# What would a world be like with cross dimensional contact? [closed]

A universe of 10 dimensions

I'm trying to build a universe with interactions between beings from different dimensions. Only dimensions 3 and up would be capable of spawning any sort of life. The most interaction would take place in the third dimension. So what would a being from another dimension look like if it came to our lowly third dimension and what would it be capable of doing?

I understand that this question tests the limit of human understanding, but please make the most educated guess you can based on current theories and such.

The dimensions:

0: A single point in time and space

1: An infinite line (x-axis)

2: An infinite plane (x and y-axis)

3: An infinite cube (our universe, x,y,z axes)

4: Fourth dimension is time, which governs the properties of all known matter at any given point.

5: A world slightly different from our own that would give us a means of measuring the similarity and differences between our world and other possible ones.

6: A plane of possible worlds, where we could compare and position all the possible universes that start with the same initial conditions as this one (i.e. the Big Bang). In theory, if you could master the fifth and sixth dimension, you could travel back in time or go to different futures.

7: We have access to the possible worlds that start with different initial conditions. Whereas in the fifth and sixth, the initial conditions were the same and subsequent actions were different, here, everything is different from the very beginning of time.

8: A plane of such possible universe histories, each of which begins with different initial conditions and branches out infinitely (hence why they are called infinities).

9: We can compare all the possible universe histories, starting with all the different possible laws of physics and initial conditions.

10: We arrive at the point in which everything possible and imaginable is covered. Beyond this, nothing can be imagined by us lowly mortals, which makes it the natural limitation of what we can conceive in terms of dimensions.

## closed as too broad by elemtilas, JBH, Bellerophon, kingledion, nzamanApr 22 '18 at 13:42

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• This looks like 7 really broad questions in one. – Mołot Apr 19 '18 at 12:48
• Well you only have to choose one of the dimensions to explain. – Efialtes Apr 19 '18 at 12:52
• No. That's not how Stack Exchange is supposed to operate. How would you compare answer to 4 with answer to 8? Which one is more accurate, and better? If you only want one explained, only ask about one in one question. But all answers are supposed to cover everything that's asked. – Mołot Apr 19 '18 at 13:01
• Only dimensions 3 and up would be capable of spawning any sort of life That sounds like containing time, so it would be 4 and up. – Jan Doggen Apr 19 '18 at 13:01
• Having x available spatial dimensions, why would an organism limit itself to x-n? In our case x = 3 and we know no 2 or 1 dimensional life form. – L.Dutch Apr 19 '18 at 13:08

The premise of the book Spaceland is very similar to this concept, which is an extension of the book Flatland.
Both are probably worth checking out.

The basic idea is that any being from a higher dimension could interact with a being on a lower dimension in their own dimension, and the higher would look like whatever the lower dimension cross section allowed.

For instance, a being from a dimension >= 4 would be able to change apparent age in the 3rd dimension at will, from very old to very young and back, all by shifting what part of it's time dimension is interacting with our space dimension. It's like sticking a pencil through a piece of paper. If you were a square living on the plane of the paper, you'd first see a small point, which would quickly grow into a circular shape. Then it would stretch to different shapes of oval, possibly become a stretched out bar, and then disappear. From the higher dimension the tip of the pencil goes through the plane, gets wiggled around a bit, laid down flat onto the plane, and then withdrawn completely. Just because the square can no longer see the pencils cross section doesn't mean that it no longer exists, it's just outside the plane of reality.

This applies to all higher dimensions too. Someone in the 6th dimension plane will be able to see all the parts of the 10th dimensional person that will fit on that plane, and that appearance will change and shift as 10 moves around. While to the 10th dimensional person 6 looks pretty flat and limited, like a sheet of paper.

Edit: More thoughts...

Theoretically, the universe has 10 or 11 dimensions. If true, those dimensions exist whether we perceive them or not. We can't see them, we can't interact with them, etc. If a being lives in the dimensions we can't interact with, they might be able to interact with us if they choose, or they might not. If their senses don't allow them to perceive our spacetime, then it's possible that they are existing alongside us and we could never know about each other.

Edit 2: Few more things

So as I was driving to work, something else occurred to me. A higher dimensional being would be able to see us as we truly are too.
Us 3D'ers are technically 4 dimensional, often referred to as 3+1D, meaning that we exist in time too. But we have no control over time. It's a bit like skydiving, we are just passing through time, and can't stop, can't go back. We have little control over how fast time passes *.

But a true 4D person that is able to see and control movement through that time dimension would actually be able to see a 3+1D persons 4th dimension, basically see you as you "truly are".

Likewise, just because we have no perception of any of the other even higher dimensions does not mean that we don't have existence in them as well. We just don't have the senses to perceive them, and so never strengthen the "muscles" needed to manipulate them.

* You ever notice that time goes fast when you're having fun, and slow when you're bored? Also, when things start moving faster, or get more massive, the rate at which time passes changes.

• Interesting side question. What would the 10th person look like to a 7th or 8th watching from their dimensional sidelines, while the 10th person was partially in the 6th dimension? – EveryBitHelps Apr 19 '18 at 17:39
• @EveryBitHelps They'd see what their senses allowed them to see. So the 7th would see 10 in the 7 dimensions that their senses could detect, and 8 would see 10 in the 8 dimensions their senses could detect. A parallel example is different wavelengths of light. UV light from the sun is all around, but our eyes can't see it. A bee on the other hand can. And don't get me started on a Mantis Shrimps eyes. The information is all there, but you have to rely on the senses you have. – AndyD273 Apr 19 '18 at 17:46

## There's going to be a lot of mumbling about "You cannot see my true form"

Depending on how much control these high dimensional beings have over their representation in lower dimensions, their appearance may be completely arbitrary. Their appearance will completely depend on the needs and whims of the Author.

Here's why: When you move from a higher dimensioned vector, say one that holds 10 values, if you want to shrink that vector down to say 3 values, the extra 7 values are either lost completely or somehow wrapped up in one of the remaining 3 values. Most of the time when authors talk about this kind of thing, the extra 7 dimensions are just lost. (Which from a clarity perspective, this makes a lot of sense since trying to describe a compression algorithm to non-programmers is hard enough. Combine that burden with the already very alien concept of an extra 7 dimensions....there's much easier ways to tell a story.)

We have no idea what a 10 dimensional being would look like if viewed through magical eyes that can see all 10 dimensions. I can't even hazard a guess. Probably the best way would be Weebly-Woobly, Timey-whimey...stuff. The Author will have to choose what dimensions to discard and which to retain. What if the author chooses to discard dimensions 3, 4 during their representation and only retain dimensions 1 and 2? The high dimension creature will appear as simply a perfect, physically impossible plane.

Anyone who attempts to communicate with this creature, perhaps a highly religious acolyte who wishes to see The Truth, could rightfully be told "You cannot see my true form. Your mind would burn with the knowledge." And the Being isn't wrong. Human brains do pretty well with 3D and okay with the fourth dimension too. That's a manageable amount of information for the fatty computer stuffed between our ears. However, the processing power required to deal with the knowledge of all universes that could be or will be would require exceptional overclocking of the human CPU. Brains do not overclock well at all.