Taking the broader point, I agree that the existence of things that cannot even be indirectly observed is possible. I'm less convinced that it's meaningful to talk about them. Which I guess is what I was saying earlier: what is the explanatory power of the spotlight? If we accept that a) it is a privileged frame, not shared by all of us, and b) makes no difference to observable phenomena, it can't explain, say, the psychological passage of time, which is subjective, i.e. relative. — Kenosha Kid

Yes, the choice of a privileged frame in the sense that is required here cannot be dictated by any physical observations. Although, digressing a bit, there are other considerations that can lead us to single out a "preferred" frame. The division between laws and that which the laws leave out - boundary conditions and such - is conventional to a degree. While relativistic laws are reference frame invariant (up to coordinate transformation), the same cannot be said about those things that the laws do not fix, such as the distribution of matter and radiation in the universe. If we take those other things into account, we can identify reference frames that are special in some way, such as the frame in which the cosmic microwave background radiation has the same energy profile in all directions.

None of which is relevant to the hypothetical frame of absolute simultaneity that would be required for presentism though; there is no particular reason, other than perhaps considerations of symmetry, to identify this frame with the isotropy of the CMB or any other observable feature of the universe. All the same,the need for a privileged frame is not fatal to presentism, although as you point out, no observation can help us identify this frame. Physics doesn't rule out this requirement, but if one is of a positivist disposition, one should find this situation disturbing.

An "absolute now" is not a concept that makes sense to me though. "Now" now is not "now" exactly a year ago: it is not absolute. But a privileged moment (e.g. 13.7 billion years ago) wrt which "now" can be referred and seen to change would be absolute and sensible, even if it has no obvious descriptive power. — Kenosha Kid

Right, there is no fact that you can add to the objective scientific description of the universe that could establish an absolute present. You could say "Now is X seconds from the Big Bang in the comoving frame" or something like that, but that could only be right in the same way in which a stopped clock can be right. So how do you establish a constantly moving now without a reference? You would need a second time axis. And then a third time axis to perform the same function for the second. And then a fourth, fifth, etc.

My point was that there is no concept of absolute simultaneity. There is no "now" that you and I share, unless we're co-moving. — Kenosha Kid

According to the principle of relativity, laws of physics don't privilege any reference frame. But that doesn't mean that a reference frame cannot be privileged in some other sense - like in the sense of indicating the absolute now. The absolute now would not be part of the known laws of physics if it existed; it would come as an extra fact about the world. But that's old news - it was as true for Galileo and Newton as it is for Einstein.

Science and common sense have pretty much always operated under the assumption that the laws of nature are time translation invariant, and that assumption has borne out well in practice. But the laws of nature (assuming that they exist) do not fix everything about the universe, and they certainly do not rule out additional facts that are not time translation invariant - otherwise the universe would have been static in every sense.

If A has causal efficacy, why can’t something from level A affect something from level B? — Olivier5

You tell me.

It is to criticize the traditional materialist conceptual toolbox — Olivier5

Reductionism is not peculiar to materialism, and neither does materialism entail reductionism. Idealism is reductionist with respect to the physical. On the other hand, there are non-reductionists among materialists/physicalists.

↪Luke
I'm done with the thread, I said what I have to say. — ChatteringMonkey

But at this point i'm starting to repeat myself again. — ChatteringMonkey

You could say that again... and again... ;)


What's ironic about the argument that there is no motion in eternalism is that Zeno's famous arrow thought experiment argues exactly the opposite (and just as badly):

"Everything, when it is behaving in a uniform manner, is continually either moving or at rest, but what is moving is always in the now, hence the moving arrow is motionless."

Nothing can change in an instant of time. Zeno, who apparently embraces presentism, says that since only the now exists, change cannot happen.

The fundamental error of reductionism is to believe that that 'small things' (e.g. atoms) always and totally determine big things (e.g. human beings), in a one-way street. But since "to all action a reaction", it stands to reason that, IF the small can have an effect on the big, then the big can have an effect on the small... — Olivier5

Completely wrong. The weakest possible reductive relationship is that of supervenience: "No A changes without B changes." So if A is reducible to B, then anything that happens at the A level must have an effect at the B level.

