We have a Resources section just for that sort of thing. A topic with resources on good argumentation and critical thinking would be right at home there.

It's patronizing and overbearing and has a whiff of... Let's just say it has a whiff of Sapientia about it :razz:

Having a sound logical structure is the bare minimum requirement for an argument, so bare indeed that it is hardly worth noting - unless the argument itself is so bare that a sound logical structure is all that it has going for it. Most disagreements that are worth arguing about are not over logic, and those that are not worth arguing about shouldn't be argued. (ETA: Just saw that said the same thing.)

Besides, I doubt that such hectoring will be pedagogically effective.

Heh, I wouldn't say 'no reason at all', but rather, for more interesting and varied reasons than we are usually prepared to countenance. — StreetlightX

Yeah, I didn't mean to imply that it's completely random and chaotic; of course there are reasons - they just aren't the obvious reasons that we like to attribute to nature.

Nature is scary and wildly facinating. — StreetlightX

It sure is. One of the more disturbing instances of antagonistic evolution is the struggle between the mother and the offspring. The (future) offspring wants to suck in as many nutrients as it can, grow as big as it can, but the mother wants to ration her considerable investment of resources more prudently, so that she has more chances to reproduce (starting with surviving the childbirth). It's hard to wrap your mind around the fact that this struggle takes place inside one and the same organism!

the question is simply: is sexual selection an independent evolutionary mechanism to natural selection, yes or no? — StreetlightX

It's not such a cut and dried question. On the one hand, there are distinctions between different types of selection, sometimes very obvious ones. On the other hand, the reason Darwin ultimately set sexual selection apart from natural selection may have to do with the fact that he tended to think about natural selection as survival of the fittest (even if he didn't coin that phrase). Later thinkers amended that formula as differential reproduction of the fittest - not as snappy, but more in keeping with the thrust of the theory. Dying before reproducing and surviving but failing to reproduce have exactly the same effects on fitness. Put that way, sex - reproduction - has everything to do with natural selection. Again, I am not a "lumper" - I don't believe that everything is the same as everything else and all distinctions are meaningless; but selection categories are not as starkly distinct as some make them out to be.

Unfortunately, this is not true. Or rather, for quite a while its been thought to be true, but has begun to crumble under large swaths of emerging evidence that it simply does not account for a great deal of evolutionary phenomena. Ascribing 'what we find aesthetically pleasing in mates to survivability alone' simply flies in the face of evidence - Prum, the Yale ornithologist who I'm relying upon here - cites case after case after case (from the wings of Manakins, to the reproductive systems of ducks, the displays of the great Argus, and so on) where attempts to account for aesthetic phenomena in terms of survivability simply does not work. The evidence itself needs to be read to be discussed, so I can only encourage that you read his work. None of this is to say that what we find aesthetically pleasing in mates has nothing to do with survivability. Only that survivability does not exhaust accounts of aesthetic phenomena. — StreetlightX

Whatever the 'metaphysics' of 'choice' at work here is irrelevant. Ironically, one of the reasons sexual selection was so violently rejected as an independent evolutionary mechanism in the time after Darwin theorized it was because the very idea that animals - specifically females! - could play any causative role in driving evolution was nothing less than an offence to Victorian puritan mores. That same regressive hangover remains an infection on our understanding of evolution today. — StreetlightX

I can see where some of the negative reaction to Prum's book may be coming from. I haven't read it, but I have seen some of the media reporting, like this New York Times piece: How Beauty Is Making Scientists Rethink Evolution. One can easily recognize a familiar narrative: a maverick scientist bravely challenges the dogma, only to be met with outraged howls from hidebound academia. And this precious flourish about "Victorian puritan mores" is a topping on the cake.

