
Evidence that the key assumption made in discovery of dark energy is in error - apsec112
https://phys.org/news/2020-01-evidence-key-assumption-discovery-dark.html
======
flashman
To know if the universe is expanding, we need to know the following: how far
away things are, and whether they're moving away from us. In an accelerating
universe, there's evidence that things were moving away from us slower in the
past.

The evidence that things are moving away from us is that as the universe
expands, the wavelength of any light travelling through it also expands,
shifting it towards the red end of the spectrum: redshift. (Think of the
wavelength of a wavy line drawn on a piece of rubber that's then stretched
out.) We've known for nearly 100 years that the universe is expanding. (Edit:
not just that the objects in it are _moving apart_ but that _space itself is
expanding_.)

The evidence of accelerating expansion is that based on the redshift of nearby
objects, we would expect distant objects to have a higher redshift than they
actually do. That means they were moving away from us slower in the past, so
something must be accelerating them.

We use the brightness of Type Ia supernovae to measure distance. Even though
supernovae aren't identically bright, their brightness follows a curve which
lets us calculate their peak brightness (they are standardizable).

This paper argues that the calculations cosmologists use to standardize
supernovae brightness fail to take into account the age of the progenitor
stars, as far as I can tell. If true, this means our distance measurements are
inaccurate and these stars are actually closer than we thought, enough to
restore to linear relationship between distance and redshift that one would
expect in a universe expanding at a constant rate.

In other words, their redshift is lower not because the expansion rate of
space was lower in the past, but because they're not as far away as we thought
they were.

~~~
bananabreakfast
Speaking from the pov as a former astrophysicist, that definition of redshift
is not quite accurate.

While we have observed the universe expanding since Edwin Hubble published his
findings 90 years ago, it was in fact the Friedmann equations produced 10
years earlier that established how it would work within the context of general
relativity.

The Universe is expanding at every known point at the same time at the same
rate. However, this is only an observable effect over > 10 Mpc of distance
(e.g. extra-galactic distances). This is far too large to effect a point
particle like a photon no matter how far it travels so I'm afraid your analogy
of a rubber sheet is incorrect.

The lengthening of said photon's wavelength comes instead from doppler
expansion due to the nature of differing relativistic reference frames.

According to our local reference frame, doppler effects of nearby stars and
galaxies are only due to local motion such as Andromeda being blue shifted as
it approaches us for our eventual merger. However, as you go further and
further out from our galaxy the metric expansion of spacetime begins to
dominate the relative motion of all bodies, leading to observing progressively
redder and redder light curves. A galaxy billions of light years away is
perceived to be moving away from our reference frame at a significant
percentage of the speed of light!

However, if you were to change our relativistic reference frame to match a
distance galaxy's you would not see its photons "stretched out" but in fact
they would look completely unshifted despite having traversed nearly all of
spacetime, expanding as it went.

~~~
dieppe
> The Universe is expanding at > every known point at the same > time at the
> same rate

This part I don't get (I am in no way versed in astrophysics).

If I am in a box, and that the box grows 10%, but that at the same time I grow
10%, what has changed?

I mean, if every point in the universe expands at the same rate at the same
time, what does it change? Relatively speaking, everything is the same size
before and after expanding right?

It feels a bit like expanding a 1 meter line and expanding the meter standard
the same rate as the line.

If anyone has an explanation and is willing to spend some time writing it
down, I would be most grateful :)

This itches my brain ^^

~~~
roywiggins
So, imagine the box is filled with hydrogen gas. The space inside the box gets
bigger. But protons don't, they're little packets of quarks that hold each
other very powerfully. You'd have to expand space very, very, very fast to rip
those quarks apart from each other, and once you did, you would have a bunch
of bare quarks, not hydrogen. The quarks aren't getting bigger, since they
appear to be indivisible and essentially pointlike, and even if they were made
of something smaller, those things will hold tight to each other, too. A nice
gentle expansion will just expand the space in between the protons.

This scales up to forces _in between_ atoms, molecules, and bits of matter.
It's only at the very large scales (larger than galaxies) that all the forces
that are holding the stuff together starts getting overwhelmed by the
expansion of space and it starts to pull things apart. The expansion is so
gentle that even relatively weak gravity can hold galaxy clusters together
even as space grows.

In other words: space gets bigger, but _matter_ doesn't. It more or less stays
the same size.

~~~
galaxyLogic
Well so in other words "space" is NOT expanding. It's particles of matter that
are moving away from each other. Right?

So fine, but then why would we say that space is expanding, that would seem to
imply we know there is some edge of space which is moving away from us, but
what evidence do we have that space has such an edge?

Saying that "space is expanding" seems to hold the assumption that space has a
(limited) width and height.

~~~
Certhas
No space really is expanding. Think of it this way: You have a rubber band and
you pull it apart, if you place two beads on the rubber band the distance
between the beads will increase (even though they don't move relative to the
rubber). But if you connect the two beads by a strong spring, then their
distance will stay the same, despite space expanding. The force of the spring
makes them move (relative to the rubber), counteracting the expansion of space
between them.

~~~
Koshkin
> _relative to the rubber_

This makes me uneasy about your analogy. It’s like saying “relative to space”
which is nonsense. Also, why would space limit itself to only expanding
_outside_ a physical body?

~~~
SAI_Peregrinus
> Also, why would space limit itself to only expanding outside a physical
> body?

It doesn't, it's just that the forces within the body (the spring in the
analogy) are stronger than the expansion.

The "relative to space" bit is the nonsense part of their analogy, but I'm not
sure of a clearer way to describe things than what they did. It's not my
field.

~~~
Certhas
Maybe a better way to phrase it would have been moving over the rubber/space?
Or through the rubber/space? It really is motion relative to the underlying
manifold though. Let's say there was such a thing as a gravitational soliton,
that is, a stable ripple in spacetime, then if you are on the same spot as
this wrinkle as expansion starts you will move away from it. You move relative
to a structure made from spacetime. This was my field for many years. :-)

The mathematically precise statement is that you are not moving on a geodesic.
You are therefore experiencing acceleration (the objects that are not bound
and have increasing distance are on geodesics and do not experience
acceleration).

------
guygurari
It is hard to overstate how important the resolution of this question is to
physics, and in particular to theoretical physics. The “cosmological constant
problem”, that is the problem explaining the cosmological acceleration (if it
exists), is arguably the most important and hardest question in high energy
theoretical physics. Many theoreticians have spent significant effort studying
this question, working under the assumption that the empirical evidence is
solid. If this is not the case, it changes the landscape of cutting edge
physics research.

