Wednesday, July 16, 2014

Non-empirical confirmation of theories

In science, confirmations are always ultimately empirical in character but science has always been more than just naive empiricism

A year ago, philosopher (and trained theoretical physicist) Richard Dawid wrote a book named String Theory and the Scientific Method where he essentially argued that science is becoming less dependent on empirical observations.

Off-topic: a huge black hole (diameter 80 meters) was discovered at the Yamal Peninsula, Siberia.

Two reviewers admitted that they haven't read the book but as homeless losers, they don't like the price of the book. I have a trouble with this kind of "reviews". If they are homeless losers who can't afford to buy a product, why don't they just shut their mouth? Reviews should be written by someone who knows what he is reviewing. If they haven't seen the book, they can't even say whether the price is appropriate.

Maybe a week ago, Richard Dawid was interviewed by the 3 a.m. magazine:
String theory and post-empiricism
The photograph suggests that Dawid is Max Tegmark's twin brother.

People like the author of "Post-Empirical Science is Oxymoron" along with assorted über-misguided critics whose names are banned on this blog (and who should be banned in the Solar System, too) disagreed with Dawid.

I am tired of these debates. The basic philosophical framework is so clear.

Science always ultimately derives its validity from observations and experiments – from the empirical data. It's been true for centuries, it's true now, and it will be true in the future. On the other hand, the experiments and observations needed to decide about the truth value of scientific questions have almost never been quite direct, aren't direct, and have been getting and are still getting increasingly indirect.

Über-misguided critics have no idea about the structure, character, and inner workings of the evidence that is actually relevant in the 21st century physics. So they would like to reduce the scientific method to the work of a mindless bureaucrat who is sitting, performing some mechanical procedures, and directly deriving the validity of scientific theories out of it. But science can't be done like that. The empirical data are the ultimate judges but one must be able to think cleverly and learn an increasingly sophisticated and complex language to translate between the seemingly disordered, boring, raw data on one side and far-reaching, conceptual, general scientific claims on the other side.

Richard Dawid realizes many important things but he is wrong to talk about a "qualitative transformation" that the scientific method is allegedly undergoing. Complicated theoretical arguments had to be added on top of the "raw experimental data" to decide about the validity of many claims since the very beginning – since the moments when Galileo Galilei established the scientific method. I could tell you lots of examples from Galileo's life (for example, whether one was allowed to use a telescope as a source of the empirical data has been controversial for many years!). The chain connecting the empirical data on one side and the conceptual foundations of theories on the other side has been getting longer and subtler since Galileo's time and the 20th century physics and string theory in particular made the chain even longer.

I also disagree with Dawid's claims such as "string theory hasn't been confirmed" or "the confirmations of string theory we have are non-empirical in character". That's just not the case. We have dozens of very important confirmations of string theory and they are ultimately of a perfectly empirical character. Even the "pure consistency" checks may be classified as being empirical. The fact that the probability is never negative (or greater than 100 percent) may be derived from the empirical data, too.

Moreover, the "directly" empirical confirmations of string theory are exactly as strong as the "directly" empirical confirmations of quantum field theory. One may demonstrate that string theory is predicting pretty much the same thing for low-energy experiments as QFT – the only difference is that the data needed to construct the right theory/vacuum are parameterized differently in QFT and string theory. In QFT, you build a theory by adding fields one by one; later, you adjust the renormalizable couplings. In string theory, both steps are replaced by a single discrete choice of the compactification – one stabilized solution of string theory is picked from finitely or countably many. From a purely empirical viewpoint, these two frameworks – QFT and string theory – are equivalent even though we prefer to use QFT to describe the collider data because QFT is "less abstract" and "more directly connected with the raw data" than string theory. But at the theoretical level, the higher abstract character of string theory is really an advantage. What we can't do is to make an actual doable, direct, empirical test that would discriminate between QFT and string theory. But you can't selectively use this as an argument against string theory; that is a completely logically invalid way to argue. Using it as an argument in favor of string theory and against QFT would be equally (il)logical.

