One photon is sufficient to cause a detectable signal and response, but without photons you'd see nothing. — jkop

Only if you are a frog. Humans require several photons to stimulate a rod/cone. Have seen estimates from 3 to 7. But anyway, one is not enough.

Thermodynamics is not symmetrical.
Surely you don't intend to suggest that the above listed theories can simply ignore thermodynamics? — m-theory

And that is one of the reasons thermodynamics is *not* regarded as a fundamental theory. The fundamental theories *are* time reversible - both the classical and quantum versions - but the set of approximations - coarse-graining, scale-dependence, etc - renders the "macroscopic" theory of thermodynamics incapable of predicting the past. There are several well known paradoxes and problems relating to this issue.

There is no axiom of free will in qm. — m-theory

This is nonsense. All of science implicitly assumes the free will of the experimenter. In QM this is made explicit in Bell's Theorem and various similar theorems. Otherwise we are super-determined https://en.wikipedia.org/wiki/Superdeterminism

Please provide the laws of physics that are non-determinisic.

Well not all laws of physics are deterministic. — m-theory

Which laws of physics are not deterministic?

Determinism is often an interpretation more so than a necessary conclusion.
This is especially true of the foundations of quantum theory, which are by definition probabilistic. — m-theory

Both General Relativity and the Standard Model are time-symmetric theories.

At a less prosaic level, the removal of the free will axiom from QM renders all physical theories deterministic.

How do you get from "what happens is a sensitive function of initial conditions" to "choice cannot exist"? What if the compatabilist defines "choice" in such a way that it, too, is a sensitive function of initial conditions? Then making choices can (and maybe does) occur even if determinism is the case. — Michael

I agree that compatibilists define "choice" in a manner that is determined by conditions that obtain at distant times. For example, I choose tea now, rather than coffee, because the big-bang determined that I would. Compatibilists define that as my choice despite it being pre-determined by the big-bang.

Fair enough. I should be judged for my decision to drink tea. I am guilty of drinking tea, and should be punished for it. I forgive you your bigotry, you are incapable of doing otherwise.

Which part of receptor (eye) in combination with signal interpreter (in this case the cerebrum) did I fail to clarify? You would be just as blind if the connection of two perfectly functional eyes to the brain was severed as you would if somebody glued those eyes shut. — Barry Etheridge

Do you think that a robot, programmed with all kinds of image recognition algorithms, sees anything?

And just as I'm talking about this, I see ... — Barry Etheridge

I think people who claim they don't exist should be taken seriously.

You don't see light. You respond to an electrical signal transmitted from a receptor in your eye which obviously isn't light at all. I — Barry Etheridge

Quite! I was hoping for at least an answer to the wave/particle question. Although that is already answered, it would be reassuring to discover what the real experience really tells us.

They would likewise define "choice" in a manner compatible with determinism, and so argue that we do have and make choices. To argue that this isn't what a choice is doesn't make much sense unless "choice" already refers to a real thing, and that the compatabilist's description of this thing is mistaken. But, of course, that would entail that we have and make choices anyway. — Michael

This is what I don't get. Under determinism, what happens is a sensitive function of the initial conditions at the big bang, or if you prefer the conditions at any other time. Choice cannot exist, neither can "testability". Playing word-games to preserve moral responsibility seems utterly futile.

So, "experiences are facts" but they need "interpretation"?

You claim to be able to see light "as it really is". What is it, and how do you do that?

As I see it, the compatibilist position is that a person 'could have done otherwise', based on an epistemological interpretation of that phrase and that, since that's the only interpretation that anybody has been able to suggest so far, that's the maximum sort of free will that anybody could imagine. — andrewk

Are you sure? Compatibilism seems more like "a person is to blame for their choices, even though 'choice' doesn't exist".

"Could have done otherwise" doesn't mean anything under determinism. If "could" refers to anything real, then determinism does not hold at that point - i.e. either the laws of physics are wrong, or our understanding of them. I don't think compatibilists complain too much about physics.

Have you ever come across the phenomenon of an "optical illusion"?

When the scientists experienced superluminal neutrinos recently, was that a fact?

Fallibilism (from Medieval Latin: fallibilis, "liable to err") is the philosophical principle that human beings could be wrong about their beliefs, expectations, or their understanding of the world

I prefer this definition:

"Fallibilism, the recognition that there are no authoritative sources of knowledge, nor any reliable means of justifying knowledge as true or probable."