There are several reasons why explaining the observed acceleration is so hard.
The cosmological constant (the measure of how much dark energy there is) is a
tiny positive number which seems to require a lot of “fine tuning” to explain
theoretically. We can easily include it in general relativity, but our best
understanding of quantum physics says that if it is there then it should be
much larger. This means there probably is something we don’t understand about
its microscopic origins. If we try to build a microscopic model that has this
small constant using string theory (our best guest at a complete theory), we
find that such models are hard to create. In fact, it is not clear that any
model that includes dark energy is even valid in string theory! Any way we
look at it, it seems more difficult to explain this number if it is tiny and
positive than if it is strictly zero (no acceleration).

Finally, theoreticians don’t have much to go on when explaining this
phenomenon besides this one single number — there aren’t closely related
experiments we can combine to come up with a coherent picture of what’s
happening. Combine this with particle physics, where accelerators provide us
with an abundance of data. It is a single tiny number that has puzzled
theoreticians for decades.

~~~
BoiledCabbage
What's more mind-boggling to me is all these thousands of scientists running
around looking at the extreme oddity of multi-dimensional string theory, and
nobody bothered to check if the cosmological constant is actually real.

It seems like physics is really being held back by perverse incentives.

And of course my pocket view that string theory will turn out to be the single
largest waste of brilliant human minds in history.

~~~
eloff
I'm not a physicist, but I don't think string theory is a total waste. It
agrees with our existing theories and predictions, so it can be viewed as just
an alternative mathematical abstraction, and there is value in that.

Whether or not tiny vibrating strings are really at the heart of things is
neither here nor there. It's about as relevant to science as god.

~~~
tylerjwilk00
The problem with string theory is that there are limitless physics universes
you can create within its framework so saying that ours fits in it is not
saying a lot. Many universes could be described by it.

------
rs23296008n1
Good. Science is meant to be a honest search for facts: data, knowledge and
wisdom. Being wrong is a feature. "I don't know" is an acceptable starting
point with no shame attached. Being certain means a mountain of data to back
it up. Being allowed to be wrong is a requirement. Anyone saying a scientist
can't ever be wrong is likely placing oddball limits on progress that will
only damage and limit the future[1]. How can you experiment if you can never
be wrong?

It would be good if people knew about the mountain-of-data aspect of science.
Even with that mountain, subtleties creep in and plenty of surprises still
remain.

Even something like water probably has properties we are clueless about.
Interesting aspects that might redefine science itself and create entirely new
approaches to medicine or manufacture or whatever. Maybe if you change
temperature and pressure enough in the right way you end up with exotic
metallic / bonding properties. Or some new water-based ion structure having
other properties. Who knows? Maybe not. Perhaps water is what it is and there
is not much more to learn. Asserting we already know everything about water
leads to dogma[2] and inflexibility. That's just one example.

Dark matter/dark energy may be a rounding error for all I know. Good. Now we
know about the error. We* likely asked a bunch of other questions as well and
now we have new answers about to appear because now that error has been
confirmed.

* not me.

[1] being wrong about bridge structure is unhelpful as you drive over it. That
kind of wrong is related but I'm not directly addressing that.

[2] dogma has expectations, rules and consequences. Science has plenty of
people who forget this and turn their understanding into dogma. That too is a
experience generating moment that will catch up with them later. Mountain-of-
data + knowledge + wisdom.

~~~
tiborsaas
Dark matter is definitely not a rounding error [0]. There are multiple
evidence for strong gravity effects where we just don't see the required
matter the explain the observed phenomenons [1][2]

[0]
[https://www.forbes.com/sites/briankoberlein/2016/09/23/rotat...](https://www.forbes.com/sites/briankoberlein/2016/09/23/rotating-
galaxies-could-prove-dark-matter-wrong/)

[1]
[https://en.wikipedia.org/wiki/Bullet_Cluster#Significance_to...](https://en.wikipedia.org/wiki/Bullet_Cluster#Significance_to_dark_matter)

[2]
[http://cosmology.berkeley.edu/Education/CosmologyEssays/Grav...](http://cosmology.berkeley.edu/Education/CosmologyEssays/Gravitational_Lensing.html)

Briefly, dark matter is very real, it's our knowledge that is dark.

~~~
rs23296008n1
I'm feeling verbose. So here we go.

Dark matter: Maybe something that we'll one day make lunch boxes out of. Maybe
also a rounding error. Of some sort. In some way. You haven't got the
mountain-of-data yet. A lot-of-data is a good start. This doesn't mean the
missing matter isn't some super-energy infused version of something we already
know about. For all we know, its simply "ordinary" matter we'd otherwise
already have accounted for but seen/detected in distorted ways due to some new
phenomena altering our perception. So, its real as opposed to unicorn
droppings[0]. But thats only a small part of the story.

Neither dark energy or matter exist as permanent fixtures, or even as just two
singulars. They are placeholders while the search for the underlying phenomena
continues. The moment the unaccounted matter/energy is discovered due to
phenomena A, B, C, D, E, F then those two broad individual placeholders will
be replaced with more detailed names, likely in honor of someone famous or
otherwise noteworthy feature of the discovery, eg shape, some quantify etc.
We'll go from "dark matter" to phenomena A,B,C to something1, something2,
somestate3 or whatever.

People like saying dark[1] because it sounds cool, mysterious and edgy. Its
the flair for the dramatic. This is fine for awhile as long as it helps. It
_is_ a mystery. But today its a big mystery and tomorrow its on someones
balance sheet. There's a lot of tomorrows to allow that to happen.

Very important note: Our knowledge is not dark. Knowledge shines light over
the unknown so we can see it for what it is. That is the whole point.

[0] I'm asserting for sake of argument that unicorns aren't real. Some could
say that horses with a horn were hunted to extinction and we just haven't
found a sample. Thats valid as well. I'd still prefer to see some evidence
like a skeleton. But for now, I'll just assume for the sake of argument they
don't exist and leave the real answer as homework for the interested[2].

[1] Dark. Or transparent. Maybe we are _seeing through_ it instead. Plastic
bags in water become "unaccounted for" and can visually disappear due to
transparency. Some ocean creature could easily call that bag the equivalent of
what we would call dark matter. Its got water in it and around it. Ordinary
matter surrounded by something they don't understand. Hydrocarbons. In
explaining it we'd mention the multiple processes and atoms responsible for
the formation because we know how hydrocarbons are formed. And probably not
just one thing. (No I'm not suggesting dark matter is hydrocarbons but I
retain the option to ironically laugh if they are a form thereof).

[2] I know an 8 year old who is highly motivated to believe they're real and
with enough skills at genetic manipulation she might make it happen. And
apparently they eat meat. The small-hill-of-data implies we should be careful
out there.

