[robbmorganf]

> overproduction of physics PhDs relative to academic positions available

Why are positions researching physics so closely tied to academic positions? We probably don't need too many more physics professors but we sure could use more physics research. Or maybe better physics research. Either way, more/better physics discoveries.

That said, our scientific communication channels seem filled to the brink. So maybe we need more efficient scientific communication before we can make good use of more researchers.

[kragen]

Maybe what we need is cheaper physics apparatus so you don't need a physics professorship or a big lab to advance the state of human knowledge. You aren't going to scale down the LHC to fit under your bed when you aren't using it, but you could surely fit an XRF, ICP-AES, AFM, and maybe an optical bench in there. For a while I worked at a satellite company whose first cleanroom was made only a few years back by covering the concrete walls with polyethylene film, and a class-10 clean bench that you stick your hands into is within the reach of lots of people. Lots of amateurs have built fusors, but mostly they aren't doing the work necessary to measure reliable, reproducible results, in part because Vixra doesn't offer any incentive to do so. Radio amateurs are one shining exception here, even if most of them are just using store-bought equipment these days.

[temporaryi3]

You'll also need to pay for the people doing the research to buy houses, have cars, retirement savings, raise families, and have a decent quality of life too.

Add that to a bare bones optics lab with a few staff and you will be running about $1 million startup costs for benches, lasers, optics, closed loop cryogencics, He4, interferometers, etc, plus half a million a year salary costs for 3-5 people in a low cost of living area.

It would also need job security to be competitive with going into something like data science, making the startup costs a careers worth of funding otherwise it would be insanity to choose.

Source: PhD in quantum optics, no longer do science.

[kragen]

> You'll also need to pay for the people doing the research to buy houses, have cars, retirement savings, raise families, and have a decent quality of life too.

Newton and Cavendish didn't have any of those, except that Cavendish had retirement savings. So while not having houses, cars, retirement savings, the ability to raise a family, and a decent quality of life might be a reason for not achieving more than Newton or Cavendish, it's not a reason for achieving less.

(I suspect that raising a family is actually counterproductive. I've seen an awful lot of promising researchers of both genders stop publishing after their first baby.)

I don't have any of those things, but while I'm no Newton or Cavendish, I can't attribute the difference to my lack of a car. Most of the people in my country don't have any of those except for houses; most of the people here who own houses built them with their own hands rather than buying them.

It's true that if you have to choose between going into data science and owning your own house and car, or doing quantum optics while living in poverty, the former is a lot better for you. But for most of us it's not an either-or choice:

1. Why not both? Lagrange did a significant amount of his work while subsisting on a day job teaching ballistics to gunners. Vipul Ved Prakash wrote Vipul's Razor by working one month out of the year in Delhi, then spending the other 11 months up in the mountains working on whatever he wanted to. Sidis deliberately didn't do anything others would consider useful, surviving on a series of menial jobs, but if he'd turned his formidable intellect on the problems of automatic computation or chemistry instead of collecting streetcar transfers, possibly he would have made significant progress. I've been living on US$6k a year, so a single year of a US$250k salary and stock package at Google or Fecebutt would allow me to survive for 40 years.

2. For most of us, it's neither. Most people don't have a data-science job available, or cars, or job security, or retirement savings. Given the choice between spending your spare time on watching Westworld and setting up experiments with Kerr cells and third-harmonic-generation crystals, what could possibly make the former a better choice? Though I'm one to talk! Here I am wasting my time commenting on the orange website, arguing about physics with people (who aren't you) whose understanding of physics evidently comes from WGBH Boston.

So, while I agree that everyone should live in material abundance, I don't agree with your apparent conclusion that more abundance of non-experimental-apparatus material goods would boost the world's research productivity. Many more people can buy houses, buy cars, have retirement savings, and raise families than 50 or 100 years ago, while the speed of scientific advancement has increased only modestly.

[Jensson]

Theoretical physics just needs pencil and paper. If you do the more computation heavy parts of theoretical physics then add a computer as well.

[kragen]

Yes, but historically great advances in theoretical physics have usually followed great advances in experimental apparatus.

[gaze]

It’s absolutely the other way around. High Tc superconductivity, quantum hall, Geiger-Marsden, etc…

[kragen]

Hmm, are you saying that high Tc superconductivity, the Geiger-Marsden results falsifying the plum-pudding model, and the quantum Hall effect were predicted theoretically before they were discovered empirically? I thought that these were three of the more spectacular cases of unexpected experimental results that bore great theoretical fruit.

