
Particle physics may have reached the end of the line - Osiris30
http://backreaction.blogspot.com/2019/01/particle-physics-may-have-reached-end.html?m=1
======
smallnamespace
I think a little context here is in order: from a 10000-foot high level, the
particles that can be seen depend on the amount of energy present in the
system, which is why we spend billions of dollars accelerating basic particles
(protons in the case of the LHC) to high energies and literally SMASH them
together, so we can see what flies out.

We see four distinct, different forces in the universe: strong and weak
nuclear forces, electromagnetism, and gravity. Our Standard Model predicts
that these forces become more unified at higher energy levels:

1\. Electromagnetism merges with weak nuclear force at 246 GeV

2\. Electroweak force merges with strong nuclear force at around ~10^16 GeV
('grand unification')

3\. Finally, quantum mechanics predicts these forces become _unified_ , which
is to say indistinguishable, at the Planck energy, around 10^19 GeV.

As we get closer to predicted unification energies, we see different mixes of
particles, and the Higgs boson is in fact the particle responsible for
electroweak symmetry breaking, with a mass of around 126 GeV.

The problem is that the LHC produces collisions of around 10^4 GeV, so from
our current energy scale up to the next unification, with the strong force,
we're off by a factor of 10^12.

Back of the envelope estimate is that a supercollider that can reach grand
unification energies with our current technology would be around the size of
the solar system.

Hence the article: particle smashing is a brute-force approach to
investigating new physics, but now there is an extremely wide gulf between
what we have discovered, and what we think lies next, hence we need to be more
clever than using brute force.

~~~
mrfusion
The solar system is already close to a vacuum. Makes me wonder if a new solar
system sized accelerator could just be a series of nodes orbiting far out to
aim and accelerate the particles around.

Still way too hard for us but also way easier than building a tube going
around the solar system.

~~~
dpq
> The solar system is already close to a vacuum

No. Not at all. You can expect particle density to be anywhere from 5cm^-3 to
80cm^-3 if you stay within 1 astronomical unit distance from the Sun. Besides,
all that plasma is accompanied by frozen-in magnetic field, plus you have
energetic particle events, recurrent fast solar wind emerging from coronal
holes and plethora of other effects and structures which are terribly
interesting to study but which will ruin your high energy physics experiment
even if you somehow acquire god-like powers and build a huge non-contiguous
accelerator.

~~~
imjustsaying
>5cm^-3 to 80cm^-3

had to look this up to see what you mean. I think you mean 5g(cm^-3) to
80g(cm^-3)

~~~
BentFranklin
Um, water weighs 1g/cm3. He means 5 particles.

------
maxander
I find it fascinating that the prevalent comment on this are variations of
"that can't be right, we still don't understand [things, such as dark energy,
etc]." It demonstrates one of the most pernicious biases in science.

Particle accelerators have been the mainstay and principle tool for particle
physics, and have produced amazing results. Further, there are obvious
questions in fundamental physics that the Standard Model revealed by these
experiments does not answer. But, it _does not follow_ these further questions
can be answered via accelerators that us humans can construct. The universe
has made no promise to us that its mysteries are accessible, least of all
through some particular method. We had a particular reason to believe the LHC
would reveal new physics (the Higgs boson prediction) and we have no such
reason for the proposed future accelerator; our evaluation should change as a
result.

My guess would be that astrophysics is a better route to understanding the
mysteries of fundamental physics; astronomers can measure distant phenomena
with surprising accuracy already, and objects such as black holes are one of
the few cases where exotic phenomena are currently widely expected to occur.
Perhaps the money is better spent on a truly gigantic space telescope?

~~~
eutropia
the James Webb space telescope was originally supposed to only cost 1 billion,
but now is around 10 billion USD. Still, we could build two more of those for
the price of a new LHC.

And the JWST is going to give us insights about galaxy formation, exoplanets,
and more!

------
dboreham
From :
[http://chaosbook.org/extras/CNYang.html](http://chaosbook.org/extras/CNYang.html)

"In the next ten years, the most important discovery in high-energy physics is
that `the party's over'."

Frank Yang, 1980

~~~
pbhjpbhj
I'm pretty sure someone said everything in physics has been discovered just
before the start of the 20th Century boom in theoretical physics too.

