
The present phase of stagnation in the foundations of physics is not normal - mathgenius
http://backreaction.blogspot.com/2018/11/the-present-phase-of-stagnation-in.html
======
tylermw
Love this comment left on the post by Peter Shor (of Shor's algorithm--the
algorithm that kicked off the quantum computing frenzy). I assume it's him and
not an imposter.

"It's not just that scientists don't want to move their butts, although that's
undoubtedly part of it. It's also that they can't. In today's university
funding system, you need grants (well, maybe you don't truly need them once
you have tenure, but they're very nice to have).

So who decides which people get the grants? It's their peers, who are all
working on exactly the same things that everybody is working on. And if you
submit a proposal that says "I'm going to go off and work on this crazy idea,
and maybe there's a one in a thousand chance that I'll discover some of the
secrets of the universe, and a 99.9% chance that I'll come up with bubkes,"
you get turned down.

But if a thousand really smart people did this, maybe we'd actually have a
chance of making some progress. (Assuming they really did have promising crazy
ideas, and weren't abusing the system. Of course, what would actually happen
is that the new system would be abused and we wouldn't be any better off than
we are now.)

So the only advice I have is that more physicists need to not worry about
grants, and go hide in their attics and work on new and crazy theories, the
way Andrew Wiles worked on Fermat's Last Theorem."

(new comment right below)

"Let me make an addendum to my previous comment, that I was too modest to put
into it. This is roughly how I discovered the quantum factoring algorithm. I
didn't tell anybody I was working on it until I had figured it out. And
although it didn't take years of solitary toil in my attic (the way that
Fermat's Last Theorem did), I thought about it on and off for maybe a year,
and worked on it moderately hard for a month or two when I saw that it
actually might work.

So, people, go hide in your attics!"

~~~
rthomas6
I wonder if some rich people could start a form of charity where they just pay
a few incredibly brilliant people a good salary to go do whatever research
they want for the rest of their lives. Sort of like patronage. Just bypass the
whole grant funding cycle and work on whatever you want, because you're a
genius and want to study things other people don't like or understand.

~~~
konschubert
The problem with education/science/welfare by charity is that it doesn't scale
as well and isn't as stable as societal contracts.

A developed country can be recognised by the fact that the society doesn't
rely on the goodwill of the rich.

~~~
rthomas6
Surely both models can coexist? I don't think there should be any decrease in
government science funding.

------
letitgo12345
Well considering that we know everything pretty much about most of everyday
physics and new physics requires energies that are almost unreachable and
billions of dollars in experimental investment and/or years and decades to
collect sufficient data, it's not a surprise at all that foundations of
physics progress has slowed. I don't think the physics community is to blame
here. Just the nature of reality

~~~
danbruc
_Well considering that we know everything pretty much about most of everyday
physics [...]_

That's true and also not true. Yes, we have a working theory that explains
essentially everything with unprecedented accuracy as long as you don't wander
too far outside of everyday length and energy scales. But on the other hand we
still do not really understand basic quantum mechanics almost a century after
its discovery or at the very least there is no consensus about what the theory
actually says. Quantum mechanics is not even self-consistent.

~~~
thicknavyrain
Sure, but there are some interesting and affordable tabletop experiments being
done to probe certain features of QM (like Weak Measurement:
[https://www.hep.ucl.ac.uk/qupot/](https://www.hep.ucl.ac.uk/qupot/)) and test
fundamental assumptions. The work on that front is progressing, but when
people think of "Laws of Nature" i.e. GR and the Standard Model, short of
expensive facilities like new particle colliders or telescope arrays like LSST
and Cosmological surveys, it's unlikely "new physics" is going to be jumping
out of the woodwork any time soon.

Which is not to say people aren't trying. Conferences are held probing this
exact question (e.g. can we come up with DM detectors that aren't just
enormous tanks of cooled liquids?) and trying new strategies. It's not like
the community isn't engaging in good faith with some of these proposals, it's
also that we haven't had a new hint of where to look from a collider
experiment since the discovery of the Higgs. Despite everyone's best efforts.
Yes, we need some experimental ingenuity to push through this frontier, but I
also agree with OP that Physics is just being very stubborn against yielding
any further secrets at present.

------
walrus1066
I think this is excessively harsh.

The only guarantees made about the LHC were, that it would prove or disprove
the existence of the Higgs Boson.

Believe me, experimental physicists are desperate to find the slightest
deviation from the standard model. I spent 2 years on one such 'stab in the
dark' rare decay analysis!

The SM's predictions have been tested to a rigor unparalleled in history. It
predicts stuff like mass of W & Z bosons, fine structure constant, the
measurements of which exceed an accuracy of 1 part per billion in some cases.

