Thomas Kuhn’s theory of Paradigm shifts state that a paradigm shift is a massive change in scientific belief and understanding in a specific field e.g. the switch from the geocentric universe to heliocentric. The Paradigm shift Wikipedia page lists all the paradigm shifts, but strangely, the last shift happened nebulously between 1960 to 1985 as “The acceptance of the ubiquity of nonlinear dynamical systems as promoted by chaos theory, instead of a laplacian world-view of deterministic predictability”. Have there been any shifts since then? If not, why is this the case? Are we experiencing a period of technological stagnation that is only temporary or have we reached the limits of what we are able to do scientifically? If the latter is true; it is potentially terrifying for humanity, as dreams of a real warp drive or Anti-gravity will remain firmly in the realm of science-fiction.
The Paradigm shift Wikipedia page lists all the paradigm shifts
It does not list all of them. At the beginning of the list:
Some [emphasis added] of the "classical cases" of Kuhnian paradigm shifts in science are:
More recently [emphasis added], paradigm shifts are also recognisable in applied sciences: ...
Just to add an example, I took a philosophy of science course several years ago, and in it, we read Night Comes to the Cretaceous as an example of a relatively recent paradigm shift in science. The Alvarez Hypothesis (that dinosaur extinction was rapid and the result of an asteroid impact) was proposed in 1980 and was pretty controversial. It took several years for it to start gaining widespread support, maybe late '80s or early '90s. According to that Wikipedia page and the Cretaceous–Paleogene extinction event page, it was endorsed by an international panel of scientists as the cause of the extinction event in 2010, 30 years after the original hypothesis.
There are many relatively young fields in science with a lot of potential to see major changes that might be considered "paradigm shifts". I've done a lot of work in conservation ecology and genetics, which continue to change massively; there are actually a ton of topics in ecology where there isn't clear agreement among scientists. Machine learning as a young field is also completely changing how some scientists do their research (I'm not sure if a "paradigm shift" in methodology really counts under Kuhn, or if it's even something he considered).
I admittedly don't have as deep an understanding of Kuhn (and other authors related to the philosophy of science) as I would like, but I'd be wary about relying too much on his perspective. It's obviously had an important impact, but I've seen criticism that his definition of "paradigm shifts" isn't very consistent, at least with his book The Structure of Scientific Revolutions. I've also seen his work described as a simplified model for how scientific research works, similar to how we as scientists try to develop models that are simple enough to use and might miss some things. For example, I don't recall him incorporating the broader role of society and culture in "paradigm shifts" (feel free to correct me if I'm wrong).
The interesting thing about fields like mine is that "paradigm shifts" might not be purely scientific but cultural as well. Methods and techniques that might have been acceptable 50 years ago now might be viewed as unethical, and at the same time, some of what scientists consider ideal conservation practices might be impossible now due to cultural, or even legal, resistance. As an example, outdated concepts in the Endangered Species Act (1973) can have significant repercussions on how species are protected in the United States. So, the type of research some scientists do and how it's applied might be entirely different under a different cultural environment.
A good example outside of my field might be stem cell research. Bans and restrictions on embryonic stem cells have driven research on alternative sources of stem cells. Would that alternative research have taken off if there were no restrictions on embryonic stem cells? Would other areas of biological/medical research have been neglected if embryonic stem cell research was the hot thing everyone wanted to work on? How might this have affected the way we view and treat patients today?
In the physics world, there are at least two big shifts going on, as follows.
First, the particle-physics-as-strings paradigm hit a dead end some years ago and the particle physics community is casting about for a new direction. A new paradigm has not yet arisen from the various candidates.
Second (also in the particle physics community), the practical end is at hand of the bigger-and-bigger particle accelerator push. The giant machines now in existence will likely be the biggest ones ever to be built, and to study phenomena at higher energies that they can currently provide will be done by observing astrophysical phenomena instead- and not by building bigger accelerators.
I suppose the OP limits its scope to physics, because there has been recent paradigmatic shifts in history (e.g. école des annales, whose members studied the socio-economics of history away from a focus on "big men"), biology (eg biosemantics, treating biochemistry as a language rather than just complex chemistry), or paleontology (e.g. SJ Gould's view of evolution as more chaotic and dynamic than the previously held view of a gradual, progressive, slow evolution).
