Everything, Everwhere, All at Once is a popular film about alternative dimensions, as is Doctor Strange and the Mouth of Madness.
They're both fun and entertaining films and they have a whimsical, fantasy approach to extra dimensions.

It's purely anthromophic:
Their idea is that different human decisions split of new universes where people turn out differently, which is nonsense for a lot of reasons-
-Why would the universe care about human decisions?
-And which decisions would it care about?
-And if it's any change at all that makes a new universe then there would be infinite universes, with almost none of them involving humans.

I think the “human decision makes a new universe” came about as part of a way to avoid paradoxes in time travel, and that has some tenuous logic, but ONLY in the context of time travel, not dimension jumping, because you NEED to make a new dimension to enable the time travel possible, human interference starts the change.

What differences really COULD start a new dimension?
The only random thing we know of is super position… All that up and down spinning in quantum physics 😅
But that stuff doesn't have any real influence on the macro universe.
Maybe it would have in the beginning of the big bang when the universe was really simple and basic though so maybe THAT is where you can derive the different dimensions from?
Im that case this would be the only one with us in it, the others will be extremely different because matter would have formed and been distributed completely differently… Like a pure antimatter universe, or one where antimatter and normal matter cancelled each other out…

It's interesting to think on.

It's the same level of anthromophic thinking with aliens.

i.e. aliens will never be human looking in any way at all, they wouldn't even be the same scale as us. They could be huge or tiny. They won't have heads with mouths and eyes on then etc.
Aliens won't be based on reptiles, octopi, insects, cats, plants, or jellyfish, all those things are related to us and are earth life.
To aliens humans, crocodiles, rose bushes, and squids would be basically the same thing, just different derivatives of the same DNA.

Ozoneocean wrote:
It's the same level of anthromophic thinking with aliens.

i.e. aliens will never be human looking in any way at all, they wouldn't even be the same scale as us. They could be huge or tiny. They won't have heads with mouths and eyes on then etc.
Aliens won't be based on reptiles, octopi, insects, cats, plants, or jellyfish, all those things are related to us and are earth life.
To aliens humans, crocodiles, rose bushes, and squids would be basically the same thing, just different derivatives of the same DNA.

Two words throw a huge monkey wrench into your hypothesis.

Convergent evolution. Similar environments inevitably cause similar forms to evolve. It's been seen repeated times over at least the past 200 million years. The same plans keep coming up in very distantly related forms.

So we might not see hairless apes building material civilizations we probably will see multi limbed bisymetrical animals with circulatory systems and eyes. But lower atmospheric pressure and different amounts of oxygen and you could have 2 meter long beetles. You could have soft bodied tentacle things like haven't been seen since the Cambrian or Permian here on our planet or maybe something like a jellyfish that lives on land semi floating in an atmosphere potentially lethal to human life.

Nah. Just a bunch of nonsense made up by some bad science fiction webcomic creator. (Cthonian from Space Thralls and Torlak'Garoth in Interstellar_Battle_Girls)

Read a lot of stuff on Cambrian and Permian life and the development and shifts in our planet's atmosphere and one thing keeps going on: Convergent evolution. Once there's large animals it's the same patterns again and again.

But you'll probably have eyes, some kind of circulatory system and a bisymetrical body plan as opposed to radial symmetry. Even if more limbs two halves is an easy plan for a living land dwelling something beyond a certain size.

And if ocean dwelling we anthropomorphic humans will miss it.

As for alternate dimensions, those movies use some scientific word salad and everything is supposition verging on fantasy usually misusing the terminology horribly. See the book The Science of Star Trek among others.

It's alternate universes, not dimensions. Their alternate dimensions are assuming that time is a physical dimension and that human actions change the flow of time, not a true alternate dimension. It gets all fuzzy and the writers make it do whatever they want it to. LOL.

bravo1102 wrote:
Convergent evolution. Similar environments inevitably cause similar forms to evolve. It's been seen repeated times over at least the past 200 million years. The same plans keep coming up in very distantly related forms.

Unfortunately this doesn't apply to aliens because all the examples we have are all related. Every single one has DNA that comes from the same place. All the same fundamental building blocks.
They all use the same lego set with the same pieces.
So that tilts the board hugely.

Like bilateral symmetry in animal forms comes from the same place no matter the creature…
Things like eyeballs have now been proven to come from the same place - the idea was that they evolved completely independently in things like cephalopds but it's been recently found that the forming of brains that causes the development of eyeballs is the same in creatures. It was there before octopi and other creatures diverted and remains the same today.

Plus, earth conditions and history are incredibly specific. I seriously doubt there will never be very similar creatures on other planets…

We imagine there will be because the alternative is too unimaginable. Like a 4 dimension shape.

bravo1102 wrote:
It gets all fuzzy and the writers make it do whatever they want it to. LOL.

Yes, They anthropomorphize them basically :(
They always base them on humanity which I find maddeningly silly.
The universe is Soooooo massive and time is so vast, humanity is the smallest, briefest little spark in that vast firmament.

But not only is the universe incredibly gigantic and time endless, when you factor in the possibility of other universes those factors increase exponentially.

I think it comes from the idea that the “observer” changes outcomes of collapsing wave forms (and causing a branching universe were it has another outcome), and they mistakenly think that “observer” must be human and watching or doing something, when “observer” is actually just a very stupid term for anything that collapses the wave form- basically any atom.

There might only be so many ways the proteins come together and code. It's possible that different proteins still code and the codes be interchangeable. It's also possible that no matter the environment certain things just always happen because it works best. You might be able to totally change the deck but the cards still deal the same way.

Convergent evolution may be more prevalent than we imagine. Different may not be as different as we think.

That's why I go back to the Cambrian for the Cthonians. They're not plants or animals and their genetic code is incompatible but they evolved in an atmosphere within the different range of atmospheres Earth has had.

A creator doesn't have to be specific with the whys and wherefore but only touch on the results. This is what it looks like to the human, this is the best they can interact and there's very little shared points of reference. Like those Cthonians whose method of communication is based on sexual stimulus. That's just how they say hello and they don't quite see why it's inappropriate to those bipedal things.

bravo1102 wrote:
Like those Cthonians whose method of communication is based on sexual stimulus. That's just how they say hello and they don't quite see why it's inappropriate to those bipedal things.

I would posit that humans communicate the same way, but that that undercurrent is just buried under mountains of societal constructs and euphemisms lol

This is interesting. I've spent a lot of time on speculative biology and alien evolution. I was inspired by the Cambrian explosion. One thing that bugs me with most made up worlds is the lack of cohesion. Like there will be some creatures with 2 appendages and others with 6. And a lot of the mideval style mix and match animal parts. If you've ever played No Man's Sky or Spore, you know what I'm talking about. There was a time when I was really into trying to comer up with unique aliens. I created a whole system: using various dice I made of wood to set there parameters of each star system and each planet. Then it would determine if any planet was suitable for life. If so, it would start with a few basic body plans and I would run them though several cycles of evolution. Usually they didn't reach intelligence. I made about 75 star systems.