~~~
jsweojtj
It does not predict the fine structure constant, that is an input into the
model.

~~~
walrus1066
Yes, you're right.

I was getting it jumbled up with the magnetic moment of the electron, which is
predicted by the SM (well, the QED part anyway), to be slightly different to
the 'classical' prediction.

Experiment measurement of this is accurate to one part per billion, and is
consistent with the QED prediction.

The electroweak bits of the SM predict the W & Z bosons, along with their
masses, which have also been measured, to around 1 part per 10,000, and match
SM predictions.

EDIT: last but not least, the Higgs Boson was also predicted by SM, with a
ballpark figure for it's mass, and other properties (how often it decays into
photons, W bosons, quarks etc). So far all measurements of these properties
are consistent with SM predictions.

~~~
muhbags
Correct me if I'm wrong, but the standard model makes no prediction for the
masses of any of the fundamental particles. To my knowledge, they are all
input parameters. It might put certain bounds on them, but in the end they are
all not predicted by the standard model itself.

This is seen as one of the big issues with the standard model, that it does
not actually explain a lot of the characteristics of the fundamental particles
like their couplings and masses.

~~~
walrus1066
For the W & Z bosons, their masses are derived from 3 other 'free parameters'
of the SM.

The Higgs mass is indeed a free parameter, but the SM wouldn't work of it's
mass was greater than 200 GeV or so. The Higgs interacts with other particles
of mass, and the strength of interaction is proportional to the Higgs mass, it
influences certain processes (like W boson scattering), the rate at which
these happen would deviate from experimental observation if Mhiggs was over
200 GeV.

That's why the LHC was such a big deal, it reached the energies required for
direct observation of sub-200 GeV Higgs, so it would either find the SM Higgs,
or rule it out and invalidate the SM. Unfortunately the former seems to have
happened.

SM free parameters:
[https://en.m.wikipedia.org/wiki/Standard_Model#Construction_...](https://en.m.wikipedia.org/wiki/Standard_Model#Construction_of_the_Standard_Model_Lagrangian)

Indirect constraints on Higgs mass in SM (a bit technical, slide 6 chart is
the key one, strongly influenced specs & mission of the LHC)
[https://indico.lal.in2p3.fr](https://indico.lal.in2p3.fr)

------
tbabb
While I don't like this ~guy's~ woman's disdainful, superior tone, I do think
his complaint has merit. Physics is notoriously bad at having curiosity about
strange, unconventional, or truly novel ideas. I just finished reading _What
is Real?_ by Adam Becker-- a history of modern physics-- and am astonished at
how aggressively physicists resisted and suppressed "unconventional"
interpretations of quantum mechanics (like the many worlds interpretation) in
favor of the obviously-wrong Copenhagen interpretation. There was a taboo for
decades around even _discussing_ quantum foundations, and people's careers
were ruined simply for trying to publish papers about it.

Physics got stuck for a short while on the understanding of QM, and then
promptly went into sour grapes mode and decided that it was meaningless to ask
any deep questions about what QM actually meant. Since then it has been
focused on mathematical formalisms and smashing particles instead of deep
questions about what it all means.

The stagnation is real, and it's the physics community's own fault.

~~~
andrepd
>Physics is notoriously bad at having curiosity about strange, unconventional,
or truly novel ideas.

Physics of today would be unrecognisable to a scientist at the start of the
20th century. Indeed the physics of 1935 would be unrecognisable to a
scientist at the start of the 20th century. Our understanding progressed
enormously AND it did so because people put forward radical theories in
complete rupture with the established, 300-year old classical mechanics. There
was no "traditionalist resistance" to it after it became apparent that
classical mechanics failed to explain phenomena that quantum theory did
explain.