Fallibilists accept even their best and most fundamental explanations to contain misconceptions in addition to truth, and so are predisposed to try and change them for the better.

Cool. How is that shown? — Mongrel

Consider a finite physical system. Due to the Bekenstein bound, any such system is a finite state machine - i.e. only a finite number of configurations is available to it. Allow the system to evolve under the laws of physics, from T=0 to T-infinity and list all of these physical environments which constitute a denumerable set:

P1, P2, P3, P4 ...

Now, consider a logical environment of this form: L1 is different from P1 at T1, different from P2 at T2 etc. L1 is clearly not in the set of physical environments, and moreover there is an infinite number of ways of constructing L1. Thus the set of logically possible environments is uncountable.

If an electron is a wave, yes. — Mongrel

The electron (and the photon) are particles according to the Standard Model. Anyway, the point is, what will happen is determined by the laws of physics.

As a matter of fact, it can be shown that "physical possibility" is an infinitessimal fraction of "logical possibility", so they are not the same thing.

When a photon travels towards a double-slit, is it logically possible that it goes through both slits?

Neither of you offered a reason to allow some kind of possibility that is distinct from logical possibility. — Mongrel

Do you think there is a relationship between physical possibility and logical possibility? If so, what is it?

Leibniz is dealing in logical possibility. So let's consider whether there really is any other kind of possibility. What argument would you put to Leibniz to convince him that there is? — Mongrel

I would try to convince Leibniz that the notion of "logical possibility that I could have acted otherwise" is physically meaningless. I would convince him that absolute determinism is true, by using his own Principle of Sufficient Reason and telling him about Relativity.

I would then ensure that he was a committed realist and accepted the explanatory nature of science. Through quantum mechanics I would show that you can recover the physical meaning of "logical possibility" and demonstrate the physical mechanism of free will.

This seems lie a balanced view: http://arxiv.org/pdf/1104.4551.pdf

I just assumed you were into the falsifiability criterion, with your talk of Popper turning in his grave. — Hoo

Let me put it this way, according to Popper there is no such thing as an experimental test that can logically falsify a theory.

He makes this point several times in his famous book, The Logic of Scientific Discovery.

Yes, but my view, which I have defended in my discussion with Question, is that the theory of relativity merely is a theory about the metric of spacetime — Pierre-Normand

Well, that is at least a bit of progress!

Consider the Andromeda Paradox https://en.wikipedia.org/wiki/Rietdijk%E2%80%93Putnam_argument

According to relativity, whether an event is in your past or in your future is determined by your motion relative to it.

The thesis is that explanation of X is deduction of X from postulated necessity. Now this postulation is the creative act, the myth or element of rationalism. — Hoo

That is utterly incompatible with the assumption of the Principle of the Uniformity of Nature, and what you were claiming about inducing THEORY from DATA, which is impossible.

I'm going to quibble about your thesis. A scientific theory *is* a conjectured explanation of some aspect of reality - the explicanda of the theory. The explanation takes the form of a statement of what exists in reality, how it behaves, and how it accounts for the explicanda. So yes, the eXplicanda can be deduced from the claim about what exists in reality, but what is this "postulated necessity"?

Theories (postulations of necessity that allow for the generations of implications that can be falsified) are seemingly going to be stronger and more falsifiable as they are projected across time and space. — Hoo

I'm losing track of this, maybe it was another thread, but I have definitely mentioned the Quine-Duhem Thesis several times somewhere. There is no such thing as an experimental test that can logically falsify a theory, if that is what you mean.

This "probability" seems to reduce to economy. — Hoo

You can't use probability calculus with explanations.

"UN" stands for the "Uniformity of Nature". This is a traditional (post-Humean) label for the missing premise, though in fact it is misleading. For UN is not simply the claim that nature exhibits regularities. It is the claim that the regularities that have emerged in my experience are among the regularities that hold throughout nature. — link below

So, you have completely abandoned the idea of explanation. That's a shame.

UN is one of the fundamental misconceptions of inductivism. It is a principle in that no one has ever been able to properly formulate, beyond vague notions such as "the future will resemble the past" or "the seen resembles the unseen". Your suggestion that it might be formulated "the regularities of experience are universal regularities"?

Let's assume that such a principle exists - the PUN, to give it its full acronym, and let's try to use it to infer a scientific theory from some data. Would you like to pick a theory?

