Found this gem on Instagram just now

Nigger if the mass of the universe is the same mass required to create a black hole the size of the universe, our universe would have a density of a black hole

/thread

You do know that the density of a black hole is inversely proportional to its size, right?
Oh wait, no you didn't. Because you're just as popsci as the rest of those fucking losers.

Not user, but where's the singularity? Where's the extreme curvature?

Hypothetically, the whole thing is the singularity. And you seem to have a fundamental misunderstanding about how space-time curvature works. Go read a book. Or four books.

Is the density of a black hole constant throughout the entire thing? Because if not, saying that the universe has the right mass for its size to be a black hole is the same as saying it has the right density to be a black hole.

Then your statements contradict.

The singularity is infinitely more dense than the surrounding space so it is required that we would see the gravity field differential somewhere in our universe.

not the original guy but there's still a finite amount of mater in a finite amount of space. Density.

My question is, and I'm not claiming to have any knowledge in this area is. If we were living in a black hole would there not be a singularity or center to it? If we were in a black whole would that by definition mean that we have passed the event horizon meaning that Light could not escape, as it would be pulled into the center? Doesn't that disprove what has been said by the OP

>Hypothetically, the whole thing is the singularity

lol

brainlet spotted

>Hypothetically, the whole thing is the singularity
kek

>not the original guy but there's still a finite amount of mater in a finite amount of space. Density.
infinite density at a point doesn't mean infinite mass in finite space
why don't you go somewhere else and stop playing scientist with things you never studied?

youtube.com/watch?v=WlHNfVctq7E

This
t. knower

nice hat.

I don't know if this is bullshit or not but the only thing that pisses me off is that likely the people who made it didn't put any effort in learning science and/or philosophy and the people who it will reach certainly haven't put any effort learning science and/or philosophy. So they should stop using science and/or philosophy as a self congratulatory tool.

>Can't exceed the speed of light because if you do you would be outside the black hole.

>blackholes are real

size of universe increase over time
quantity of matter is constant over time
thus the quantity of matter needed to make a black hole the size of the universe need to increase.
Thus it's bullshit.

size of the universe is unknown

density of big black holes is quite low

The Schwarzschild radius of the observable universe is about 13.7 billion light years. The observable universe has a size of 93 billion light years.
Thus the observable universe is not a black hole.

>not proof that the universe has the mass to cause a schwarzschild radius the diameter of the universe.

>size of universe increase over time

Probably the size of the universe is increasing because the universe is a black hole sucking matter from another source, since the radius area-mass relation the black holes have, this could be the explanation of the universe expansion.

>quantity of matter is constant over time

You can easily detect the space expansion, but the mass increasing is not that easy to detect.

Probably the universe is sucking so many mass at such elevate rate, that space expansion is getting faster than c.

Theoretically there is not an impediment for that.

If our black hole Occupies the entire universe, then how does it suck mass from some other body?

Because the universe is way larger than we used to think about?

>The Schwarzschild radius of the observable universe is about 13.7 billion light years. The observable universe has a size of 93 billion light years.Thus the observable universe is not a black hole.

/thread

We define the universe as "intrinsically infinite" so it has infinite mas in a infinite space. Then a black hole whit the mass and size of the universe would contain a infinite amount of mass in the infinite size of the universe, this last part doesn't make sense at all

ahem
radius is (93 bn ly)/2

Alright, then we should change the term, inst the "universe", is "our universe"

Seriously, science can't in any, any way explain the accelerated expansion of space, the only reasonable explanation is the increase rate of the radius - mass of a black hole, is the only thing that fits the observation.

>observable

Actually the black hole theory needs less mass than the "black energy/matter" theory to match observation.

U means unknown, t means not necessarily proven, but I think is true, x means not real, ... means it's complicated, blank means I'm not going to acknowledge that, and ? Means I don't know what you're implying.

Anyone who's input is worth shit should be able to deduce what FP means in this context.

>science can't in any, any way explain the accelerated expansion of space
dark energy

>the only reasonable explanation is the increase rate of the radius - mass of a black hole, is the only thing that fits the observation
no, it isn't. Also that theory is contradicted by directly observable facts such as the universe not having the mass/energy to produce a large enough Schwarzschild radius to define the boundary. Also you failed to consider than nature of space/time within a black hole's event horizon and how it is not like what our space time is like. Also there is not extra mass/energy appearing at the edges of the universe, everything that was created is all there is.

just because the universe is expanding and black hole event horizons can expand does not prove the universe is a black hole. Different things can share general properties without being the same thing.