>am astonished at how aggressively physicists resisted and suppressed
"unconventional" interpretations of quantum mechanics (like the many worlds
interpretation) in favor of the _obviously-wrong Copenhagen interpretation_
[emphasis mine]

Ahahaha, you clearly have no idea what you're talking about. There is nothing
"obviously wrong" about the standard Copenhagen interpretation (unless you
have some new insight you would like to share), nor was there any suppression
of ideas. Many debates have been waged in the past ~100 years, and many
alternative interpretations have been put forward, like Bohmian theory,
superdeterminism, or "shut-up-and-calculate".

>decided that it was meaningless to ask any deep questions about what QM
actually meant

Physics, indeed all science, studies observable reality. Any "deep" questions
about why or about things not measurable, quantifiable, or empirically
observable, are by definition outside the scope of science. It is therefore as
unreasonable as complaining about why don't geologists study epistemology. The
answer is the same: it's outside the scope of their study.

I also don't like that your phrase seems to imply that what physicists study
is not "deep" as opposed to your philosophical questions. There are many deep
and beautiful ideas in physics.

~~~
tbabb
> There is nothing "obviously wrong" about the standard Copenhagen
> interpretation

Can you tell me how to calculate whether a system of particles will cause
another system of particles to collapse or not?

Can you tell me under what circumstances a system of particles will evolve
unitarily or not?

Can you shade the region of the spacetime diagram of EPR where the
wavefunction is collapsed? How about in a delayed choice quantum eraser
experiment?

If you tell me "you're not allowed to ask those questions" (or "hm, I never
thought of that!"), then you're directly illustrating the complaint here about
physics!

The common narrative is that Copenhagen, many worlds, and the other
interpretations of QM are all equivalent, but they are not. Copenhagen adds an
extra physical event-- collapse-- where the wavefunction is suddenly
nonunitary. The burden is on Copenhagen to tell me how and when this happens,
and in fact to prove that it happens at all. Many worlds, on the other hand,
predicts the same phenomenon-- the apparent collapse of a wavefunction to an
eigenstate-- without adding unitarity violation, or any other phenomena at all
beyond the normal, extremely well-verified mechanics of multi-particle system
scattering; it merely treats the environment is a multi-particle quantum
system.

Many worlds is the null hypothesis (no, the extra worlds are not extra
suppositions, they are _predictions_ of known physical laws), and the burden
is on Copenhagen to show that unitarity violation exists, and the burden is
extremely high (possibly insurmountable?) for EPR and eraser experiments.

When Copenhagen was devised, most believed that there was some "underlying
state" in QM, and that measurement told you something about what the
underlying state was. Bell's theorem should have sent a shockwave through the
community which forced everyone to reevaluate fundamental assumptions and
self-correct wrong ideas. But by accident of history, John Bell was too shy to
publish in a major journal, and no one even read his result for _four years_.
The implications of Bell's theorem were slow to diffuse through the community,
and so the disruptive moment of reckoning that should have happened never
came. By the time it was well-accepted, the narrative in physics had become
"you're not allowed to ask about what quantum mechanics means, just shut up
and calculate", and so the cognitive dissonance was cast aside. Annealing this
attitude and this misstep away is taking excruciating decades.

EDIT: I also don't mean to imply that there aren't deep and beautiful things
in modern physics. There are! But physics is concertedly avoiding asking deep
questions in areas where (I strongly believe) it is most important. The claim
that "the meaning of QM is outside the scope of science" is exemplary, I
think, of that attitude.

~~~
andrepd
>Can you tell me how to calculate whether a system of particles will cause
another system of particles to collapse or not?

You appear to be somewhat mistaken. Copenhagen interpretation _does not_
postulate any specific explanation or mechanism for wave-function collapse,
merely that "upon measurement, the wave-function collapses into an eigenstate
of the observable being measured". This, of course, is a physically verified
phenomenon. Now Copenhagen _purposefully_ leaves the precise meaning of
"measurement" undefined, since in my view there is no convincing empirical
evidence that supports a specific mechanism for this phenomenon. Other
interpretations posit mechanisms (decoherence (doesn't fully account), von
Neumann "consiousness" (not empirical), etc.) for this collapse.

My biggest complaint about many-worlds interpretation is how it is in its
essence a non-scientific theory, as it makes assertions about an unobservable
reality. It postulates other parallel realities that by definition do not
communicate. Again, this makes it intrinsically a non-scientific theory.

>Can you tell me under what circumstances a system of particles will evolve
unitarily or not?

Everywhere except on measurement, in which the state collapses.

>How about in a delayed choice quantum eraser experiment?

