Thread 16775576

how wide is the universe
>93.016 billion light years
how old is the universe
>13.8 billion years

how does this work?

>how wide is the unvierse
Observable universe.
>how does this work
Expansion of the universe. Light emitted from a point that, 13.8Ga ago, used to be 13.8 lightyears away from Earth is now further than 13.8 lightyears away.

>>16775576 (OP)
what is the universe
>it's dark matter
and what is dark matter
>we don't know
so how the fuck do you know how the universe started, how it will end, or how big it is, if you don't even know what it is?
>cause reasons

the absolute state of astrofags

>>16775576 (OP)
since the universe expanded faster than light.

93 billions light years is its current position, but the light detected is only 13.8 billion years old and its source was way closer to us.
The discrepancy? expansion, red shifts allows us to calculate the relative position of light we receive so you can extrapolate the red shit of closer objects, its distance and the red shift of the oldest observable objects that are the farthest ones.

>>16775585
>when you notice that this is the "steel is heavier than feathers" statement

>>16775581
>how the universe started, how it will end
Astronomers don't claim to know these things.
The big bang theory merely sees that the universe is expanding, and runs the tape backward and deduces that the early universe was smaller and denser. It doesn't account for or try to answer why the big bang happened or where the singularity came from.
It's like how if you have a video of a balloon inflating and expanding, and you watch part of it in reverse, you can deduce that it started with a smaller or empty less-inflated or non-inflated balloon, without seeing the beginning or knowing where it came from or who set it up.

>>16775617
So there is this system.
You can only see a part of it (unknown how big, could even be infinite).
And of that part you can only perceive 5% of it.
And of this 5% you only understand a small amount.
How confident you are that you can predict how this system works?

If you answered anything other than 0% you are a moron.

Now defend astrophysics without sounding mad.

>>16775581
>what is the universe
>>it's dark matter
By the same shitty logic you are water.

>>16775619
We can see the same rate of expansion in the entire visible universe.
Does the universe have some property where, outside of the visible part, the expansion isn't uniform and some parts of it are behaving differently (expanding at different rates or remaining constant or contracting instead)? If so, it's something completely unknown to us and unscientific and unfalsifiable since it's beyond our reach to study it in any way.
It's kinda like when those hoping aliens are out there go
>maybe we haven't found signals from them because they communicate some whole other way besides the electromagnetic spectrum
It's unscientific and you can't do much with that speculation because it would require some whole new property of the universe that we've never detected a hint of and can't study or test

>>16775652
>I recognize that we should not be saying the universe is expanding.
>That said, I shall now continue doing so because I refuse to apply my logic to my own statements.

>>16775652
dude you are the one who is unscientific
the math literally doesn't math so you conjured up an idea of dark matter
only the only thing you accomplished is proving that you know jack shit

let's assume that "the big bang" is true
why the fuck do you think that's all there is?
the big bang could be but a tiny spec of dust in an infinite universe where infinite big bangs happen all the time where matter density becomes too low

this makes much more sense

>inb4 you have no proof
neither do you but my model makes much more sense than an infinitely dead universe which just happened to be alive for a fraction of infinity and we happened to be living in it

and one thing that is for sure is that our universe is based on logic

what happens once will happen again and what will happen again will happen again and again and again

>>16775652
Moreover I would like to add that in your "unique big bang until heat dead universe", us existing is so improbable that it's borderline impossible.
In the infinite big bangs universe us existing is inevitable.

And yet we exist, that's for sure.
So you would rather bet our existence on some kind of miracle that only happened once and we were lucky enough to win the 1 in 6 gorillion lotto chance.

Whereas I bet on the theory that it's inevitable that we exist.

So who is the unscientific, unmathematical, miracle believer?

>>16775657
I never recognized that. The observable universe is expanding at a uniform rate and I will continue to say so.
>>16775658
>>16775664
You are attacking strawmen. The big bang principles don't impose the limits you refer to and don't require there to be only one universe or only one big bang ever. Once again, all it really says is that this universe is expanding and must have been smaller and denser in the past. No reason the same thing couldn't apply to other universes or to some sort of infinite cycle, and so on.

>>16775578
if this was true, then time would have expanded too and the big bang would have happened 93 billion years ago

>>16775723
Time is expanding though?

>>16775727
meaning?

>>16775727
as in, it would take longer to get there

>>16775576 (OP)
My intuition tells me that black holes collapse faster than the speed of light. But what we perceive as the collapse of a black hole is actually the expansion of another universe, going kind of orthogonally to our universe.
We expand because everything around us is chasing our own singularity, which collapses ever faster. So what we perceive as an increasing distance between matter is in truth a direct reflection of our singularity becoming ever smaller.
Black holes manage to get out of that chase by collapsing themselves, effectively leaving the pull of our singularity. Note that the further our singularity collapses, the easier it becomes for any mass to become a black hole. It's relative to the size/expansion(collapse) of our universe. So even smallest pieces of matter would eventually turn into black holes because their tiny spacetime curvature is all thats required for leaving the grip of such a small (therefore distant) singularity.
Also note that the collapse speed is unburdened by any constant speed of light limitation, since 'distance' itself defined inside the black hole / new universe by the collapse itself. Meaning that the speed of light is, when looked at across this distance, getting slower and slower.
This in turn would explain why our universe is bigger in lightyears than its age in years. Because as of right now light DOES take this long to reach that observable edge of our universe. It didn't back then.

