Science had little use for that sort of accuracy back in those days.
They worked out F=MA without need of it.
— noAxioms

Really? I thought time was part of A (acceleration)? Were Newton's laws theoretically derived? — TheMadFool

Without the precision required to navigate a boat. I didn't say it was done without time measurement.
Massive precision is needed only for more recent physics like the relativity experiments done a century ago.

Imagine a world with a radioactive element x that decays at the rate of 1 atom every true second.

Let's suppose we have a clock that is irregular too: one tick is supposed to be 1 second but actually tick1 = 1 second, tick 2 = 2 seconds, tick 3 = 1 second, tick 4 = 2 second and so on.

If we study the element x for 4 ticks (4 seconds by the defective clock) of the clock
6 atoms decayed because 6 true seconds have passed (1, 2, 1, 2)
Time passed by the clock = 4 seconds
Rate of decay = 6/4 = 1.5 atoms/second

But...

The actual time passed = 6 seconds ( 1, 2, 1, 2)
True rate of decay = 6/6 = 1 atom/second

If the defective clock is used universally then we will never notice the error.

What do you think? Thank you for your replies. I've learned a lot.

Sounds like you have the beginning of a competing set of laws in which time is defined alternatively. But it fails the falsification test.

I have two such samples. One of them does 6 ticks, and the other does 2. Next iteration, the former does 3 and the latter does 4. Clearly the radioactive samples are not measuring actual time since they're not matched.

I remember in high school I read something about the pendulum's period depending on g (acceleration due to gravity) and L (the length of the pendulum). — TheMadFool

This is true of weight pendulums like the one in a grandfather clock. Such clocks run slow on the moon for instance. There is a mass-pendulum in my watch, and in a typical 400-day clock. Those stay pretty accurate on the moon. Similarly your weight is dependent on G, but your mass is not.

However, I don't think this really solves the problem because quantification comes first in physics and time is a quantity. In other words, we need to possess accurate instruments before we can discover the quantiative laws of nature.

Right. So they know the length of the day was stable (plus/minus 30 seconds), so eventually they needed to build an instrument that said the same value day after day. The hourglass was not accurate enough. Oddly, it was the train and boat people, not the scientists, that drove the technology for the first accurate clocks. Train folks needed it to prevent crashes, and the boat people needed it for navigation. Science had little use for that sort of accuracy back in those days. They worked out F=MA without need of it.

Now, here's something that I just thought of...

If you'll agree with me that time measurement isn't as accurate as we think then could it be that all the laws of nature we've discovered so far are wrong?

The laws we know result in models that give relatively accurate predictions, and are not something that is wrong or right. If you want to posit different laws, you are welcome to do so, but if they make worse predictions, they're less useful laws.

They're just approximations at best and completely bogus at worst. What if there are no laws of nature and all the patterns we see in nature (at least those dependent on time) are simply illusions created by our failure to measure time accurately?

If there are no laws, then there is no time to measure inaccurately. The statement is thus incoherent, You're asking that if there is no map, is the territory an illusion? What if I have a completely bogus map that has no correspondence to the territory, and yet the nonsense map gets me where I want to go every single time? How bogus is the map then? Seems to be what you're asking.

Is there a physical law that proves that the day length is constant? And how do we know that? — TheMadFool

It is reasonably constant, and the Newton's laws of motion (the first two mostly) say this. This is not proof, just a very successful set of laws that make good predictions. Come up with different laws that do as well but make the day length much more variable, and then you can introduce doubt.

I say 'reasonably' constant. When precision was needed, the second was eventually redefined against something even more regular (the caesium vibrations). Each day is longer than the same day last year, a trend that will continue (assuming other variables stay nearly the same) until the day and month are the same length. Over long times, the day length is anything but stable, ranging from around 10 to 1500 hours. But it has been consistently 24 hours for the very short duration of humans measuring it, and that consistency is what made it our arbitrary standard of time.