~~~
tylerjwilk00
Unicorns are real. They're just call by a different name, Elasmotherium
sibiricum [1], a now extinct species of rhinoceros that shortly co-existed
with man.

[1]
[https://www.google.com/search?q=Elasmotherium+sibiricum&tbm=...](https://www.google.com/search?q=Elasmotherium+sibiricum&tbm=isch)

~~~
rs23296008n1
I consulted the relevant and qualified[0] unicorn[1] expert who presented
evidence[2] to confirm this is all legitimate[3] so it is deemed[4] to be
true[5]: Rhinos or mammoths can't be unicorns. There was mention about not
being able to ride[6] them but that is not a convincing argument.
Domestication of a more horse-like animal was the larger deciding factor.

That said I fully get how a mammoth / rhino could inspire and may actually be
the real root of the folk story. While Subject Matter Experts[0] can be wrong
the folk story now has its own definition[1] and physical evidence[2].

Sidenote: Now I know why Pratchett likes footnotes.

\--

[0] 8 year old who has read everything about unicorns

[1] reference for the horselike resemblance
[https://en.wikipedia.org/wiki/Unicorn](https://en.wikipedia.org/wiki/Unicorn)

[2] relevant toys and pictures presented as proof

[3] like a lot of political "facts"

[4] someone authoritatively says so

[5] or true enough, see [3], to meet perceptual expectations[1].

[6] rhinos can be ridden if you're suitably enthusiastic and are also able to
run _faster_. Mammoths with horns were probably similar. This is logically not
much different to how wild unicorns[1] would be so I'd not discount too much.
The riding aspect is therefore a weak disqualifier.

------
sparker72678
> Taken at face values, the luminosity evolution of SN is significant enough
> to question the very existence of dark energy. When the luminosity evolution
> of SN is properly taken into account, the team found that the evidence for
> the existence of dark energy simply goes away

Cosmology is great because there's still so much in flux. There are so many
fundamental things that are still in active research. I find it all very
exciting.

~~~
tomrod
My exact thought was "Yaye for science!" I love that science has self-
correction built into its core.

------
jshevek
"...Prof. Young-Wook Lee (Yonsei Univ., Seoul), who led the project said,
"Quoting Carl Sagan, extraordinary claims require extraordinary evidence, but
I am not sure we have such extraordinary evidence for dark energy. Our result
illustrates that dark energy from SN cosmology, which led to the 2011 Nobel
Prize in Physics, might be an artifact of a fragile and false assumption.""

Is he implying that other cosmologists have proceeded as if dark energy is
well evidenced?

~~~
AnimalMuppet
It is my impression that dark energy is generally accepted in cosmology.
Whether that counts as "proceeding as if dark energy is well evidenced" is
perhaps a different question. If everyone believes it's there, but nobody
knows what it is, well... there was still something that convinced them that
it was there. That something should be evidence. Is it enough to count as
"well evidenced"? Perhaps not, especially if this new study is correct that
one piece of the evidence does not actually support dark energy.

~~~
ncmncm
I don't know of any other evidence for dark energy, other than that
mathematical physicists think the equations would be prettier with some,
although they sort of wish there was more. It is quite embarrassing that the
value was so close to zero without being zero, so that might be one
embarrassment less.

We already knew there was likely to be something fishy about the most distant
supernovas, because we have two divergent values for the Hubble constant, one
of them based on these same supernovas.

~~~
AnimalMuppet
Hmm. Is this new result in the right direction to solve the Hubble Constant
problem?

~~~
ncmncm
Haha, it would be fun if we now have three Hubble constants.

~~~
trhway
my personal favorite value for the Hubble constant is the "c" divided by the
age of Universe, it results in 70.8 km/s/Mpc, right in the middle of the other
2 established Hubble constant's values, a very nice coincidence that the
objects at the Universe age distance are running away exactly with "c".

~~~
AnimalMuppet
A coincidence? I think it might be an identity.

But that would mean that disputes about the value of the Hubble Constant are
also disputes about the age of the universe, and vice versa.

~~~
ncmncm
Right, and that has been revised a few times recently.

------
crazygringo
Do I understand correctly that this is actually saying that _accelerating
expansion of the universe_ may be in error? That there is, instead, no
accelerating at all, but merely constant expansion?

Or can there still be acceleration without dark energy? I'm unclear if they
are essentially the same hypothesis or if there are more complicated
subtleties I'm missing.

~~~
philipov
There are very few ways to modify Einstein's Equations and still have them
make sense. An easy one is to add a constant term. Such a term is known as the
Cosmological Constant, and a positive value for it would result in a constant
repulsive force between masses regardless of distance. This results in an
accelerating expansion of the entire universe, but, with a supremely small
value it only becomes noticeable at large scales, where it starts to dominate
attractive gravity. This appears to model what we're observed happening with
galaxy clusters.

Dark Energy is a hypothesis for explaining why such a very small cosmological
constant might exist, suggesting that the universe is permeated with a
constant negative energy field. However, the article refers to observational
evidence measuring the expansion of the universe, not dark energy. There is no
evidence for dark energy as such, and if you listen to colloquia on cosmology,
you will hear about the cosmological constant, not dark energy. It is not
necessary to hypothesize the existence of negative energy particles to model
what we've observed, and you'll only really hear the term used in the popular
press because it sounds sexy.

~~~
pdonis
_> Dark Energy is a hypothesis for explaining why such a very small
cosmological constant might exist, suggesting that the universe is permeated
with a constant negative energy field._

No, that's not what dark energy is. "Dark energy" is just a general term for
"anything that acts like a cosmological constant in the Einstein Field
Equation". It could be an actual physical constant, just an inherent property
of spacetime, or it could be some kind of energy field. We don't know. (Btw,
the energy associated with dark energy is positive, not negative; the
_pressure_ is what's negative.)