Michelson (of Michelson-Morley fame), apparently, IIRC. I'd warrant that
despite his credentials Yang (of Yang-Mills fame) is making a similar mistake.

But I do think we're likely to see a retarding of the pace of change in
fundamental physics (I think we're on to a reflective phase, where science
consolidates, and social change progresses; leading to more focus on higher-
order sciences - biology and such).

~~~
Anon84
The difference is that back then there were experimental observations that
couldn't be explained and that led to completely new branches of physics like
general relativity and quantum theory. Right now that is nothing than can
point the way. General Relativity, Quantum Mechanics and Electromagnetism are
extremely successful with no obvious flaws (other than not always working well
with one another) and the few things about which we have no clue (dark energy,
dark matter, etc) are so removed from our capabilities that they're
intractable.

~~~
davrosthedalek
There are a lot of dark matter searches out there which would disagree with
your last statement. But further than that, we still have a lot of puzzles to
solve. Proton radius, muon g-2, proton spin, ...

~~~
Anon84
And they'll keep searching... and finding nothing. :o) And is solving those
puzzles worth the tens of billions of dollars needed to build the next
generation of accelerators? How much further would that same amount of money
go if invested elsewhere?

Hell, invest a few billion in building a true quantum computer or working
towards true AI (just to name two areas where there are many more puzzles and
obvious directions to explore) and see how much more impact that has and how
much faster you can solve those same physics puzzles.

~~~
craftinator
There is currently no quantum computer that can factor the number 15. And no
one knows how to make one that can. Is this a useful field?

~~~
Someone
[https://phys.org/news/2014-11-largest-factored-quantum-
devic...](https://phys.org/news/2014-11-largest-factored-quantum-device.html):

 _”New largest number factored on a quantum device is 56,153”_

Still something you can do in your head in less time than reading the paper
takes, but more than 15.

------
peterlk
Several years ago, shortly after the Higgs discovery, I sat down with a couple
CERN people, and their comment was that the current problem is that we need
more theoretical physicists coming up with measurable predictions. As many of
the other posters state, obviously there is more to learn, but we could learn
faster if we had better (and more) predictions about what we might find.

~~~
v_lisivka
It's harder and harder to do without well developed intuition. To develop good
intuition, we need to make good mental model, but we got good (but incomplete)
mathematical model instead.

~~~
akvadrako
I agree and I think the main reason is the anti-realist camp in physics which
has taken hold in the past 100 years.

This view probably developed because the realist models of quantum mechanics
were too difficult for people to accept. It was easier to say that intuitive
models are outside the scope of science than to change their set of
inconsistent preconceptions.

~~~
pbhjpbhj
Could you expand on your comment; I thought a (small?) majority of
theoreticians were, shall we say, "super-realists" such that they view the
Many-Worlds Interpretation as actuality rather than merely a model?

When you say "intuitive models" do you mean ones that echo somewhat
Newtonian/Classical physics?

Perhaps part of the problem is that schools follow a method of teaching
physics where they teach what is easy to teach, knowing it's wrong, and then
teach something a little more complex, knowing that's wrong too, etc.. Perhaps
we need to start off teaching that the world is non-Newtonian, that it has
Quantum weirdness and relativistic effects (according to our best models), and
allow that to underlie our intuitions.

~~~
akvadrako
Many worlds is one of the more popular realist models, but it's quite rare for
physicists to claim they think it represents reality. It's not taught in any
textbooks I'm aware of and even now papers often dismiss experiments having
multiple outcomes without even mentioning that they are doing so, coming to
absurd conclusions as a result.

The situation has certainly improved a lot since the days of Everett, who was
basically dismissed as a crack-pot.

