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.

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. — SophistiCat

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. Future events already exist, so have they already happened? Also, I still have no idea how you account for the illusion mentioned in the article.

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. — SophistiCat

I'm not sure what you were previously defending then, if not eternalism. But I understand if you don't wish to continue.

But if you prefer an objective reality and take scientific knowledge seriously, you are confronted by situations like the following:

If you pass someone in the street, your present, among other things, includes that person. You consider that person to be real, and equally subject to the laws of physics. If this person is real, and independent of you and your present, relativity tells you that she also has her own present, which is as real to her as your present is to you. Your presents are not the same. — Inis

Yes. The way I would state it is that our knowledge (of reality) is reference-frame dependent. In my reference frame, I make a distinction between the past, present and future. Per that distinction, other people and many other things exist, but dinosaurs do not exist. Similarly, while each person has their own reference frame (and thus present), dinosaurs do not exist for them either.

So I think on that view, presentism, relativity and realism are compatible.

For the "eternalists" and "block universe" advocates on the thread.
I want to know the status of "dinosaurs"? Are they truly extinct and vanished from the universe (except for their bones and descendants)?
Or are they still moving and inhabiting the earth in their region of the 4D space time block and the only reason we can't get back there is because our timeline won't curve enough to take us back?

Luke, Please note that I don't intend to argue that eternalism is true, only that the reductio ad absurdum style argument you make does not succeed. Indeed, it may even be the case that eternalism is false, but not for the argument from experience that you make. — Walter Pound

I don't believe that I've made any argument from experience. I have only been trying to point out to those who are quick to dismiss presentism, that eternalism has problems of its own.

The argument you are making seems to follow this rationale:
Premise 1. I experience a changing state of affairs.
Premise 2. If I experience a changing state of affairs, then becoming is a real feature of the reality.
Premise 3: If becoming is a real feature of reality, then eternalism is false.
Conclusion: Therefore eternalism is false. — Walter Pound

I wouldn't argue only from my own experience; it seems that we're all in this together at present (or, at least, you and I are). More than just my personal experience; physical aging, our use of calendars, many of our scientific theories, and the one-way arrow of time all support the "argument" (or require the fact) that time actually passes or that we pass through time.

The eternalist will counter this experience based argument for the A theory of time with an analogy with space. You are only ever aware of one location in space and that is the one you experience, which we tend to call "right here." You experience your location in space, but you do not experience any other location in space or all locations of space. However, simply because you experience your location of space that does not mean that that location of space is the only location of space that exists. Indeed, I may never go to China or to Pluto or outside the milky way galaxy, but I don't assume that those locations are simply mental fictions. If someone asked, "if other locations in space exist, then why don't I experience them" it would be best to respond with "why would one assume that X exists only if one experiences X?" — Walter Pound

I find it odd that you attached articles by someone who does not support this spatial analogy (see the author's example of the red and green rooms in the 'experience.pdf' article you posted). The author of those articles advocates the moving spotlight theory, which is a mixed view of eternalism and presentism. Furthermore, the analogy is quite weak. Unlike my freedom of movement in space, I am not free to travel to the past, and I am extremely limited in my "choice" of future time travel destinations.

But neither am I arguing only in favour of presentism, so this is neither here nor there (so to speak). Nevertheless, I enjoyed the articles which again note that illusion of passage is an intrinsic feature of the B-theory, so thanks for posting them.

but time is completely subjective. time is only relevant to us a conscious beings because of the very limita of our processing power. I'm not suggesting reverse time travel that goes into faster than light travel following einstein's prediction. however by approaching light speed time around you slows. But in a more practical sense time is completely subjective and therefore a result of our own awareness. Simply by overwhelming the mind with more stimuli such as smells sounds or other internal and external stimuli time can slow to a craw. In reversal hyperfocusing on a task like talking to a close friends or watching a entertaining movie allows our minds to ignore outside stimuli and time processes faster. in retrospect the universe came expanded and deteriorated in a metaphorical blink of an eye. we are merely conscious for this fraction of time. as humans advance and lifespans increases perhaps our conceptions and identification of our own limits given our bodies constraints. I'd argue the notion that all time has passed and we are simply a conscious memory of a universe that popped into existence and disbanded just as quick.

Yes. The way I would state it is that our knowledge (of reality) is reference-frame dependent. In my reference frame, I make a distinction between the past, present and future. Per that distinction, other people and many other things exist, but dinosaurs do not exist. Similarly, while each person has their own reference frame (and thus present), dinosaurs do not exist for them either.

So I think on that view, presentism, relativity and realism are compatible. — Andrew M

Except you have just argued for observer dependence.