Possibly you intended to post your comment in reply to one of Jensson's comments rather than mine?

[gaze]

I accidentally read your comment the wrong way around -- sorry about that!

[Jensson]

Like Einstein or Newton? Theoretical physics tends to be way ahead of experimental physics, it took 50 years from higgs boson existing as a theory to finding traces of the higgs boson in the LHC etc.

Physics is done using the true scientific method. First you make a theory, then you make experiments to test the theory. Theoretical physicists made a theory and proposed some possible experiments to test it. Then 50 years later data was found in those experiments to match the theory. What we lack today to further physics isn't experiments, we lack theories that are well formed enough that we can perform experiments to test them.

[labcomputer]

"The fasted way to get the right answer is to post the wrong one on the internet"

Actually, Kepler came before Newton. Kepler's laws of planetary motion were derived from observations of others. They also follow straightforwardly from Newton's laws of motion. In particular, Kepler's second law is equivalent to conservation of angular momentum. Kepler's third law is equivalent to "Newton's universal gravitation + conservation of angular momentum". And Kepler's first is a consequence of Newtonian kinematics. That is to say, Newton generalized Kepler's laws.

The order is:

1. Astronomical observations (Brahe et. al.) 2. Kepler's laws 3. Newton's laws + universal gravitation.

Similarly with Einstein: His theoretical treatment of Brownian motion was based on observations by... Robert Brown half a century ealier. The photoelectric effect (for which Einstein was awarded the Nobel Prize) was an extension of theoretical work by Plank, who started theorizing to explain observations made by Hertz.

Special Relativity resolved a conflict between E&M and Mechanics, but it was really needed to explain why the Michelson-Morley experiment couldn't find a difference in the speed of light, despite increasingly-sophisticated apparatus (which was an unsolved paradox for a quarter of a century before SR was invented).

And, while not on your list, quantum theory had many experimental inspirations. The Millikan oil drop experiment, for one. And spectral lines in stellar observations, for another.

[kragen]

Yes, like Einstein or Newton.

Einstein's work on relativity (01905) was inspired by the Michelson-Morley experiment (01887), less than 20 years before, and its many improved replications. His work on the photoelectric effect was inspired by Hertz's experimental discovery of it (also 01887), followed by numerous further experiments which clarified the nature of the effect. Although Brownian motion had been observed, in some sense, since Lucretius (00060 BCE), Brown's 01827 observations under a microscope less than a century before were crucial to Einstein's theorizing about it.

Newton's work on orbital mechanics, which gave rise to understanding of universal gravitation (published 01687 but finished years earlier), derived from Kepler's laws of planetary motion (01621, say) and his published tables of planetary observations (01627), the Tabulae Rudolphinae. Not coincidentally, Kepler is also known for his dramatic improvements in the tele-scope, but much of the improvement in the Tabulae was actually due to the meticulous work done at the pre-telescope observatory of his predecessor Brahe, a huge stone structure.

Certainly the traffic between theoretical physics and experimental physics is not entirely a one-way flow from experiment to theory; that would lead only to the sort of overfitting we find in Ptolemy. But neither is it, as you paint it, entirely a one-way flow from theory to experiment.

It's probably true that we aren't going to resolve the problem of quantum gravity, dark matter, or consciousness with experiments, because our theories aren't good enough to design the experiments yet. But turbulence, magnetohydrodynamics, and especially quantum computers are eminently subject to experiment.

(Although I disagree with your comment, it certainly seems to be made in good faith, so I deplore the knuckle-draggers who are downvoting it.)

[ntr--]

I'm curious about your reasons for prefixing years with an additional 0 in all your posts.

[gaze]

No. No no no. It’s extremely standard to measure a material that’s known to be “weird” and not know what you’re going to see.

[hoseja]

There's no Einstein without the Ultraviolet Catastrophe.

[Jensson]

The Ultraviolet Catastrophe was discovered immediately after theoretical physicists derived the radiation law, the limit was theory and not experiments there as well. And the most important part here is that another physicist had already derived an alternative radiation law at the time that fit perfectly with the observed deviation and had a good explanation for it: Quantum Physics.