Only there seems to be something wrong with this story, starting with the subtitle of the book: "How Darwin's Forgotten Theory of Mate Choice Shapes the Animal World - and Us." Now wait a minute, Darwin's theory of sexual selection was never forgotten or abandoned, as Prum claims (judging by the reporting that I have seen). Challenged, modified, developed - yes. It is true that Alfred Wallace, Darwin's younger colleague and the co-discoverer of the theory of evolution, was skeptical about the role of female preference, but the idea that female preference is one of the most important drivers of sexual selection has been the received view since at least Ronald Fisher's 1930 hugely influential work on population genetics (he was the one who introduced the idea of "runaway" evolution in connection with sexual selection). Yes, purely adaptationist explanations of sexual selection have been put forward (starting from Darwin himself), and, as it often happens, some scientists tried to put all their chips on that idea, but it never became the mainstream dogma. For example, one idea that gained some popularity, which is that females choose bizarre and maladaptive male traits precisely because they are maladaptive (a male who thrives in spite of the handicap must be very strong indeed) has been extensively criticized, including by Dawkins in The Selfish Gene.

Distance education

"The first distance education course in the modern sense was provided by Sir Isaac Pitman in the 1840s"

This, though, is a non-sequitur through and through. The whole question of intentionality is an irrelevancy - the question is simply: is sexual selection an independent evolutionary mechanism to natural selection, yes or no? — StreetlightX

As far as a particular gene/genome is concerned, the source of the selective pressure is of no consequence: it is the same heritable variation/selection mechanism. Of course, from a wider perspective of a species there is a difference.

What accounts for the difference? In the simple Darwinian scenario the environment - and thus the fitness landscape - is fairly stable, and the population either adapts to it gradually, through successive generations, or goes extinct. However, in the case of sexual selection the fitness landscape is not only dynamic, its evolution is tightly coupled to the evolution of the population genome. This is now a very different game.

Those who studied the basics of partial differential equations may be familiar with a variant of the following problem. An island is populated by goats and wolves. Goats eat grass, wolves eat goats. The populations of grass, goats and wolves grow or shrink in response to the availability of food and/or predation. This can be modeled by a system of coupled partial differential equations. The model is so ridiculously simple that it actually has an exact analytical solution (a rare thing in real-life modeling). And yet even this extremely simple setup gives rise to an interesting dynamics in the phase space, with loops, spirals, regions of stability/instability and tipping points. The reason for this complicated dynamics is the mutual dependence of processes that make up the toy model.

And now imagine something similar in principle, but hugely more complicated - that is what the dynamics of sexual selection is like. But not just sexual selection: similar antagonistic evolution results in arms races between males of the same species
or between predators and prey.



From the naive point of view such antagonistic evolution is counterproductive: wouldn't it be better if we could all get along instead of wasting resources on pointless competitions? Make love not war! But of course nature doesn't care about such "commonsense" sentiments: it just does what it does for no reason at all.

As I said, it really depends on your definition where to put the line between natural and artificial and that is arbitrary. Artificial is meant as "man made rather than occuring naturally". My issue with that, is that anything man made is natural in my view. Perhaps it's easier to just do away with "artificial" and simply say man-made as something understood as a more specific process found in nature. — Benkei

This insistence on everything being natural is a self-inflicted semantic confusion. The point being made is silly: everything is natural, because nature is everything, by definition. This does not say anything meaningful, it's just a tautology. Yeah, I get it, you don't believe in gods and the supernatural. If that's what you want to say, then say it (though why you would want to bring that up in the present context - I have no idea). But why do violence to language?

If you step back far enough then everything is like everything else and you are staring at one featureless mass. As you note yourself it's no use insisting that everything is "natural"; this isn't any more meaningful than clearing your throat.

There are advantages to stepping back some way and looking at ourselves and our purposeful activity, such as building dwellings - and yes, breeding sheep - as being a kind of ecological adaptation in itself - and thus being a part of the same dynamics that is exhibited in the "natural" world. But so too there are advantages to stepping closer and distinguishing different varieties of selective pressures and adaptations. And of course in appropriate contexts there are any number of reasons for distinguishing "man-made" from "natural."

These are all natural agents, their rationality is irrelevant, and there is no reason to single out man as something different, or unnatural, as Darwin actually did, when he theorized about the difference between natural and artificial selection. — Hrvoje

No, you still don't understand Darwin's argument - maybe if you actually read the book where he introduces his terms, you would see where he was coming from. That selection practiced by a sheep breeder or a horticulturalist on the one hand, and by non-anthropogenic environmental factors on the other hand - both resulting in differential reproduction - was rather his point - a point that would not be immediately obvious to his readers. So he starts by describing something his readers would be well familiar with - what he calls Man's selection or artificial selection, offers an explanation for it, and then proceeds to apply that same explanation to other forms of selection that had been in operation on Earth long before sheep breeders and horticulturalists.