I'm not familiar with this experiment.

>If you tell me "you're not allowed to ask those questions"

By all means, ask as many questions as you want. That's after all the essence
of scientific endeavour. But it's not very nice to misrepresent other
positions, nor is it to claim everyone else is deluded (without strong
evidence on your side at least).

>Bell's theorem should have sent a shockwave through the community which
forced everyone to reevaluate fundamental assumptions and self-correct wrong
ideas.

Bell's inequalities force no re-evaluation. They simply prove that the search
for a local hidden-variable theory is impossible. It certainly raised
important ideas for research, but it does not do anything to discredit
established QM.

>The claim that "the meaning of QM is outside the scope of science" is
exemplary, I think, of that attitude.

If a physical argument can be made about this problem, then it's in the scope
of physics. Otherwise, it is not. As simple as that.

~~~
trainingaccount
You really want to look into the delayed choice eraser... it's mind blowing.

~~~
ymolodtsov
And it is still explained by the Copenhagen interpretation and there’s no
problems with it. It’s like all those SR paradoxes that sound interesting but
don’t disprove the theory — just the fact you don’t fully understand it.

The major interpretations of QM are all similar in the fact that they are not
testable and don’t really affect the resulta. It’s metaphysics.

------
cli
I suppose this is as an appropriate time as any to ask for advice: I am a
multimillionaire from inheritance, and am about to complete my masters in
physics. I wish to work on long term theoretical physics problems that do not
seem to be possible under the current publish-or-perish academic system. The
plan was to complete a PhD, then leave academia, but lately I have been having
severe doubts about continuing onto a PhD, partly due to the cruft that comes
with academia. Obviously, future employability due to financial reasons is
completely irrelevant to me.

I would greatly appreciate any advice.

~~~
akvadrako
It sounds like you are in a good position - you can have total control over
what you work on. You could even write your own grants and get other people to
research what you want alongside you. Since the traditional PhD path isn't
showing that much success, doesn't it make more sense to just research what
you want?

All the papers are free online and authors will generally discuss their work
with you if you have intelligent questions.

BTW, this is what I do. I freelance about 20% of the time and spend about 50%
of it reading physics papers. So far I haven't produced anything new, but I
have greatly increased my intuitive understanding.

------
apo
_... I have spelled out many times very clearly what theoretical physicists
should do differently. It’s just that they don’t like my answer. They should
stop trying to solve problems that don’t exist. That a theory isn’t pretty is
not a problem. Focus on mathematically well-defined problems, that’s what I am
saying. And, for heaven’s sake, stop rewarding scientists for working on what
is popular with their colleagues._

It seems that some examples might be useful here.

Which specific groups are trying to solve problems that don't exist?

What are some mathematically well-defined problems that aren't getting enough
attention?

As for rewarding scientists for working on what's popular, that's a science-
wide problem that stems from the way that science is funded and decades of
inbreeding. Still, examples of how to break physics out of its funk on this
score would also be useful.

------
coldtea
Btw, something to think on. Consider this slowdown in physics, and the oft-
repeated ideas that we'll sure to colonize not just the solar system, but
eventually even the galaxy...

E.g.: [http://www.antipope.org/charlie/blog-
static/2007/06/the_high...](http://www.antipope.org/charlie/blog-
static/2007/06/the_high_frontier_redux.html)

~~~
sliken
Dunno, seems pretty out of date. The mentioned price of $15,000 per kg to the
moon is already 3 times cheaper, even if you need to get it to mars.

They also mention a wildly optimistic "I'm not holding my breath" $20k per kg
to mars, which is already is 4x higher than a SpaceX BFR launching stuff to
mars.

------
cletus
I'm no physicist but this leaves me scratching my head.

You have some people saying the university funding system is to blame by not
accepting crazy ideas but we have all sorts of ideas in physics like:

\- String theory. As best as I can tell the only reason string theory exists
is because if dimensions=11 the equations for general relativity pop out.
Importantly though string theory has made no testable predictions and it's
unclear when or even if that will be the case.

\- Supersymmetry. Interesting idea but no evidence of this yet.

Other more interesting ideas to me at least (again, as non-physicist):

\- Octonion Math underlying the standard model (maybe) [1]

And some interesting experimental work:

\- Possible violations of lepton universality from the LHCb detector [2]. This
was, last I heard, still well below statistical significance (5-sigma) and
could well disappear (as other bumps have eg at 750GeV) but it's interesting
nonetheless.