Edit: The problem with physics today is exactly like back then, we have no predictions to test. If someone comes up with a new theory that joins quantum physics with gravity in a way that is consistent with all past experiments, then we can test that. But there is no such theory today, nobody has figured out a way that the domains can work together.

[gaze]

It requires collaboration and mentorship too. These don’t scale super well.

[kragen]

No, but they do scale exponentially. Consider a random mathematician from a century ago, who I selected because he had a student in common with Sierpinski: https://www.genealogy.math.ndsu.nodak.edu/id.php?id=15165

Rajchman had two students, one of whom (Antoni Zygmund, who also studied under Mazurkiewicz, and founded the Chicago school of analysis) had 40 students, five of whom had over 100 students of their own. 18 of those 40 had at least one student of their own. Consequently Rajchman had 1658 descendants in only a century, a mentorship growth rate of 7.7% per year despite Rajchman himself having his career cut short by being murdered by the Nazis in 01940 and apparently ceasing to mentor anyone officially for the previous 15 years of his career.

[gaze]

Yes but the exponential scaling doesn't really work to anyone's benefit. It just means that N people can each mentor an average of N people and so on and so forth. An active community means that the people who are working on the problems can all share results and bring people up to speed. I'm not convinced THIS scales well.

I can buy more people in physics working on more problems. There are a wealth of interesting problems in physics and more people all going in different directions would be great. But ten times as many people working on the LHC? A hundred times as many people working on string theory? I don't buy it.

To me, the ideal model of fully open, accessible research is the speedrunning community. I don't see speedrunning as all that different from experimental work. You probe, you hypothesize, you have breakthroughs, you compete in what's generally a pretty healthy way, and you communicate and document. Look at how this scales, how many people get in and get obsessed, etc. To really master quantum hall, you need to have have a devotion to the field that's comparable to "completing Super Mario 64 with half an A press."

[kragen]

Yeah, although maybe mentorship can scale reasonably well (or at any rate much faster than we are scaling it at present), I agree with you about collaboration: ten times as many people working on the LHC (or HEP in general) probably wouldn't be very effective. Now that we have Sci-Hub, the General Index, Wikipedia, Stack Exchange, and Google Scholar, we can probably collaborate a little more effectively than before, but not enough to cram orders of magnitude of people into a given subfield.

There might be a path forward in the work on making computational work easily reproducible, by people like Konrad Hinsen, Yihui Xie, Jeremiah Orians, Eelco Dolstra, Ludovic Courtès, Shriram Krishnamurthi, Ricardo Wurmus, and Sam Tobin-Hochstadt, but clearly it hasn't been a panacea so far. Speedrunning results are in many cases reproducible by virtue of nailed-down console hardware and bit-identical game images, but that's harder to achieve even for FEM simulations of turbulent MHD systems, much less actual experimental MHD systems like a Farnsworth fusor.

How do people initially get up to speed on speedrunning? Are there tutorials, the equivalent of a textbook with problem sets, some other onramp? Can we gamify learning quantum mechanics? (I've tried QiskitBlocks but so far haven't been impressed.)

[gaze]

Scientific apparatus is by definition “pre-engineering.” It’s low volume and generally designed by a few people with no BOM optimization. OTOH, everything that’s engineered is generally just EE or optics lab stuff that’s already high volume and aggressively cost optimized. Good luck making a cheap MBE or dilution fridge, and good luck making a 10 GHz oscilloscope cheaper.

[kragen]

I've been seeing a lot of 3-D printed FDM parts showing up in labs in recent years. Of course you can't 3-D print an MBE or FIB, but maybe you could automate the manufacturing of some significant apparatus to the point where you really could download a cutfile from Thingiverse, cut it out on a CNC plasma table, and have it MIG-welded together by robots, so that, like custom T-shirts or FDM-printable parts, it can be cheap even without being high-volume. Even some high-vacuum apparatus might be accessible by that kind of route. A friend of mine has been doing a lot of optics fabrication via UV stereolithography.

[gaze]

I really detest the word "just." It's the ultimate signifier that someone hasn't properly engaged with a problem.

[kragen]

Duly deleted. Thank you for the feedback. I'm doing my best to properly engage with the problem.

[avsteele]

There are quite a few places like this:

* GTRI * Johns Hopkins Applied Physics Lab * MIT Lincoln Labs * ~All the national labs (NIST, Argonne, etc...)

They are still mostly full as I understand.

If I was to write an article on what might be improved: We need more translational research (product focused, using existing knowledge) and less academic research.