If the universe is larger and the black hole is sucking matter from another body that means the black hole isn't occupying the hole universe because there is another body which isn't contained into the black hole

yes

>dark energy

Ether v2.0

>>observable
What is the size and mass of the actual universe, genius? Oh, it's infinite! That means we can only treat those numbers as a ratio, thus density, and it follows from the cosmological principle that it is uniform all over the universe, hence: the observable universe does not have enough density to be a black hole -> the universe is not a black hole.

The burden of truth is on the claimant, always, and the claim here is that we know the size of the universe, which we do not. We have a measure of the observable universe, but not of the whole universe.

why should the universe be larger than the sphere defined by the time since the big bang and the speed of light?

One single intelligent post in this entire thread.

Google "radius of the observable universe" for a bit. Come cosmic fuckery happens when space itself, the medium through which light travels, expands, so it's not as trivial as the speed of light and the amount of time that that light has had to travel.

Black hole density is necessarily greater than neutron star density, samefag.

1. speed of light limit does not apply to expansion of space

2. we dont even know the size of the universe before inflation began, it could have already been very large/infinite, and just increased in size further

13.8 billion is the age of the universe but it really does not say anything about its size

Nope.

>First, the average density of a supermassive black hole (defined as the mass of the black hole divided by the volume within its Schwarzschild radius) can be less than the density of water in the case of some supermassive black holes.

en.wikipedia.org/wiki/Supermassive_black_hole

I am learned now, the knowledge of two men. You've only made me stronger, you fool.

>radius is (93 bn ly)/2
I remembered that when I gathered the numbers, but then I forgot it again when I made the post.

>gravity field differential somewhere in our universe.
en.wikipedia.org/wiki/Dark_flow

>Explain why, and show your working.
is this worth reporting, are trolls banned from Veeky Forums upon report?
for those who care: any amount of matter is exactly enough to make a black hole of the same mass. and we don't live in a black hole because we'd either see other stuff in the universe approach us as we are all falling towards the same point (if we were far enough from the singularity) or feel the tide forces if we were close (the stuff that falls from other directions towards the same singularity seems to get closer to us at an ever slowing rate, but when this rate becomes so small it's hard to measure, tidal forces are already noticeably trying to rip things apart).
either way, we see stuff in the universe getting away from us. so yes, OP's picture is unmitigated hogwash.

>in essence it is true

I wholeheartedly disagree.

>dark energy

Theoretical force, built upon upon theoretical force, upon theoretical invisible force that isn't really a force but instead an emergent property of mass.

There is no proof that gravity exists therefore the entire offshoot of arguments derived from gravity's theoretical existence are inherently philosophy in essence rather than scientific..

/thread

>a black hole inside the universe
>a black hole inside a black hole
>a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole inside a black hole

No

Wow I never knew this, I thought it would always just be insanely dense. Guess I was dense myself, all this time.

>can be less than the density of water
someone explain this to me in human language, because this completely shits all over everything I think I knew, about how black holes actually work

let's recap
- to make a black hole, you need enough mass in one place, to generate gravity strong enough to turn spacetime inside out
- you literally need matter compressed more than goddamn neutronium, which itself is already a deformed state of matter that cannot physically exist outside of the gravity of a neutron star
-some black holes are less dense than fucking water

what.the.fuck?

seems like the diameter of the event horizon enlarges more rapidly than linear with addition of extra mass.

This would be interesting if true. What I ASSUME they are asserting is that the Schwarzschild radius of a black hole is dependent on mass, and that the Schwarzschild radius of the universe as calculated from the estimated total mass of the observable universe is the same as the radius of the known universe.

A Schwarzschild radius is given by R = 2GM/c^2. The source people.cs.umass.edu/~immerman/stanford/universe.html estimates a 6e51kg of mass in the observable universe. Plugging this mass in, a black hole with the mass of the universe should have a Schwarzschild radius of R ~ 8.9*10^25 meters, or about 10^26 meters.

The same source gives the estimated radius of the universe as 1.7e26 meters. That's already sort of spoopy, but the lower limit within the 20 percent error range given in the source is about 1.35*10^26 meters.

Now, these numbers aren't what you would call fantastically in concordance with one another, but it is eyebrow raising that the estimated Schwarzschild radius of a black hole with the mass of the known universe is clearly within the same order of magnitude as a black hole, the ratio of the real radius to that theoretical Schwarzschild radius being about 1.9. So people are wrong to say there is *absolutely nothing* interesting about examining this question.