And there are host of open problems with otherwise successful theories.

My favourite extremes here is the prediction of magnetic moment of an
electron, which is ~12 significant digits in agreement with experimental
results. At the other end is QFT predicting the energy density of a vacuum,
which is ~120 orders of magnitude off [3].

Anyway, a lot of this exists in the current academic system.

[1] [https://www.quantamagazine.org/the-octonion-math-that-
could-...](https://www.quantamagazine.org/the-octonion-math-that-could-
underpin-physics-20180720/)

[2] [https://cerncourier.com/beauty-quarks-test-lepton-
universali...](https://cerncourier.com/beauty-quarks-test-lepton-
universality/)

[3]
[https://en.wikipedia.org/wiki/Cosmological_constant_problem](https://en.wikipedia.org/wiki/Cosmological_constant_problem)

~~~
T-A
Depending on how strict you are, you can trace string theory all the way back
to the 1940s, or at the very least to the late 60s [1]. Supersymmetry is from
the early 70s [2]. They are exactly the mainstream kind of thing which
Hossenfelder is referring to when she writes about "physics beyond the
standard model which the Large Hadron Collider (LHC) was supposed to find".
For every lone wanderer exploring a long shot like octonion math, there are
thousands writing yet another paper on some variation of the old theme.

[1]
[https://en.wikipedia.org/wiki/History_of_string_theory](https://en.wikipedia.org/wiki/History_of_string_theory)

[2]
[https://en.wikipedia.org/wiki/Supersymmetry#History](https://en.wikipedia.org/wiki/Supersymmetry#History)

------
adamnemecek
Once upon a time, researchers were independently wealthy

[https://nadiaeghbal.com/independent-
research](https://nadiaeghbal.com/independent-research)

~~~
titanix2
It was also a time when the whole societal landscape was different: peasants
farmed because it was their way to survive and the aristocracy lived on the
labor of the former without having to work. What changed now it that almost
everybody need "a job" and the attention and time of a lot of smart people is
distracted by that. That's also the reason why people professionalize
themselves by going to the academia. In my case, I would do research and
experimenting new ideas no matter what, but joining an PhD program is the way
to put bread on the table.

~~~
TangoTrotFox
Today the number of people that don't have to work, both in raw numbers and as
a percent, has absolutely skyrocketed. I mean if a person is simply interested
in e.g. pursuing research and not so much with material niceties then it's
extremely easy to live abroad in developing nations, indefinitely, starting
with around $200k. Bump that up to a million and you can live practically
anywhere so long as you have the discipline to live far below your means,
which is perhaps the hardest part of it all.

~~~
akvadrako
It's pretty easy to leave below your means if you are really engrossed in
research. The hard part is finding the time to spend money.