~~~
philipov
Thank you for the correction

------
platz
Sabine Hossenfelder comments on this paper:

Dark Energy might not exist after all

[https://youtu.be/oqgKXQM8FpU](https://youtu.be/oqgKXQM8FpU)

~~~
ncmncm
Amusingly, this video is about entirely different work that _also_ calls into
question the basis for claims about dark energy.

Nobody seems to be saying how the two results interact. Taking away dark
energy twice could give us negative dark energy, which would be fun. I don't
know whether unexpected negative dark energy would be more embarrassing than
unexpected zero dark energy.

~~~
platz
Ah, that is funny - I just assumed i didn't understand the different
descriptions because I'm not an expert. That they are different explains my
puzzlement.

* indeed this is the same result as [https://www.quantamagazine.org/no-dark-energy-no-chance-cosm...](https://www.quantamagazine.org/no-dark-energy-no-chance-cosmologists-contend-20191217/) which is different from the OP paper

------
nxpnsv
So these guys criticize SN-!a as standard candles, and then rely on other
results criticizing BAO and CMB measurements also indicating accelerating
expansions. However, why all these measurement would err in the wrong
direction is not clear. I'm not convinced yet.

------
ncmncm
Haha, called it!

Feynman warned about this specific phenomenon: basing new physics on the
points at the extreme end of your graph, where the measurements are least
reliable.

In this case, these points correspond to demolition of the most distant and
youngest stars in the sample, which could differ in many ways from the common,
much more recent events. Low metallicity is a difference that is obvious to
every AP, but there is no reason to assume it is the only one. We just don't
get to study any young-universe stars that haven't blown up.

Did anybody even discuss metallicity and possible effects on brightness of t1a
sn's, when DE was first proclaimed? If not, why not?

~~~
dmix
Does this have any affect on the search for dark matter? Are the two
interconnected at all?

~~~
lanstin
No. Dark matter is assumed to exist from the excessively quick rotation of
stars around the cores of galaxies. Dark energy is/was assumed to exist in
anomalous expansion of the universe based on redshifts.

~~~
stan_rogers
>Dark matter is assumed to exist from the excessively quick rotation of stars
around the cores of galaxies.

That's what initiated Zwicky's notion in the '30s. It is far from being the
only, or even the main, evidence for dark matter (which can be read as "mass
effects we can detect not associated with matter we can currently detect").

~~~
ncmncm
More accurately: motion dynamics not compatible with both General Relativity
and the mass we can see and reasonably infer. There is of course a
stupendously huge amount of mostly invisible "interstellar medium", and even
more "intergalactic medium", mostly ions of loose atoms and small molecules,
and we use estimates of how much of that there must be. If its motion has
anything to do with plasma fluid dynamics, all bets are off, because those
equations are what mathematicians call intractable, and physicists would call
career-limiting.

They will happily declare 3x more unknowable Dark Matter than normal stuff
before allowing plasma dynamics to have any effect on anything. Can hardly
blame them.

------
j-dr
Even if this paper is correct, there is still overwhelming evidence for dark
energy provided by other observations, in particular those of the Cosmic
Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO). This
article provides some details on why Dark Energy is in no danger of being
called in question: [https://www.quantamagazine.org/no-dark-energy-no-chance-
cosm...](https://www.quantamagazine.org/no-dark-energy-no-chance-cosmologists-
contend-20191217/)

~~~
ash
As far as I can tell, Quanta Magazine article does mention the original post
findings. Additionally, the Quanta article and the findings preprint were
published just a week apart. Not enough time to formulate a good response:

* Quanta Magazine article: 17 Dec 2019

* Arxiv preprint: 10 Dec 2019 [1]

CMB and BAO are mentioned in the original post too:

> Other cosmological probes, such as the cosmic microwave background (CMB) and
> baryonic acoustic oscillations (BAO), are also known to provide some
> indirect and "circumstantial" evidence for dark energy, but it was recently
> suggested that CMB from Planck mission no longer supports the concordance
> cosmological model which may require new physics (Di Valentino, Melchiorri,
> & Silk 2019). Some investigators have also shown that BAO and other low-
> redshift cosmological probes can be consistent with a non-accelerating
> universe without dark energy (see, for example, Tutusaus et al. 2017). In
> this respect, the present result showing the luminosity evolution mimicking
> dark energy in SN cosmology is crucial and very timely.

[1]: [https://arxiv.org/abs/1912.04903](https://arxiv.org/abs/1912.04903)

~~~
ash
Correction: "Quanta Magazine article does NOT mention the original post
findings"

------
Hoagy
Late to the party but does anybody know if this is connected to the findings a
few weeks ago that this Quanta article is replying to?
([https://www.quantamagazine.org/no-dark-energy-no-chance-
cosm...](https://www.quantamagazine.org/no-dark-energy-no-chance-cosmologists-
contend-20191217/))

I know they are proposing different mechanisms for the error in calculation
but it gives a sense of a 'moment' shifting against dark energy. Coincidence?

------
SiempreViernes
Preprint is here:
[https://arxiv.org/abs/1912.04903](https://arxiv.org/abs/1912.04903)

------
exabrial
Can someone eli5 why if space itself is expanding, how can an observer detect
that if they too are expanding at the same rate?

~~~
osbertlancaster
As I understand it:

We are not expanding. Size of e.g. a hydrogen atom is not changing.

~~~
magicalhippo
And we are not expanding because other forces are stronger at short range.
Similar to how the electroweak force is preventing you from falling through
your chair, even though the gravity of the entire earth is pulling you.

Dark energy, as we thought before this paper at least, would overcome gravity
only on the grandest scales, between galaxies.

------
mannykannot
When dark energy was first accepted, it seemed to me, as an outsider, that it
happened very quickly, without, apparently, any time as a possibly-
contentious, 'could this be so?' hypothesis in the way that, for example, dark
matter did (and, to some extent, still is.) That surprised me because, up to
that point, there seemed to be a problem with the cosmological distance
ladder, with different methods getting different results, and with there being
stars that seemed older than the universe supposedly was.

In comparison, when superluminal neutrinos were tentatively announced a few
years ago, there was a lot of justified skepticism about there being
experimental error (admittedly, overthrowing special relativity is an even
more extraordinary claim than dark energy.)

------
flick
Not so fast. See [1] and [2] for an explanation. There are good reasons to
suspect that there are errors made in this analysis.