The business of science is to come up with theories, and the best theories win more peer approval. What is the "best" theory? Ideally - one that has the most theoretical virtues. As we have discussed, providing a good fit to data is an important, but not the only virtue. Otherwise the best theory would just be an enumeration of all known observations and measurements: that would guarantee maximum fitness. But the best theories can actually sacrifice some fitness in favor of other virtues, such as simplicity, and of course they venture to extrapolate beyond available observations. That latter feature is pretty much a sine qua non for a scientific theory: if it does not offer theoretical predictions that go beyond what has already been observed, then it is not much of a theory.

Where can "indefiniteness" fit into all this? I can think of a few aspects. One is where a theory is altogether silent about some question, leaving it (as far as that particular theory is concerned) completely open. Another is an explicitly stochastic element of a theory, such as can be seen in classical statistical mechanics, population dynamics or quantum mechanics. Finally, there is an uncertainty associated with theory choice, which owes itself to insufficient or uncertain data or to theoretical controversies. As far as cosmology is concerned, this latter "indefiniteness" is the most relevant, I think.

The amount and the quality of data that is necessary to determine the topology of the universe is necessarily limited, nonuniform and biased. Scientific methodology, such as statistical model selection, is also somewhat controversial - no more so as when data is scarce. Astrophysicists and cosmologists understand this, but there isn't much they can do about it. I said that infinite space models are currently favored as both the simplest and the fittest, but there actually are publications in scientific journals that argue that finite topologies provide a somewhat better fit to observations. I don't have any expertise to evaluate this research, but my general impression is that if you ask most experts who are well-versed in this topic, whatever their own opinion is on the question of the size of the universe, they will freely admit that there is a lot of uncertainty here, and that this is probably how it will always be.

It is not the function of scientific terminology to cater to your narrow ideological agenda (such as avoiding any hint of setting humans apart from nature).

Also you should not confuse notation with meaning. No one who reads scientific literature expects to encounter some specialist term or symbol and instantly understand its meaning without any explanation or context. The fact that, when taken out of context, notation can be misunderstood is not a serious concern. Some care is usually taken to make a term appropriately suggestive and not grossly misleading, but in the end this is a matter of personal taste.

Even more to the point, Darwin opens the presentation of his new theory in On the Origin of Species with a chapter on selective breeding, which had been well-known in England, and had been studied by Darwin before he wrote his magnum opus (he bred pigeons himself). Darwin does not even get to natural selection until the fourth chapter of the book. The very obvious point of his chosen terminology is to draw an analogy between the purposeful actions of a farmer and the unconscious processes elsewhere in nature. He argues that on an abstract level such seemingly disparate phenomena can be described by the same process: variation and selection. So natural selection here is compared with artificial selection (both Darwin's terms). Is it "anthropocentric"? Well, of course it is - appropriately so!

Then what term would you use to describe having to pass the 0.5m mark before the 1m mark, the 0.25m mark before the 0.5m mark, the 0.2m mark before the 0.25m mark, and so on? — Michael

"Ordered." Rational and real numbers can be ordered, just in the way that you describe - indeed, that is how they are usually ordered. But they cannot be put into a sequence in that order.

Here is are a couple of hints:

1. A number in decimal notation can be written as $d_0 + 10d_1 + 10^2d_2 + ...$, where $d_0, d_1, d_2, ...$ are digits.

2. Can you prove that if you subtract 1 from any of those decimal factors ($10^n-1$), the result is divisible by 3?

Are you sure that a scientific theory can have "implications" - which I presume means predictions - that are not verifiable through observation? If we have such a theory, how would we verify it? Specifically, how would we determine which of two theories is a more accurate descrition if they only differed in their implications for the non-observable. — Echarmion

Good question (and excuse me for not quoting the rest - I believe the following will suffice to address the substance of your post). So to recap, what's at stake are our epistemic criteria for selecting among alternative beliefs - in this case, scientific theories. What are the virtues of a theory? Well, being testable is paramount. But what does that mean exactly? If a theory has any generality to speak of (we are not talking about the theory of how much change I have in my pocket right now), then chances are that as a practical matter, we can't test all of its predictions because there are too many of them and many (indeed, most) are impractical or even physically impossible to test. So, although we say that theories should be testable, we get by with testing only a manageable sample of their predictions and generalizing from that.