------
narrator
I kind of like the model of the turn of the 19th century where you had great
geniuses like Tesla who would just get funding to create whatever kind of cool
crap they could think of. Are there still any people like that in physics?
Legendary scientists/engineers who run there own lab and just make cool stuff?

~~~
canhascodez
Tesla is a bad example for almost any given point, but in this case it's
relevant to note that he was not a scientist, and his funding model did not
work.

------
beefman
This criticism may have some merit on the particle physics side of things, but
from the 'gravity' side I see exciting recent progress. In particular, the
AMPS firewall and literature that followed, including the introduction of
computational complexity into physics, ER=EPR etc. With LIGO and various space
telescopes soon coming online, the experimental future looks bright too.

------
mymythisisthis
The stagnation become with the end of the USSR. No need for physics anymore,
no one was building missiles, or going to space. Then the Internet happened
and smart people made money off that. Looks like the wages for developers is
going down. China, Japan, etc., art going to space. Physics will pick up
again.

------
poelzi
[http://www.pnas.org/content/112/24/7426](http://www.pnas.org/content/112/24/7426)

It is proven that physicists are in fact, the most ignorant folks of all
scientists. Real, proper physical models are always interdisciplinary, unified
theories. The most ignored category of all.

I can assure everybody, that the model that might get accepted in 100 years is
already here. As I'm personally using one of those fringe models, I can assure
you that using this in public will get you mostly negative points online and
quite interesting conversations offline. Nice side-note: You will be able to
filter out non scientific thinkers quite easily and I can assure you, there
are lots of them in the "scene". Interestingly chemists are much more open to
different models, in fact, most of them know that our models are rough
approximations at best.

It is funny when you think in models that explain everything, but are quite
far from the standard perspective. It becomes hard to explain effects because
the details obviously start to diverge the closer you look. On the other hand,
I think every adolescent is capable of thinking the model I'm using. (PS: I'm
not the origin of the model I'm using, I seriously would have never been able
to come up with such a minimal, absolute logical and elegant solution)

------
kristianp
Two earlier posts of hers that got a lot of commentary on HN (2016).:

Why not string theory? Because enough is enough.
[https://news.ycombinator.com/item?id=11885036](https://news.ycombinator.com/item?id=11885036)

and

The LHC “nightmare scenario” has come true.
[https://news.ycombinator.com/item?id=12238197](https://news.ycombinator.com/item?id=12238197)

Very similar theme of lack of verifiable theories.

I wonder what the experimental physicists have to say about this topic? I feel
like theories are also driven by new observations. However the observations
that the theorists have to go on are very indirect compared to those of 100
years ago. "The mass of this galaxy is out by x percent" isn't doesn't give
many clues as to what's wrong.

Compare that to observations of Mercury's orbit that happened 2 centuries
before Einstein published his Relativity theories. (
[http://archive.ncsa.illinois.edu/Cyberia/NumRel/EinsteinTest...](http://archive.ncsa.illinois.edu/Cyberia/NumRel/EinsteinTest.html)
)

------
js8
As an outsider, I wonder, what happened to Nima Arkani-Hamed and his new ideas
about the nature of spacetime? That seemed pretty interesting.. even just as a
strategy of what should be researched.

------
scottlocklin
Nobody has mentioned John Horgan's book "the end of science" yet, so I figure
it is time to do so. It's even more relevant now than when he wrote it in
1996.

------
amai
Maybe physics is suffering from the
[https://en.m.wikipedia.org/wiki/Streetlight_effect](https://en.m.wikipedia.org/wiki/Streetlight_effect).
Colliders used to produce helpful results for fundamental physics, but maybe
it is time to look somewhere else.

~~~
ymolodtsov
Colliders are certainly not the only thing scientists use.

------
xupybd
Is there an element to this that the problems left are simply harder than the
ones solved by previous generations?

------
akvadrako
If you are doing theoretical research all your really need is an office, a
computer and a basic salary; it's not like university pay is great.

If the need for funding from existing sources is hindering your research, try
to find another way to support it, like by freelancing 20% of the time or
Patreon.

------
enjalot
clearly it's the sophons.

(reference to the Three Body Problem, an awesome book)

------
amai
Isn’t she just complaining that nobody is listening to her? That sounds a lot
like a crackpot to me. Instead of complaining she should better work on a
useful new theory explaining the masses of neutrinos or dark matter and dark
energy. But of course this is much harder than writing blog posts.

------
no_identd
I wish physicists would dare blame themselves for (insufficiently dis)trusting
their statistician, mathematician & philosopher colleagues.

The reason for physics research becoming more wide, limited & shallow instead
of more narrow, broad & deep seem to stem from the foundations of mathematics.

See here for the foundations of math itself:
[https://mathoverflow.net/a/25385](https://mathoverflow.net/a/25385)

[http://math.andrej.com/2016/10/10/five-stages-of-
accepting-c...](http://math.andrej.com/2016/10/10/five-stages-of-accepting-
constructive-mathematics/)

(If you struggle with comprehending the above, try drawing Venn diagrams of
the logical operations involved to gain a geometric understanding of the
matter.)

And here for the foundations of probability theory:

[https://link.springer.com/chapter/10.1007%2F978-88-470-2107-...](https://link.springer.com/chapter/10.1007%2F978-88-470-2107-5_5)
Gian-Carlo Rota - Twelve Problems in Probability Theory No One Likes to Bring
Up, The Fubini Lectures, 1998 (published 2001)

Two decades old, but the title still rings as true today as it did twenty
years ago, unfortunately.