~~~
pbhjpbhj
I've seen Hawking quoted as saying MWI is obviously right.

My statement was based on an IoP survey result I saw some years ago (I'm a
theoretical physics graduate); I'll try and dig it up as my recollection could
be wrong.

~~~
akvadrako
Hawking said it was right but that it's "just probability". It's not clear
what he really thought about all those worlds being real. He didn't seem to
believe in quantum immortality, so I don't think he took it seriously.

There have been a few surveys over the years, but mostly of conference
participants. The results depend heavily on which conference you attend.

------
sprash
I could not disagree more with the general statement of the author.

Actually, we are now going from a boring phase of particle physics where the
theory was able to predict anything we were able to measure afterwards to a
phase where no theorists has a clue what might happen.

This phase is called "exploration". It consists of many "blue shots" of which
many will probably have zero results but have to be done in order to find out
what is really going on. Theorists had a good run with prediction, now it's
the experimentalists turn to lead the way with exploration by producing new
data.

When the Muon (basically a heavy version of the electron) was first discovered
it 'seemed so incongruous and surprising at the time, that Nobel laureate I.
I. Rabi famously quipped, "Who ordered that?"'[Wikipedia]

The new CERN collider has got to be build. To risk to miss the next great "Who
ordered that?" moment would be grossly inconsequential.

~~~
Anon84
Usually, when we reach the limits of theoretical physics we have unexplained
experimental results or when the experimental side starts getting boring, we
have theories that can be used to make new predictions. Right now, the problem
is that there is no clear direction in which to proceed. No new theory
predicts anything that can be feasibly tested and there's nothing
experimentally surprising that can't be explained theoretically. Until there's
a breakthrough, a theoretical framework with testable experimental
predictions, there is no point in wasting a few more billion to build bigger
holes on the ground in Switzerland.

While I am a theoretical physicist by training, I have no doubt that those
same billions could be much better used by many other fields such as biology,
chemistry, computer science, ai, etc...

~~~
sprash
This is the classic theorist talking who apparently knows nothing about the
real world. It takes a lot of expertise to build a particle accelerator. This
expertise will literally die off, if we stop building accelerators for say the
next 50 years. The next generation will have to start at zero again and it
will take 80+ years to build the following one instead of 20.

In my phd thesis I had to partly rebuild an experiment that was done 35 years
ago. (We were not able to improve the systematical errors. The statistics was
vastly improved due to modern electronics though). All people who were
involved in the old experiment were either retired or dead. The practical
problems we encountered were "theoretical trivial" but plenty and time
consuming (e.g. finding the right glue with has the right optical density and
which does not dissolve the radiation hardened wavelength shifters). If we had
just one person to talk to who had done the old experiment we could have done
it in 1/4th time or better.

~~~
arcticfox
> This is the classic theorist talking who apparently knows nothing about the
> real world. This expertise will literally die off, if we stop building
> accelerators for say the next 50 years.

If we're talking about that being the best argument in the real world for
building accelerators at the moment, let's spend _$200 million_ on a project
to archive every conceivable piece of information related to building an
accelerator and save 99% of our budget.

~~~
sprash
In my case the problem was indeed that things that were "obvious" were not
documented. Some of those "obvious" things were in fact the result of decades
of trail and error. In the end the student did it in that particular way
because it has always been done that way and for that reason found not
necessary to document it.

But even if you document everything many essential things will be gone.
Especially knowledge about things that have been tried but don't work because
failures are usually not published or documented.

It is a little bit like having a document with runes of an ancient language
where you may be can find out the meaning of the words and sentences. But you
will never find out how the language actually sounded like.

------
jgoodknight
I do think it's worthwhile to question building an incredibly expensive
particle collider without a specific purpose in mind, when the money could go
towards fields like fusion energy, quantum computing, or cancer research

~~~
Filligree
We have more than enough money to do all of the above. Science is a sideshow;
it absorbs a nearly infinitesimal part of the economy, and could be easily
funded by a military funding decrease small enough that it'd scarcely be
noticed.