I have no idea why you think our knowledge is reference-frame dependent. We all know relativity, and it has nothing to do with which particular reference frame we happen to be in.
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For the "eternalists" and "block universe" advocates on the thread.
I want to know the status of "dinosaurs"? Are they truly extinct and vanished from the universe (except for their bones and descendants)?
Or are they still moving and inhabiting the earth in their region of the 4D space time block and the only reason we can't get back there is because our timeline won't curve enough to take us back? — prothero

Dinosaur world-lines exist in the distant past.

Except you have just argued for observer dependence. — Inis

No. Dinosaurs existed in the distant past independent of any observers. Whereas our knowledge of dinosaurs depends on observation.

I have no idea why you think our knowledge is reference-frame dependent. We all know relativity, and it has nothing to do with which particular reference frame we happen to be in. — Inis

We know relativity as a consequence of theorizing about what is observed (in our reference frame).

We know relativity as a consequence of theorizing about what is observed (in our reference frame). — Andrew M

You think you can observe your present?

You think you can observe your present? — Inis

I think I can observe things in the present.

I think I can observe things in the present. — Andrew M

Well you can't. Everything in your present is space-like separated from you.

Thats already inherent in the notion of "observation" isn't it? Or are you arguing that gaining any information is impossible?

Thats already inherent in the notion of "observation" isn't it? Or are you arguing that gaining any information is impossible? — Echarmion

Frankly have no clue what you mean. Nevertheless, permit me to reiterate:

Your present hypersurface is inaccessible to you. If you seek information about any of the simultaneous events that make up your present, you have to wait for the information to become part of your past light-cone.

Frankly have no clue what you mean. — Inis

I think they might be suggesting that the present moment is when observations are made. Why do we need to define it as time of observation minus information processing time instead?

But I still observe the objects in my present. Either we are referring to an objective present, in which case all information I currently observe refers to an objective past, or we are referring to my subjective present, in which case I can observe objects in my present.

Well you can't. Everything in your present is space-like separated from you. — Inis

I now observe the moon as it was a second ago and everything on my desk even sooner. The timing can be factored in as needed.

The point is that relativity is a theory that explains what human beings observe and measure in a specific frame of reference.

Your present hypersurface is inaccessible to you. If you seek information about any of the simultaneous events that make up your present, you have to wait for the information to become part of your past light-cone. — Inis

Under presentism, there is no hypersurface or light cone, both 4 dimensional concepts. So if you seek information about any of the simultaneous events that make up your present, you have to wait for the information to come to you, at which time the information is no longer about the present.

Same thing, but my attempt to word it the presentist way. Walter Pound (the rarely seen OP) put it quite well in his post on the prior page.

But I still observe the objects in my present. — Echarmion

The observing is done in your present, but what is observed is only right here, nowhere else. I cannot see the present moon, but I see light in the image of moon right now. That light is right here, and from that image, I deduce a moon in the past and infer the moon still being there in the present, totally unmeasured. This process is automatic and not usually noticed. Andrew M points this out.

Either we are referring to an objective present, in which case all information I currently observe refers to an objective past, or we are referring to my subjective present, in which case I can observe objects in my present.

What you refer to is probably a proposed objective present. In that scenario, present reality is observer independent, and the present defines you, not the other way around. That present is not reference frame dependent, and thus reality is the same for everybody (as it should be for any observer-independent stance).
It is almost self contradictory since nothing you see is real. The moon you see cannot be real because you see a past version of it that cannot exist. I don't find that contradictory. You just cannot see anything real, but it is an observer-independent view, so it still exists just fine.

In an observer-defined reality, each observer observes a different point in the universe, and observes only that point, with other objects existing relative to that observation, and each observer defines a different reality, which can be a local state (presentism), or a light cone (eternalism) .
I am sort of in this observer-defined camp myself. I have a relational view of existence, sort of like idealism except it has nothing to do with people or consciousness, and things cause themselves to be real to me, or to the rock over there, whereas under idealism, my conscious observation I think causes those things to be real.

I cannot see the present moon, but I see light in the image of moon right now. — noAxioms

I wouldn't say that this is "right now", because the image is created, and that takes time. The light hitting your eyes is processed, and the image is created. So even the light from the moon hitting your eyes is in the past by the time you see the image.

I wouldn't say that this is "right now", because the image is created, and that takes time. The light hitting your eyes is processed, and the image is created. So even the light from the moon hitting your eyes is in the past by the time you see the image. — Metaphysician Undercover

Quite true, but it is still at least 'right here', or at least as much as 'here' can be defined for an entity which doesn't exist all in one place.

Quite true, but it is still at least 'right here', or at least as much as 'here' can be defined for an entity which doesn't exist all in one place. — noAxioms

What do you think it means for an entity not to exist all at one place? Could one part of that entity be in one frame of reference, and another part be in another?