Dont know shit about physics but it kinda feels right.

>>16775576 (OP)
Inflation+Expansion+Acceleration
Idk either.

>>16775700
>I never recognized that
...
>unscientific and unfalsifiable since it's beyond our reach to study it in any way.
...
>this thing must have a single specific cause that we can't prove or disprove because it's what I was taught to assume

>>16775723
Only space is expanding.

>>16775787
>single specific cause
You are deliberately ignoring a lot of what you're replying to and making up your own garbage to argue against. But I'll say it again: the big bang theory doesn't try to answer the question of how/why it happened or where it came from. It doesn't say and doesn't know what the cause was. All it says is that the universe is expanding and if you run the tape backward you get a universe that was smaller and denser and hotter in the past.
But by all means, keep mischaracterizing it and arguing against something different from the words you are reading

>>16775802
>mischaracterizing
What part of "we are unable to prove the universe is expanding" are you unable to understand?
It is not the only possible cause of redshift. Electromagnetic waves are known to propagate differently depending on wavelength, but somehow this isn't permitted when talking about redshift.

>>16775576 (OP)
just wait till you find out that there is a good possibility that the universe is infinite in size and contains a infinite amount of universes within it

>>16775576 (OP)
>>16775616
nothing can move faster than the speed of light
but two things moving away from each other at the speed of light are moving twice the speed of light relative to each other
and nothing can also move faster than the speed of light because nothing (space) expands by dark energy while matter in space expands away from other matter, so the expansion ends up being much faster than light

>>16775576 (OP)
space expands at every point
adds up to about 2cm/s per ly
At 15 bn ly away, stuff is receding at the speed of light.
At the edge of the observable universe, it's 3c

>>16775897
>if I say it again no one will notice what he's saying
>>16776001
Ah, yes, 3C. I wonder what the resulting wavelength of that doppler shift is.

>>16775797
And were magically right in the center.

>>16775797
time is just a dimension of space. there's not a single difference between time and space. so why would space expand but time remain still

how much of the universe is not observable? what percentage do we make up?

>>16775700
>No reason the same thing couldn't apply to other universes
it's not other universes though
this "parallel universe" shit is misleading
it's one universe where big bangs occur and seed stars, where matter density gets too low

>>16775585
It's expanding at every point between gravitationally bound galactic clusters. The expansion rate isn't that fast yet, but it's accelerating.

>>16776001
>space expands at every point

Only in regions between gravitationally bound clusters of galaxies. Gravity counteracts expansion.

>>16775652
can you detect love?

>>16776277
We are in the center of our field of view by definition, yes.

>>16776543
>Gravity counteracts expansion.
That's the mass. The space itself expands.

>>16776009
Nothing magical about it. We are in the center of OUR OWN sphere of observable universe, because we can see the same distance in all directions.
Aliens somewhere 50 billion or whatever light years away would also be at the center of their own observable universe, which covers a different volume than ours.

>>16775578
how did they make a ruler big enough to measure the size of the observable universe

>>16778501
A bunch of unprovable assumptions that have now gained the status of fundamental precept despite not being fundamental in any way.

>>16776284
Depends. Nobody knows. But it appears flat to us. Meaning for us to see no curvature either means it is infinite, or way, way larger than we can see. Like if you're on earth it looks flat from your perspective. So for it to appear flat to us, and if it isn't, would require us to see a tiny fraction of its size.

>>16778516
Fundamental error of localized measurement constraint.
We can't even check our constants aren't variable.

>>16778519
What are you even arguing? It's just saying that for us to see the universe as flat it has to at least be X times larger than we see. That's just factual and necessary to be true if it is to be both flat and finite. Or it could be infinite. We don't know. But we can know that for us to see it as flat at all, it's one of those two. We are either seeing a tiny fraction of the overall universe and off about its size by like 250x. Or it's just infinite.

>>16778521
>What are you even arguing?
>Fundamental error of localized measurement constraint.
I don't know, what do those words mean together?
>know gravitation fucks with things
>fail to remember while measuring everything from earth

>>16778530
It's a property of a sphere. Hence why I compared it to earth and how it seems flat to us despite being round. It's how Greeks got as close to the size of the earth as they did. You measure the curvature. But to seem flat it has to be at some X distance minimum. Or we would see positive or negative curvature. We looked and found none. So that means two possible things. By brute force and necessity.
1. There IS curvature since it is finite. We just cannot see it. So minimum it has to be 250 times larger for us to not see such.
2. There is no curvature because it extends infinitely.
There are only two possibilities available.