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That’s one speculative possibility, but we don’t know. It could be infinite, or finite with a boundary just out of sight (beyond the edge of the observable univ
by jl6 2y ago
That’s one speculative possibility, but we don’t know. It could be infinite, or finite with a boundary just out of sight (beyond the edge of the observable universe), or some other more exotic geometry. There’s no solid evidence either way.
My money’s on non-infinite, just because I’m not sure infinity is a well-defined concept outside of mathematics. We’ve certainly never observed any other infinite phenomena.
- voidUpdate 2y agoIt's only been a finite time since the universe was very small, so unless it's expanding infinitely fast, I don't see how it could be infinite
- immibis 2y agoWas the universe infinitely small or was it just extremely or infinitely dense? Anyway, we don't actually know that, since we do not have a time machine. The theory that the universe used to be much smaller is something we infer based on the snapshot we see today, just like we infer rotation based on the snapshot we see today. Either one could yet be proven wrong.
- atkailash 2y ago[dead]
- ben_w 2y agoIt's (mathematically) allowed for it to have always been infinite, and still grow. If you take the number like and apply f(x) = 2x, it was infinite before and after.
- voidUpdate 2y agoyes but if x is finite, any f(x) will still be finite. So the universe has either always been finite, or always been infinite, and given that it started out being very small in a big bang, it would imply the former
- lumost 2y agonot if x is the set of all Real numbers. All points could have been infinitely close to each other at the big bang, and the universe could still have been infinite in size.
- ben_w 2y ago> yes but if x is finite, any f(x) will still be finite. The number line is not finite, even though every value on it is. The universe may be like the number line. > and given that it started out being very small in a big bang, it would imply the former The universe started out denser, which is not quite the same as "small" when talking about infinities. The currently visible universe gets both things at the same time, but only because the visible bit is finite. Apply f(x) = x * 1e-60 to the number line, and things which were previously spaced out every integer, are now much more densely packed, but the number line as a whole is still the same size — infinite.
- AnimalMuppet 2y agof(x) = tan(x) f(x) = 1/(1-x) So if x is finite, f(x) can still be infinite.
- adgjlsfhk1 1y agowe don't know that the universe was ever small, just that it used to be a lot denser than it is today.
- XorNot 2y agoExcept plenty exist - every electron is an infinite phenomena. They're point-like particles made up of no constituents. You can get infinitely close to an electron and still get closer to it. Infinity extends both upwards and downwards in scale.
- lambdaone 2y agoBelow the Planck distance, "closer" ceases to be a meaningful concept. Similarly, distances larger than the size of the observable universe may also be meaningless.
- deleted 2y ago[deleted]
- hnuser123456 2y agoThe co-moving radius of the universe is about 3x larger than the observable universe, but I don't think there's any practical measurements larger than that. We don't know how much is beyond that because potentially a large chunk of the universe is already forever outside our past and future light cone.
- kstrauser 2y agoWhy is that? I've heard this before but don't understand what it actually implies. Like, why can't 2 things meaningfully be half a Planck distance apart?
- Nevermark 2y agoImagine that at some small distance, space itself is quantum, so quantized. I.e. at the bottom, space is a discrete graph with incredibly small edges. Possibly very tangled and not even layed out in obvious dimensions over short distances. We don’t know if that is the case. That is only one possibility. But it seems very clear that whatever happens at the Planck distance or lower isn’t simple smooth space as we model it for larger scales.
- gitaarik 1y agoI always like to think that finity can only exist in a context of infinity. So even if the "universe" is finite, it exists in a context of infinity. Because they're opposites, they depend on each other's existence. Like hot cannot exist without cold, or light doesn't have any meaning if there is no darkness.
- ForOldHack 1y agoMy money is on Joe Haldmans sawtooth cosmogony. Build an accelerator to simulate the big bang... Instead it recreates it.
- ForOldHack 1y agoI want to address this specific comment: "or some other exotic geometry..." And ask conceiveavle or inconceivable? Of conceiveable by future beings? Far future beings? Current sci-fi authors? My uncle Ian? Only Joe Haldman?