
Why is there a normal galaxy sitting at the edge of the Universe? - Santosh83
https://www.syfy.com/syfywire/why-is-there-a-normal-galaxy-sitting-at-the-edge-of-the-universe
======
tectonic
Nice gravitational lens observation! We're hoping to use the same technique
with the Sun to observe exoplanets by launching a fleet of small satellites to
547 AU (80 billion km / ~3 light days). The craft would sample the distorted
Einstein ring around our Sun from that vantage point, then combine and
reconstruct an image of the disk of an Earth-like exoplanet up to 100 light-
years beyond, at a resolution of 25 kilometers / pixel.

[https://orbitalindex.com/archive/2020-07-08-Issue-72/#more-o...](https://orbitalindex.com/archive/2020-07-08-Issue-72/#more-
on-that-solar-gravity-lens-focus-mission)

~~~
trimbo
> it’d still take 25 to 30 years for them to reach a vantage point .... >
> mission designers would have to pick carefully because they could observe
> only a single target

It will take 30 years to get in position but then we can only look at one
target? While it sounds very neat, I'd rather fund something we can use more
than once, and sooner.

~~~
augusto-moura
You CAN use for more than 1 target, you just need to reposition the telescope
a bit. See [1], is a great great video on the subject. I can't recommend
enough

[1]:
[https://www.youtube.com/watch?v=NQFqDKRAROI](https://www.youtube.com/watch?v=NQFqDKRAROI)

------
iwonderwhy
All right hackernews. Genuine question, not sure where else to ask.

If galaxies and stars at the other “end” formed out of matter resulting from
the big bang, just as the matter we are made of, how did we get here at the
same time that that matter got there?

Is it because speeds faster than light are possible, and around the big bang
all matter was spread near instantly at that speed? I don't understand how
matter of the same “kind” was spread throughout the universe all at the same
time without traveling at speeds greater than the speed of light. Because if
we watch the ”opposite” direction from where the big bang occurred we don't
really observe matter in a state closer to its original state, or parts of the
universe in radically different states - which should result from that matter
traveling further than the matter we are made of, as for us to now catchup
with light that is “younger” than that towards the core of the universe. Am i
missing something?

~~~
zemnmez
this is because things aren’t ‘moving apart’— space itself is expanding (into
what? nobody knows). it’s not that the galaxies are being propelled apart from
a force in a particular place either; _everything_ is expanding away from
_everything else_.

On the traditional balloon model, the surface of the balloon represents space
itself. Those dots on the surface of an expanding balloon are not moving
relative to space (the surface of the balloon), and so despite the distance
increasing between us, the rate of increase of that distance is not bound by
the speed of light, which only limits passage _through_ spacetime.

The wikipedia page on redshift describes well how redshift applies to objects
which are in space that is expanding:
[https://en.wikipedia.org/wiki/Redshift#Expansion_of_space](https://en.wikipedia.org/wiki/Redshift#Expansion_of_space)

~~~
dumpsterdiver
>"space itself is expanding (into what? nobody knows)"

I have a terrifying theory on this (granted, the Earth will be long gone).
What if the universe is not actually expanding in the sense that it is being
propelled by an initial explosion, but instead falling towards a much greater
mass - the end of time so to speak, where all mass ends. Considering that
gravity is a "weak force", the scale of such a mass makes me uncomfortable to
think about.