Well, that is your own assessment of the situation. While general relativity on its own may suggest (rather than logically entail) something like the block universe view, quantum mechanics rather suggests that the fundamental laws of physics are non-deterministic. There also are no-collapse interpretations of QM, such as the many-world view, that may be construed as deterministic, but that would still make the evolution of individual coherent histories, as experienced by sentient observers such as ourselves, non-deterministic. — Pierre-Normand

General Relativity mandates a stationary space-time block. All general relativists admit this. Those who do not like it, for whatever reason, are engaged in overturning GR.

As I mentioned earlier in the thread (perhaps more than once), non-collapse versions of QM lead to the Wheeler-DeWitt synthesis of GR and QM, which surprisingly has achieved some experimental corroboration. The wavefunction is stationary and timeless, much like spacetime.

No idea what you think Coherent Histories has to do with this?

The article indeed seems to portray the view as being, if not contestable, at least contested. While Andreas Albrecht was defending it, Avshalom Elitzur, Lee Smolin and George Ellis were arguing strongly against it. Jennan Ismael, a philosopher rather than a physicist, was only arguing that our experience of the flow of time is consistent with the block universe view. — Pierre-Normand

The physicists, many of whom are prominent experts, who do not like the block-universe implication of Relativity, are doing the right thing - they are trying to discover new physics. They have to do this because they are experts, and they know relativity implies the block. Best of luck to them because they have met with zero success so far!

Try this http://philsci-archive.pitt.edu/2408/1/Petkov-BlockUniverse.pdf

You are simply refusing to accept an inescapable consequence of our best theories. Nothing in reality has ever been discovered to contradict GR, or the standard model, both of which are time-symmetric theories.

This is why most scientists don't believe in free will, because it doesn't fit with what they know.

OK, but will there be assumed uniformity of nature in 5 minutes? — Hoo

But you claim to be interested in the meaning of "explanation" while promoting the compete absence of one!

How does the "assumed uniformity of nature" constitute an explanation for anything?

And, if you are interested in Popper, relying on such an assumption is a fundamental mistake.

Newton's gravity is incompatible with special relativity: it allows action at a distance and is not Lorentz invariant. Whatever you might want to construct out of "gravity", it can't be a 4D spacetime block with a Lorentzian signature, and no such construction is forced upon you. Under relativity it is unavoidable. So Newton's laws are deterministic, i.e. the future is determined by the past, while according to relativity, the future already exists. Under gravity, time is a universal parameter, under relativity, it is a dimension. If you were to describe relativity as fatalistic I wouldn't argue.

As I mentioned earlier in the tread (perhaps more than once), free will is axiomatic in science and explicitly so in quantum mechanics. If you remove the free will axiom - or the FW loophole as some prefer to call it - then, quantum mechanics is superdeterministic.

Something I didn't mention in the OP was the postulation of unseen entities. That's very important. But I thought I'd focus on the "projection" of necessity. Of course the assumed uniformity of nature figures into this. — Hoo

You've just made Popper turn in his grave, and Deutsch has just banged his head on his desk. There is no assumed uniformity of nature!

I'm trying to think of a single scientific theory that does not involve unseen entities. Maybe you could help? As Deutsch points out, what we see is a spot on a photographic plate, and if you analyse that fully, we don't even *see* that. The explanation however, involves planets, the sun, and spacetime curvature.

It is interesting to note that Boltzmann killed himself in 1906 because the German scientific establishment would not accept the existence of molecules or atoms, because they could not be seen!

Anyway, I cannot find fault with Deutsch's definition of explanation - a statement about what exists in reality, how it behaves and why.

And, I think Deutsch's discovery of his "hard-to-vary" criterion is new.

What do you think of this explanation of "explanation"?

That would make no sense. For example, the first sentence is this, "Einstein once described his friend Michele Besso as 'the best sounding board in Europe' for scientific ideas." That in no way amounts to a claim that block theory is the received view. — Terrapin Station

Do I have to cut and paste the entire article, paragraph by paragraph?

Einstein once described his friend Michele Besso as “the best sounding board in Europe” for scientific ideas. They attended university together in Zurich; later they were colleagues at the patent office in Bern. When Besso died in the spring of 1955, Einstein — knowing that his own time was also running out — wrote a now-famous letter to Besso’s family. “Now he has departed this strange world a little ahead of me,” Einstein wrote of his friend’s passing. “That signifies nothing. For us believing physicists, the distinction between past, present and future is only a stubbornly persistent illusion.”