One problem I see is that there just isn't the springboard from academic research to commercialization in physics like there is in comp sci or biotech.

Granted I'm biased. I founded my company (zeroK NanoTech) to capitalize on laser cooling research. Two Nobel prizes and countless professors pushing the boundaries on this stuff since the 90's. And my little company is going to be the first to deliver a product that's a black box to the user wrt to the science but delivers some new capabilities. The ion trap quantum computing may yet pay (much larger) dividends to society and those guys are also now making big pushes as well. Might be fair to count the resurgence of rocketry and fusion in this category as well.

So maybe things *are* looking up after all!

[jollybean]

" there just isn't the springboard from academic research to commercialization"

I worked in tech transfer for a bit.

There isn't such a thing as 'translation of science' because knowledge itself is pretty useless, even applied research is.

Products - which hopefully embody some of those things - are what people buy and the things that go into making good products are a bit orthogonal to classical R&D approach. Thinking about things from a 'user centric' instead of things having 'intrinsic' value is a big leap that I think takes a few years for some to get.

In Academia we think of knowledge as having inherent meaning and value unto it's own - which is totally fine I'm not hear to argue otherwise.

But in the real world, it's almost as if you have to view Science as just 'fancy pants tooling' and give it about as much love as your ruler or hammer, i.e. think of it as just a tool to meet some 'ends' wherein the 'ends' is not 'publishing a paper'.

In biotech, the 'ends' maybe more mappable, i.e. 'this drug regrows hair in men and women' but as you indicate, it mostly doesn't work this way.

Even then, even if we got our surplus PhD's into industry, we still may have this over-capacity.

So all of that aside, maybe we are entering the phase where the standard/normative level of education is just really, really high. Like in one of those corny Star Trek places where everyone has a PhD.

Just like many of the wealthy, effete folks in the past who got degrees because they were rich and not even interested in pursuing something applied or interesting, 'we're all getting rich now' and perhaps should turn our focus to the 5B people on planet earth who still have material needs.

[zozbot234]

Translational research is its own subfield in biotech too. And it's plausibly one key place where a lot of low-hanging fruit might still be hidden, both in biotech and in the harder sciences. In general, it would be nice if academia did its part as an alternate, fully formalized source of what's usually left to tacit "folk" know-how in all sorts of industry-relevant pursuits.

[jollybean]

True that, with the caveat that biotech has much longer development cycles, and often socialized markets, which make them an odd fit for scrappy entrepreneurs and VC.

[robbmorganf]

Personally I think we are turning discoveries into products pretty fast, at the least faster than any time in history. My thought was that we need more fundamental discoveries (e.g. like understanding gravity or theories that predict and unlock high temperature superconductors), but the people who discover those things needn't be teaching staff.

[lmm]

> Why are positions researching physics so closely tied to academic positions?

Because it's cheaper that way. A lab that had to pay market-rate salaries would be outcompeted by the ones that sucker grad students with the promise that a few of them might get tenure someday and pay them peanuts in the meantime.

[thaumasiotes]

There's nothing stopping the new lab from also offering the possibility of tenure. Why would it be outcompeted?

[lmm]

It would be outcompeted because other labs could hire many more grad students for the same cost.

[thaumasiotes]

Why?

[Frost1x]

Academics can subsidize some research costs through tuition and splitting work researchers do to teaching. It's a business model that has been working well because of ever increasing demand for people to get at least a bachealors degree. It's not really about tenure per se, it's more that the academic business model can provide a stable revenue stream for some research work.

Labs that don't have this often require either a business to subsidize their work or they suddenly become completely reliant in grants. These environments are highly unstable in terms of job security. Positions are tied to a grant or a mixture of grants and difficult to maintain. If one or enough sources fail and the role is completely paid through grant money, it suddenly becomes untenable and people leave the role. The advantage academic environments have is that revenue stream to cushion the instability and provide stability.

It also lures in cheaper labor from grad students and post docs which helps.

[thaumasiotes]

I had the impression that even at very prestigious schools lab funding is mostly from grants.

I'd be interested to see how much of, say, the UNC Chapel Hill chemistry department's research expenditures come out of grants. Do you know how I'd find the information?

Two other points:

> Labs that don't have this often require either a business to subsidize their work or they suddenly become completely reliant in grants.

In what sense is the first case, a business sponsoring the lab, not "grants"?