Perhaps what we observe as the fabric of space-time itself "stretching" is
actually a similar process to what happens to matter as it enters a black
hole?

~~~
meowface
From my layman's perspective, I think this is plausible, and many physicists
seem to agree it's plausible. Maybe another plausible explanation could be the
reverse: maybe before the Big Bang, our/the universe was in the state you
describe, and the Big Bang is our perception of it "snapping back" and
exploding violently outward (aka a white hole).

Carlo Rovelli and others propose that black holes actually only appear as they
do to us due to the extreme time dilation, and similar to how a photon's
"perspective" is that it's experiencing all of time at once, a black hole's
perspective is that it's basically a massive explosion that occurs at
essentially the same moment it forms. So under this hypothesis, a black hole
never reaches a true singularity, but as close to a singularity as physically
possible, and then it almost instantaneously bounces back like a taut rubber
band that's stretched back as far as it'll go. From our perspective on the
outside, it's an intense explosion occurring in very slow motion, and from the
perspective on the inside, it's an intense explosion happening all at once.

Rovelli posits a Planck star, not a singularity, exists past the black hole's
event horizon, and the Planck star is the state of maximal compression between
the black hole and white hole phases. And somewhat related to this, if I
understand the theories correctly, our universe might be a supermassive white
hole, and we might hold the perspective of being inside of a
super(super)massive black hole that's turned into a white hole and is
exploding and jettisoning everything inside of it. Or some stage after that.
The ultra-compressed energy before the Big Bang would be an (extremely massive
and dense) Planck star.

I have no idea how likely the Planck star theory or white hole universe theory
might be, but my blind speculation is that if it's true, maybe dark energy is
whatever's fundamentally responsible for gravity/curvature causing our white
hole explosion to bend some outer medium - the hypothetical potential medium
which our black hole/universe originally formed in - and interact with other
extreme contractions and explosions also happening in that medium, in complex
and multivariate ways. Maybe a white hole being pushed into or prodded or
yanked by many other black holes and white holes from different directions and
angles could be perceived from the inside as accelerating expansion of space
at certain scales.

Maybe this is happening recursively, even; maybe that outer medium is itself
within another even greater medium, which also is within another greater
medium, etc. Maybe the nesting depth is small, or near-infinite, or infinite.
Or maybe there is no outer medium to our universe, in which case that whole
idea's shot.

And I'm not sure if this could be related, but Rovelli suggests the
hypothetical Planck star cycle of black hole to white hole applied to
primordial black holes that formed in our early universe could explain dark
matter, so even without the outer medium idea there could be something here
that helps us understand our large-scale observations. Maybe there could be
some relation to the "dark fluid" and negative energy idea, too:
[https://en.m.wikipedia.org/wiki/Dark_fluid](https://en.m.wikipedia.org/wiki/Dark_fluid)

I have absolutely no clue if your or my speculation is reasonable or not
(there's currently zero evidence of any sort of outer medium, as far as I
know), but the general concept of our universe being the result of a black
and/or white hole does definitely seem to interest a lot of physicists.

~~~
Aerroon
> _So under this hypothesis, a black hole never reaches a true singularity,
> but as close to a singularity as physically possible, and then it almost
> instantaneously bounces back like a taut rubber band that 's stretched back
> as far as it'll go._

Kind of like a graph of 1/x, where everything behaves predictably, but there's
that one point that doesn't fit?

~~~
meowface
I'm absolutely terrible and uneducated when it comes to math, so I'm not sure
exactly what you mean. But if you mean 1/x where x = infinity, then yes, the
classical idea of a singularity (such as what's been theorized to exist within
a black hole, curving to an infinitely small point) is basically like
1/infinity or dividing by zero.

Rovelli hypothesizes this never actually happens and is not physically
possible, and rather, when the most physically extreme possible level of
curvature does occur, it "snaps back". If true, this ensures black holes do
actually behave predictably, and physics doesn't actually break down; it just
gets as extreme as it can possibly get.

So under this hypothesis, x gets really high, but the universe prevents it
from ever reaching infinity. This would also potentially resolve some
paradoxes related to black holes.

~~~
edjrage
I'm not terribly educated either, but if you don't mind a minor possible
correction, I suppose GP would have meant x = 0, which is the only point where
the function would be typically undefined, and the closer x gets to 0, the
more f(x) approaches infinity. Conversely, the more x approaches infinity, the
more f(x) approaches 0. Also, because of the way these things are usually
defined, it doesn't make sense to say x = infinity, it only makes sense to say
x _approaches_ infinity (but it might make sense in nonstandard calculus,
where infinitesimals are defined - here my ignorance already shows).

