https://www.forbes.com/sites/startswitha...e20953df80
EXCERPT: . . . So what can we say about the part of the Universe that's beyond the limits of our observations? We can only make inferences based on the laws of physics as we know them, and the things we can measure within our observable Universe. For example, we observe that the Universe is spatially flat on the largest scales: it's neither positively nor negatively curved, to a precision of 0.25%. If we assume that our current laws of physics are correct, we can set limits on how large, at least, the Universe must be before it curves back on itself.
Observations from the Sloan Digital Sky Survey and the Planck satellite are where we get the best data. They tell us that if the Universe does curve back in on itself and close, the part we can see is so indistinguishable from "uncurved" that it must be at least 250 times the radius of the observable part.
This means the unobservable Universe, assuming there's no topological weirdness, must be at least 23 trillion light years in diameter, and contain a volume of space that's over 15 million times as large as the volume we can observe. If we're willing to speculate, however, we can argue quite compellingly that the unobservable Universe should be significantly even bigger than that...
MORE: https://www.forbes.com/sites/startswitha...e20953df80
EXCERPT: . . . So what can we say about the part of the Universe that's beyond the limits of our observations? We can only make inferences based on the laws of physics as we know them, and the things we can measure within our observable Universe. For example, we observe that the Universe is spatially flat on the largest scales: it's neither positively nor negatively curved, to a precision of 0.25%. If we assume that our current laws of physics are correct, we can set limits on how large, at least, the Universe must be before it curves back on itself.
Observations from the Sloan Digital Sky Survey and the Planck satellite are where we get the best data. They tell us that if the Universe does curve back in on itself and close, the part we can see is so indistinguishable from "uncurved" that it must be at least 250 times the radius of the observable part.
This means the unobservable Universe, assuming there's no topological weirdness, must be at least 23 trillion light years in diameter, and contain a volume of space that's over 15 million times as large as the volume we can observe. If we're willing to speculate, however, we can argue quite compellingly that the unobservable Universe should be significantly even bigger than that...
MORE: https://www.forbes.com/sites/startswitha...e20953df80