What do you think it means for an entity not to exist all at one place? Could one part of that entity be in one frame of reference, and another part be in another? — Metaphysician Undercover

All (reasonably local, like not outside the Hubble Sphere) parts exist in all frames.
Being not all in one place means I am not in a defined state except to an event which has measured that entire state, which can only be in the future of the state being defined.

Being not all in one place means I am not in a defined state except to an event which has measured that entire state, which can only be in the future of the state being defined. — noAxioms

Why would this event, which measures all the defined states as one state, need to be in the future of those states? Can't the different defined states just be compared as occurring in different frames of reference?

The light hitting your eyes is processed, and the image is created. — Metaphysician Undercover

Measurement doesn't require processing. The light hits me somewhere (eyes, toenail, whatever) and I've measured the moon. It exists to me now. The processing is only necessary for me to know it exists, but knowing doesn't define existence except under idealism where the photon never hit me at all.

Why would this event, which measures all the defined states as one state, need to be in the future of those states? Can't the different defined states just be compared as occurring in different frames of reference? — Metaphysician Undercover

It takes time to gather all information about the spread-out state into one point (said future event) which can be anywhere, not necessarily an event that is part of me.

Choosing different frames of reference just defines a different set of events to be 'my state'. Under presentism, there is only the preferred frame, and other frames don't represent my actual state.

Measurement doesn't require processing. — noAxioms

Of course measurement requires processing, it is a process. You cannot measure something without actually measuring it. That's the measurement problem which SR claims to resolve, the problem that we cannot get to the another pov to measure what happens from that pov. The fastest relation between one point of view and another is the speed of light, so light speed becomes the standard for comparing one pov to another. But even to measure something using light takes time, and the thing might be moving in that time which it takes to measure it.

The processing is only necessary for me to know it exists, but knowing doesn't define existence except under idealism where the photon never hit me at all. — noAxioms

Measuring creates a knowing. If there is no knowing, then there has been no measuring.

Choosing different frames of reference just defines a different set of events to be 'my state'. Under presentism, there is only the preferred frame, and other frames don't represent my actual state. — noAxioms

Wouldn't you agree that the movements of my arms and legs ought to be understood as occurring in a different frame of reference from the movements occurring within the neurology of my brain, and my nervous system?

Of course measurement requires processing, it is a process. You cannot measure something without actually measuring it. — Metaphysician Undercover

We have different definitions of measurement. I'm speaking of measurement in the QM wave-function collapse sort of way. That interaction is 'actually measuring it'.

Measuring creates a knowing. If there is no knowing, then there has been no measuring.

Yes, I figured that was the definition under which you were working. I'm not talking about knowing.

Wouldn't you agree that the movements of my arms and legs ought to be understood as occurring in a different frame of reference from the movements occurring within the neurology of my brain, and my nervous system?

I don't see how any of that doesn't occur in all frames of reference. Maybe I don't understand how you're using the term. I'm interpreting it as 'inertial frame of reference' but maybe you mean POV or something, except no POV is specified then.

We have different definitions of measurement. I'm speaking of measurement in the QM wave-function collapse sort of way. That interaction is 'actually measuring it'. — noAxioms

Sure, but not every interaction is an act of measuring. An act of measuring is a particular type of act. So it makes no sense to say that light hitting your toe, or hitting your eye is an act of measuring that light. This would be like saying that light hitting a rock is an act of measurement. In QM experiments, the interaction is with a special type of equipment, a measuring device, it is not a case of light hitting a rock, and the rock measuring that light.

This would be like saying that light hitting a rock is an act of measurement. — Metaphysician Undercover

I had mentioned the rock above. Yes, it very much is a measurement. Thing X (source of photon) has now caused an effect on said rock, and X now exists to the rock. That's how QM measurements work. It causes the state of X and the state of the rock to become entangled. The special equipment in labs is only special because it records the measurement precisely for the purpose of the knowledge of the lab guys, but measurement itself is trivial.

You can assert otherwise, but then we're just talking about different things. You asked me what it means for an extended object (not all in one point in space) to not be in a defined state at the present, and this is what I mean by that.

Under presentism, there is no hypersurface or light cone, both 4 dimensional concepts. So if you seek information about any of the simultaneous events that make up your present, you have to wait for the information to come to you, at which time the information is no longer about the present. — noAxioms

Under presentism, there has to be a present hypersurface, and there has to be only one of them. Unless you pull the trick of denying objective reality etc.

The hypersurface will be 3D, and defined by all simultaneous events - i.e. by everything in reality. The light-cone will be a convenient mathematical tool for figuring out how long ago events happened, and why different observers disagree about such things.