So the idea that mind is an epiphenomenon contradicts the laws of physics. — Olivier5

Again, epiphenomenalism is not the same as reductionism. You can maintain that A is in some sense reducible to B without denying the reality and causal efficacy of A.

Epiphenomenalism has always puzzled me by its outsize place in the philosophy of mind. Seen in a larger context, one could use the same causal exclusion premise to construct any number of parallel arguments to the effect that special sciences are causally inert. For example, chemistry must be causally inert if it doesn't play any causal roles over and above underlying physics. So it would seem that epiphenomenalism with respect to the mental is a minor special case of a much larger question of intertheory relations.

Observations? It's intended to be more of a synthesizing exercise, bringing some concepts and points of view together, in the context of my own understanding. Several people appear comfortable with the way reductionism is being characterized, it's neither complicated nor a far reach. — Pantagruel

Yes, some people are comfortable with such breathy, substance-free rhetoric that amounts to little more than "Boo reductionism!" ("Boo materialism!" "Boo scientism!) There are any number of critical discussions to be had about reductionism (cf. the SEP article that you just googled), but unfortunately, this is not one of them.

Isn't it a bit more than this? That the special sciences are in principle replaceable by a single fundamental science, usually physics. That means causation is bottom up, and there's no strong emergence of any entirely novel properties. — Marchesk

There isn't a generally accepted meaning of reductionism, but yes, there is a widely shared view that presents the program of scientific unification as a kind of pyramid with the most fundamental science - usually taken to be physics - at the bottom, underlying all other sciences. However, the exact nature of this underlying is a contested matter. It can be cached out as a loose supervenience, or as Nagelian bridge laws, or something in between.

The line between a reductionist approach and a non-reductionist approach is pretty clear, and I don't want to get bogged down in versioning. — Pantagruel

So clear that you still haven't managed to identify it. Reductionism isn't even an ontological thesis, and yet the actual target of your vague vituperations seems to be some cartoonish eliminativism.

You don't really say what you mean by reductionism, nor is it clear who the target of your vague criticism might be. Like materialism and scientism, reductionism is one of those labels that everyone likes to rail against, but the targets of such criticism are rarely clearly defined and identified.

Reductionism in science is the idea of unity of science: that different special sciences present different aspects of the same fundamental order of nature. If you believe that such an order is at least plausible, then you should not find the idea of reductionism objectionable.

What on earth are you talking about? Is this something to do with American football? Why is this in General Philosophy? If you just want to post some random rant, there's the Shoutbox in The Lounge.

Free will is to do so undirected by controlling influences. — Lida Rose

That's a preposterous definition of free will.

This is exactly what I was refuting in the quoted bit. I suspect maybe the word “phase” is leading you to this conclusion, because a phase implies a temporal process, which is why I also named the synonymous term “configuration space” which has no such connotations. — Pfhorrest

I know what a phase space is. A phase space describes relationships between free variables in a particular theory. A different theory will give rise to a different phase space with a different basis, depending on its ontology.

Point being, you already know what time is, since you are a competent user of English. And indeed, the questions you ask are about time, hence presuposing that knowledge. — Banno

It is fine to ask for an explanation of something that you already know and have a word for; we do that all the time, whether in physics or in philosophy. But when asked out of context "What is X?" you should reply back: "Why do you ask?" What sort of an answer are you looking for? A reductive definition? In terms of what? A contextual explanation? In what context?

I offer two similar definitions given by Charles Sanders Peirce.

Time is that diversity of existence whereby that which is existentially a subject is enabled to receive contrary determinations in existence. — Peirce, c. 1896


Time is a certain general respect relative to different determinations of which states of things otherwise impossible may be realized. Namely, if P and Q are two logically possible states of things, (abstraction being made of time) but are logically incompossible, they may be realized in respect to different determinations of time. — Peirce, c. 1905 — aletheist

These definitions will fit any parameter in a parametric description: position in space, population density, Mach number, household income, etc.