[1]: [https://arxiv.org/abs/1912.02191](https://arxiv.org/abs/1912.02191)

[2]: [https://www.quantamagazine.org/no-dark-energy-no-chance-
cosm...](https://www.quantamagazine.org/no-dark-energy-no-chance-cosmologists-
contend-20191217/)

~~~
knzhou
Hold up, this is a _different_ thing than what [1] and [2] are responding to.

~~~
crazygringo
Yes, I'm totally lost. Was there accidental confusion here? Or is the new
paper (by completely different authors) somehow building on those other papers
and flick is implying it suffers from the same criticisms?

Would love to know if this is genuinely newsworthy or not.

------
scotty79
Are galaxies in old universe more densely packed than in our neighbourhood?

Can expansion be seen not in redshift but in angular distances of galaxies?
I'm asking in general not in relationship to the article. It wouldn't help for
the problem raised by this article.

------
scotty79
Do you know any good source where I could follow through the whole argument
that universe is expanding and the expansion accelerates? Without handweaving.

------
layoutIfNeeded
So... Big Rip is postponed indefinitely?

~~~
gbrown
I thought there was little reason to expect a big rip, because it requires
assumptions about an increasing cosmological constant, which there’s no
evidence for.

~~~
6nf
What do you mean? There's lots of evidence that the expansion of the universe
is accelerating and that's the whole reason we believe that dark energy
exists. Most cosmologists do believe we're heading for a big rip.

~~~
pdonis
No, "big rip" and "accelerating expansion" are _not_ the same thing. A big rip
would require that the density of dark energy in the universe is increasing
with time. We have no evidence that it is, and most cosmologists do _not_
believe we are heading for a big rip.

~~~
gbrown
Exactly.

------
cerealbad
radiation spreads and matter clumps. in this universe matter was allowed to
form but radiation dominates. island chains swallowed up by a rising ocean.

------
vectorEQ
if you look at the magnetic soup we call matter, or maybe electromagnetism is
a better term, is dark matter / dark energy / anti-matter (&anti energy??)
just the same thing of a higher frequency

say if matter / observables go from 0hz - 30+ Zhz.. is dark energy from 30+Zhz
to ???Zhz and perhaps anti matter / energy from ???Zhz to ???????Zhz? (more
question marks being higher ? :D )

or is this completely invalid and a dumb thought?

~~~
_Microft
Electromagnetism is only one of a number of fundamental forces [1]. See [0] if
you are curious about EM radiation at different frequencies. Radio and
microwaves, infrared and visible light, ultraviolet light up to x-rays and
gammarays are all part of the EM spectrum.

[0]
[https://en.wikipedia.org/wiki/Electromagnetic_spectrum](https://en.wikipedia.org/wiki/Electromagnetic_spectrum)
[1]
[https://en.wikipedia.org/wiki/Standard_Model](https://en.wikipedia.org/wiki/Standard_Model)

------
btilly
[https://xkcd.com/955/](https://xkcd.com/955/) comes to mind.

I am going to wait to get excited about this until it is replicated by others.

~~~
ncmncm
Ya, I should have placed bets that dark energy would turn out to be illusory.

------
imvetri
One less thing to worry about.

------
yeahigotgoats
the science is settled! the science is settled!

------
tus88
"discovery"

------
zipotm
Read more about the Primer Fields.

~~~
civilian
seems like quackery [https://www.quora.com/Has-anyone-considered-the-primer-
field...](https://www.quora.com/Has-anyone-considered-the-primer-fields-as-a-
solid-theory)

~~~
AnimalMuppet
After a bit of looking at it, I agree: It looks _very_ much like a quack.

------
mathiasrw
If you find things like this interesting I suggest you look on youtube for
videos on the electric universe.

The main take is that our current models having gravity as the main driving
force shaping our universe is a misunderstanding - hence rejecting the idea of
dark matter / dark energy that was "invented" to make for math for gravity
work with the observations of expansion.

~~~
_bohm
It should be noted that among cosmologists, electric universe is widely
considered to be bunk science.

~~~
briantakita
And Plasma Physicists think that "dark matter", "dark energy", & the assertion
of gravity (ignoring plasma) being the dominant force in the Univese is
mathematics without physical evidence. Thus "pathological science". Irving
Langmuir, discoverer of the double layer effect in plasmas & coined the term
"plasma" physics, came up with the definition of "Pathological Science". He
was also around during the birth of the "Standard Model".

[https://en.m.wikipedia.org/wiki/Pathological_science](https://en.m.wikipedia.org/wiki/Pathological_science)

~~~
tsimionescu
They may feel that way, but the difference is that standard cosmology is a
highly-successful predictive model consistent with all popular physical
theories, while plasma cosmology is proposing physically unlikely phenomena
that have never been observed, interpreting prehistoric art for
'observations', and fails to account for many modern observations. It's
perhaps not as bad as the so-called electric universe, but it is certainly a
much more likely example of pathological science than standard cosmology is.

~~~
briantakita
Good luck finding physical evidence of "dark matter" & "dark energy" then. How
many more billions will need to be spent chasing windmills?

We already have the equations from Oliver Heaviside & James Maxwell, btw. But
have fun playing math games with no physically reproducible experiments.

~~~
tsimionescu
Maxwell's equations won't help you understand how time works, so you can't run
a successful GPS, for example. They also don't explain why stars introduce le
sing effects.

Perhaps dark matter and dark energy are indeed a wrong conclusion - Sabine
Hofstadter, to take a mainstream scientist, thinks so as well, and proposes
some explanations that don't throw the baby out with the bath water.

Either way, physics thrives when we have observations which don't match our
theories, and the only thing we can do to bring them closer is to experiment.

If a paradigm shift turns out to be necessary, then it should happen once the
new paradigm is actually capable of explaining at least most (if not all) of
the currently understood phenomena. For example, special relativity was
perfectly in line with Newtonian mechanics, and could be used to derive the
same conclusions for planet motion that Newton had painstakingly measured 400
years ago. If it hadn't been consistent with those (and with Maxwell's
equations) than it would have never been accepted. And in fact, it wasn't
entirely accepted until one of its more outlandish predictions - gravitational
lensing - was observed experimentally, not just in general lines, but down to
the actual measurement predicted by the maths.

~~~
briantakita
Or the lensing is explainable using standard optics...

