I don't think it's that possible. We wouldn't be ourselves because we're someone else in another dimension. What makes us who we are is... who we are. The person living in the alternate dimension wouldn't be us because they only would share a few qualities similar to us, while we're unique. In another dimension we could exist as 2D, we could exist as rocks, although we'd think it's exciting... really, who'd want to be a rock? Even if there was someone similar, your experiences help make you who you are and their experiences might be opposite to yours, making you a completely different person there.
You can say that for some talking dogs make sense but really, if you refer to science and the genetic makeup of dogs, you'd see that it is impossible. Oh yeah, adding to this, if dogs could talk in another dimension, the dimension would be different. Every single person would be different, altering one thing means that you might not even exist. The dimension we live in now... it makes sense.
The only other dimensions we can really experience are in games (which stretch the imagination, allowing us to explore different types of realities - being someone else, living their life) and in dreams, where our imagination can expand, and all the things we wish would happen actually occur (not including nightmares), but really, our reality being someone else's dream... that would be logical except dreams come from our experiences and things that make us happy so really... that's impossible too.
I just really think that a dimension that is alternate to our own is impossible because nothing would be the same anywhere else.
This kinda reminds me of believing in reincarnation, like your spirit becoming another. Isn't this similar-- yeah, your spirit also makes you who you are, without your spirit you basically don't exist, so therefore, if there were to be an alternate dimension, there would be so many spirits. What would happen if all of them went into heaven? Are there multiple heavens? Is there more than one God? What is right and what is wrong? If there really were alternate dimensions, all these questions would just appear... we're born who we are and we're apart of only one dimension. However, for the alternate dimensions theory, there could be a dimension in which robberies didn't occur, people were nice... there was dimension peace. But... really, dimension peace is impossible unless there's only one person in the dimension. Everyone has different wants and needs, and to cater for those may cause conflict. Therefore, alternate dimensions would have to be based upon an entirely different concept of life. This would mean that it would not be anything that we have imagined, that meaning ... everything humans on this earth desire in their lives can't be achieved on another dimensions because there will always be faults with that - yeah, try imagine flying to space. If it really was an alternate dimension, we'd still have similarities with said dimension. Examples of this are clouds in the sky, trees on the ground, but something would have to be altered significantly. Thus in order to achieve a level of similarity between both dimensions, eventually the groundwork within our dimension would need to change in theirs because in order for civilisation to be maintained, the dimension that we live in needs to stay the same.
Imagine taking away democracy. Nothing would exist without it. You couldn't live in a society without democracy, it would be impossible to achieve anything. This would end up with the eventual destruction of the earth. People can't get what they want, nothing is fair, and people will begin resorting to stealing, lying, hurting…breaking the cultural mythology and values/attitudes that society believes in, which in itself, would no longer make it an "alternate" dimension, as that in itself is large enough to alter the entire dimension if taken away. A world without rules even… just that would be terrible to imagine, or a world without light, a world that doesn't know the difference between good and bad… all will eventually end in chaos.
Let's think about the natural side of it now. For this, we're just assuming that an aspect of nature COULD be altered. If there were to be no trees for example, no plants… how would we get the basic nutrients that both we and animals need to survive? We surely couldn't live on meat, as without grains, seeds, vegetables, animals couldn't survive either. Also, with animals, yeah, if the dinosaurs were still around in one dimension… do you really think any of us would be alive there?
Now, our personalities… what if they were altered? Yes, I already touched upon the spirits side of it, but what IF everyone was the opposite gender to who we are now? Simple. You wouldn't exist. If your mother was a male, and your father was a female, yeah, they might have still met, but their dominant cells would be different. The child would turn out different personality wise because your mother and father would be different to who they would have been in this dimension. How do I know this? Because of their experiences. Socially, they would lead different lives and develop opposing personalities to those now. Your children, as a result, would then be a mix of different genes compared to those they would have in this dimension and have different personalities too. Imagine a singer you worship never getting noticed because their mother and father were opposite genders, meaning you could have been an opposite gender. This singer would therefore have to face different obstacles to those they have now in this dimension, meaning they could not succeed at all and end up as a normal person. Therefore, that would not be an alternate dimension because every aspect of them would be different to what they are now.