In physics, it seems to me we are on the verge of some pretty big shift. Present day physics are in a highly unsatisfactory state, where we can compute some stuff, using some formulas, but we don't know what the computation means. For instance, we know that the liquid drop model and its so-called semi-empirical mass formula can be used to approximate the mass of an atomic nucleus for some elements but not all, and that the nuclear shell model works better for those other elements, but we don't know why. That the reason may have to do with so called "magic numbers" is not very reassuring. Another example would be the cosmological constant problem, deemed "the worst theoretical prediction in the history of physics".
It's untoward to speak about this huge explanatory gap at the heart of modern physics, enshrined in the principle to "shut up and calculate". That is: don't ask what the formula means, just calculate it. This reduces scientific theory to a bag of tricks.
And what to do then, when the calculations don't work?
If you believe Popper, you throw away your theory. But Kuhn knows best: you don't abandon a theory, even if it's merely a bag of tricks, untill you found a new and better one. Untill then you just fiddle with what you have.
Which is exactly the point at which we are now: waiting for a new paradigm in physics. Fidling with the old one in the meantime.
For cosmologists, there are loads of new data coming from the James Webb telescope that call in question the standard model. For QMists, there's the LHC trucking again after a long shutdown. These are exiting times.
Let's begin with a few quotes, to clarify Kuhn's description.
“Paradigms are not corrigible by normal science at all. Instead, as we have already seen, normal science ultimately leads only to the recognition of anomalies and to crises. And these are terminated, not by deliberation and interpretation, but by a relatively sudden and unstructured event like the gestalt switch.”
“Normal science, the activity in which most scientists inevitably spend almost all their time, is predicated on the assumption that the scientific community knows what the world is like”
“To reject one paradigm without simultaneously substituting another is to reject science itself.”
"Political revolutions are inaugurated by a growing sense, often restricted to a segment of the political community, that existing institutions have ceased adequately to meet the problems posed by an environment that they have in part created. In much the same way, scientific revolutions are inaugurated by a growing sense, again often restricted to a narrow subdivision of the scientific community, that an existing paradigm has ceased to function adequately in the exploration of an aspect of nature to which that paradigm itself had previously led the way. In both political and scientific development the sense of malfunction that can lead to crisis is prerequisite to revolution.”
"Max Planck, surveying his own career in his Scientific Autobiography, sadly remarked that “a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it."
“Because scientists are reasonable men, one or another argument will ultimately persuade many of them. But there is no single argument that can or should persuade them all. Rather than a single group conversion, what occurs is an increasing shift in the distribution of professional allegiances.”
"Characteristically, textbooks of science contain just a bit of history, either in an introductory chapter or, more often, in scattered references to the great heroes of an earlier age. From such references both students and professionals come to feel like participants in a long-standing historical tradition. Yet the textbook-derived tradition in which scientists come to sense their participation is one that, in fact, never existed. For reasons that are both obvious and highly functional, science textbooks (and too many of the older histories of science) refer only to that part of the work of past scientists that can easily be viewed as contributions to the statement and solution of the texts’ paradigm problems."
-Kuhn, The Structure of Scientific Revolutions
Kuhn's picture is above all meant to be from observations, rather than about declaring correct or ideal methods, like say Popper.
There are some big problems with Kuhn. He didn't believe in a truth of the world accessible by science; discussed here: Why is postmodernism apparently so ill-perceived in philosophy of science? And his picture that disputes are settled in science by consensus, is just wrong, rather consensus is settled by evidence; discussed here: Is there any “stability metric” for scientific fields?
I'd say the examples in the Wikipedia list have been chosen because they have reached the stage of being in textbooks, and have contributed to the 'spine' of accepted knowledge told as the unstoppable cumulative march of progress.
So I would look for a modern example, to Bell's Theorem. The experimental tests of this recieved the Nobel prize last year, so highest peer group approval. And Sean Carroll is planning a text book which takes entanglement, linked to the non-locality results, as fundamental rather than 'tacked on' (see eg his Space Emerging from Quantum Mechanics blogpost, or the attached paper for more). As much as relativity of simultaneity the challenge to locality, is a fundamental shift in understanding of 'what the world is like'.
We need to be able to get some perspective on ideas, to see them as truly paradigmatic. Cultural factors may obscure the scientific discourse, for instance overhyping String Theory because it made for good journalistic copy, or hiding the overwhelming agreement on human-driven climate change which has been the scientific paradigm for decades.