I really appreciate your comments! If you're interested in hypothesizing about
physics, I think it would do you a lot of good to learn at least a bit of math
to go with it.

~~~
dumpsterdiver
> "I really appreciate your comments! If you're interested in hypothesizing
> about physics, I think it would do you a lot of good to learn at least a bit
> of math to go with it."

Not disagreeing, I just wanted to suggest that the ideas come first, right?
The math simply frames the ideas in a way that we can quantify and discuss,
while also providing a "line in the sand" that other ideas must be compatibile
with in order to be accepted among other the ideas that have already crossed
that line. Those are very important things, but I would suggest that they are
merely supporting an original idea that does not require math to intuit.

------
rcarmo
It's likely to be the parking lot for The Restaurant At The End Of The
Universe, no?

(I can't help but wonder what Douglas Adams would make of this sort of thing -
or the present time, for that matter.)

------
Randor
I found an interesting paper on the subject over on the European southern
observatory website:

[https://www.eso.org/public/archives/releases/sciencepapers/e...](https://www.eso.org/public/archives/releases/sciencepapers/eso2013/eso2013a.pdf)

------
djsumdog
I've always been puzzled by the estimated age of the universe at being 13
billion years. That's just the size of the observable universe, correct? Isn't
there a future horizon beyond which light will not currently reach us?

~~~
vkou
No, 13 billion years is the age of the universe. The observable universe is a
sphere with a diameter of ~93 billion light years (And is likely to only be a
subset of the entire universe).

~~~
dumpsterdiver
I have a question: Just over 20 years ago when the accepted view was that the
expansion of the universe was slowing down, would you have backed that
position with as much certainty as you are backing this one? That the universe
is a mere 13.7 billion years old?

We cannot prove the absence of light in a place that is already so far away
that it's light will never reach us. Do you agree? We can prove what we can
observe, and from that proof we can make inferences about what we cannot
observe.

The entire premise of dating our universe is based on its observed rate of
expansion. This was accomplished by extrapolating data from observable light
and tracing it back to the so called Big Bang.

I see a lot of problems with this one dimensional assumption, which to me seem
really obvious.

First of all, let's assume that we actually got it right this time and
accurately traced light back to the Big Bang - how can anyone be sure that it
was the first and only Big Bang?

Pangea, the super continent, for instance - many may think of as a single
place and time in history, but in fact it's more likely that many Pangea's
have come and gone in various states as the planet roils on. There will likely
be another in the far future.

Perhaps the Big Bang was merely a "localized" event and there are Big Bangs
occuring in distant places whose light will never reach us. Perhaps we have
gone through many Big Bang / Big Crunch cycles. We simply cannot prove it one
way or the other, and so to take a strong position on this would be
unscientific.

More food for thought - imagine that the universe has already been through a
near infinite number of Big Bang / Big Crunch cycles, it begs the question, do
we reset the clock every time or do we let it run?

In my opinion, currently accepted theory is akin to believing that the Earth
is the center of the universe and the sun revolves around us. We were wrong
about that too.

~~~
outworlder
> Just over 20 years ago when the accepted view was that the expansion of the
> universe was slowing down

Was it ever a mainstream view? I thought it was just a conjecture, leading to
the 'big crush', and was disproven long ago, way more than 2 decades ago.

> The entire premise of dating our universe is based on its observed rate of
> expansion

Also there's the cosmic microwave background radiation. We have mapped it, and
this has also allowed us to corroborate when the universe has formed, what
temperature it had, and when large scale structures appeared.

There's probably other sources that allows us to estimate the age of the
universe.

> how can anyone be sure that it was the first and only Big Bang?

We can't. But it is an irrelevant conjecture outside of philosophy, we can't
observe anything _before_ the big bang.

> but in fact it's more likely that many Pangea's have come and gone in
> various states as the planet roils on

Sure, but that's a planet. We can't extrapolate much from that and apply to
the universe at large.

> Perhaps the Big Bang was merely a "localized" event and there are Big Bangs
> occuring in distant places whose light will never reach us

Unobservable, therefore unfalsifiable, therefore unscientific. Philosophy
again.

> imagine that the universe has already been through a near infinite number of
> Big Bang / Big Crunch cycles

Unless the rate of expansion starts to slow down or we have indication that it
will ever reverse, there's no big crunch. The rate of expansion is
_increasing_

> currently accepted theory is akin to believing that the Earth is the center
> of the universe and the sun revolves around us

Not really. You are dismissing generations of people dedicated to the study of
these things. We have a _pretty good idea_ of what's going on based on the
scientific method, not conjectures from single individuals.