Yes, a larger collider is unlikely to find much, but it's cheap enough that we
should do it _anyway_. As bets go, it's a good one.

~~~
titzer
> it absorbs a nearly infinitesimal part of the economy

In 2018 the NSF requested $6.653 billion. (More than the stupid wall--don't
tell Trump.)

That's some real money, and it should be well-spent. A new collider is
probably not well-spent.

~~~
Voloskaya
Or 1% of the budget of the department of defense. In other words, a sideshow.

~~~
raverbashing
The trick is to make the military finance your science project by finding a
military justification for it.

~~~
mturmon
It worked for Galileo: [https://www.wearethemighty.com/articles/galileo-was-
one-of-t...](https://www.wearethemighty.com/articles/galileo-was-one-of-the-
worlds-first-defense-contractors)

------
_cs2017_
Can someone please help me understand why anyone outside of a small circle of
curious science buffs should care about particle physics?

It seems the field has advanced so far that EVEN IF new discoveries emerge,
they would be of no practical value.

I'm not saying it's not interesting (I like reading about it FWIW), and I'm
not saying it will never ever prove useful. But from resource allocation
perspective, tens of billions of dollars required for high energy experiments
seem to be much better spent on other areas of physics. That is, until the
civilization advances far enough that understanding the depths of particle
physics or cosmology becomes relevant.

~~~
hashkb
> It seems the field has advanced so far that EVEN IF new discoveries emerge,
> they would be of no practical value

Particle physicists would disagree. A complete understanding of quantum
mechanics, squared with general relativity, is very likely to have practical
applications.

Cliche analogy: if you thought the world was flat and ships were falling off
the end of the ocean, you might be investing your money in world-edge-
detection; and you might say there's no point in studying the edge of the
world itself because no practical value can come of it. You wouldn't have any
idea that circumnavigation was (relatively) easy once you understood more
about the nature of the world.

~~~
_cs2017_
> A complete understanding of quantum mechanics, squared with general
> relativity, is very likely to have practical applications.

But anything observable in the world of reasonable energies (up to whatever
modern colliders achieve) can be predicted with existing theories.

If we discover something that only happens at astronomically high energies,
would it really be that useful?

~~~
hashkb
> But anything observable in the world of reasonable energies (up to whatever
> modern colliders achieve) can be predicted with existing theories.

This is classic "world is flat" / geocentric argument. Breakthroughs are
impossible to predict but can't happen if we give up.

Edit:

> If we discover something that only happens at astronomically high energies,
> would it really be that useful?

We don't know. World being round turned out to be pretty useful.

------
raverbashing
Maybe the real way of progressing is not by building bigger accelerators with
the same technology (and of course a LHC successor would need several new
_evolutionary_ developments), but finding out ways of producing higher energy
collisions without resorting to accelerating particles in a tube.

We're not even sure if there's anything in those higher energy ranges, there
are certainly knowledge gaps, but maybe a bigger collider is not the answer.
At least not until we have some other hints and new theoretical ideas.

------
kakarot
I still think we have a lot to learn from Bose-Einstein condensates.

If we're hitting a wall with respect to increasing energy in a system as much
as possible, maybe we should make sure we've picked all of the low-hanging
fruit from decreasing energy in a system as much as possible.

------
dwaltrip
It seems very strange to say that "particle physics may be done", given that
are several enormous mysteries and problems in physics that clearly indicate
our knowledge is incomplete.

A few examples: QFT and GR are not integrated, dark matter, dark energy, the
vacuum catastrophe, and so on...

One could make the argument that a larger collider is not the best way to
attack these (I have no idea), but that is a different statement.

~~~
archgoon
The author's argument is not that there are not questions that still need to
be answered; but there is no reason at all to believe that a larger collider,
that we are capable of building with today's technology, will answer any of
them. (This point is made explicit in the comments).