Yes but what verifies the day? — TheMadFool

But to know this we would have to rely on another clock, say A, and to check A we need another clock B...ad infinitum. — TheMadFool

No. No clock is needed to know this.
The average length of the day is the arbitrary standard. There is nothing against which it needs to be verified.

Anyway, we know that standard is reasonably stable since it would require incredible force to alter that rotation rate. — noAxioms

But to know this we would have to rely on another clock, say A, and to check A we need another clock B...ad infinitum. — TheMadFool

No clock was used to verify this. Clocks were made to sync to this. The day verifies the clock, not the other way around.
For the length of the day to be significantly variable would require a complete rewrite of the most basic physics. The Earth rotation is regular because of the complete lack of significant force to alter it.

That is what I was saying (in the bold) in my post.

Another thing is the assumption (is there a physics law for this?) that the pendulum swing will remain constant. — TheMadFool

It is not constant. Ever notice all the complexity of the pendulum on a grandfather clock, with all those bars made of different metals? It's not just decorative. It is an attempt to cancel out the normal variations in the period of that pendulum which would significantly reduce the accuracy of the clock.

The standard of time was the average length of a day, with a second being defined as a 86400th of that. I say average length because the day is about a minute longer in December than it is in June.
It would have been more accurate to slice up the time of one rotation (about 1436 minutes) since that doesn't vary significantly over the year, but nobody had a use for hours defined that way.

Anyway, we know that standard is reasonably stable since it would require incredible force to alter that rotation rate. OK, said force does exist, and we have leap-seconds to compensate. Eventually the day will be long enough that we need more than one leap second each day. Scientific definition of a second will diverge more significantly from a clock second, the former corresponding to a day length back when it was first accurately known, and the latter being a function of whatever the current average day-length is.

We need the single best process that could be used at any time and any place. Radioactive decay would be that. — apokrisis

Multiple posts that radioactive decay makes a good clock. It is unpredictable, uncaused and makes a crappy clock. Radioactive dating is accurate to no better than several percent. It serves where no other methods are available, but accuracy is hardly it's forte.

Essentially, going by our findings so far, there simply shouldn't be a universe.

Wrong conclusion. It finds that current models don't necessarily match what is seen. If the findings were accurate, the universe should be different, but concluding that it should not exist is an absurd category error.

The universe didn't even start out with matter/antimatter that mutually annihilated. That stuff formed later. Yes, the imbalance has been noted and any model needs to account for that. Apparently not all models do.

This seems problematic (for me) because how do we know the vibrations of the atom used to define a second is regular? — TheMadFool

Because you get the exact same result from countless repeatings of the experiment.
I get different results from the time measurement of my grass to grow 5cm, so using grass growth as a clock works, but not very accurately. Good clocks use very consistent processes.

Sure, a tagged oxygen atom is likely to survive 2000 years I think, and would most likely be found still on Earth, in a place of highest oxygen density, which is probably any liquid water anywhere. Altitude has little to do with it since water isn't particularly more dense under pressure.

Not so much a science question as a statistics one. It is more likely to be in a cubic meter of water than a cubic meter of anything else on Earth except for perhaps laboratory liquid oxygen.

Events are still usually ordered under determinism. 2017 is after 1917, so the relations 'before' and 'after' have meaning just like the relations 'above' and 'below' have meaning in any space where the direction 'down' is sufficiently defined. Likewise 'then' has meaning just like 'there', so long as some point is identified. The word does not require a 'now' or 'here' respectively.

On a lighter note, I notice that time identity is not associative under presentism: "The future is now" is true, but "Now is the the future" is false. So A = B, but B ~= A, a contradiction, therefore presentism is false.
That's my attempt at the dumbest proof of etermalism ever posted.

Nope, because under eternalism, it simply isn't the case that Christmas "will exist". Christmas doesn't just pass into existence and October out of it. Instead it already exists at a part of the block universe and it is located later to where October-2017-noaxioms is located on the block. The Christmas located on a Sunday of 2016 is located earlier to the same individual. — Mr Bee

So all of language is wrong if eternalism is the case? I don't consider saying that "Xmas will be on a Monday" to be an assertion of presentism. It's just how language works.