> It's not really about tenure per se, it's more that the academic business model can provide a stable revenue stream for some research work.

But the original claim was that the cost of employing researchers is lower for an academic lab than it would be for a new lab. ("other labs could hire many more grad students for the same cost.") That has nothing to do with the availability of funding or cross-subsidies! Is it true or not?

[lmm]

Because if you pay less per worker then you can hire more workers for the same cost. I struggle to see how that's confusing?

[thaumasiotes]

I'll ask this for the third time, then:

Why would the other labs pay less per worker than the new lab?

[native_samples]

Do we need more physics research? I guess it depends a lot on how you define physics, but it seems like outside of possibly better silicon nodes, there isn't a whole lot of low hanging fruit in physics at the moment. When physics does get research funding it gets dropped into building giant machines that, at vast expense, have discovered virtually nothing.

It feels like right now most areas of academia are consuming far more resources than their useful output could really justify, which is perhaps why in so many fields it's so heavily dependent on government funding (vs say computer science where academic/corporate lab collaborations are quite common).

[mandevil]

It is really hard to predict when research will become valuable- the most valuable US Government grant ever just might turn out to be the NSF/DARPA grants for information science management that funded Brin and Page in their initial work on the PageRank algorithm.

But my favorite example of how research flows into a better world is the Sagnac effect. In 1913, French Physicist Georges Sagnac built a circular interferomter and found interference bands. He thought that this disproved Relativity and showed that an aether existed, but it turned out that German Physicist Max von Laue had predicted the existence of those interference bands under relativity two years earlier, so 10 points for Einstein.

For the next 50 years Sagnac interferometery was a dead end, a minor curiosity in the history of physics. Then in 1963, Macek and Davis at the Sperry Gyroscope Co. figured out how to build this in a laboratory environment with the recently invented lasers. The coherent beam of a laser unlocked the usefulness of the Sagnac effect. Meaning that just another 30-odd years of work by hundreds of people around the world got to a situation where ring-laser and fiber-optic gyros are superior to mechanical gyroscopes and capable of things that mechanical gyros could never do.

So, the Sagnac effect itself was worth nothing, and for a long time afterwards was just something that a few scientists even knew about. But a century later the world depends on it.

[pydry]

"There is nothing new left to be discovered in physics now. All that is left is more and more precise measurement." -- Lord Kelvin, 1900

[analog31]

In addition to all that's been said about this quote, in my view there can actually be new physics in those precise measurements. For instance astronomical measurements are where you learn if there's something wrong with our accounting of the amount of mass in galaxies, or our understanding of gravity.

Now, I'm not personally likely to discover any new physics, but I'm a physicist, and my bag is precision measurement. And it's a blast. It involves not only physics but also often optics, electronics, mechanics, math, and programming. It's recognized as a branch of physics, and is intensely experiment driven. Among the small handful of people who are crazy enough to be interested in all of those things at once, most are physicists.

Precision measurements are also an area where physics discoveries tend to escape the lab and end up in practical use. When a new effect is announced, I always wonder to myself: "When will they turn that effect into a sensor?" I can think of all kinds of measurements that benefit people, including GPS, atomic clocks, and blood oxygen sensors, that are practically all over the place.

[kiba]

What is the likelihood of discovering a new phenomena or largely unexplored field of science akin to the discovery of electricity and electrochemistry?

There may be a finite amount of works on physics that we can do, or technological niches that we can exploit thanks to discoveries in physics or any relevant field of knowledge.

The well of discoveries isn't running dry today, but it may in future generations.

[JumpCrisscross]

> What is the likelihood of discovering a new phenomena or largely unexplored field of science akin to the discovery of electricity and electrochemistry?

We have zero idea how gravity works, how to predict the properties of vast stretches of new materials, if the island of stability is real, what the limits to know propulsion technologies are, what the limits to know fusion technologies are, et cetera. And I’m not even getting to batteries or biology or hosts of related fields.

[PKop]

Part of this question is whether there is a limit to human cognition that we can leverage to answer increasingly difficult questions. It isn't whether there are still unanswered questions. So this is truly an issue of diminishing resources and exhausted low hanging fruit. One of those resources is human cognitive ability, relative to difficulty of finding new discoveries.