[https://arxiv.org/ftp/physics/papers/0409/0409124.pdf](https://arxiv.org/ftp/physics/papers/0409/0409124.pdf)

Here's the EU critique:

[https://www.thunderbolts.info/wp/2015/11/26/lensing-by-
refra...](https://www.thunderbolts.info/wp/2015/11/26/lensing-by-refraction-
not-gravity/)

The thing is there were mulitiple ways of interpreting phenomona & through
certain cultural choices, a certain orthodoxy was created. The problem we are
seeing with modern astrophysics is that in order to explain the working of the
universe using only Gravity, theories require esoteric mathematics that are by
nature not observable.

Instead of putting all of our eggs in one basket, we should look at each of
the foundational assertions of modern cosmology with skeptism & reevaluate our
positions, particularly when there are non-observable mathematical artifacts.
We have better technology & instruments now. We don't need to double down on
the same religious beliefs using ever more esoteric math that is increasingly
not falsifiable...

From the definition of "pathological science". Looks more like it applies to
the Standard Model from these points...

* The maximum effect that is observed is produced by a causative agent of barely detectable intensity, and the magnitude of the effect is substantially independent of the intensity of the cause.

* The effect is of a magnitude that remains close to the limit of detectability, or many measurements are necessary because of the very low statistical significance of the results.

* There are claims of great accuracy.

* Fantastic theories contrary to experience are suggested.

* Criticisms are met by ad hoc excuses.

* The ratio of supporters to critics rises and then falls gradually to oblivion.

~~~
tsimionescu
When you look at pictures like [1] it's very hard to accept a kind of
galactic-cluster level atmosphere that would produce that type of lensing.

You're also ignoring the observed clock differences between clocks in LEO and
clocks on the ground - which happen to have the exact values predicted by GR.

And these are just some of the more neatly observable consequences of GR.
There are many others that are more sophisticated to notice, but that an EU
theory would have to explain rigorously before it could even be seen as an
alternative theory, not to mention hoping to be accepted.

Mind you, it is very likely that GR has some holes, as does QM - after all, we
do know that they are not compatible with one another. We also have dark
matter and the positive cosmological constant which are iffy. We also see that
the maths of GR have a singularity when analyzing what would happen in the
center of a black hole, and since we know that these objects exist, it's
likely that there are unknown effects that the math doesn't predict and that
would prevent the mathematical singularity from forming.

But noting that a theory which has made highly successful and precise
predictions has some limitations as well is by no means a reason to throw it
out and start from scratch. It's much more likely, just as happened with
Newtonian Mechanics, that we will find some extension of GR and QM that can
successfully account for the discrepancies. Perhaps dark matter will actually
be observed directly, perhaps extending the Standard Model of particle
physics. Perhaps some unexpected limits similar to the speed of light will be
found that can explain what happens inside a black hole. Perhaps dark energy
is simply an artifact of the linear approximations we are using to solve the
non-linear equations of GR [2].

[1]
[https://en.wikipedia.org/wiki/Gravitational_lens#/media/File...](https://en.wikipedia.org/wiki/Gravitational_lens#/media/File:The_Sunburst_Arc_PSZ1_G311.65-18.48.jpg)

[2] [http://backreaction.blogspot.com/2019/10/dark-matter-
nightma...](http://backreaction.blogspot.com/2019/10/dark-matter-nightmare-
what-if-we-just.html)

~~~
briantakita
To your point about throwing out the baby with the bathwater, here is the
strength of the EU argument:

"The EU community is a challenger to the standard gravitational model,
believing space-time to be a misinterpretation of the Universe. The things we
see in the Universe – from large scale filamentary structures connecting
galactic clusters, to Earth’s climate and meteorology – are plasma phenomena
driven by electromagnetic forces."

Note that it's still in an early phase & the physics is being figured out.
This includes a heavy reliance on reproducible physical experimentation &
unified models from small to large. Existing classical physical models are
preferred. Custom math may come later, as one can create a Hamiltonian to
model the phenomona, but the equation does not bring understanding of what is
occurring without an underlying physical explanation.

> When you look at pictures like [1] it's very hard to accept a kind of
> galactic-cluster level atmosphere that would produce that type of lensing.

It's also difficult to accept that space-time is warped, especially without
physically reproducible experiments, however we somehow trained ourselves to
think this is the orthodox opinion. It was also once difficult to imagine the
Earth _not_ being at the center of the Universe.

The EU critique is that plasma is ubiquitous in space & the phenomenon has not
been explored. It's only recently that we have discovered the onmipresence of
plasma throughout space, which is something that Einstein did not account for
in his models.

[https://thedailyplasma.blog/2015/12/23/lensing-by-
refraction...](https://thedailyplasma.blog/2015/12/23/lensing-by-refraction-
not-gravity/)

[https://en.wikipedia.org/wiki/Astrophysical_plasma](https://en.wikipedia.org/wiki/Astrophysical_plasma)

QM does have a connection with Maxwell's Equations as QEM.

[https://engineering.purdue.edu/wcchew/qem_papers/QEM_NewLook...](https://engineering.purdue.edu/wcchew/qem_papers/QEM_NewLookMain1.pdf)

Plasma Physics offers a way to, with physically reproducible experimentation,
create a bridge with astrophysics.

There's even multiple hypothesis to explain the nature of Gravity.

Black Holes have not been directly observed & the Plasma Physics/EU
explanation is that Quasars are a z-pinch in a galactic Birkeland Current.

[https://www.everythingselectric.com/birkeland-
currents](https://www.everythingselectric.com/birkeland-currents)

How do we know that the Atomic clock frequency itself is not be affected by
gravity? It seems like a simpler explination than "space-time" being affected
by gravity while the Atomic clock frequency remains consistent in the
reference frame.

~~~
briantakita
To your point re: supplementing experimentally backed systems (i.e. Newtonian
Mechanics):

"...what is really wanted for a truly Natural Philosophy is a supplement to
Newtonian mechanics...and introducing the additional facts, chiefly electrical
- especially the fact of variable inertia - discovered since his time..."

"...it may be that when the structure of an electron is understood, we shall
see that an 'even-powered' stress in the surrounding aether is necessarily
involved. What I do feel instinctively is that this is the direction for
discovery, and what is needed is something internal and intrinsic, and that
all attempts to explain gravitation as due to the action of some external
agency, whether flying particles or impinging waves, are doomed to failure..."

\-- Sir Oliver Lodge - Nature, Feb 17, 1921

~~~
tsimionescu
I'm not sure what this quote is meant to illustrate. The structure of the
Electron is now understood in QM (it is structure-less, an elementary
particle), the luminiferous aether is disproven, and gravity is understood as
equivalent to acceleration, essentially through E=mc2, instead of being
carried by particle or wave (though it can cause waves, as recently detected).
On the other hand, other fields, such as the electrical field, are shown to
reduce to particles flying around (photons, for the electric field), so if the
quote was meant to say that electrical charge could replace a graviton, that
has proven wrong.