Science exists to help us correct for our biases and misplaced assumptions. Practical tools, like publishing and peer-review, have consequences for how the discourse happens. Similarly funding sources matter to what ideas get developed, and tested. And the diversity and details of structures of education and research organisations matter - I think of the impacts of the Institutes of Technology, like of MIT and CIT, and the Perimeter Institute, and longer ago of James Watt as an instrument maker at the University of Glasgow where the break with the role of university as primarily for studying Classics to go into law or the church happened much earlier.
Kuhn made the claim to go from the stories scientists tell about the development of their disciplines or fields, to observations. But I'd say his significance as a thinker was to point in that direction, rather than to live up to his claim. He made his points confrontationally, and his model of paradigm shifts is interesting and compelling. But it can also be misleading, and he framed the discourse of science as orientated around power not evidence, with scant and anecdotal evidence.
So I see his ideas as better thought of as a gauntlet thrown down to scientists to give better sociological accounts of science history, rather than as anything like the last word, even on the use of his own terms. I see Kuhn's picture of relativising rationality to an era, as the echo of Hegel's dialectic and zeitgeist. That is, fine for telling stories, but shockingly bad for making predictions. No wonder most working scientists dislike the work of both.
Edited to add:
To explicitly address your speculation about some kind of 'end of science', that's a non-sensical notion. Any field touched by the impacts of accelerating computation will be changing rapidly towards iterations in picture of the world. The 'end' of innovation discussed more explicitly here: What will humanity do IF and when technological progression ends?
Sean Carroll addresses the perception that developments in fundamental physics have slowed or ceased, in this Mindscape podcast episode The Crisis in Physics. We have to understand how technology and professionalisation and state support for scientists, led to an era of accessing low-hanging fruit, whereas the future of such physics is likely to depend on studying vary rare and distant cosmological events, or otherwise accessing the smallest scales.
Kuhn's framing of 'picture of the world' skews towards paradigms as about fundamental physics, by describing them as about 'picture of the world' in ways that affect everything else, like the nature of space and time. But the Modern Synthesis in biology or Germ Theory in medicine is every bit as much a paradigm as the Standard Model of particle physics or Lambda-CDM in cosmology. Methodology or technology can be as key to what new paradigms can be evidenced, as much as the new hypothesis being generated and championed. Regarding everything as 'fundamentally' being physics is like saying all of literature is fundamentally alphabets. Discussed here: Is the idea that "Everything is energy" even coherent?
Albert Michelson famously said
"The grand underlying principles have been firmly established... further truths of physics are to be looked for in the sixth place of decimals."
-Albert Michelso, in a speech at the inauguration of the Ryerson Physics Laboratory in Chicago 1894
With his Michelson-Morley experiment in 1887 they failed to find the 'luminiferous aether' and showed the Newtonian picture to be fatally flawed, and heralding the relativistic era. This sentiment is more commonly and incorrectly attributed to Lord Kelvin. We cannot predict how science will develop, and it's hubris to do so. But look to technology and social change, as much as to ideas, for where change will arrive.
Perspective from a practicing scientist: Not even close :)
You can see the areas which are not well handled by existing theories, either in places where existing theories contradict each other (quantum gravity), or where there are experimental results which seem nonsensical within current theory (and therefore everyone happily ignores). There are a few absolutely massive examples of the first one (mainly in physics), and hundreds of examples of the second one which I've encountered in my work. Both of these are almost like little flags that say "a new theory will show up here in the future".
Lastly, there is the complexity problem - what good is a theory which is "correct" but so complex it cannot be used in practice? Theories don't really get tested until both the hardware, and practical calculation techniques for making good approximations, catch up, and they get widely applied. For example, quantum mechanics was in some sense "complete" in the late 20s to early 30s, but the Kohn-Sham equations which are the basis of modern DFT methods were only worked out in 1965, and what is a good density functional is still a highly active area of research; DFT now in practice is far better than 20 years ago. You can call this part more engineering than science, but it's not such a clean separation either. Quantum electrodynamics and string theory are basically at this stage, "correct" but unusable.
Related to this: it seems like we'll need a really big unifying theory of complexity...
In the world of astrophysics there appears to be a big paradigm shift coming up. Because there are several phenomenon that can not be explained by the current models:
- The inability to determine the Hubble Constant (the rate of expansion of the Universe). Different ways of measuring it result in very different results. That should not be the case.
- Dark matter: It appears that galaxies contain a lot more matter than they should, but nobody can answer with certainty in what form that matter exists.