And how do we distinguish between theories that fit the evidence equally well? We consider other theoretical virtues: simplicity, cohesion with other theories, fecundity.

Now to take an example, forget speculative cosmology (I brought that up just for fun) and consider something much more intuitive and uncontroversial. It was long thought that space was infinite; indeed, only since advances in mathematics and Einstein's General Relativity did it become even theoretically conceivable that space might not be infinite in extent. In earlier times people worried about possible problems, such as gravitational collapse (Newton) or Olber's paradox, but in the 20th century these issues have received satisfactory resolutions. So far an infinite space remains the simplest model consistent with astronomical observations. So we are on pretty safe ground here.

If space is infinite, then how much stuff does it contain? Well, we can only observe a finite volume, but from what we can see, even this finite neighborhood looks to be pretty uniform beyond a certain scale. We could still posit that beyond the limits of observation stars and dust and all other matter end and the rest is just empty space, with out cosmic bubble being like an island in an infinite ocean. But a simpler theory says that the rest of the universe looks pretty much the same as what we see around us. Another way to put this can be expressed as the so-called Copernican principle: we have no reason to assume that the spot from which we look out at the universe is special, and so we should not so assume.

So to conclude: we can only practically observe a finite amount of things, but other theoretical considerations lead us to believe that there's a lot more stuff out there - indeed, perhaps an infinite amount. Direct observation is not the only criterion by which we determine what exists.

I am not sure what is unclear about my position, but anyways "in principle" means based on the attributes of the theoretical object. A ship beyond the horizon is still a ship, which means it should for example reflect light. It is observable, even if you cannot practically observe it currently. — Echarmion

OK, let's go with ships then. According to some speculative calculations in quantum cosmology (cf. Many Worlds in One by Garriga and Vilenkin) not only is the universe infinite, but it is infinitely repetitious: you might say that quantum reality is not diverse enough to come up with an infinite variety of objects, and so when it gets big enough, sooner or later it begins to repeat itself. The consequence of this is that an infinite universe contains within itself an infinite number of Earths just like ours. Of course, such twin Earths are so rare that statistically, we would expect them to be too far apart to ever make contact. There almost certainly isn't another Earth in our Hubble sphere. But we are talking in principle, right? As you say, these Earths (and any ships sailing their seas) reflect light and so are in principle observable.

So there you go, an infinity of physical objects can (in principle) exist, even by your own criteria of existence.

I do not put these constraints "on the world". Observable reality can only consist of that which is observable. I am not talking about the nature of objective reality here. — Echarmion

That "observable reality can only consist of that which is observable" is a truism, but remember, the question is not what is observable, the question is what beliefs about the world are warranted. I agree that our knowledge of the physical world comes primarily from observation. This necessarily constrains what warranted beliefs we can have about the world. But those constraints alone don't uniquely define an epistemology. Specifically, this broad empirical principle is not equivalent to the dictum that one can only have warranted beliefs about that which one has seen with one's own eyes. Nor is it even equivalent to your vaguer observable-in-principle criterion.

We routinely form beliefs about things that cannot be verified by direct observation - for example, things that have occurred in the past. Neither does the scientific method require that every single implication of a scientific theory be verifiable through observation. And this is why science doesn't really have a problem with an infinity of physical things.

Define "in principle." If you were living on an island with no seafaring vessel, anything beyond the horizon would be unobservable in principle for you. Would you then be obliged to believe that the world ends just at the horizon? If we expand the possibilities implied by "in principle" to anything that is not strictly forbidden by relativistic physics, our horizon would expand to the size of the Hubble sphere centered around Earth. Does the world therefore end there?