QFT was historically found before string theory but that's just a fact about the history or sociology, not a fact about science. In science, one theory can't be considered "more correct" or "more empirically rooted" just because it is older. The existence of black holes wasn't affected by the death of Karl Schwarzschild who caught a bad disease when he calculated trajectories of projectiles in the Great War.

Competent high-energy theoretical physicists find it important to pay attention to what string theory is saying about various problems not only because string theory is a remarkably consistent, rigid, predictive, unifying mathematical structure and these adjectives are "cool" which is why the competent folks know that string theory is a "more correct" framework than QFT. These adjectives are actually needed for the theoretical research to have an added value.

What do I mean? If you work within quantum field theory, a particular quantum field theory makes lots of predictions about particles, fields, and phenomena in general. But aside from the Standard Model low-energy approximation, we don't know the right quantum field theory to use for "all of Nature" (just like we don't know the right string theory compactification – yet). On the other hand, theoretical physicists have gotten so good in analyzing quantum field theories that the translation between "assumptions about the field content and parameters of a QFT" and "the implications of that QFT" has become "almost straightforward".

For this reason, when we are thinking about implications of particular quantum field theories, we aren't really learning much about Nature. We are just translating the "assumptions about new physics formulated in one way" (in terms of the directly observed data) to the "assumptions about new physics formulated in another way" (the field content and interactions in a QFT).

While some clever phenomenological papers might be said to add some "small value", after all, string theory provides us with the only known (and, quite likely, the only mathematically possible) collection of underlying principles that still produce effective quantum field theories at low energies but that systematically constrain them in new ways so that we can actually learn something new without assuming the same thing in different words! String theory gives us new principles that imply that one particle spectrum or one set of low-energy interactions or one type of values of the parameters is more justifiable than another.

Even though it must undoubtedly sound surprising to the ears brainwashed by a decade of hostile anti-scientific propaganda by the Shmoitian scum, string theory is being studied exactly because it is more predictive than the framework of QFT that string theory has superseded.

There is a sense in which I even disagree with the statement that "it has become very difficult to test theories experimentally". Whether this sentence is true or false depends on the theories you want to test. If you cherry-pick theories that have been carefully adjusted to agree with all the known empirical facts and that are decorated with an additional, possibly unmotivated cherry on the top of the pie (new phenomena at very high energies added on top of the Standard Model), then indeed, it may be difficult to test such theories because you may need a collider that is too big or too expensive.

On the other hand, if you talk about sufficiently generic theories that naturally follow from some simple enough principles and that someone unfamiliar with the pyramid of known experimental facts could propose, it has become much easier to test such theories simply because the amount of experimental data that scientists have collected is huge and it is still getting larger.

It is therefore extremely easy and fast to falsify more or less every theory of this kind. A random theory constructed from scratch is pretty much guaranteed to contradict some empirically established facts! For example, it takes a few minutes to prove that everything that any of the professional string theory critics has proposed as a new theory in his life is wrong. For a theory to be viable in 2014, it must be extremely similar to the Standard Model (or, more generally, QFT) in many ways, otherwise they contradict the data. We also want theories that are "original" at least in some respects, otherwise we're not adding much to physics. Theories obeying both conditions in the previous two sentences are very rare and string theory is really the ultimate representative and perhaps the only "comprehensive prototype" of such theories.

There are theories like "the Standard Model with an added heavy particle" etc. that can't be falsified that easily but it's really because these theories were constructed to resemble the known "minimal" viable theories (the Standard Model in particular) and to deviate minimally, in aspects that are not really independently justified by anything. So such (often) unoriginal "new theories" or "potential competitors of the Standard Model" really violate Occam's razor in most cases. The added stuff doesn't really make the theory any prettier, more sensible, coherent, consistent, or universally applicable.