------
ltbarcly3
I guess people are going to act like I'm a lunatic, but of course it's wrong.
Dark Energy violates basic conservation of energy, and the evidence for it has
never been strong or convincing. Lots of us have been saying this since
forever.

~~~
ncmncm
Conservation of energy has only ever been observed in local conditions. The
universe is not obliged to respect our local expectations, and has always
turned out to violate them in uncomfortable ways.

The ground looks flat near you (at least in Nebraska). The Sun seems to go
around Earth.

~~~
ltbarcly3
Which is more likely, that you can have infinite free energy or that the very
careful measurements of the distances to supernova that happened billions of
years ago on the other side of the universe, and for which we have virtually
no standard yardstick to compare against are not accurate?

You are just making an appeal to ignorance. All of physics and astronomy is
based on the assumption that the rest of the universe follows the same basic
laws that the part we can study follows.

That the universe is isotropic and homogeneous is a necessary basic assumption
to even begin to measure the distance to objects that are very far away. If
you can't assume that the basic laws of physics operate the same everywhere,
then you have no basis to make _any_ claims about anything that isn't local.

~~~
cthalupa
This is a false dichotomy. We have known energy is not (always) conserved
since long before we began discussing dark energy.

This is such a misunderstood topic vis a vis dark energy that Discovery
specifically has an article on it:

[https://www.discovermagazine.com/the-sciences/energy-is-
not-...](https://www.discovermagazine.com/the-sciences/energy-is-not-
conserved)

~~~
ltbarcly3
Nope. We have no actual evidence of a violation of the conservation of energy.
What has happened here is that astrophysicists got way out on a branch. They
were quite excited and came up with a theory that seemed to explain why there
appeared to be increasing redshift with distance, and later that theory was
shown to violate conservation of energy. Doubling down, they waved their hands
and said that conservation of energy must not hold at 'cosmological scales',
without _any_ evidence to make such a claim.

~~~
mr_mitm
Please read this and let me know if you are still convinced that energy must
be conserved in General Relativity:
[https://www.preposterousuniverse.com/blog/2010/02/22/energy-...](https://www.preposterousuniverse.com/blog/2010/02/22/energy-
is-not-conserved/) (edit: Nevermind, this is the same content as the Discovery
article linked above, except with better formatting).

In short: conservation of energy is a result from the Noether theorem, which
says it must be conserved iff the laws of physics are invariant under time
translations. That's the case in Newtonian physics where we also have plenty
of experiments supporting it, but not in GR. Precisely because of the
expansion of the universe, the metric is time dependent and thus there can not
be an associated conserved quantity. This has been known before we knew about
dark energy or even the expansion of the universe.

~~~
ltbarcly3
You are using circular reasoning. Energy is not conserved if the universe is
expanding. I am saying of course that isn't happening, the evidence for
expansion is poor and now has been shown to be unreliable. Without expansion
energy is conserved. The example from your article is expansion, which it
assumes to be a fact based on the poor evidence that is now invalidated.

~~~
mr_mitm
I don't know what you are talking about. The expansion of the universe is an
observational fact. The evidence is overwhelming and you'll be hard pressed to
find a single professional cosmologist who won't agree.

Now whether the expansion is accelerating is another question, which is what
the article of this thread is about. That's something that is still considered
a fact, but the evidence is not quite as overwhelming. It's still strong, but
questions about the validity of standard candles should be taken seriously.

~~~
ltbarcly3
The expansion of the universe is consistent with our best astronomical
observations. Saying it is a 'fact' is just wordplay.

~~~
cthalupa
It is a fact in as real a sense as most anything is a fact when it comes to
science. Arguing against the expansion of the universe without providing any
evidence whatsoever to show it isn’t expanding is a waste of time. Questioning
things is fine, when productive - you are not presenting any evidence to the
contrary or even a hypothesis to explain even a portion of what expansion
explains, shortly after showing that your understanding of the subject matter
is not solid. Please do further research on these subjects before putting
yourself in a position to mislead others.

~~~
ltbarcly3
To what end? If someone is mislead about the interpretation of astronomical
observations on a cosmological scale there is absolutely no consequence. Your
sensitivity to any suggestion that the most popular interpretation may be
incorrect is, to be blunt, inappropriate.

It's not my burden to prove that expansion isn't well founded. It is
consistent with the best data available, however it is, in the best possible
light, still a post-hoc interpretation of that data. It requires significant
assumptions that do not have any basis.

So lets unpack that. Given the assumption that the universe his homogeneous,
what we observe isn't different from what would be observed from any other
position in the universe. Given the assumption that the universe is isotropic,
the universe should be the same no matter which direction we look. There is no
evidence for either of these assumptions. Since we can only observe the
portion of the universe that we are able to observe, we can only assume that
our cosmological observations are (in the ways we are debating here) not a
function of our position in the universe. This is no different from whom we
may consider a less sophisticated observer on Earth who looks around and
decides that the universe is full of breathable air. After all, the universe
is homogeneous and isotropic, therefore it must be entirely full of air and no
matter where you look you would see air. Obviously this is not consistent with
our observations, but to someone without telescopes and a modern understanding
of physics it would be the logical conclusion given the _same assumptions_ you
are making.

The point is that these assumptions are assumptions. We have no evidence for
them, except that the best observations we can make do not currently
contradict our most recent version of the conclusions we take from those
assumptions when combined with the best data we have. The problem is that this
is always true, even for the unsophisticated observer who just sees air
everywhere they are able to look with their primitive technology.