Which statement(s) in that article to you take to imply that the block theory is the received view? — Terrapin Station

All of it. This is getting tedious by the way.

So you'd say that the block universe theory of time is indeed the received view in the sciences? — Terrapin Station

Knock yourself out: https://www.quantamagazine.org/20160719-time-and-cosmology/

I am not sure what you mean by IDENTICAL. Is there some way in which the phenomenal qualities of colors, sounds, feelings and the private subjective worlds in which they appear are identical to the objective particles and their interactions ? — lorenzo sleakes

When you are defeated by a computer at chess, what has occurred is IDENTICAL with the physical processes that have taken place inside your laptop. Nevertheless, what has *also* happened is that an abstract object - a computer program - has beaten you at an abstract game.

We understand a large class of abstractions well enough to be able to instantiate them on suitable hardware. When we do this, we have two compatible descriptions: the microphysical and the abstract, which need to be in some sense IDENTICAL, though only one is explanatory.

The qualia you mention are just a software feature we don't yet know how to implement.

You're claiming that the "prevailing conception of science" is the block universe theory of time simply because the block universe theory of time is isomorphic with general relativity? — Terrapin Station

Not quite what I wrote, but anyway. I'd be surprised if anyone found anything non-standard, let alone contentious, in anything I wrote. Relativity mandates we take a 4D view of reality, and there is no way of escaping the block. We are space-time worms. We don't have free will.

But of course, you could argue in the other direction and show that because we *do* have free will, general relativity must be at best, an approximation. You are unlikely to convince anyone however, I've certainly not been able to.

Strong causal determinism hasn't been the received view in the sciences for something like 140 years now. — Terrapin Station

General relativity is isomorphic with the statement that Reality is a stationary block spacetime. The Wheeler-DeWitt synthesis of gravity and quantum mechanics is a stationary wavefunction. In the absence of the free will axiom quantum mechanics is superdeterministic.

So, according to the prevailing conception of science, Reality is fully determined. Given the state of reality at any time - initial, final or any time in between - and the laws of physics, it is possible to predict what has occurred, and retrodict what will occur.

We are not only at the state of knowledge where we are able to predict the big-bang, but also the fine details of that event!

Thus most educated people are avowed determinists.

It seems to me that to be self-aware is to be aware of (or to make) a distinction, self/not-self in experience. In which case, to be aware but not self-aware consists of not making that distinction, rather than not having one side or the other as experiences. — unenlightened

And, no one has put forward any argument to explain how, once "awareness" is attained, what exactly restricts its focus. If you are aware of something, then what mechanism prevents you becoming aware of something else?

It seems preposterous to propose that "awareness" - a property that we find it difficult to even describe - contains some detailed internal structure in which certain entities can be switched on or off.

It's worse than that. Reality is a static space-time block.

I'd say more that unless someone has very unusual mental phenomena, a rejection of free will is far more likely to be based on faith, since there's no good evidence that all phenomena in the world are strongly causally deterministic. — Terrapin Station

No idea what could constitute "good evidence", but one assumes that Reality obeys the laws of physics, which are deterministic.

"If the universe is finite, then what's outside it? What does it expand into?"

You might be in a state of delusion, or an artificial construct in a more subtle reality etc. — Punshhh

If by "subtle" you mean "assuming a cognitive ability in your reader", then perhaps.

I'll try to be less subtle:

The density parameter of the universe has been measured. If the parameter = 1, the universe is flat. The result obtained is: Ω = 1.000 +/- 0.004 . The universe is flat.

We also know (via similar measurements) that the universe is homogeneous and isotropic, and expanding at an accelerating rate.

The notion that the universe is not simply connected doesn't seem to attract much attention. I suspect that if it were not, evidence would be found in CMB, and it's a strange idea anyway. The universe is not a Klein bottle or a torus.

Given that we know the universe possesses this geometry, we may now address the question of finiteness.

According to current cosmological theories there cannot be such a [finite] spacetime. If it is flat it must be infinite — andrewk

Now while andrewk's statement is true, it is not logically correct. There is no logic that prevents you from ad-hoc modifying GR to create a finite universe with a boundary, which is precisely what you are forced to do if you value finiteness more than reason. And, if you choose that course, you will be asked "what such a universe is expanding into" by someone.