The frameworks, theories, and principles that naturally produce predictions that agree with the empirical data – i.e. contain quantum field theories or the Standard Model as a good approximation – but that also give us a new, prettier, more unified, more robust perspective on the natural phenomena must be taken very seriously because they're really the only alternatives that may be meaningfully investigated before one experimentally observes their consequences.

Such valuable frameworks, theories, and principles include string theory, supersymmetry, grand unification, and – to a lesser extent – several other interesting "conceptual enough" ideas in modern theoretical high-energy physics.

But if you think about possible new theories without this coherence and new formidable foundations, e.g. about a theory that just adds a single heavy particle to the Standard Model, there is really nothing much to study over there. You may just stop this research and wait for the moment when the new heavy particle is (hypothetically) observed. When this occurs, you may quickly do the research that you're doing now – and you're doing it along with hundreds of similar analyses that are bound to be useless because they assume the existence of other particles that don't exist.

String theory, grand unification, supersymmetry, and other "broad enough" frameworks drive many science haters up the wall because they're sophisticated theoretical structures and the science haters don't have good enough brains to understand the internal logic of these theories or frameworks. There's just so much to learn before you can make meaningful contributions. But this is actually exactly one of the key reasons why the research into these things is justified. Even if or when we discover experimental signatures of SUSY, grand unification, or string theory, there will still be lots of difficult questions to settle. That's the real reason why people are doing "preemptive" research of these questions now. The predictions are more than a guesswork. They have some robust internal logic and it takes some time and energy to unmask this logic.

At this general philosophical level, the debate is meaningless and most of the participants don't really know string theory (or another, similarly "assaulted" theory) at the technical level so they're just worthlessly bullšiting about something they don't really know.

To make similar debates more meaningful, we would have to talk about more particular assumptions or preliminary conclusions that decide about theorists' research. When you do so, you will be forced to notice that string theory predicts tons of wonderfully general, universal, yet conceptual things about the observable properties of Nature. It predicts string, brane, or black hole microstates with densities that behave in some ways, with interactions that also behave in some ways, phase transitions and gradual transformations between objects and geometries of various kinds, and so on. Many of these patterns are similar but many are very different from what one could guess based on the quantum field theory expectations.

The aspects that are the same are examples of the perspectives that make quantum field theory and string theory "basically equivalent" from an empirical viewpoint. And the aspects in which quantum field theory and string theory differ are capable of discriminating the two frameworks. Physicists have to choose which of the views seems more likely to them and they must use some arguments or ways of thinking to determine their subjective probabilities.

For example, string theory adds its extremely powerful voice to the debate about almost any sufficiently deep question in quantum gravity. In quantum field theory, you could – and Hawking did – expect that the information has to be lost when a black hole evaporates. String theory seems to clearly imply that all the arguments making the information loss "unavoidable" were artifacts of approximations and string theory is actually capable of circumventing all these "would-be proofs" of the information loss, and in many well-defined superselection sectors, string theory actually demonstrably does preserve the information! The tricks that allow string theory to preserve the information seem very clever, delicate, yet natural. They're surely not something that a wise and professional physicist in the field could ignore.

Now, imagine a quantum gravity researcher. Will he be affected by the incorporation of all these questions within string theory? Unless he is an incompetent sloppy moron, he clearly should be. String theory really proves that the previous arguments "proving" the information loss are flawed. Stephen Hawking who pioneered those "information loss is inevitable" arguments has understood that despite their apparent cleverness within the approximate QFT context, these arguments have been shown flawed by string theory for a decade or so.

This is just one general example of a more particular technical question where string theory actually affects what people believe. Because the theory is all about predicting some in principle observable data and because the theory – with some assumptions about the right vacuum – actually produces empirical predictions that agree with everything we have observed, these arguments based on string theory must be considered empirical in character. And they still matter and affect competent people's beliefs about the existence of the "information loss" and hundreds of others, sometimes much more technical, questions in theoretical or high-energy physics.