If the funding for your field is predicated on building a larger collider to
discover new particles; then you're in trouble. That is the sense 'Particle
Physics may be done' is meant in this context.

~~~
dwaltrip
Ok, I see where the argument is coming from, thanks. I am having trouble
buying the idea that without new colliders, there is nothing left to do in the
field of particle physics or even with the Standard Model. But I could off
base here, or perhaps my interpretation of the article is overly literal.

------
AnIdiotOnTheNet
Well there is good news: The Universe contains structures capable of
accelerating particles to the energies we want to observe and blasts them in
our direction occasionally. It may take a lot longer, but we can observe
those.

------
ForHackernews
Collider physics is not the whole of particle physics. There are in fact known
inconsistencies in the standard model (for example, experimental evidence
shows neutrinos have mass[0]) that remain unexplained and need further study.

[0]
[https://en.wikipedia.org/wiki/Neutrino#Mass](https://en.wikipedia.org/wiki/Neutrino#Mass)

~~~
FreeFull
There's also the whole issue of figuring out what dark matter is made out of.
Neutrinos account for a small part of it, but the rest is completely unknown.

~~~
mpc755
Dark matter is a supersolid that fills 'empty' space, strongly interacts with
ordinary matter and is displaced by ordinary matter. What is referred to
geometrically as curved spacetime physically exists in nature as the state of
displacement of the supersolid dark matter. The state of displacement of the
supersolid dark matter is gravity.

The supersolid dark matter displaced by a galaxy pushes back, causing the
stars in the outer arms of the galaxy to orbit the galactic center at the rate
in which they do.

Displaced supersolid dark matter is curved spacetime.

~~~
FreeFull
I have a few questions:

1) What exactly do you mean by a supersolid?

2) How would this be described mathematically? What predictions would your
theory make?

3) How does this account for some galaxies seeming to have large amounts of
dark matter, and others seeming to have less?

4) What predictions does your theory make with regards to the expansion of the
universe?

5) What predictions does this theory have with regards to places with extreme
gravity, such as neutron stars and black holes?

------
Mugwort
That simply isn't true. Not discovering a new particle outside of the standard
model, not discovering supersymmetry, or bumping against an energy desert does
NOT spell the end of the line for particle physics any more than GR isn't over
just because they discovered gravity waves. What you guys don't understand is
that model building is not a hard activity at all. SU(5), SO(10), E6 whatever.
Graduate students do those calculations all the time. What is hard is
understanding concepts and there are more than a few surprises hidden away
inside the standard model. Strange matter is poorly understood. There may be
ways to pretty up the standard model that haven't been discovered yet. People
like to go around complaining how "ugly" it is. It's not. It's prettier and
smarter than they are, they're just jealous. Particle physics is doing just
great and the only thing wrong with it is that it is dramatically underfunded.

------
vertline3
Before we throw huge money, we have to make sure we are really using it the
best way. These ever larger colliders are big investments. The Higgs was an
obvious hole missing in the puzzle, let's find another obvious hole in the
puzzle.

------
zwaps
Damn the sophons :<

------
ajuc
Saying particle physics is dead because we discovered all basic particles that
we could with our resources - is a lot like saying biology is dead because we
discovered DNA.

------
unreal37
Particle Physicists are going nuts in the comments.

