws will become too screwed up to allow a coherent system to represent itself. Even though somewhere even farther on that line universes exist, they're just bizzarely different.
Moving a universe in the 8th dimension will change it just as well, but this time in some other way; if we assume movement in 7D will change, say, the constant of the speed of light, then moving in the 8th dimension will change the strength of gravity or some other important constant. As you mentioned in your videos, 7th and 8th dimension are more about the scope of reference, the values an observer chooses to observe changing.

This is where my imagination hits a wall. I realize it's not really possible to move in or even observe the 10th dimension, but I don't quite understand the ninth. I grasp something along the lines of "the ninth dimension somehow deciding which systems of physical laws would represent a coherent universe and which won't", but how a point (a 6D universe) would change if it were to shift its position in the 9th dimension? Would a universe that previously worked just fine fall apart because it's physical laws, however sensible a moment before, suddenly stop making sense only because they're in a different 9D position?
If it only provides an additional degree of freedom — like the 6th dimension does, allowing us to ignore limitations of causality — then what limitations does it allow to transcend? What ARE limitations of the 7th and 8th dimensions?

Here's my answer:

Good job! Here's how I think about it.

We always have to keep in mind with each of these dimensions that there are different "versions" or "states" for each. There's not just one third dimension, there's a series of third dimensions that make up a 4D duration. You understand this but we have to keep that in mind as we move through the extra dimensions (physicists prefer "extra" to "higher" because it's not like if we look into the sky we're seeing higher dimensions and down to the ground we're seeing lower ones, it's just semantics really but that's something to keep in mind).

The other thing that happens consistently is with each version of a dimension if you can think of it in its entirety, or as its "phase space", then that becomes a point in the additional spatial dimension, which is at right angles to the one you're currently examining. So the entirety of 3D space becomes a point in the fourth dimensional duration. The entirety of a 4D timeline connects to a probability space of 5D causally connected outcomes. The entirety of a 5D "spacetime tree" becomes part of the 6D phase space of all possible states for a physical universe such as ours, which includes all the non-causally connected durations. This 6D phase space becomes a point in the 7th dimension. If that point were to move, it would be moving to a point representing some other universe with different physical laws, or a universe which somehow remains coherent while some aspect of its physical laws is changing. Ignoring for a moment that some physicists have produced evidence that  our universe's laws may have changed somewhat back at the very beginning before settling in, we know that our universe is now an unmoving point within the seventh dimension and beyond, because our universe has locked in physical constants which do not change.

So from here on we're not talking about our own universe because it's "locked in" at the seventh dimension, and that's interesting to compare to the string theory idea that our universe is embedded within a d7 "brane", or membrane.

So let's imagine a line in the seventh dimension connecting to a point representing some other universe. If there was just one constant (like gravity) changing along that line, then other universes with the same gravity as ours would not be on that line. If some or all of the constants were changing proportionally along that line, there would still be lots of other universes not on that line, so we need the additional degree of freedom afforded by the 8th dimension to be able to freely slide through this 8D phase space representing all possibly physical universes.

So now we get to the 9th dimension, and it's just like thinking about the limitations of the previous ones. Our "flatlander ant" needed the third dimension to pop from one position to another within his 2D plane. As I'm moving through 4D space-time I can't suddenly be on the other side of the planet because there are things which are impossible - I would need to use the fifth dimension to pop from one point to another without traveling through the intermediate duration. Or we would need the 7th dimension to pop from one 6D universe's phase space to another. So likewise, the 9th dimension is what you move through to pop from one position to another within the 8D phase space representing all possible physical universes, and the 9th dimension includes patterns which cannot be expressed as physical universes at all.

When you take the entirety of the ninth dimension's phase space and perceive that as a single unchanging point, you are in the tenth dimension, which is ten dimensions of space without time. M theory says there are ten spatial dimensions plus time and counts that as 11. I say time isn't really a dimension, it's just a direction, and as soon as you add "time" to the tenth dimension you are spilled back into the other dimensions to create a universe such as ours or any other.
That's my two bits, good luck!

I appreciate your interest, and you're ongoing support, Sevireth. Many thanks!

Enjoy the journey,

Rob