String theory has the power to change these opinions (about the "information loss" and hundreds of other questions) because it is capable of reorganizing the known empirical data in a way that makes much more sense than the previous picture that string theory has superseded. In some sense, it has found previously unnoticed patterns in the experimental data, something that can be extracted from the empirical data even though people had not noticed this pattern or derivation before string theory.

When string theory affects the "information loss" debate or another debate, should we be saying that it is an example of a "post-empirical science"? I don't know and I don't care – although I would choose "No". "Post-empirical science" is just a sloppy philosophical cliché, a cliché that someone uses as a compliment while others use it as an expletive. In one way or another, it is a demagogic label. But compliments and expletives don't really matter in science. What matters is whether a well-defined statement is right or wrong. And be sure that the information isn't fundamentally getting lost when the black hole evaporates!

Be sure that any general answer to similar conceptual questions that string theory brings us – whether it agrees with the quantum field theory's preliminary answer or it differs – is right. But to show why it's right – and why credible physicists believe it is right – you must actually penetrate into the technical beef of the given physical question. General bullšiting about "post-empiricism" – whether you use the word as a compliment or as an insult – isn't enough. In many cases, it is spectacularly clear that it would be utterly foolish to ignore the insights that string theory has already brought us.

So science is always ultimately deriving its authority from the empirical data but the raw empirical data have to be processed by layers of transformations – an increasing number of increasingly structured layers – and this fact has been an inseparable part of science since the very beginning. The character of the layers may be gradually changing with time. It is clearly wrong to dismiss a new science just because it is doing things differently than we are used to!

The relative importance of "old experiments" and "new experiments" is changing, too. Of course that once it becomes very hard to increase the collision energy of protons at colliders, scientists will have to pay a relatively larger attention to the older data and the (known or overlooked) patterns in them simply because totally new data may become scarce. But if the inflow of "really new" empirical data slows down, it in no way means that the discipline is becoming "non-empirical" or "post-empirical".

Old empirical data are as empirical as the new empirical data! And we arguably know more than enough about Nature – so that with this knowledge, a smart enough person or civilization should perhaps be able to complete the final theory. We still want some new data but we should be ready to appreciate that our thirst may have gotten silly and we should perhaps think more carefully about the data we have already collected.


  1. These people are intimidated as HEP becomes increasingly irrelevant with government budget cuts in the same fashion that manned space flight became an outlier (in terms of career choice) in the last 40 years or so. They see their (HEP's) hegemony in experimental physics being chipped away by the astronomy/cosmology crowd, viz. BICEP2, of which they want no part, i.e., using telescopes to do particle physics.

  2. LI could tell you lots of examples from Galileo's life (for example,
    whether one was allowed to use a telescope as a source of the empirical
    data has been controversial for many years!)

    I think you mean, "... had been controversial ..."

  3. Už čekám na ten moment, kdy různí Woitové a spol. založí sbírku proti teoretické fyzice.

  4. Hi Lubos. I am getting a bit sick of the unscientific language used in your blogs and would like to encourage you and all other scientists to use these scientific terms rather than the ones that are floating around. eg.

    GWH = Global warming hypothesis
    CCH = Climate change hypothesis.
    AGWH = Anthropological global warming hypothesis.
    GWHA = Global warming hypothesis alarmists
    GWHD = Global warming hypothesis deniers
    Alarmists = Hypothesis alarmists
    Deniers = Hypothesis deniers
    Climate fearmongers = Climate hypothesis fearmongers.
    Climate optimist = Climate hypothesis optimist

    When I used to mention the Higgs boson online in the early noughties I was always shouted down by my peers and asked to add the word hypothetical or hypothesis.
    I can't see any difference here with the global warming hypotesis or the climate change hypothesis and would like to see the same vigour used for this new hypothesis. Thankyou.

  5. Apologies, I didn't understand most of your comment, and concerning the parts that I did understand, I don't know whether you meant it seriously or as a joke.

  6. 'One may demonstrate that string theory is predicting pretty much the same thing for low-energy experiments as QFT.'