The assertion that we may live within a black hole obviously requires more detailed work. But for a popsci assertion, it's a surprisingly accurate characterization of the estimations, as long as you use the Schwarzschild radius as the "size" of the black hole.

One thing that throws this calculation off is an estimate that the universe's diameter is 93 billion light years, which is 46.5 billion light year radius, which is 4e26 meters, and therefore is significantly more off.

Obviously, varying estimates of the mass-density of the observable universe and the radius of the observable universe are going to throw things off.

Overall, though, the black hole universe theory isn't substantiated by this line of thought alone.

That image isn't even a black hole, it's a wormhole.

>are trolls banned from Veeky Forums upon report?
Seeing how these stupid " 0.9999999 = 1 " are being started and the OP isn't being banned, I'd say no.

The observable Universe is not dense enough to be a black hole. The supposition is incorrect.

This sounds like a bastardization of the holographic principle.
It was probably made after reading some shitty clickbait article about it.

More unfalsifiable claims from the physicist-shamans

>autism bingo

No, it's true if you take "big" as referring to mass rather than volume. The top part says that the mass of a black hole is related to itself, and the bottom part says that the mass of the universe is the same as the mass of a black hole with the mass of the universe. It's tautological and meaningless, but it's true.

The very last part is wrong though. I'm sure there would be other signs of it if we were living in a black hole.

If the universe is a black hole, then light couldn't escape the universe, because light can't escape a black hole, but I don't see why that would mean that light emitted by things inside the black hole wouldn't be visible inside the black hole. I mean the bigger issue is that humans probably can't survive inside a black hole.

Ether hasn't actually been disproven btw

It is of course nonsense. Firstly the universe is expanding, it's not described by the Schwarzschild Metric. Secondly the geometry of the universe on large scales is measured to be flat from the cosmic microwave background and galaxy clustering, a black hole universe is inconsistent with that.

>I know nothing about this topic but let me tell you how every export is a moron.

No. The cosmological constant is a natural term in the Einstein Field Equations, you can't just wish it away. Even setting it to zero is an assumption.

Surely the (observable) universe is almost all empty space, so nowhere near enough mass to be a black hole? It could only have enough mass if all the matter in the universe was way, way, WAY more dense than...black holes, which would mean almost ALL matter would BE black holes.

The observable universe is infinite? So you can see further than 14 billion lightyears?

But still, anything we can see still has a finite limit on how far away it can be since the universe has a finite age which we (approximately) know.

It's easy to understand. If Earth was millions of times bigger, same density, its surface gravity would be strong enough to make it a black hole. I think.

t. engineer

They didn't mention the observable universe.
And the distance to the edge of the observable universe is more like 46.5 billion light years, due to special expansion.

>Philosophy and science
Holy shit, people follow this? The fucking swartzchild radius of the observable Universe is around 14 Billion Light years, the diameter of the observable universe is around 95 billion light years. Can pseudo science die in a hole like it should of with the rest of the fedora explorers?

Gravity doesn't exist? You mean as a force right?

>the mass of our universe is the exact amount needed to make a black hole with the mass of our universe

Really made me think...

A black hole is literally the opposite of our universe. The FRW metric has a spatial singularity at exactly t=0 whereas the Schwarzschild metric has a temporal singularity at exactly r=0.

Starts off with greentext:
>observable

This is confusing me.
So the definition of 'observable universe' includes things so far away, 93 billion light years, that we can't see them. And if they're expanding away from us at a greater rate than c then we'll NEVER EVER be able to see them?
I understand that we can see things that NOW are that distance away, but we're seeing them as they were when they were much closer than that, so aren't we (educated) guessing about the edge, rather than observing?

Great Attractor is that singularity

lemme get gravitational waves for 500 alex

The most stuff you have, the less dense it needs to be to become a BH. A star sized BH needs to be denser than neutronium, a supermassive BH needs to be as dense as water, and a universe sized BH needs to be as dense as the universe.

The reason that the universe isn't a black hole is because stuff outside our observable universe pulls outward.

I did some calculations and this meme, surprisingly, turns out to be correct.

The question I have know is... why doesn't our universe collapse into a black hole? If

I know right. This is a very good q

ether is real, dipshit, I use it all the time in the lab

What is schwarzschild radius

Yes but that's the meme density of black holes we don't know the "actual" density. For example, my meme density is really huge (my mass corresponds to some schwarzschild radius too), but my actual density not so much.

>aren't we (educated) guessing about the edge, rather than observing?
Yes, it's all models on top of models, stack 'em as high as your intellect can go.

oh tu shadilay