Just as there are true limits to for example pursuing economic growth from burning finite cheap fossil fuels, "growth" in the forms that pertain to the issue at hand... economic, cheap energy consumption, scientific discoveries, human cognitive ability to solve problems..these can all certainly bump up against at least short term limits, and the issue of cost matters greatly in a given time period because even bringing to bear the actual resource we have to develop new science and technology suffers from crowding out if economic "growth" is constrained because of diminishing cheap energy.

This shouldn't be surprising if one conceives of what consistent and steady compound growth even at small rates results in after a relatively short period of time. Inevitable that limits in many inter related areas will be reached...and either a collapse occurs or a long period of low or negative growth happens with all the sort of conflict that entails (competition within scarcity).

[JumpCrisscross]

> this is truly an issue of diminishing resources and exhausted low hanging fruit

The fulcrum of disagreement is the power of paradigm shifts. Paradigm shifts change how existing knowledge is interpreted, even by a feeble mind. These are, from what we can tell, randomly distributed. There is no indication that we are running out of them. If anything, their rate of discovery is increasing.

Since paradigm shifts are about prospective, not knowledge, there is no reason to believe they are limited. If anything, our growing knowledge base implies the next shifts will be more powerful than the prior ones.

[Invictus0]

Everyone here is missing the point. It's not that physics is running out of questions to ask. It's that the questions are getting increasingly more expensive to answer, and the answers are increasingly less compelling. The low-hanging fruit picked long ago, modern physics produces fewer discoveries that change people's lives in the way that radar, lasers, microwaves, and transistors did, which makes science investment less compelling to the public.

[kragen]

There's always a time gap.

Remember that from the first public microwave demonstrations in 01895 by Bose to the first deployments (as radar in the 01940s) took 45 years; the Amana Radarange brought microwaves into people's homes in 01967, another 27 years later; and microwave ovens didn't really go mainstream until about 01990, another 23 years after that, 95 years after Bose's first public demonstrations. The LASER was first built in 01960 (following numerous physics advances starting in 01917) but the first mass-market laser product was the CD player, introduced in 01982 and surpassing vinyl records in sales for the first time in 01988, 28 years after Maiman's first LASER.

If anything, the time gap seems to be shortening, but the place to look for "discoveries that change people's lives" is not in basic physics research of today but basic and applied physics of a few decades ago turning into common practice more recently. And in that case there are a lot of examples, especially if we go further afield from just physics discoveries:

- modern LED lighting comes from the physics discovery of how to make stable blue LEDs (though, for reasons of market failure, most LED lights still last only 3000 hours instead of 30,000);

- modern cellphones, computers, GPS, broadband, and in particular broadband wi-fi come from numerous physics discoveries that have enabled chip feature sizes to continue reducing over the last 20 years;

- optoelectronics advances are largely a question of physics, and without even counting blue LEDs, better optoelectronics have over the last 20 years dramatically improved TV screens, computer monitors, cellphone screens, fiber-optic communication, Blu-Ray data storage, and LIDAR for, e.g., self-driving cars;

- the mRNA vaccine for covid, while a biological discovery rather than a physics discovery, was designed within a few day after the genome was published, and seems to have both higher efficacy and less side effects than previous kinds of vaccines (though unfortunately for political reasons it wasn't rolled out for another 9 months, during which tens of millions of people died);

- lithium-ion batteries have gone mainstream, enabling a transition to electric cars and wireless power tools;

- better power electronics, resulting from solid-state physics research, have made induction stoves widespread;

- modern solar panels cost a tenth of what they did a decade ago, in significant part due to physics discoveries over the past 20 years, now account for the majority of new power generation capacity being built, and will probably dramatically drop the cost of energy by 02030;

- due to chemistry discoveries, Spectra/Dyneema fishing line is cheap, strong enough to make bulletproof vests, in fact as strong as the strongest steel, and floats on water;

- superhydrophobic coatings, a physics discovery, are going mainstream now.

Radar, microwaves, transistors, and nuclear physics (which you strangely forgot to mention, even though it's fundamental to modern oncology, and produces a significant part of the electrical power in many countries) resulted from WWII. We've had an atypically low level of great-power wars over the last 75 years, which has been great, but it wouldn't be surprising to have another great-power war in the next decade. If that happens, maybe the survivors will be reduced to sticks and stones, but if not, you can bet that they will have spent a lot on physics research.