It may not make sense at first, but think about it, if you were born a dog for example, how could you have the same spirit in two dimensions? Your spirit is who you are, there's only one of it, so how come it's possible to be in two dimensions? Yeah, back to the dog part, if you had the spirit of a dog and the spirit of you… you just wouldn't be you. Technically, you'd have to be born a human for it even to be considered alternate in terms of opposite or even partially similar. But let's just say you can somehow magically have the same spirit in two dimensions and you were born a dog in another dimension. You would be completely different due to your experiences. You wouldn't even know the concept of alternate dimensions unless you were intelligent, educated. This could only happen if humans were subordinate to dogs as if both were educated, there would be rivalry, resulting in eventual clashes and destruction of the dimension. Hey, dogs might not even be dogs. They could be a type of dog hybrid, bred for entirely different purposes. Pets may not be pets, if so, that could alter the dimension completely and you may not exist. Any slight change to our dimension would cause you to possibly not exist. If you didn't exist, someone else may not have existed – your future children in this dimension which could spark a chain reaction of lives that would have never existed. What would the future actually entail for those in the alternate dimension?
Oh yeah, what about a dimension with robots? They wouldn't even have spirits. If that were the case, you would literally not exist in an alternate dimension. You wouldn't have emotions, society would be different. Guess what? You couldn't even reproduce. So where would all these robots come from? There would have to be some human there to have created the robots, but for an entirely robot dimension, that is impossible. Therefore, can't be an alternate dimension because something would have to be primarily similar. In a dimension of robots, everything would be different. Yeah, you can say it's alternate because there are robots and no humans, but really you wouldn't even exist. Nobody would exist. Nothing could be the same. The robots could also be dangerous, armed… there would be no point to existing. It would just be war. There wouldn't even be blood either, nothing that makes us who we are…
What if, in an alternate dimension you were in the body of another that exists in both dimensions that you actually know? Would that be counted as an alternate dimension even if you aren't you? No. It's alternate if it's you, and… in this case, it can't be. If your parents were in different locations you probably wouldn't exist, or might have different parents, you may be abused, hurt, die at a young age… you don't know all the bad things that could occur from such an alteration. What if music didn't exist? Would that really affect you—what if the entire concept of sound was gone in an alternate dimension? This would be interesting. Communication would quite different. I'm pretty sure without sound… well, a lot of people would be dead, the same for being blind. Without those two senses we can't get warnings visual nor via sound when we're in danger from others therefore would the dimension really be safe to live in? In a sense, you can also consider other countries alternate dimensions to a sense. This is because of different accents, different cultures, different languages, different lives…yet they still abide to the social culture within the dimension. Does this mean we really need a literal alternate dimension when we have such a multicultural dimension?
On another note, what about magic? Many people would consider it to exist in at least one alternate dimension… but that concept was invented by those apart of this dimension, therefore unlikely to exist within another dimension because the other dimension would have no knowledge of other dimensions existing. And yeah, if there were alternate dimensions, there would have to be one without love, right? Again, you would be a completely different person do to that. Therefore can't be considered alternate as you may not exist due to that. What about a dimension without electricity, too? What if there was a dimension that didn't know of time? All these instances would alter everything completely… everything we have in this dimension makes life worth living and makes the dimension actually logical.
In a dimension without natural disasters, or even deaths, there would still be flaws… and an imbalance. With the dimension we have now, we have a balance between bad and good, making it a good dimension to exist in. Humans would be different… but yeah, it couldn't really be considered an alternate dimension unless it is almost exactly similar to ours with only blue pens being red, for example. However, since pens … and basically everything we have in this dimension were invented by humans living in this dimension… basically, in another dimension, nothing we have would be there, it would not even be considered alternate. Even if the world stopped spinning… even that, it would mean that dimension wouldn't exist. It may only be my opinion, but really, it's quite logical after thinking about it and this taking up about four typed pages… but that's what I believe in. XD;
Although I would love a dimension in which you can touch the clouds up close, but that's what dreams are for. :D