Any way you look at it, it seems that your epistemology puts a priori constraints on the world, in that it can only be such as to be "in principle" observable. It seems strange to make such egocentric demands of the world, which doesn't seem to care about you one wit.

The things that we have actually observed, in the loosest sense of the word, are a tiny (if not infinitesimal!) fraction of the things that we believe to exist. That goes equally for physical sciences and for everyday observations and beliefs. So are we all wrong in your opinion? Are you some kind of arch-empiricist who will not acknowledge anything that he has not observed?

One can read your problem statement as "What is the probability of a 65 year old male of Czech ancestry winning the lottery?" Given that there is at least one 65 year old male of Czech ancestry in the pool of participants (you), and that the chances of each participant are the same (by assumption), the probability in question is at least as high as the probability of any single participant winning the lottery. If there happen to be two 65 year old males of Czech ancestry playing the lottery, the probability of a 65 year old males of Czech ancestry is twice as high as the probability of any single participant winning.

BTW, congratulations! How much did you win? :)

I think you are mixing two unrelated issues. Time travel is not the same as reversing the arrow of time: as you correctly point out, fundamental physics is time-reversible, so from that point of view all that's needed to go backwards in time is just a sign change in the equations. But empirically such reversal would be indistinguishable from the "normal" chronology: you wouldn't suddenly be able to remember the future. - unlike the case of the "real" time travel.

Perhaps the no-deal-Brexit is something equivalent to the Y2K scare? Not something to get hysterical about. — ssu

These myopic references to the "Y2K scare" are a pet peeve of mine. If people didn't get hysterical about it and didn't spend hundreds of billions of dollars and untold hours working overtime on fixing the problem, the story would have had a different ending. But since the threat was successfully averted, a lot of people somehow came to the conclusion that it was nothing to worry about. And now it's a cautionary story about how when experts tell you about an imminent threat, you can just tell them to go where the sun don't shine.

Adding another controversial issue into the mix is not going to help your cause.

So, if I was going to convince an evolutionary sceptic, I would start by convincing her that evolution is just a word we use to describe part of a deterministic process which began at the big bang, and resulted in the biodiversity we see around us. — Evola

Pedagogically, that's just about the worst approach I can think of for convincing an evolution skeptic (within the bounds of civility). Not to mention that this is an extremely controversial - I would even say fringe - thesis.

Perhaps we shouldn't derail the thread. Would you like to start a new topic and elaborate your thesis a bit?

Darwin wrote about these metaphysical commitments in the last chapter of his most important book. I think he understood his own theory quite well. — Evola

That may be so, but Darwin's metaphysical commitments are of interest to Darwin's biographers; they matter little to modern biology and its philosophical interpretations.

Relativity is a theory of the arena, and thus underlies all scientific theories. It requires all other theories to be expressible as tensor-valued fields in spacetime, and puts some constraints on the motion of those fields. There is nothing stochastic or random in this picture. — Evola

Your picture of intertheoretic relationship is false as a statement about actually existing scientific theories, and it is untenable as a normative statement.

An opinion about gravity is that it does not exist as a force, but rather it is the effect of objects travelling along space-time geodesics. In this picture, the universe is an ontologically deterministic 4D structure, in which all world-lines are instantiated in their entirety. I'd go so far as to suggest that this opinion on gravity, is the prevailing opinion.

An opinion on evolution is that it requires ontological indeterminism. This was the opinion of Darwin and it seems to be the opinion of most biologists. — Evola

General Relativity is a deterministic theory (with some caveats), and GR is our best account of gravity. But GR is not a theory of everything - it is only a theory of spacetime and gravity at large scales. We don't have to be committed to ontological determinism writ large just because of GR.

Darwinian evolution deals with random variation in populations. That is statistical indeterminism - it also does not force upon us any metaphysical commitments.

If you were a little confused about evolution and couldn't 100% tell if you agreed on it or not, would you want a quick and easy guide to access it? — ep3265

I would google something like this or this or this. Many resources for beginners there, from one-pagers to short courses. On the other hand, I would be wary of a non-expert trying to educate me, especially one who comes across as evangelical (that doesn't necessarily describe you).

