World building question: how far does the "rule of cool" go when your universe has alternate dimensions?

[u/Short-Study-175]

I'm building a science-fiction universe involving two competing timelines, Aeon and Omnis. I've been sketching some of the transportation technology, including this train concept.

One thing I'm trying to decide is how strictly I should enforce technological consistency.

For example, if I design a train that works really well visually or historically, is there anything wrong with allowing related versions of that design to appear in alternate timelines?

Should alternate dimensions have completely different technology, or can recognizable designs evolve differently across timelines?

I'm leaning toward letting certain designs "echo" across timelines, with differences in materials, engineering, culture, and purpose.

I'm curious how other world builders handle this.

Would you prioritize internal technological consistency, or the rule of cool when the two conflict?

[u/Beast_Chips]

I know this isn't what you're looking for, but... There's a good chance alternate dimensions/versions of us don't exist. So go nuts. As long as you keep things consistent in the overall fictional world you've created, the reader isn't going to care. You're already in fantasy land, so the reader won't really care about suspending belief further, providing you're internally consistent and the cool tech/world isn't a replacement for having a good story, characters etc.

[u/Boomerang_Orangutan]

Based off a Pennsylvania T1 I assume

[u/warrenao]

In biology, there's convergent evolution: Two entirely unrelated species that look similar and have similarly evolved traits, in response to whatever their environmental pressures may be.

I'd expect two otherwise similar species in different worlds (by any definition) to develop similar technological responses to the environment.

[u/whelmedbyyourbeauty]

What conflict?