    I dropped out of high school, but I think even I understand how this fact simply and obviously helps confirm string theory. If you have a theory 'a' that completely explains only facts 'c,' 'd' and 'e' of the world and that is less complex than a theory 'b,' and if both theories completely explain facts 'c,' 'd' and 'e' while theory 'b' completely explains more facts ('f' and 'g'), then not only can both theories be said to be confirmed, but theory 'b' can be said to be more comprehensive and thus better—regardless of whether theory 'a' was devised first. And then the unproven statements that theory 'b' says are true of the world can be assumed to be true with a high degree of confidence.

  7. Exactly, thanks for saying that more clearly than myself.

  8. These tenses are too hard for me. 600 years ago, we have had been having had been had a similar tense in Czech, too.

    Isn't "has been" a more general formulation that contains the "had been" cases as a special subset? The difference is that the "had been" processes must have stopped in the past, but I am not sure whether the telescope controversy has really stopped, after I read the rest of your comment, so maybe "has been" is more accurate? ;-)

    You can't go to Jupiter. Nice, funny, but do you actually endorse the objection? I find it totally ludicrous. I personally trust a person who looks at Jupiter through his telescope more than I trust a person who likes to go to Jupiter. Why should "going somewhere" be more trustworthy than "looking at something through the telescope"?

  9. If empirical falsification is discarded for consensus, physics transitions from individual to collective baloney. That puts it somewhere between macroeconomics (wrong) and management (not even wrong). Both are incapable of predictively modeling reality (scientific socialism and Milton Friedman to Detroit and Washington).

    HP produced the HP-35 against every business model. HP rejected the first Apple motherboard ("what does it do?").

  10. "For a theory to be viable in 2014, it must be extremely similar to the Standard Model "

    In the fashion sense, sure.

    The real history of science however shows that new theories that eventually turn out to work better than the older ones are usually not as good as existing theories at replicating existing data.

    Observation bias is one huge hill to climb, for example. The petabytes of data at CERN are all interpreted with the Standard Model in mind, and re-interpreting them for a new theory - even a small change to a current mode - would take a decade or more and hundreds of PhDs. Lubos has in fact noted recently that some data could be re - looked at as SUSY evidence.

    So its _not_ the job of a new theory to first replicate all the features of the Standard Model. Its just too much work for one person or team. Thinking that a new theory has to be extremely similar to the Standard Model is too narrow, and automatically throws out any theory that is paradigm shifting.

  11. Dear Tom, I know it's often said that the better theories may be "worse" at replicating data but it's really a myth.

    Heliocentric theories were not "worse" than the geocentric theories with epicycles etc. What was worse was a simplified version of the new theories but the simplified version was really worse than the older theories. On the other hand, the heliocentric paradigm obviously did include the potential to add all the fine corrections analogous to the epicycles, and when corrections of this type are added, things are at least as accurate as the older theory.

    I chose geocentrism but it's totally analogous with all older theories that are superseded. The progress never tolerates to surrender something - or some accuracy - that had clearly been achieved before!

  12. -1, you have no clue about the scientific method and how scientific knowledge is built up.

  13. Chalmers' book "What is this Thing Called Science" dismisses naive inductionism, ie the idea that scientists look for patterns in observations and then induce theories by pointing out that the number of things to observe is virtually infinite and therefore you have to have a theory already in order to decide what to observe.

  14. Here you go Luboš! Practice makes pluperfect. Or something. :)

    Punctuate this to make sense:

    Luboš while John had had had had had had had had had had had a better effect on the teacher

    Tee hee! :)

    Answer here. No peeking without at least the full 5-second effort! :)

  15. A whopping ten years ago on this blog you covered information loss in black holes:

    “Hawking and information loss

    In response to a question (about the recent status of Hawking's 2004 claims) from David Goss, let us start with some well-known history. Hawking was the first person who in 1974 successfully merged (even though just approximately, in what we call the "semiclassical approximation") the laws of general relativity with the laws of quantum field theory to derive a nontrivial quantitative result - namely the Hawking radiation, including its spectrum. Via thermodynamics, it can be also used to derive the black hole entropy.”