[kragen]

Well, maybe we won't find anything akin to electricity again; the electroweak force is one of the three fundamental interactions we know affect matter in the universe, and knowledge of electricity as such dates back at least to Plato, 2500 years ago. It was unified with magnetism in 01873, and unified with the weak force in the 01970s. Maybe we'll find a fourth one; maybe we won't. (Gravitational waves weren't observed until 02015, and they solved the mystery of short gamma-ray bursts in 02017.) Here's a list of candidates for similarly fundamental discoveries:

1. Maybe we'll find a fourth fundamental force that we just haven't noticed yet. This sounds stupid until you realize that we hadn't noticed Archaea until 01977 or dark matter (85% of matter in the universe) until 01980 (though the phrase is from the 01930s), and we still know almost nothing about the behavior of dark energy, the existence of which wasn't known until 01992.

2. Maybe we'll find a way to reconcile general relativity with quantum mechanics ("quantum gravity").

3. Maybe quantum computers won't work, demonstrating a flaw in the assumptions of quantum theory in the same way that the Michelson-Morley failure to detect an ether wind demonstrated the flaw in the assumptions of Newtonian physics that Einstein resolved with special relativity. More likely, they will work, and this will change a lot of things; their computational power is still poorly understood. They were originally proposed (by Feynman) as an engine for simulating quantum physics.

4. Maybe dark matter and dark energy don't involve a fourth fundamental force like the strong force, gravity, or the electroweak force, but we still know almost nothing about how they behave. So almost everything about them is unknown. Can we use them for communication, propulsion, computation, energy sources, mass sources, etc.?

5. General relativity hasn't been shown to conserve energy or (equivalently) momentum. Does that mean reactionless drives and perpetual-motion machines are possible, or (more likely) that there's a more subtle symmetry to GR that hasn't yet been discovered?

6. Where does consciousness come from? It's the most perceptually salient phenomenon in the entire universe, but we don't have any convincing account of what it is.

7. We know very little about plasma dynamics. We don't know how to make a usable plasmoid gun, we don't know how ball lightning works (or even if it belongs in this item), and although we know they're a magnetohydrodynamic phenomenon, we don't know how solar prominences are formed, and similarly for solar flares, which accelerate some particles to GeV speeds by means we don't understand at all. We don't know why the solar cycle happens. Coronal waves weren't discovered until 01995. We don't know how to stabilize fusion plasma in a tokamak. We don't know if there are significant magnetohydrodynamic phenomena at scales larger than a star, much less larger than a galaxy. We don't know what heats the corona. This is important because a large majority of the matter in the universe is plasma, and our understanding of it is mostly just empirical, like stamp collecting. We're used to thinking of plasma as an undifferentiated homogeneous continuum like a well-mixed liquid, where nothing interesting happens, quite unlike all our complicated organic molecules (which can't survive in it), but obviously from looking at the sun that isn't the case; we really have no idea about the possible complexities. Is this where the Hercules-Corona Borealis Great Wall comes from? Perhaps more excitingly, if MHD makes stable structures possible in large-scale plasma systems (as it evidently does in the sun), are there analogous phenomena that can occur in a quark-gluon plasma?

8. Forget about magnetohydrodynamics for a moment. We don't even understand regular hydrodynamics. Tao's most famous result (02014) was a finite-time blowup in a version of the Navier-Stokes equation, for which he had to use results from automata theory: https://terrytao.wordpress.com/2014/02/04/finite-time-blowup.... What this means in practice remains unclear (Tao: "In principle, it might even be possible in this case that the speed and the wave number both go to infinity in finite time, a scenario known as finite-time blow-up. Of course, such blow-up does not mean that a physical fluid such as water can exhibit this behaviour, but it does mean that the Navier–Stokes equations cease to be an accurate model for such a fluid in these cases."), but it's clear, if Tao's result can be extended to the real Navier-Stokes equations, that it means we don't have an adequate model for fluids in such cases.

9. Okay, and what's up with the profusion of apparently random physical constants? Could they have been different? Are they different elsewhere in the universe?

10. How did the universe start out with such low entropy? Equivalently (or possibly not, depending on the nature of CP violation), why is the past different from the future?

11. Is spacetime continuous, or is it like a sort of foam? Is the foam size really of the Planck-length scale, or is it much larger, as the holographic principle suggests? What happens when you approach that scale? Fundamental particles like protons are far too big to do experiments like this, but in theory we ought to be able to make black holes that are much, much smaller than protons to do these experiments. (You think NIMBY is bad now...)