There are things that we don't know yet. On a macroscopic scale, dark matter.
Things don't really behave as they should based on observations, so this is
why we have dark matter as a hypothesis. There could be another mechanism,
research is ongoing. But as far as the macro universe goes, that's the major
thing we don't understand yet.

Most discoveries will likely come from a better understanding of the 'building
blocks', of which quantum physics is at the forefront.

There's probably much more we don't know yet. But the _age_ of the universe,
as we observe it, is not among them.

~~~
HideousKojima
>Unless the rate of expansion starts to slow down or we have indication that
it will ever reverse, there's no big crunch. The rate of expansion is
increasing

Unless space wraps around like a globe and we'll all meet at the "south pole"
(with the big bang being the "north pole") or something to that effect. Which
is itself wild, unfalsifiable conjecture, but there are other ways for a Big
Crunch to happen other than the expansion of space slowing down or reversing

------
sandworm101
>>> Like this one, it’s not understood how it can exist.

I don't like that phrase. It suggests the possibility that this galaxy might
not exist, that this could be observational error. I think it does exist. We
understand exactly how it exists because we can observe it existing. The more
accurate phrasing might be "it's not understood how it could have evolved so
quickly".

~~~
newacct583
> that this could be observational error

This could _absolutely_ be observation error. Messups in science happen all
the time. You never take a single data point at face value without question,
in any field. The spectrum might be polluted by another more distant object,
the line matching might have been faked by some other intervening medium, the
modelling for the lensing galaxy could be wrong. I agree, it looks good.

But it could totally be a mistake.

------
SloopJon
I find it funny when scientific articles (esp. pop astronomy) describe
something as weird, bizarre, or extremely unlikely. We're reversing the
effects of gravitational lensing on a galaxy at a distance that's a
significant fraction of the radius of the observable universe.

Are astronomers that confident in their models that the inferred shape of this
galaxy is bizarre? I'd love to have that level confidence in software.

~~~
slg
That is the premise of the article. It is bizarre in relation to our models of
the universe. We don't know if it is unusual in relation to the universe
itself. As the article states:

>Clearly, the theoretical models are wrong, or at least (and more likely)
incomplete. Obviously, there’s more to learn about galaxies that exist at the
edge of the observable Universe.

I am reminded of that tale about how "Eureka!" is not exclamation of good
science but instead "That's odd.". This article is saying "That's odd." in a
way that signals we are on the verge of new scientific discovery.

------
sktguha
I wonder if any intelligent civilisation was there on that galaxy,how
incredibly advanced it must be by now , assuming it has survived till now.

------
DoctorOetker
perhaps they look less chaotic because the rays at each point of the the ring
when reconstituted was not emitted at the same time, so the picture we
computed is a reconstitution of a large spread of time during which movement
of the stars in the galaxy blurred substantially giving the impression of a
more homogenous and orderly galaxy (a chaotic galaxy at astronomical shutter
times might look orderly)

------
bitwize
They had to build Milliways somewhere...

------
BurningFrog
First thought is that it can be a small blob galaxy in front of a bigger one.

~~~
giantrobot
But the odds of that happening are _astronomical_!

------
pier25
Isn't it possible that the galaxy is much younger and it actually moved faster
than light?

I seem to remember reading that "islands" of spacetime could do that.

~~~
dylan604
Which sci-fi author wrote that? That might make for interesting reading if you
find it and share with the rest of the class.

~~~
pier25
[https://phys.org/news/2015-10-galaxies-
faster.html](https://phys.org/news/2015-10-galaxies-faster.html)

~~~
SahAssar
That article explains that the galaxies are only moving faster than light from
our perspective since every part of space between us and it is expanding.

So, no it's not moving faster than light. The space between it and everything
else is expanding.

------
rinze
They're looking at us, wondering exactly the same thing.

------
brian_herman__
syfy really good science information for being a entertainment channel I wish
more places would do this like the history channel.

------
excalibur
> Why is there a normal galaxy sitting at the edge of the universe?

To facilitate the restaurant?