- Large early-universe galaxies. The JWST discovered various galaxies that existed in the early universe that are far larger than they should be possible to form under our current models of the formation of the universe and the formation of galaxies.
The more we observe, the more it becomes apparent that something about the way we think the universe works is fundamentally wrong. What exactly? If I knew I would have better places to write about it than here on Stack Exchange. But if someone figures it out and is able to prove it, then that will probably cause a big paradigm shift that might very well have implications for other areas than just astrophysics.
What you seem to be asking is will there be more paradigm shifts? The answer, if you look at history, is almost certainly yes. Radical transformations in worldviews, even by carefully considered positions that scientists vet, are likely to continue to happen because reason is defeasible (SEP). From the SEP:
Reasoning is defeasible when the corresponding argument is rationally compelling but not deductively valid. The truth of the premises of a good defeasible argument provide support for the conclusion, even though it is possible for the premises to be true and the conclusion false. In other words, the relationship of support between premises and conclusion is a tentative one, potentially defeated by additional information.
Right now, the scientific establishment endorses the claim there are four fundamental forces. However, there has been speculation and call for trying to resolve some apparent anomalies with a fifth fundamental force. Right outside of Chicago, there's some work that seems to tease that this is on the horizon. If there's a fifth fundamental force introduced in our theory, there's likely to be a transformative effect that might both meet resistance from some physicists, and at the same time qualify as physics beyond the standard model. Science works by discovering new facts that support new theories which do not align themselves with the current theory. When the misalignment is radical, a paradigmatic shift can occur. If it turns out that there are additional fundamental forces, the implications on relativistic physics and quantum mechanics could be profound. Suddenly, what we know about motion, force, matter, and energy in the universe could be transformed substantially. And it is likely, there will be stiff resistance to the new way of thinking unless the evidence is overwhelming.
Paradigm shifts aren't necessarily obvious when they're happening. People come up with new ways of looking at the world all the time, but only a few of those have the sustained, large-scale generative impact that marks a paradigm shift. Others might be sterile, or debunked, or just never widely adopted. And even those that are ultimately successful will almost inevitably be dismissed by the "old guard" as nonsense. So it always falls to a later generation to certify a paradigm shift.
Given that, the gap that you're seeing is likely a marker of the fact that the more recent paradigm shifts aren't old enough for everyone to be sure about yet.
Obviously, we are at the verge of a paradigm shift in the field of philosophy, psychology and neurobiology, brought about by AIs.
The new large language models like ChatGPT are close to passing genuine Turing tests. It is conceivable that fairly soon, AIs will be indistinguishable from intelligent beings. At the very least, this latest leap in AI has made it almost inconceivable that this will not happen at some point in the next decades. Perhaps the language models have inherent limitations that cannot be overcome; but then, the next AI revolution will, if not in 5 years, then in 50.
These AIs will reflect back to us what intelligence and consciousness is, either through similarity or through difference, likely through both. For the first time in our history we will be able to test hypotheses, to perform real science, to gain real insight into ourselves.
Another computer related paradigm shift has already happened: A computation-centric, information oriented look at nature. The universe can be understood as a giant computing machine, a cellular automaton, a just gradually more complex version of Conway's Game of Life.
Each age has had its specific paradigm underlying its concept of the world: A magic dreamworld for early man, a playground of very human gods in the advanced societies of antiquity, a clockwork for the Baroque thinkers. Each time the dominating cultural, social or technical new hot thing informed the angle at which people looked at the world.
Unsurprisingly, for us it is the computer.
In this sense, paradigm shifts will continue to happen because our societies continue to change.
Whether there is a "bottom" for science, akin to MineCraft's "bedrock", beyond which we cannot mine new science I don't know — but intuitively I doubt it. Especially I'm afraid that the idea that we have reached that bottom is laughable hubris showing nothing but our limited fantasy. It is in fact a strong indicator of an impending scientific revolution, as it was in the late 19th century.
Not least there is always the study of arbitrarily complex emergent phenomena, something that Robert Laughlin considers as more important than the underlying "substrate".
Many excellent opinions. I'm taking it a step further. I'm going to argue that the only answer worth discussing is the answer "Yes, paradigm shifts have come to an end." The other answer is trivial since nothing really changes wrt to how scientific research is conducted and funded.
If paradigm shifts come to an end, the consequence is the knowledge that science will only move forward in "small" steps instead of with the occasional "huge leap".