If you can't see why it is not valid to make these assumptions at this point
you should sit and think a bit.

~~~
cthalupa
>To what end? If someone is mislead about the interpretation of astronomical
observations on a cosmological scale there is absolutely no consequence.

Except further propagating bad foundational knowledge.

>Your sensitivity to any suggestion that the most popular interpretation may
be incorrect is, to be blunt, inappropriate.

I'm not sensitive to suggestions that have something backing them up. I am
annoyed by people being overtly wrong, and quadrupling down on it. This whole
thing is a distraction from the fact you completely misunderstood the study
this entire discussion was spawned off of, and have yet to even acknowledge
that.

Instead we're now on this bizarre discussion of isotropic vs anisotropic where
you're making strange false analogies and making incorrect statements. Our
understanding of cosmology is built on top of observations yes, but those
observations are stacked up against experimentally verified data, and they pan
out. Yes, we assume the universe is isotropic, and we've got such a large
amount of data to support it that the human mind is incapable of grasping the
enormity of it. There's also nothing inherent to an anisotropic universe that
would rule out expansion - it's weird to suggest that is the case, and once
again shows you have some fundamental gaps in your knowledge here. At any
rate, the more we study the universe, the more the evidence continues to mount
for us being in an isotropic one.
[https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.11...](https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.131302)

>It's not my burden to prove that expansion isn't well founded.

I mean, fundamentally, it is. You're making a new assertion. If you were to
say that gravity isn't real, at this point, the burden of proof is on you.
When people asserted that the universe was expanding, the burden of proof was
on them. And they succeeded in doing so. If you want to challenge that, you're
going to have to provide some evidence or reasoning as to why it is, and it's
going to need to be one that makes sense - claiming we're in an anisotropic
universe is something that is not only almost certainly inaccurate, but also
something that says nothing about whether or not the universe is expanding.

~~~
ltbarcly3
> Our understanding of cosmology is built on top of observations yes, but
> those observations are stacked up against experimentally verified data,

And a cave man who was curious would also do lots of observations. He would
observe by the river, by the big tree, by the big rock, up at the top of the
hill. No matter where he goes, he can breath. He can feel the air when he
swooshes his hand through it. He keeps collecting data for 50 years, and
everywhere _that he can check_ he sees the same thing. Therefore, using the
same level of proof you propose, he can conclude that there is air everywhere.
Someone else might come along and say, well, he is assuming that the universe
is the same everywhere, then checking where he is actually able to measure.
The same is true for you, you can't make measurements of any kind beyond the
CMB. We have _no idea_ how large the universe is or how much of it we can
observe. We can assume the stuff we can't see is just like the stuff we can
see, but it's an _assumption_.

> There's also nothing inherent to an anisotropic universe that would rule out
> expansion

Sure there is. We might just be in a location where stars are diverging.
There's no way to distinguish an area where the visible universe is diverging
from one where the universe is expanding. Why do you think people are so
excited about accelerating expansion? It would be evidence of expansion rather
than divergent proper motion.

In fact, lets say there were some kind of massive explosion in space. If you
took measurements from near the center of mass from the explosion after a long
time, you would see the things that are far away red shifted more than things
that are near by. Why? The things far away were the things which were ejected
from the explosion with higher velocity than things that are nearby (that is
why they are farther away now).

~~~
cthalupa
It's incredibly frustrating replying to you, because your arguments are
fundamentally anti-science. Everything you're saying can basically be
condensed down to "Well, we though we've known things before, and we think we
know things now, but we can't EVER REALLY BE SURE, can we? It's all an
assumption!"

Trying to compare our current understanding of the universe to that of a cave
man is quite silly. We've nailed down quite a bit of the why and how of the
structure of the universe, the laws of physics, etc. It's not perfect, there's
parts we don't understand, and there's parts we may never be able to
understand, but the scope is so much broader and understanding so much deeper
that trying to act like it's meaningful to compare our understanding vs. that
of a cave man is so disingenuous.

A cave man would have no idea why that would be the limit of his observations
- no understanding of physical laws that would make it so. But we understand
why there are limits to what we can see. We understand that there is a maximum
speed for a massless particle in a void. We understand why we cannot examine
objects under a certain size - because the energy requirements would literally
create a black hole if put into the space needed to see. A cave man could not
understand why there is not more out there for him to observe. We can.

>Sure there is. We might just be in a location where stars are diverging

You seem to be misunderstanding either the meaning of the word "inherent" or
the phrase "rule out". An anisotropic universe can 100% be expanding. It can
also not be expanding. But you were previously arguing that our (evidence
backed) belief that the universe is isotropic being incorrect would
immediately rule out expansion, when it simply isn't the case. It's also not
particularly relevant, because all evidence points towards the universe being
isotropic.

~~~
ltbarcly3
All the evidence points to everything being isotropic, so long as you can't
see very far.

All the evidence the caveman could collect said the universe is isotropic. And
full of air. All the evidence that you are able to collect can lead to
incorrect conclusions.

------
mikorym
As a mathematician, I will inherently be biased against dark matter and dark
energy (if you're calculations don't fit, then your mathematics is not
suitable, so change the math before you change the physical description). What
is the relationship between dark matter and dark energy, and does this have
any effect on the r^2 law assumptions and the introduction of dark matter?

For example, does this mean that when we thought that r^2 was not strictly
followed that in fact we had the _positions_ of the bodies wrong?

~~~
has2k1
> if you're calculations don't fit, then your mathematics is not suitable, so
> change the math before you change the physical description

Physics is littered with mathematical formulations predicting new phenomenon
(forces and particles).

> What is the relationship between dark matter and dark energy

There is no known relationship between dark matter and dark energy. They could
have been called unknown matter and unknown energy! The absence of a good
account for each does not infer a relationship between the two.

~~~
mikorym
> Physics is littered with mathematical formulations predicting new phenomenon
> (forces and particles).

Sorry, I should have clarified: I mean I would spend all my days doubting the
mathematics, rather than doubting the physical universe. If that makes sense?
Of course all of mathematics can be argued to have a physical sort of root.

~~~
has2k1
You cannot choose your allegiance and stick with it. The reality is that there
is always various types of evidence to contend with.

Chances are if you were a physicist/cosmologist you would be of the same
opinion as the majority because you would be exposed to just about the same
evidence.

~~~
mikorym
> You cannot choose your allegiance and stick with it.

Exactly, yes. In mathematics we are also discoverers rather than inventors. I
am just making the point that personality does play a role. Think of Newton's
calculus vs. Leibniz's calculus.

------
fluxby
Personally, I’m a fan of ideas of Quantized Inertia [1] [2] which proposes
that Dark Energy does not exist at all. We’ve been on a wild goose chase after
dark energy for 30 years, which so far has proven to be an untestable theory.

[1] [https://youtu.be/1itasiXNUPg](https://youtu.be/1itasiXNUPg)

[2] [https://youtu.be/VYdebV9YlnI](https://youtu.be/VYdebV9YlnI)