~~~
disown
Not that anyone cares what I say, but the Restaurant is on the other end of
the universe.

~~~
AnimalMuppet
Right! _This_ galaxy is there for the Big Bang Burger Bar.

------
tresCommatoso
When i was a kid, we used to dream about the "ping-pong" machine of light.
Basically- the light bending of the black holes allowed for images of the sky
to be stored, distorted and bounced around to almost noise - of skys objects
in diffrent times.. Drive it through a simulation, and you could see a nova
light up, reflected back from the ping-pong machine over the aeons.. There was
this nasa book, "Cycles of fire" we sat and daydreamed about..

------
natch
I never understand why articles like this use present tense to talk about past
events. It _was_ churning out a lot of new stars.. not is.

I guess the “as seen from our current vantage point” is understood, but to me
the needless emphasis of that perspective just muddies things, no?

Anyone of you downvoters care to enlighten me?

~~~
erulabs
Strictly speaking our observations are not continuous. We pointed a large
array at it and then the array probably went on to other work and looked
elsewhere - so technically “was” is more correct, since we do not know what it
“is” doing, rather only what it appeared to be doing.

Either way it’s a pretty uninteresting difference in tense.

~~~
natch
I find it a very interesting difference, because it and other fuzzy writing
like it has a devastating impact on science literacy, leading to lack of
comprehension of concepts. Weak thinking on science in turn contributes to
many of the problems we face as societies today.

------
adventured
> The thing is, where they found it is not normal: The light we see from it
> left the galaxy 12.4 billion years ago, meaning we’re seeing it as it was
> when the Universe itself was only 1.4 billion years old!

It's not confusing at all. It's because the long-worshipped, conventional big
bang theory is wrong. The universe doesn't have a beginning or end. It's
eternal. The original sin of that theory is that it's tainted with forced
space for a deity belief at the center and always has been. The universe
cycles unevenly through phases of motion, it doesn't magically start from
nothing and then 'die.' The conventional big bang theory is as bad as any
other children's tale going, it's up there with Santa Claus.

We're going to find a lot more supposed abnormalities like this over time.
They're not abnormalities, it's the entrenched incorrect theories that are the
problem.

The universe (everything that exists) is drastically larger than we already
think it is. Humans are arrogant, we didn't realize the extent of the micro
world, and the same exact mistake is being made at the macro scale. What they
think is a singular ~14-15 billion year old universe, is nothing more than one
collection of galaxies, there are many more like it nearby (many as in
trillions and trillions). The micro world was far smaller than we imagined;
the macro world is far larger than we're imagining. It's the same mental
mistake playing out, caused by the same arrogance. What's beyond the
'universe' that we can see so far? More massive collections of galaxies,
similar to the one we inhabit that we mistakenly call the universe.

~~~
depressedpanda
Strong claims, but can you back them up?

How do you explain the apparent accelerating expansion of the universe, i.e.
that the farther away something is, the more redshifted it gets?

How do you explain the cosmic microwave background radiation enveloping us in
all directions?

~~~
outworlder
Of course they can't back this up.

What the universe really is, is a simulation. We are trapped in it.

"Lightspeed limit": this is because the simulation has a finite computing
power. You can either move in time normally, or you can move in space. If you
go to the max allowed speed, there's no processing left over to simulate time,
therefore time stops for that entity. At intermediate speeds, slow down time
accordingly.

"Planck length": resolution of the simulation. It's discrete, and you can't go
any smaller.

"Heisenberg uncertainty principle": another simulation optimization. Instead
of simulating all particles, just use a probabilistic function. You actually
don't have to simulate it, just the macroscopic effects, _unless there 's an
observation_. In which case you can compute either the position or speed of
the particle. See also: atom orbitals

"Superluminal" expansion: it's just so we don't try to get to other galaxies,
which are only being simulated in a macro scale. This was left by the
developer to turn the 'lightspeed bug' into a feature. Also closes bug
UNIVERSE-001 where the background radiation was still visible, but other
galaxies visibility was off due to performance concerns. Now they can be
enabled.

"Dark matter": other civilization experiments that we don't have permissions
to see. Still there and interacting with matter. Bug is still in the backlog.

See, anyone can come up with whacky stuff.

~~~
menybuvico
> See, anyone can come up with whacky stuff.

Any habitual stoner could tell you that. Once your blood THC levels are high
enough, the secrets of the universe will unfold before you. And it's 100%
certain, because I mean, you totally observed it, Man!