Nearly all science throughout history has been in small increments so the removal of paradigm shifts will not alter the way science is conducted or funded. Every paper published or graduate thesis written is a testament to this. Paradigm shifts affect the rate at which science "grows" with time.
So it doesn't really matter what the answer to your very interesting question is since the business of science will not change either way.
The first part of this answer may look crazy which must not be too much of a surprise because indications of a radical counter-intuitive paradigmatic shift has not been initially met nicely in past history either. So many today's intellectuals who recognize an eminent paradigm shift also feel the unease of a transition period until the evidence necessitating the shift is more widely recognized for they find evidence more than adequate and humanity bound to face up to it sooner or later.
Now what am I, at all, talking about?
There are two sources of an eminent major paradigm shift in science and our worldview. I explain them one by one:
1) UFOs and associated truths
Committed researchers of UFO phenomena, despite all the painful challenges involved in holding up their work against the derision by the mainstream, have complied vast evidence and testimony, even official evidence obtained extra-legally or illegally (!), for the fact that many UFO sightings are not only true (not optical illusions and the like) but their implications are also clearly attested to by evidence and informed testimony. They involve existence of super-technologies able to cancel the force of inertia and gravity, in turn enabling, among other things, inter-stellar travels at ultra-high speeds (say hundreds of thousands if not millions of miles per hour!), AND the existence of extra-terrestrial life. Now until very recently, it was more convenient to ignore these claims without reading the evidence, but with the recent suggestions of reality of UFOs and ET life by the US media and government, the UFOs old messengers have been feeling both delight (and alarm). Now getting into specifics is beyond this forum and answer. For anyone interested in evidence, they are best advised to read works, interviews and lectures by Steven Greer, perhaps the most knowledgeable, committed and authoritative living UFOlogist who has also a cohort of more than three hundred former USG officials and contractors who have testified and disclosed to him on UFOs and ET, several dozens of whom having appeared before camera to make their testimonies public.
2) A substantial form of mind-body dualism and proof of survival
This is the second source of a paradigm shift. Evidence, empirical and analytic, for fundamentality of consciousness and even its survival of bodily death is growing and reaching a head. Many mainstream philosophers of mind testify that there can be in principle no physicalist explanation of mind and consciousness. On the other hand, evidence from studies of paranormal phenomena such as NDEs and physical research for a strong mind-body duality and survival of human consciousness after death is overwhelming--for those who have adequately studied the evidence or are willing to do so. This has already encouraged scientists at DOPs to confidently herald the end of physicalism and only wait for a widespread recognition. They actually do indicate that a paradigm shift is soon in order.
In contrast with the prevailing production model of the brain/mind relation, as described above, these “rogue” data collectively support an alternative class of models which view the brain not as the generator of mind and consciousness but as an organ of adaptation to the everyday environment, selecting, focusing, channeling, and constraining the operations of a mind and consciousness inherently far greater in capacities and scope. As Myers (1903) himself expressed it:
There exists a more comprehensive consciousness, a profounder faculty, which for the most part remains potential only . . . but from which the consciousness and the faculty of earth-life are mere selections. . . . [N]o Self of which we can here have cognisance is in reality more than a fragment of a larger Self,—revealed in a fashion at once shifting and limited through an organism not so framed as to afford it full manifestation. (Vol. 1, pp. 12, 15)
The primary purpose of the present book is to develop this central concept in greater depth and detail. Before moving on it is also worth pointing out that IM added a rich empirical dimension to what appears to be a rising chorus of theoretical dissatisfaction with physicalism as a philosophical position (for example, Chalmers, 1996, 2002; Koons & Bealer, 2010; Nagel, 2012; Velmans, 2009), coupled with resurgent interest in formerly “deviant” philosophical views including not only interactive dualism (Baker & Goetz, 2011), but panpsychism or panexperientialism (for example, Griffin, 1998; Seager & Allen-Hermanson, 2013; Skrbina, 2005; Strawson et al., 2006), neutral and dual-aspect monisms (Velmans & Nagasawa, 2012), and even absolute idealism (Sprigge, 1983). Our cumulative sense of the philosophical situation is that we are at or very near a major inflection point in modern intellectual history. (Edward Kelly et al, Beyond Physicalism, xiv)
They proceed to say that what remains to be done is coming up with a metaphysical and cosmological system that accommodates the clear evidence for survival and a transcendental principle for consciousness (a god? dare you say?).