As I just explained, it’s not really about observation, it’s about causation. If two objects can never possibly interact, then are they really in the same universe?
Looking out in space is also looking back in time. Anything (roughly) that is further than we can observe in the microwave background would be further back in time than the beginning of time, and therefore doesn’t exist at all in our universe. It a bit brain bending.
I guess I don’t trust the human understanding of ‘never’. It’s more like ‘we don’t currently believe its possible’, which has in the past been unreliable.
I would say yes they are part of the same universe because if you changed your position it would reveal things you didn’t see before and mask thing you use to see. Not that that is possible yet, but there are no laws of physics preventing it, only our super short live spans.
That’s just it. The laws of physics, at least as far as we understand them, absolutely preclude changing our position in any way that would reveal anything outside our observable universe. Lifespans don’t come into it at all. If you lived forever traveling at the speed of light, you would never achieve that change of position.
The cosmic background is the leftover “noise” of the big bang, and we observe it roughly uniformly in every single direction. So where did the big bang occur? Everywhere. Everything that exists is precisely at the center of the universe, right where the big bang happened.
It’s all about the concept of spacetime. Spacetime isn’t space and time considered together, it’s a singular thing that operates by rules that we are ill equiped to comprehend intuitively.
The laws of physics, at least as far as we understand them, absolutely preclude changing our position in any way that would reveal anything outside our observable universe
Tinidril@midwest.social 3 days ago
As I just explained, it’s not really about observation, it’s about causation. If two objects can never possibly interact, then are they really in the same universe?
Looking out in space is also looking back in time. Anything (roughly) that is further than we can observe in the microwave background would be further back in time than the beginning of time, and therefore doesn’t exist at all in our universe. It a bit brain bending.
NotLemming@lemm.ee 3 days ago
So when you say never, do you mean not in the ‘lifetime’ of our sun, or?
JohnDClay@sh.itjust.works 3 days ago
Not till the heat death of the universe.
NotLemming@lemm.ee 3 days ago
I guess I don’t trust the human understanding of ‘never’. It’s more like ‘we don’t currently believe its possible’, which has in the past been unreliable.
Clinicallydepressedpoochie@lemmy.world 3 days ago
I would say yes they are part of the same universe because if you changed your position it would reveal things you didn’t see before and mask thing you use to see. Not that that is possible yet, but there are no laws of physics preventing it, only our super short live spans.
Tinidril@midwest.social 3 days ago
That’s just it. The laws of physics, at least as far as we understand them, absolutely preclude changing our position in any way that would reveal anything outside our observable universe. Lifespans don’t come into it at all. If you lived forever traveling at the speed of light, you would never achieve that change of position.
The cosmic background is the leftover “noise” of the big bang, and we observe it roughly uniformly in every single direction. So where did the big bang occur? Everywhere. Everything that exists is precisely at the center of the universe, right where the big bang happened.
It’s all about the concept of spacetime. Spacetime isn’t space and time considered together, it’s a singular thing that operates by rules that we are ill equiped to comprehend intuitively.
iriyan@lemmy.ml 2 days ago
flat earth on a flat universe, MUFA make-the-universe-flat-again
Clinicallydepressedpoochie@lemmy.world 3 days ago
I do not agree.