------
Mugwort
Stephen Hawking said something to the effect that since the Higgs was
discovered particle physics was less interesting. To him but not to me.
Particle physics is better off than ever. Experimentally, things are going to
change immensely. Deep learning revolutionize particle physics and it's only
going to get better. Technology gets better. Regarding theory, I personally
think particle physics is in that same awkward stage as calculus before
Weierstrass, Dedekind and Cauchy made their pioneering discoveries in
analysis. Even after that there was still much to do. That was just the
beginning Lebesgue, Danielle integral, Moore-Smith convergence. We're at the
very beginning stages of particle physics theory. Nobody even knows what the
Feynman integral really IS. Most of the mathematics we currently use is
sophisticated but in another sense, quite dippy. Even superstring theory is
suffused with what we'll likely look back on as broken maths. All the easier
discoveries have been made and now the game is going to be different. That's a
great place to be.

~~~
blancheneige
> Particle physics is better off than ever.

yeah but at what cost? how many more billions of taxpayer money need to be
poured into this only to further push the theoretical constraints of our
parameter space?

------
Sniffnoy
Non-mobile link: [http://backreaction.blogspot.com/2019/01/particle-physics-
ma...](http://backreaction.blogspot.com/2019/01/particle-physics-may-have-
reached-end.html)

------
OscarCunningham
Perhaps quantum computers will help break the deadlock? They'll make it
possible to extrapolate the consequences of theories that were previously
intractable. This might mean that a large number of candidate theories could
be tested wholesale to see of they match existing evidence. In particular I
know that it's currently very hard to get predictions from quantum
chromodynamics, which means that the standard model hasn't yet been fully
tested.

------
fhood
This is unfair. Obviously our knowledge is incomplete. We have yet to make
that all important connection between general relativity and qft and as far as
I can tell, next steps towards that process are not clear. So banging shit
together even harder to see if it can produce some anomalies doesn't seem like
the worst possible idea, and at the very least it might rule out more
possibilities.

~~~
danharaj
The author's point is that you wouldn't expect to see quantum gravity at any
scale we could feasibly probe for the next few centuries. If one can't come up
with a theoretical justification for such an anomaly then perhaps that money
should be put towards a more promising project.

It's all about opportunity cost.

~~~
magicalhippo
> The author's point is that you wouldn't expect to see quantum gravity at any
> scale we could feasibly probe for the next few centuries.

However the next-gen gravitational wave observatories should be able to start
poking at quantum gravity, from what I understand.

------
mnl
Well, as far as I know (I might be wrong) she hasn't done any HEP
phenomenology, so maybe at this moment she can't get that electroweak
precision tests at a Higgs factory aren't a question of if, but when. She has
enough training to understand why, so it'd be an interesting exercise for her
to explain why that'd be futile, leaving aside the blogging standards.

~~~
mnl
I'm surprised this has been downvoted. I just can't understand how can be
relevant the opinion of a physicist about something they've not worked on just
because they have a blog. Sabine is on some kind of crusade nowadays, that's
not science, it's something else. You can't dismiss the whole field of
particle physics just because, get into the details you're supposed to be
aware of and then you'll be adding something more than noise. And I'm sorry
she thinks there's nothing worthwhile to be found with upcoming feasible
experiments, that's incredibly disappointing, to say the least. The SM is an
effective theory, the details of any underlying physics are coded into
observables that we aren't done measuring yet, how's that not important?

------
giardini
I can only hope we've reached "the end of the line."

I believe little additional monies should be directed to more powerful
particle accelerators until compelling evidence of something worth pursuing
comes from theoretical physics. Meanwhile there are many problems where the
investment will provide a predictable and useful return.

~~~
maxnoe
The thing is, theory can never provide evidence for anything.

This is what experiments do.

~~~
giardini
You misunderstand: I am not critical of physics experimentation in general; I
am critical of the never-ending pursuit of evermore powerful particle
accelerators.

At this time I oppose further pursuit of ever-bigger accelerators which draw
interest and money away from other more productive areas of science.

------
X6S1x6Okd1st
What has particle physics given us after it gave us fusion and fission?

~~~
aeternus
Faster computers, modern transistor design takes quantum effects into account.

Better microscopes.

A priceless sense of wonder.

~~~
monochromatic
Quantum mechanics sure. Particle physics no.

~~~
maxnoe
There is no difference. Quantum Mechanics is the current theory of particle
physics.

~~~
monochromatic
Quantum mechanics is not the same as QFT.

------
arcanus
'There is nothing new to be discovered in physics now. All that remains is
more and more precise measurement.'