A phase space, or configuration space, doesn't have to imply anything about time being presumed simply to conceive of that space. It's just a spatial representation of all the different possible states that a system could be in. — Pfhorrest

But before you can conceive of a phase space, you have to conceive of a theory that gives rise to that phase space. The phase space is just a slice of the theory; you need to lay out the theory first. And as you do, time will already be there, even if you haven't specifically identified it as such. So first you build the stage and place the backdrop and the decorations, and gather actors and give them their parts, and set the play in motion. And then you can point to one of the actors and say: that is time. The play will not make sense without this central character, but neither will the character make sense outside the context of the play. The character of time emerges from the narrative of a physical theory, which in turn needs this character for its coherence. There is a mutual dependence here that makes straightforward reduction ("A is nothing other than B") impossible.

It's the same with time and clocks (@A Seagull): you can't conceive of a clock without already operating with a notion of time, but neither can you conceive of time without representing it using a clock, a physical process of a certain kind. The two notions are mutually dependent but not reducible to each other.

You (@Pfhorrest) make time specifically a thermodynamic actor, but of course time is present in other physical theories as well. It is just that continuum and statistical thermodynamics happen to be the only theories that we have in which time has a preferred direction. At thermodynamic equilibrium time disappears in the description of the macrostate, but it will still have a part to play at other scales and in other theoretical frameworks. It just won't have an overall preferred direction. ("Join the club!" says space. Space also has preferred directions, but only at some scales in some theoretical frameworks, e.g. in Earth-bound sciences.)

Time is what a clock measures. — A Seagull

Great. Now define clock and measurement without referring to time.

The dimension across which that gradient occurs is a dimension of the phase-space. The gradient gives directionality to a span across that phase-space. Without that directionality, a span of the phase-space wouldn't be recognizable as time, so the existence of that gradient in the phase-space is what constitutes the existence of time as we mean it. — Pfhorrest

Let's not put the cart before the horse. "Span across phase-space..." - which phase space? The phase space of classical thermodynamics, apparently. You need to start with the framework of thermodynamics, which, as the name suggests, involves time. That is the important bit. That the positive direction of the time is conventionally chosen as the direction in which entropy increases is almost an afterthought. The essence of this definition is that time is implicitly defined by classical thermodynamics. Which is OK as far as it goes, but we need not define time so narrowly and specifically; we can generalize this definition by stating that time is implicitly defined by dynamical laws of nature.

By "entropic anisometry" I assume you mean entropy gradient in the forward time direction, aka the 2nd law of thermodynamics? You realize that's circular, right? You can reduce the direction of time to entropy gradient (maybe), but you need to have time before you can talk about its direction. The 2nd law already assumes it.

oh but it is about the language, if children were taught from the beginning of their lives that humans are humans and not that there are sub-categories of humans like "black" "white" etc then they would not have a conceptual framework in their brain structures that would allow them to prefer one sub-category over the other
racism would be gone in a matter of a generation or maybe 2 depending on the extent of rate of adoption of this amongst parents — dazed

You are overthinking it. We should just raise everyone in the world as non-racist. There, problem solved.

This may sound like a joke, but that's because your proposal is a joke. Even if such a language change could accomplish anything (of course not), how the hell is this supposed to work? If you have no idea and are just daydreaming, then why set your sights so low? Why not daydream about everyone living happily ever after? If that could be achieved, then we wouldn't have to worry about such petty concerns as racism.

(Of course, daydreaming about reforming language in order to cure racism is only marginally more asinine than daydreaming about a world social revolution as a cure for all ills.)

I suspect the hypothesis is bullshit. — Benkei

These are ivory tower bullshit — StreetlightX

You are taking ernestm way too seriously if you think that his take on the Sapir/Whorf hypothesis has much to do with "ivory tower" anything.

If I pick A + B then there's a 99% chance that I win $1,000 and a 1% chance that I win $1,001,000. — Michael

At the time when you are making your decision the money either already is or is not in the box. Your decision cannot change this fact (unless you entertain some strange ideas of backward causality). So if the money is in the box, then the choice is between $1,001,000 and $1,000,000. If the money is not in the box, then the choice is between $1,000 and nothing. Either way, you get more by two-boxing.