You try to bring in talk of "will" and "was" to the mix, but that just confuses things, as they are commonly associated with the passage of time. — Mr Bee

Yes, I agree that the tenses should be avoided when speaking in eternalist terms, but only because of the lack of a reference point.

It is a basic fact that eternalism is commonly associated with the rejection of the flow of time, but I highly suggest you look at any corner of the literature if you're not convinced. This is why the article says that every event exists "right now", but I am not sure why you disagree with it. — Mr Bee

I disagree with the reference to "right now". What does that mean in eternalist terms?? There is no "right now".

Of course there are simultaneously occurring phenomenon. How else do we measure time if not by the simultaneous rotation of the Earth with a movement of the hands of a clock? — Harry Hindu

You misunderstand me. Stanford eternalism entry says that 1917 say, "exists right now", tempting one to imply that 1917 and 'now' are simultaneous. Eternalism does not assert that.

I think it legal to use these tenses, but the reference point must be explicit, lacking an objective present.
— noAxioms

No it isn't. If you don't believe in an objective flow of time then there is no meaning to saying that events have occurred or will occur. That is really the main crux of the eternalist vs presentist debate, the existence of this passage. The only tense that makes sense is to say that all things "are", which is to say that they are all exist now in the way we normally understand things existing right now. — Mr Bee

Assuming I am an eternalist (I'm not really), is it not legal for the October2017-noAxioms to say that Christmas will be on a Monday this year and last was on a Sunday? If the October2017-noAxioms can legally use those tenses, surely it is valid for the October2016-noAxioms to assert that this Christmas will be on a Sunday. Or do you disagree? Not sure what you're saying is invalid to do.

That is just a basic fact. To say that something "has happened" or "will happen" would require a flow of time. — Mr Bee

I think it legal to use these tenses, but the reference point must be explicit, lacking an objective present. So from 1910's present, WWI will happen. Events are still ordered and the tenses are not completely invalid. But to imply a present when speaking on eternalist terms is to refer to an ambiguous event.

Eternalism is not an assertion that all times 'currently exist'.
— noAxioms

From the Stanford entry:
According to Eternalism, non-present objects like Socrates and future Martian outposts exist right now, even though they are not currently present.
— Alec

What is the difference between "existing right now" and being "currently present"? — Janus

I'm on record for not liking the way Stanford words that whole section. My interpretation of that statement (You also edit out the disclaimer that explains what they mean by "existing right now") is that at any given moment ('now' for instance), the other moments ontologically exist equally. Thus I do not disagree with the entry, but I find it poorly worded. Alec interprets all moments "existing right now" to imply that they're all simultaneous, which is a temporal statement, not an ontological one. All moments are not simultaneous under eternalism.

Saying that something exists at a certain time ('now' for instance) leads one to imply that it does not exist at some other possible time. The Stanford entry says it doesn't mean that, but everybody is ignoring that disclaimer (OK, Mr Bee sees it).

This is similar to the idea that "right here" could be anywhere is space, or in other words is applicable in general to everywhere, not merely specifically to where you or I happen to be.

Yes, it is similar to exactly that: "Every point in space exists right here." That means that despite being right here, it does not imply that other locations do not exist. They all have equal ontology, and there is no preferred 'here'. Saying they all exist right here does not imply that all points are at the same location, but the statement "Every point in space exists right here." tempts one to interpret the statement exactly that way. Hence I don't like the Stanford wording.

And so they currently exist which I have quoted you as saying. — Alec

I didn't say that, unqualified like that.

This is a good example of misrepresenting what I said. Did I bring in anything temporal? I was speaking strictly and purely from an ontological standpoint, and all uses of the word "now" and its synonyms are in the ontological sense.

Stanford qualifies the difference. If it states that there is an ontological present, then it is not any form of eternalism that I'll agree with.

Like I said, everything is strictly ontological, so you can't dodge the problem like before.