  16. I am afraid that Kepler and Copernicus don't fit.

  17. Oh sit Gabor melos just beat the crap out of mr. haze with a 3.83+.

    Now its your turn lubos do do the same!

    Everybody else is stuck at a 3.76 or so.

  18. Could you please stop posting these comments to such obviously and staggeringly off-topic threads? Thanks.

    Out of the 1020+ contestants, only 2 are in the vicinity of 3.76, so your comment that "everybody else" is stuck there suggests that you are high.

    I am near 3.79, for example, and I've tried about 7 new potentially revolutionary tricks in recent days and none of them has improved the score substantially. The things in my queue aren't expected to be revolutionary.

    So I don't really think it's my turn in any sense.

  19. Of course I don't endorse the telescope argument for nowadays! But I don't
    know enough history to know if it was non-idiotic for Galileo's time. I
    know that the philosophy of "science" for thousands of years had said
    that we should be passive observers of Nature, without experiments or
    artificial contrivances. This strikes me as similar to our own idea
    that animals in zoos may not be exhibiting their natural behavior, so
    maybe the argument was non-idiotic.

    No, "has been" does not contain "had been" as a subset. The events to which "had" may apply are a subset of the events to which "has" may apply, but "has" and "had" are not those events.

    I've found an amusing example of the misuse of "has": One must not say of a deceased person, "He has eaten" or "He has been eating." I disagree slightly. :-) If he has just now choked to death on a piece of steak, and someone just now has misdiagnosed the cause of death as starvation, both the error "He has not been eating," and the objection "He has been eating!" would be grammatically OK, even though "had" would be better. :-)

    I was about to say, if the Czech verb system is simpler than the English, Czech must be one amazing language; English has only 6 tenses, while Spanish has 14 and used to have 16. But then I decided to try to get some glimmer of the Czech system, and I learned that Czech has a different and more complex way of making the distinctions, although maybe it misses some of them (just my impression).

    I've found a Czech document (written in English) saying that both Czech and German lack the perfect tenses. That's not true of German!

  20. Here's another difficult intellectual puzzle. Parse:

    Fuck fuck fuck fuck fuck fuck fuck fuck fuck fuck! :-)

  21. I personally trust a person who looks at Jupiter through his telescope
    more than I trust a person who likes to go to Jupiter. Why should "going
    somewhere" be more trustworthy than "looking at something through the

    That has nothing to do with which one you'd have trusted more in Galileo's time. I don't see why you don't understand this. Suppose Aristotle were brought back to life. Don't you think he'd be skeptical of some of our explanations of things? It seems to me that you're making the error of "presentism" (evaluating things in the past from the viewpoint of present-day knowledge and thinking).

  22. Just some basic questions:

    1. what do you think the next stage should be ,is it just waiting for the right compactification to be found.

    2. Any idea on taking it further or do you think it is the right theory as is and has no need for any major development.

    3. Are you investigating any new directions or you have decided you are past your prime and you are leaving it for others.

    4. Of course I see many people working in string(like 2014) but I get the feeling that they are only interested in very low ambitious type questions(i.e. don't steer too far) .please, correct me if I am wrong.

    5. You keep repeating about morons who don't understand string, yet so many make PHDs on the subject with many of its inventors alive today, but I don't see them making statements passionately about correctness of string. Why is that, is it personality or something else.

    From my point of view, experiment or not the theory has to be accepted by the majority to be considered correct whether actually right or wrong. My theory is 100% correct, but if I can't get the majority to agree it is as good as... choose you word!

  23. The whole point is that the facts "f,g" are considered controversial in one aspect or another. It is like one of those beauty contests. people can't decide if it is the personality, the face or other parts more attractive. Luckily in a such a case, a small number of judges make that decision for us.