But let me backtrack a little from what I said earlier. Writing about a subject is a good way to learn it, to organize and internalize what you've learned. So if nothing else, this will be a good experience for you. If it also helps someone else - that's an added bonus.

However, I am troubled by your thinking about your potential readers as stupid and simple-minded. To be sure, there are stupid and simple-minded people among those who are skeptical about evolution, but here I have these concerns. One is that your direct approach of presenting facts and logical arguments (my arguments are airtight, surely they'll see the reason!) isn't going to work well with stupid and simple-minded people. You will require better-suited pedagogy. Another concern is that a patronizing attitude may push people away. Finally, I am wondering about your motivation in the whole endeavor. What do you need with these people? Why is it important for you that they accept the truth of evolution (of all things)?

There are tons of resources available, from short and entertaining to rigorous and comprehensive. The Internet, the book and multimedia market, the educational institutions are saturated with excellent information about evolution. Finding information is easy - but you have to want to find it in the first place. Your mind has to be open and ready for change.

But when you meet a skeptic and start shoving your facts and arguments in their face, all you ever do is entrench them even further in their skepticism. Even someone who started out pretty indifferent to the issue will come away with a much stronger opinion - and not in your favor.

This phenomenon is by now well-known in psychology, but I didn't even need psychologists to tell me about it, because believe me, I've observed it first-hand more times than I care to recount.

You must be pretty new to the Internet, or more generally, to interactions with people, if you think that you can "explain evolution to a skeptic." No "skeptic" of evolution (climate science, physics, medicine, etc.) has ever changed their opinion as a result of being confronted with relevant facts and arguments.

He's been banned several times on this forum and the old one. IIRC his previous incarnation here was "tom". I thought then that he'd reached the limits of his imagination in coming up with new sock-puppet names.

That's a dodecalemma ;)

Anyway, what use is my knowledge to me if I have died?

A "physical property" is, first of all, a theoretical concept. Different theories posit or imply different physical properties. So in one sense, one can quite easily imagine a physical property that did not exist before: just assume a historical stance and consider, for instance, that temperature was not a "thing" before it was made part of 19th century thermodynamics, and even then different theories defined and operationalized in different, sometimes contradictory ways. Other theories do not even include temperature in their ontology of properties. Future theories, such as theories of quantum gravity or perhaps new theories in climate or materials sciences, may introduce heretofore unknown physical properties.

Flip this property/theory relationship, and you can readily imagine physical properties that do not exist even in principle. One end of a scientific theory is an abstract construct - the other end is supposed to be anchored in reality. Lift that anchor and use your imagination freely to construct a theory that does not seek to model anything in reality. Chances are, this theory will have nonexistent physical properties built into it.

This morning I decided to drink a cup of tea with my breakfast, it was departing from my habit of drinking coffee. It seems to me that I arrived at this momentous decision freely being under no duress whatsoever to do so, I even had a rationale for that decision having read somewhere about the health benefits of drinking tea. However, that is not the way a determinist would look at my decision — Jacob-B

Why?

I am not asserting determinism, but just want to point out that nothing that you said is in any tension with determinism.

You say that the concept of motion is available to eternalists, but it seems logically incoherent to me. You claim that motion or change can(?) happen in the past or in the future, but it fails to explain when anything actually happens in the block universe. — Luke

I don't understand your question. Again, motion is change (specifically, of position, or more generally, of any property) over time. How is this a problem for eternalism? There are timelines, and there are properties that change along those timelines. What, specifically, is incoherent in this picture?

Future events already exist, so have they already happened? — Luke

You are just needlessly confusing yourself with this existence business. Like I said, I don't see much use for it, but if you insist on talking about it, just think logically. Every event in a block universe has a spacial and a temporal coordinate: (x, t). So if you ask when an event exists, the only sensible answer is the obvious one: it exists at t. Just as if you ask where it exists, the answer would be x.

You seem to be saying that motion is separate from temporal passage, but isn't the present moment when motion occurs and events happen? — Luke

We directly perceive motion with our senses in our subjective present (obviously), but we conceptualize motion as change over time, which can happen in the past or in the future, here or there, perceived or unnoticed. This concept of motion is available to both presentists and eternalists, but presentists will additionally qualify it with an objective temporal modality.