12. String theory posits a number of other spatial dimensions. Is spacetime really only four-dimensional?

Quite aside from these fundamental problems, any one of which promises a "largely unexplored field of science akin to the discovery of electricity", there are a huge number of things we can create that don't even require discoveries of fundamental new phenomena like those above. Electrochemistry, to take one of your examples, is extremely underexploited because in most cases we don't know what conditions we have to control in order to make our experiments reproducible, and of course medicine is full of unknowns.

Of course anything could happen in future generations, but there's nothing to suggest that your prediction will happen. Rather the other extreme: the well of discoveries is overflowing today, but may become a geyser in future generations.

[oblio]

Considering the fact that what we don't know is potentially infinite, and what we don't know we don't know is a potentially infinite chunk of that, how could that ever be true? :-)

Well, I guess we could hit a local minima where we need some out-of-this-world resources or research to level up, but let's not be so pessimistic so soon. We've only been doing this modern research thing for a few centuries. You could go back 4-5 generations in an especially long lived family and you'd find someone in the family tree that was still alive before the modern scientific method was created.

[pydry]

I'd say the likelihood seems a lot higher now than it did in Kelvin's time.

[native_samples]

I suspected I'd get an answer like this. Please read again: maybe there's not much low hanging fruit at the moment. Invictus0 has it right: this isn't the same thing as "no new discoveries ever".

Fields do have dry periods where for whatever reason, making progress is hard. Most famously AI had its "AI winter" for decades. We know now that there were new discoveries waiting to be made there but they required technology and datasets that simply didn't exist at the time. The last decade of AI progress has depended utterly on the growth of the public internet and then fast GPUs for processing that data. No matter how much funding the government had given symbolic AI in the 80s and 90s it'd have got nowhere. At least not on the use cases people seem to care about.

I find canned answers to this question increasingly tiresome. Academia and government funded research operates on a massive scale. It's unacceptable to me, as one of the people who actually pays for all this, that researchers entirely opt themselves out of any questions of utility or accountability. Fundamental physics in particular should take a good hard look at itself as it's both very expensive and in recent years, delivered very little. Consider string theory. It's been developed since the 1970s. 50 years now and for what? As far as I know this has delivered nothing concrete.

This isn't unique to physics, that's just an example. Epidemiology went down the statistical modelling rabbit hole 20 years ago and never emerged: I've yet to encounter a non-misleading claim coming from this field. If the entire field had been defunded 20 years ago we'd have a much healthier and saner world.

It's also not true that simply labelling something research means it'll one day be useful. Phrenology was once considered to be research. Critical race theory is labelled research. I think we can safely say these fields will never be useful and in fact have had sharply negative utility.

[ClumsyPilot]

The 'normal' matter is 5% of the universe, do we need to know what the other 95% is? Do we need working nuclear fusion? Etc.

[nickelpro]

An incredibly short sighted view of academic utility. Maxwell's work on radio waves took 30 years to be developed into a "useful output".

The purpose of scientific advancement cannot be understood on the timetables of capitalistic utility.

[enkid]

Is this actually the case? There is a lot of research that is occuring in the private sector or research labs and the such. A lot of it is being done at universities, but us there an actual quantified measure if what percentage of research is not in a teaching institution versus what is?

[pydry]

Instead of trying to quantify research (not really measuable in any meaningful sense) perhaps ask yourself how physics has improved your every day life and then ask yourself which improvements you think society should have given up in exchange for a greater supply of quants.

Things like the microchip, wifi, rocketry, satellites, jet engines, etc.

If the answer is "none of it" that tends to suggest underproduction.

[AmericanChopper]

This is some rather flawed logic. The productivity of physicists at the time the microchip was invented doesn’t suggest anything at all about the productivity of physicists today, and the utility of productive physics research doesn’t suggest anything at all about the existence of non-productive physics research.

[pydry]

Are you saying that there is a better measure than past performance?

[oblio]

> Why are positions researching physics so closely tied to academic positions? We probably don't need too many more physics professors but we sure could use more physics research. Or maybe better physics research. Either way, more/better physics discoveries.

It's the American system, frankly.

In Germany research institutes are frequently separated from universities.

[Spooky23]

Because those are the places hiring physicists.

When we were focused on building hydrogen bombs and rockets to obliterate civilization, everyone needed a friendly neighborhood physicist.