Of course, if everyone reasoned that way, then the predictor would have had a lousy track record, contrary to the stated assumption.

I don't understand how it's a paradox. — Michael

Yeah, that's how most people react to it. The paradox is that half of those people who think that the answer is obvious do not agree with the other half :)

Vacuum energy has to be positive, according to the quantum field theory, and its presence is supposed to explain the experimentally observed Casimir effect. However, it may be counterbalanced by the negative potential energy of gravity.

I never like these predictor-type puzzles. If you have a predictor you can ask it to predict if its next statement will be a lie. If it says yes then then it told the truth, making the statement a lie. You get a contradiction.

Therefore there is no such predictor. The very concept of a predictor is contradictory, hence anything follows. All such puzzles are vacuous. I get that they're popular, but I don't see the appeal. — fishfry

The predictor may be limited to predicting that one thing and nothing else, so you can't defeat it that way. Also, the predictor doesn't have to be infallible, it only needs to be better than chance. Let's say the predictor is known to be right 55% of the time - not all that implausible. With a large enough leverage, the statistical argument still says that you should one-box, while the causal argument says that you should two-box.

But I take your larger point that in general, with such puzzles one should not automatically assume that the described scenario is possible, even if it sounds pretty coherent.

The expansion of space deals with the problem of waste heat, but I couldn't find anything about generating new energy. — Echarmion

If the energy of space itself (vacuum energy) is positive, then expansion produces more energy, in the sense that a volume that expands with the universe (comoving volume) will encompass more and more space, and thus possess more and more energy over time.

Yeah, I don't know. Simple metrics like these don't say all that much. Here's an example: consider a finite volume of gas within a larger volume of the same gas. Let's say the gas is not at thermodynamic equilibrium, so that its entropy is less than the maximum entropy. Now expand the boundary of the smaller volume. Both the current entropy and the maximum entropy inside the boundary will have grown proportionally. Naturally, this purely formal move has not produced any new dynamics. Don't take me wrong, I am not saying that this example reflects the situation in an expanding universe - I am just saying that gross numbers for entropy and energy (calculated how?) aren't enough to conclude anything.

Anyway, here is a classic review paper; it is better than two decades old, but AFAIK it is mostly up to date with what we know in its outlines: A dying universe: the long-term fate and evolution of astrophysical objects (FC Adams, G Laughlin - Reviews of Modern Physics, 1997). It goes into various possibilities for the long-term evolution of the universe, from something like the classical heat death to spontaneous tunneling into a true vacuum state that can annihilate and radically transform the universe in an instant. Scenarios of continuous, indefinite entropy production are also considered. However, such scenarios don't imply the continued existence of the world as we know it; the future in that case may hold nothing more life-affirming than a continual production and evaporation of black holes or clumps of cold dark matter.

Not a cosmology expert by any means, but as far as I know, expansion of the universe is every bit part of the heat death scenario (how could it not be?) Whether energy is being created in the course of the expansion depends on how you do the calculation (there isn't a unique procedure for this in GR). But energy is not everything; for interesting stuff to happen you need entropy gradient.

Presumably, that depends mainly on your interpretation of the equations, i.e. on metaphysical speculation. If it's many worlds, maybe you are an infinite number of persons at once. — Echarmion

Not infinite, the number of superposition states in a finite system would be finite. And assuming that we are in a superposition state at any time (or at all times, as per Everett), then there had better be a coherent account of how it is that we feel as if we were always in a pure state, i.e. all the classical observables always seem to have definite values. A number of such accounts, more or less detailed, have been proposed using somewhat different assumptions regarding conscious observers and with different interpretations of QM.

Note that one does not necessarily need to have a fully worked out theory of consciousness to answer these questions, nor is there necessarily a need for any mysticism. Some explanations posit nothing more than a system with memory, like a photographic plate for instance, one that can keep a record of measured eigenvalues.

