4 ms·
Because we exist. If infinite density existed, our atoms would be in there.
by swamp40 3y ago
Because we exist. If infinite density existed, our atoms would be in there.
- tomcatfish 3y ago(This is not sarcastic) How do we know we aren't?
- senttoschool 3y agoWell, there have been thoughts that we are living in a blackhole from another universe. So there's that. These questions aren't answerable at the moment. It's all just speculation.
- danra 3y agoNot true. For example we could be surrounded by a sphere of uniform infinite density, in which case our atoms wouldn't be pulled in either direction.
- zdragnar 3y agoFor those of us like myself who are terribly naive, why wouldn't that just cause all of the atoms to be torn apart? Unless the sphere were infinitely far away, only the center point would be in balance, and everything else would be immediately sucked to the edge of the sphere. If the sphere's radius was infinite, that might explain the expansion of the universe itself, but not the presence of infinite density within the universe itself.
- consilient 3y ago> Unless the sphere were infinitely far away, only the center point would be in balance This is false. https://en.wikipedia.org/wiki/Divergence_theorem https://en.wikipedia.org/wiki/Divergence_theorem
- Dylan16807 3y agoWhen you do the math for gravity inside a shell of material, the quadratic falloff exactly counteracts the distances and the total pull is exactly zero. https://en.wikipedia.org/wiki/Shell_theorem https://en.wikipedia.org/wiki/Shell_theorem
- swamp40 3y agoIf the sphere had infinite density, wouldn't that mean that every atom in the universe would be inside? So how could our atoms be outside?
- deleted 3y ago[deleted]
- cyberax 3y agoWhy? At a distance, gravity doesn't really care about density, only mass. An infinitely dense object would shred anything it touches by its infinitely high tidal force, but there's only a limited amount of material it can touch within a given time and the Universe is not infinitely old.
- Dylan16807 3y ago> but there's only a limited amount of material it can touch within a given time and the Universe is not infinitely old Okay, to be precise something like that can't have existed in the observable universe (at the time we observe), but could exist in a distant bubble that's expanding at the speed of light.
- vitehozonage 3y ago>the Universe is not infinitely old You don't know that. Claiming that there is a start to the universe is an absurd, religious ex nihilo argument.
- deleted 3y ago[deleted]
- echelon 3y agoCompare the infinite set of integers to the infinite set of reals. Infinite sets can be subsets of much larger infinite sets. Also, density is mass divided by volume. You have two variables to play with. But all of this detracts from the notion that infinity and singularity may have no physical analog. They're mathematical constructs.
- NegativeK 3y agoHow does that follow?
- tomcatfish 3y agoThere would be infinite m/v there, and finite everywhere without infinite density, so literally every single random draw of a single mass-unit would be in an area of infinite density, or so goes the idea.
- abdullahkhalids 3y agoEvery theory has a domain of applicability, determined by tests within that domain. I don't think its reasonable to assume that the domain of applicability of any our theories extends to various infinities.
- NegativeK 3y agoThat's presupposing that the mass portion of m/v is infinite, which, from our understanding of black holes, we have no reason to believe. Pathological local densities tell you nothing about the mass distribution of the universe precisely because they're so pathological.