If I threw a ball in the air yesterday, and that event eternally exists according to eternalism, then is that ball still in motion (now) according to eternalism? — Luke

Yeah, this is where I definitely part company with both parties. Not that I think that either of them is wrong - I just think that this talk of existence is both confusing and pointless. I'll leave it to advocates to untangle this mess.

I still don't understand. If presentism posits a passage of time while eternalism does not, then how is motion possible according to eternalism? — Luke

When presentists posit a passage of time, what they mean (or at least what some of them mean) is that the present time is an objective fact. Time flows by way of the present time constantly progressing forward - and that too is an objective fact of the world. This present time, which is like a moving index on every timeline, is not implied or required by any physical law. As far as physics is concerned, positing such an index is unjustified. And that is what moves (at least some) eternalists to deny the objective existence of such an index.

Why is it referred to as a static block universe? — Luke

I think that the use of the epithet static in relation to the block universe is pointless and misleading. At best, it indicates that the block as a whole does not change - which is just a way of saying that there isn't a second time dimension, along which the block could be changing. But since no additional time dimensions were ever on the table in the presentist/eternalist debate, it is unclear why this needs to be brought up at all.

The existence of the one and only time dimension is acknowledged by both presentists and eternalists - with all that that implies: where there is time, there is motion.

We all have our metaphysical preferences when it comes to time (eternalism, presentism, possibilism). What we should not be doing is claiming that our preferences have been verified by the only possible interpretation of physics (either general relativity or quantum mechanics). — prothero

Presentism is commonly thought to be incompatible with the relativity of simultaneity - a fundamental implication of Special Relativity. It does not depend on any particular solution or interpretation; it is not in conflict with quantum mechanics (quantum mechanics has been formulated in SR); and it is very well established experimentally.

However, whether presentism is indeed ruled out by relativity depends on exactly what claims are made in the name of presentism. Lots of arguments have been put forward for and against compatibility - go and look for them, if you are interested. (But who am I kidding...)

Why does the article say that the flow of time, or passage through space-time, "must presumably be a mental construct or other illusion"? — Luke

Because it is talking about "the flow of time, or passage through space-time," rather than motion. There is no difference in dynamics between eternalism and presentism. In fact, there is no physical difference, period. The difference is entirely metaphysical and has to do with metaphysical notions, such as the objective present, the passage of time, the existence of past and future, etc.

It may help to know that it was shown in the early 20th century that any set theory that allows there to be a 'set of all sets' is inconsistent. So if your 'domains' are like sets, your theorem will probably be doomed to the same fate (that's one reason why it's crucial to define "domain"). — andrewk

Yes, this is why the ZFC set theory - which since its introduction as a replacement for the naive set theory in the early 20th century has become a standard axiomatization of sets - includes the Axiom of Regularity, which implies that no set is an element of itself.

Well, they 'rewind' along with the rest of 'history', which isn't even a violation of physics. Only what you (the 'traveler') are doing is a violation. — noAxioms

What do you mean "they rewind"? The idea of time travel is that someone (or something) is moving in time (at a different than normal rate), while everyone and everything else goes on as if nothing happened. But how this divergence is possible if there is only one now is something I can't wrap my head around. It would make sense if now diverged as well.

What I've said is that, according to my view of presentism, no other times but the present time exist, and time travel can only be viewed from an eternalist or B theory perspective of time. — Luke

No times but the present exist, and wherever the present is, that is what exists. Yesterday the present was thataway, and now the present is thisaway. Nothing about presentism says that the present has to stay in one place.

I know about industry sponsorships and grants, but those are mostly relevant to graduate and faculty research projects. The college gets a cut, but most of the money goes towards paying grad students/post-docs and for research expenses like equipment and travel. Bottom line is that much of research in engineering, CS, some social and human science and some fundamental science pays for itself; not so much in pure math and humanities, I guess. But undergraduate programs are payed by tuitions, endowments, investments, etc. (That joke must have been made up by an undergrad.)