And here, for the obligatory philosophy slap fight abound in statistics:

[https://www.quora.com/For-a-non-expert-what-is-the-
differenc...](https://www.quora.com/For-a-non-expert-what-is-the-difference-
between-Bayesian-and-frequentist-approaches/answer/Jason-Eisner)

The philosophical solution to which basically boils down to this image macro:

[https://i.imgur.com/MPAntbK.jpg](https://i.imgur.com/MPAntbK.jpg)

But for which we lack a sufficiently advanced & logically consistent
mathematical formalism, both due to people mostly ignoring, out of ignorance
[because from where else do you get the action of ignoring!], the
philosophical solution, and, more importantly, because we lack a sufficient
mathematical formalism for it due to, among other things, the issues with
probability theory.

And here, a small shimmer of hope in the foundations of statistics:

[http://mysite.science.uottawa.ca/phofstra/Simpson.pdf](http://mysite.science.uottawa.ca/phofstra/Simpson.pdf)

There exists another, unrelated to the above presentation, avenue of highly
interesting research out of Brazil, but their results haven't yet reached a
stage of maturity where people throw together easily understandable powerpoint
slides, which I'll neglect mentioning here for now, because I'd consider that
bad etiquette.

Personally, I feel partial to blaming all of this on this Euclid translation
error, albeit I say that in partial jest:

[http://cgm.cs.mcgill.ca/~godfried/teaching/dm-reading-
assign...](http://cgm.cs.mcgill.ca/~godfried/teaching/dm-reading-
assignments/Euclid-Second-Proposition-Math-Intell.pdf)

...which people still fall for, even in 2018, as exemplified in quite a few
papers on the foundations of geometry published in recent years.

In closing:

Physicists don't stand the furthest to the right in this xkcd comic, and out
of frame, even further to the right from the already left out philosopher,
there exists a recursive boxing match between numerous fields of science
conveniently left out of the graphic to maintain a sense of strict hierarchy &
order in a reality that lacks such hierarchy:

[https://xkcd.com/435/](https://xkcd.com/435/)

Also, I'd like to point out that the title of that blog post technically
represents a statistically testable hypothesis.

------
informatimago
[https://www.youtube.com/watch?v=MwKT9XqbCI8&list=PLWy9gm0ulp...](https://www.youtube.com/watch?v=MwKT9XqbCI8&list=PLWy9gm0ulp7nvCU4p7BrLlhkTAcA2UL2O)

[https://jp-petit.org/science/scientific_summary.htm](https://jp-
petit.org/science/scientific_summary.htm)

------
buboard
> That a theory isn’t pretty is not a problem

On what premise? 'Theories' are human constructs, hence why physicist are so
adamant about their Truth and Beauty. It's wrong to say that, when most
sciences rely heavily on Occam's principle (an aesthetic argument) for reasons
unknown. It's pretty likely that the human brain is guided by both principles
to model the world, and that should be reflected in the formulation of our
theories.

------
ackfoo
We’re stuck in a paradigm that doesn’t result in any valid fundamental
predictions. The idea that running the expanding universe backward makes
everything denser and hotter in the past is just dumb.

The universe is not like a loaf expanding from dense batter to fluffy bread.

Instead, the chaotic vacuum produces, for want of a more accurate concept,
particle-antiparticle pairs at random that exert a “pressure” seen as the
Casimir Effect and a force that underlies the expansion of space-time.

These pairs are mostly ephemeral, but under certain conditions they can
randomly transition to a stable state. This eventually results in matter. (It
results in a lot of things, but we’re biased toward the minor component,
matter, because we’re made of it.)

The process happens a lot in very empty space, and almost not at all in space
that is constrained by the existence of matter already. This is why “dark
matter” exists out there and not down here. The Casimir Effect will give this
to you; constrain the available space and some wave equations are excluded,
resulting in a measurable inward pressure.

Run the expanding universe backwards: space-time contracts and we have exactly
what we have right now. Run it forward and space-time expands, again giving us
exactly what we have right now. Of course, things are different, but the
physics is unchanged. The universe doesn’t get hotter or cooler, there’s no
era of total ionization or inflation.

The fundamental ground state of the universe is chaos. Anything can arise out
of that chaos, but specific events are constrained by probability: some are so
unlikely that we never see them; some are so likely that they are certain and
they happen all the time.

Mathematics, so useful a tool in the past, cannot describe this situation. The
only way to describe this system is by using the system itself; there are no
shortcuts.