\--Albert Michelson 1894

~~~
sidcool
To better my understanding, what new discoveries were made post 1984? Few I
can recollect:

1\. Higgs

2\. Gravitational Waves

3\. ???

~~~
qwerty456127
> 2\. Gravitational Waves

You probably mean Narendra Modi Waves[1] :-)

[1] [https://www.bbc.com/news/world-asia-
india-46778879](https://www.bbc.com/news/world-asia-india-46778879)

------
qwerty456127
Perhaps it's time to stop building colliders bigger and bigger, start building
the ultimate big one (like around the whole planet) and concentrate on doing
math and other kinds of experiments until it's finished.

------
Abishek_Muthian
"There is nothing new to be discovered in physics now. All that remains is
more and more precise measurement."

\- Kelvin, 1900

Prof. Stephen Hawking mentions this in general context that, 'they thought
physics was a closed subject in early 20th century' & proceeds to state how
the universe was unfolded in theoretical physics in 'Brief Answers to the Big
Questions'.

~~~
throwawaymath
Yes, we get it. You're the second person to cite that quote in this thread.
But the article is not saying there is nothing new to be discovered in
(particle) physics.

~~~
Abishek_Muthian
My bad that I didn't see the earlier comment, interesting that it was
attributed to Albert Michelson; seems a similar statement was made by him as
well.

As far the article is concerned, I didn't quote to suggest they say it is end
of particle physics. I just didn't agree with,

> But with the Higgs found, the next larger collider has no good motivation

Theoretical physicists were in consensus that to find precise answers w.r.t
what happened during Big Bang we need high energy collider of the size of our
solar system, that didn't deter them from creating LHC.

------
cageface
This is reminiscent of the plot of Cixin Liu’s “Three Body Problem” trilogy of
science fiction novels, where an alien race actively interferes with particle
physics experiments on earth in order to limit the progress of physics
research. Highly recommended for fans of hard sci-fi.

~~~
T-A
> Highly recommended for fans of hard sci-fi.

Only if they are willing to believe that entanglement enables superluminal
communication and that protons can be "unfolded" to macroscopic branes.

~~~
mr_luc
Aha! This is the perfect place to ask this!

I've dipped back into reading SF after a long time of only reading the
classics (Heinlein et al), and the Three-Body Problem, which I read a few days
ago, _did_ seem to me to fit into that mould.

But what are some other modern "hard SF" books you've enjoyed?

~~~
hindsightbias
Recent - James Corey (what the Expanse is based off of). Daniel Suarez would
be popular in these circles, but more Crichton-y science than next 100 years.
Some of Stephenson's books (Seveneves, etc). Others Stephen Baxter, Richard
Morgan (Altered Carbon).

All great, but I'm more old-school, William Gibson, James P. Hogan, Greg Bear
(Eon series), Mary Doria Russell (The Sparrow).

------
quantumwoke
While I do believe our knowledge of particle physics is still incomplete, the
money spent plumbing its depths seems disproportionately high. When was fusion
energy meant to be produced again?

~~~
PavlikPaja
Nuclear fusion won't work, because stars are not powered by fusion. What
happens in the stars is that heavier elements capture protons, until they
eventually reach lead, where it keeps cycling - lead 206 captures proton,
turns into bismuth 207, which decays into lead 207, captures another proton,
turns into bismuth 208, captures yet another proton, turns into polonium 209,
which either decays into lead 205 (releasing a helium core), or captures
another proton and the resulting astatine 210 decays into polonium 210, and
the polonium 210 decays back into lead 206 + a helium atom.

Which is why direct fusion of hydrogen/deuterium will never work at expected
temperatures and controllable speed, it can only work in explosions, if at
all.

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jerf
If what you say was true, the bombs wouldn't work either. The bombs are based
on the same math as stellar physics.

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PavlikPaja
They're explosions though, they can't be controlled. And they contain heavy
elements as the trigger.

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jerf
Neither of those sentences is relevant to, or contradicts, what I said.