The OP question is not as stupid as it sounds. I would reformulate it as "What does it feel like to be in a quantum superposition state?" There is some discussion of this and related questions in the literature on the foundations of quantum mechanics.

On this forum I have come across quotations from classic works that are sourced from that site; unless there is reason to doubt their reliability, I see no problem with that.

Use the one in this thread: https://thephilosophyforum.com/discussion/5738/ignore-list-browser-extension/p1

After watching Nuri Bilge Ceylan's Climates this melancholy little piece is stuck in my head!

Having gone through a journey of discovery, I find I have firmly landed as a hard determinist. But I am having a heck of a time finding any writing that addressed how we should live our mental lives as a hard determinist. I have a lot of ideas on the topic but was hoping not to have to try to reinvent the wheel. My moderate search over the last few months has only turned up a few paragraphs that directly address this problem. I'm hoping to find a writing on how to view justice, personal motivation, and the like, for a hard determinist. Anybody know of such a how-to writing?? — Brook Norton

Compatibilism and related approaches (e.g. some strains of libertarianism) deal with these questions as axiological issues that are largely decoupled from physics. I know that you said that you reject compatibilism, but that is owing to your peculiar definition of free will that reduces it to physics. We do not need to get sidetracked by terminological disputes. If you want answers to the questions that you ask in the OP, then don't change the subject - think about those questions. What do they have to do with physics? On the face of it - nothing. You jump from one to the other too hastily; I don't think you quite thought it through.

If "free will" means you can weigh the pros and cons and then decide how to act, then I'm a compatibilist. But if "free will" means you could have done otherwise, then I'm a hard determinist. I think the later definition is the more meaningful as I believe it is what most people intuit when they speak casually of free will. — Brook Norton

It's not as simple as that. Experimental philosophers and social psychologists have done quite a bit of research over the last couple of decades to try to find out what it is that folk actually believe about free will. It's a mixed bag: neither consistently compatibilist, nor consistently incompatibilist, but some of both.

That's a nice piece.

The Sapir-Whorf hypothesis basically says that people will only call something as they know it to be called. — Anthony Kennedy

That's not Sapir-Whorf hypothesis, that's an obvious fact.

Depending on where people come from, there are many practices that are practiced there, but not allowed elsewhere. But should they be? Say it were illegal in place A to eat a strawberry before they have done their chores. In place B, strawberries can be eaten at any time. Say that person B from place B visits place A and eats a strawberry. Should person B be held to the same law as person A even though they both have a different idea as what is right? — Anthony Kennedy

Your example is too ambiguous. You need to decide whether you want to talk about legal practice, or moral relativism, or multiculturalism - all different questions with different answers.

Is Euclid's line the same thing as the set of real numbers? We take as an unspoken axiom that it is; but if we remember that this is just an assumption, we can resolve our confusion over where the extra points go. — fishfry

@aletheist will be along shortly, I am sure, invoking the ghost of Charles Sanders Peirce and insisting that Euclid's line is not a collection of points at all. He would have a point, at least to the extent that it isn't a given that a line is identical with a particular collection of points.

This is really funny. I’m listening to the birds, the sounds of nature. Who does that? — Becky

There was a blackbird who used to sing right outside my window some time ago (I spotted him a few times). That was very cool. Birds are quieter now, but still present.

Speaking of which, I've recently been listening to all things avian in Messiaen, who loved birds.

Well, "the number line" in its usual sense is just a visual metaphor for the real numbers (it will do for the rationals as well, though see above about "holes"). So in that sense, no, the number line is not missing anything. You have to work harder to motivate things like infinitesimals and hyperreals. And then you have to work even harder just to reproduce all the things that we can already do with real numbers, like addition and multiplication.

One way to make it kosher is to consider it a generalized function. I never worked with those either.

https://en.wikipedia.org/wiki/Generalized_function — jgill

Sure, I shouldn't be surprised that these nasties have long since been tamed, just like infinitesimals and infinities were earlier.

The inept and corrupt populists do what they typically do in such situations: pander to their base.