Math, philosophy, reason and order are inapplicable because they are only
rules-based approximations of a chaotic state.

~~~
a_crc
That's an interesting idea. Do you have any thoughts on the fact that the
structure of the cosmic microwave background radiation is exactly what we
would expect it to be if the universe had expanded from a tiny state to its
current state?

I'm unwilling to assume it "just randomly looks like that" given that a random
distribution on a universal scale seems highly unlikely to show the large
scale structures notable in the CMB.

~~~
TangoTrotFox
I'm in no way endorsing this individual's proposal, but the argument you're
using here is not as strong as you'd expect. A recurring trend in the past
several decades has been that a contradiction in prediction is often simply
massaged back into that prediction, at times quite arbitrarily. Then that
previously contradictory observation can be used as 'evidence' for the newly
retrofitted prediction. Of course that's at best circular logic and, at worst,
something that can start sending us spiraling down the wrong path, faster than
light.

So for instance the CMB did not support the big bang, it contradicted it. See:
the horizon problem [1]. To reconcile this inflation theory was invented which
arbitrarily suggests that the universe hit the accelerator hard, then slowed
back down. There's no logic, mechanism, rationale or falsifiability. But it
makes what we see fit what we predicted we'd see, so it's a pretty widely
accepted part of modern physics. And this retrofitting now has a cascade
affect that enables other theories to provide support for yet other theories
-- such as what you're proposing here in that the CMB now 'supports' the big
bang. It does so only if you add a very big asterisk there.

[1] -
[https://en.wikipedia.org/wiki/Horizon_problem](https://en.wikipedia.org/wiki/Horizon_problem)

~~~
a_crc
I'm not a physicist, so maybe I'm misunderstanding the article you linked, but
it seems to support my 1st post.

If you'll reread it you'll see that I mentioned nothing about a Big Bang, but
rather that the CMB provides evidence that the Universe expanded from a
smaller state to its current state, which is larger than its starting state.

From the linked wiki: "Differences in the temperature of the cosmic background
are smoothed by cosmic inflation, but they still exist. The theory [Cosmic
Inflation evidenced by the Horizon Problem] predicts a spectrum for the
anisotropies in the microwave background which is mostly consistent with
observations from WMAP and COBE."

~~~
TangoTrotFox
It doesn't. First to clarify what the CMB is. It's basically just heat
residuals that seem to indicate that the universe was much hotter in the past.
The problem is that these heat residuals are relatively homogeneously
distributed. In terms of thermdynamics this makes perfect sense - the entire
temperature of an area will gradually converge, like a pot of boiling water
will eventually reach room temperature.

But physically what we observe does not make any sense. Like you probably
know, nothing -- including action -- can be perceived to travel faster than
the speed of light. The sun is about 8 light minutes away from us. If it
somehow just suddenly disappeared, we'd still see it in the sky and continue
to revolve around, what would 'now' be nothing, for about 8 minutes. The
observation of its disappearance and the effective causality of its
disappearance (and its effect on our orbit) would happen at or very near the
exact same time.

The problem with the CMB is that areas of space that should not be causally
connected since light itself has not had time to go from one to the other,
seem to be causally connected. In other words, with our boiling pot in a
kitchen room - the eventual equilibrium that the kitchen reaches (if we assume
that that entire little region is all of the space in existence) is going to
vary quite substantially whether you have an e.g. 100 cubic meter kitchen or a
200 cubic meter kitchen. We should observe both sides of space acting like two
independent 100 cubic meter kitchens, instead we seem them behaving like a
single 200 cubic meter kitchen.

This is a major and unresolved problem that threw much of what we know out the
window. It directly contradicts the big bang. To 'resolve' this, we started
creating a arbitrary special conditions. Cosmic inflation is one of these.
There is absolutely no reason to believe that cosmic inflation ever happened -
its sole and only reason for existence is to work as a 'fix' to make what we
observe fit what we thought we'd observe. This makes it illogical to use
derivative things as "evidence". In particular the nature of our current CMB
is in no way _meaningful_ evidence of inflation, because inflation was
hypothesized, after the fact, in no small part to fit the CMB to what we
thought we'd see! In other words calling the CMB meaningful evidence of
inflation is trying to provide support to a hypothesis by suggesting that the
observation said hypothesis tries to explain is meaningful evidence of that
hypothesis.

Any not completely idiotic hypothesis will obviously be 'evidenced' by what it
tries to explain. But we have a major problem when that 'evidence' becomes all
you have to rely on, and that is exactly the case here.

