Do we know enough about matter to rule out the possibility of a micro universe?
If the possibility existed for a micro universe would contacting this universe be equally as challenging as contacting something light years away?
If you’re refering to the scifi idea of an entire universe existing inside the volume of a proton, then yes, that’s just pretty much scifi.
Yet, Niply Elder, on behalf of the OP, you have not answered the question with anything more than painting with a broad brush. How do we categorically, conclusively know it is not possible? Or, that our whole universe is not in the back pocket of some giant? A friend asked me such obscure questions ages ago in middle school. I couldn’t rebut this. Yet, even knowing more about science now, can it be proven? If not directly, can it proven by indirect methods (if you are familiar with an indirect proof)?
This was a common theme for conversations when we were kids. I like to revisit it now and then in case anything has changed.
I think we would have a hard time contacting it without destroying it.
Well, it is generally accepted that one cannot prove a negative, from a logics standpoint. One cannot prove that God doesn’t exist, as well as pink unicorns and green leprechauns. We can however affirmatively prove other stuff does happen/exist. As far as physics is concerned, we have the standard model with the fundamental particles, which are so small, it’s hard to seriously hypothesize there’s even a family of particles smaller still which form entire universes in what we would already consider an incredibly small volume. So basically no.
Current particle physics points strongly to the notion that matter and subatomic particles are fields or points of pure energy. A lot of these particles decay in zillionths of a second, etc. etc. So according to our current understanding of the Standard Model of physics, these are truly fundamental (or very close to fundamental) particles and it doesn’t get any deeper than that.
Extrapolating this into the idea our universe is some atom in a larger universe then doesn’t make sense.
Total Sci-Fi and no basis in fact, but an interesting model for a science fiction relation to the perception of time between different sized universes.
Because of various laws of scale, it wouldn’t work in an ordinary sense. You’d have to break through a level of singularity, so that, for instance, an individual electron might be an entire cosmos, but sealed off unto itself, with its own laws of physics that do not interact with our universe in any way.
You can’t just shrink down to it. Isaac Asimov goes into some detail on this in discussions of his novelization of the movie Fantastic Voyage.
This is reminding me of a quote I ran across, once, and may not be remembering with complete accuracy. I also don’t remember who said it. Google was no immediate help.
“Stuff is made of atoms, so atoms cannot be made of stuff.”
As** cmyk **said, subatomic particles like protons, neutrons, and electrons are not solid objects. Quarks are even freakier. If there are small universes, they’re nothing like the one we live in.
Or you can quote Terry Pratchett: " . . . because of quantum."