  24. Dear Qsatheory,

    1) I think it's unlikely that the right compactification will be found in a foreseeable future. There are lots of other directions where significant progress is more realistic. Many things that occur in science are completely unexpected. It is silly to imagine that important things in science will proceed according to a five-year plan. Joseph Stalin and Lee Smolin might like such plans but they're just not good ways to approach science.

    2) String theory is the right theory in the sense of predicting the right numbers - lots of numbers, functions, spectra, interactions, transitions - but people may (or should) discover a more human-comprehensible set of principles that underlie all these predictions.

    3) I am surely not past my prime.

    4) As I said, people are researching where they see a realistic chance of products. It would be wrong if everyone got lost in some unrealistic dreams in the sky. But yes, I do think that the number of people who are spending enough time with really ambitious things in/around string theory is smaller than I would find appropriate.

    5) Some people even in string theory don't understand what I do, many others - like Witten - surely do but they are opportunists of a sort who decided it's better not to enter a minefield that other people have made controversial.

    The scientific truth isn't being decided by "majorities". Science isn't politics and the majority is deluded about most things, not only cutting-edge science.

  25. Dear Smoking Frog,

    well, one may define the word "idiotic" in many ways.

    For example, you may find many powerful people in the Catholic Church who think it is "not idiotic" to pretend that the telescope data aren't real.

    Well, I don't think that having many Catholic apparatchiks who believe an idea is enough to show that the idea isn't idiotic.

    The reason why it's idiotic to deny the telescope-like evidence is that one may immediately see - and even theoretically justify, without direct tests - the stunningly accurate correlation between the things we may see in telescopes and those we may see by naked eyes which is enough to claim that the telescopes are showing things that are as real as those seen by naked eyes.

    Many advances in science have occurred since Galileo's time but frankly, I don't see what could have dramatically changed concerning the simple argument in the previous paragraph which is why I think that to deny the body of data from the telescopes was as idiotic during Galileo's life as it is today.

    Czech has lots of complicated things, 7 cases in declension of nouns, dozens of templates for declension and other transformations of nouns and verbs, and so on. But the real-world Czech doesn't really have a complicated structure of tenses. I would say that well over 99% of sentences people say or write in the real world use one basic past tense, one basic present tense, and/or one basic future tense, and nothing else is really needed.

    I do understand what sort of chronological information one could express with more convoluted tenses but this extra temporal information about the processes looks rather contrived to me and may be expressed differently than by inventing new tenses - which is why I find it sort of sensible that the real-world Czech language has more or less abandoned all the tenses except for the three.

    In the 19th century, Czech would still be full of participles, to mention an example that isn't a "pure verb". I have used several of them in my books and translations, too. But I had to check the form because those are fancy things I don't "really" use in the real life which has implications. So even though the participle sometimes sounds "really cool, apt, and appropriate", we can live without them, too.

    Concerning the non-basic past tenses, we were still taught some rough counterpart of "had verbed" – e.g. "lidé bývali byli ušlechtilí" (people had been noble, or something like that). The words "bývali byli" are forms of "be", like "been" and "were".

    You may say simply "lidé bývali ušlechtilí" - people used to be noble - which counts as a normal past tense, just like any other. The extra "byli" (were) clearly shifts the process further into the past, but aside from this quantitative difference (which may be expressed by mentioning that the time is really a long time ago, in one way or another), I am not aware of a major qualitative difference.

    Similarly, if someone had been doing something but stopped, you just use a normal past tense but you also say that he stopped. These are really two pieces of information and I think it's excessive to have special linguistic tools to express them by one sentence.

    Of course, it's a matter of habits and tastes - like the difference between Intel processors and ARM processors with limited instruction sets. When it comes to the diversity of tenses, Czech is ARM and English is Intel. When it comes to many other features of the language, it's the other way around.

  26. This begs more questions.

    Did the "climate optimists" consume less energy because they are more virtuous than "climate alarmists" or was it because they are, on average, poorer.

    If it was the latter then that would also provide a possible explanation as to why they were "climate optimists" in the first place - poor people are less future-oriented than richer people (also one of the reasons why they tend to stay poor).