Even if parallel universes do exist (they don't)
And you have proof that they don't? Pretty bold assertion to make without experimentation don't you think?
the fact that these people think we'd ever be able to know is just unbelievable.
Searching for what is and is not is kinda what science is all about.
These universes would not collide, as they would not even be on the same physical plain as our own. And this is why these conversations are stupid.
Another unfounded assertion. Amazing how you have privileged knowledge as to how dimensional collision works. You could offer these insights to the scientific community and save them a lot of trouble actually researching things!
Seriously though, you are free to think such musings are stupid, but it is through such discussions and endless curiosity (as opposed to predefined assertions that reality is a specific way) that new knowledge is gained and new technologies developed.
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There is no shame in not knowing; the shame lies in not finding out