In a strictly ontological sense (there is also a temporal sense), there is no 'currently'. Current with what? Eternalism is not a statement of the simultaneity of all events. Time is a dimension, not a point.

But they are all currently existing. Again, I must emphasize that part of your post. You keep saying that that they aren't. Unless you want to backtrack on that. — Alec

They are existing in an ontological sense, but not a temporal sense. I don't like to reference the present when speaking of ontological sense since it has no ontological existence. But the temporal present can still be referenced and that is what the Stanford post is doing. Such mixing of senses only serves to confuse.

Perhaps you meant to say that there is no temporal now?

Sure there is. Temporal now is today, the day this forum post is submitted.

If you're saying that there is no sense of an ontological now, then you're contradicting what you just quoted. Everything exists right now under eternalism, in the ontological sense.

Good example of mixing senses, leading to confusion. Everything exists (ontological, italics) right now (temporal, bold). Eternalism does not give temporal existence to Socrates, nor give any ontological status to 'right now'.

But if you agree that every time in the universe's history currently exists in the ontological sense, then we can move on to the bigger problem in the OP, which is how, if all times of our life currently exist, and that we are currently a 4D object that extends throughout our life, can be reconciled to our current experience of only one of those times.

I cannot agree to a statement with mixed senses like that. Be explicit. Every event (there is no 'every time' since something like '1945' is ambiguous outside the context of Earth) currently (temporal sense) exists (ontological sense).
That's utterly confusing, but at least spelled out.

Are you saying that relativity does not order my parents' birth before my own? The ordering is ambiguous or nonexistent?
— noAxioms

I would ask if you're disagreeing with the relativity of simultaneity.

No, I don't disagree with relativity of simultaneity, but my parents are still born before I was.



Going offline for quite some

Agree with the post. I've said elsewhere that it reduces to temporal realism vs. idealism.

'Simultaneous' is a temporal term, not an ontological one. So Earth, 2045 and 1945 both exist (exist now in an ontological sense), but there is no simultaneity to that. Temporally, the two years are 100 years apart and hardly simultaneous.

Relativity I suppose says that the temporal distance between the two events is frame dependent, but the ordering is not. Relativity is not a statement of ontology (despite being suggestive of it), so it is pretty mute about the ontological sense of the two events.

Sorry, but this is just false:

One version of Non-presentism is Eternalism, which says that objects from both the past and the future exist just as much as present objects. According to Eternalism, non-present objects like Socrates and future Martian outposts exist right now, even though they are not currently present. We may not be able to see them at the moment, on this view, and they may not be in the same space-time vicinity that we find ourselves in right now, but they should nevertheless be on the list of all existing things.
— Stanford Encyclopedia entry on Time (My emphasis)

Maybe you should read up on more on the view before talking about it. — Alec

It does indeed say that, with the note that Socrates is not currently present. So there's a difference, and they are apparently allowing the use of an implied reference to a present.
You cut away the distinction between temporal sense and ontological sense of the concept of 'exists right now'

It might be objected that there is something odd about attributing to a Non-presentist the claim that Socrates exists right now, since there is a sense in which that claim is clearly false. In order to forestall this objection, let us distinguish between two senses of ‘x exists now’. In one sense, which we can call the temporal location sense, this expression is synonymous with ‘x is present’. The Non-presentist will admit that, in the temporal location sense of ‘x exists now’, it is true that no non-present objects exist right now. But in the other sense of ‘x exists now’, which we can call the ontological sense, to say that x exists now is just to say that x is now in the domain of our most unrestricted quantifiers, whether x happens to be present, like you and me, or non-present, like Socrates. When we attribute to Non-presentists the claim that non-present objects like Socrates exist right now, we commit the Non-presentist only to the claim that these non-present objects exist now in the ontological sense (the one involving the most unrestricted quantifiers). — Stanford

So in my posts, I consider references to the present ('right now', 'currently', etc.) to be temporal references, not ontological ones. There is no ontological now, nor a time that is ontologically the current one.

No, events are still ordered if within each others' light cones. My parents were born before me, in any relativistic reference frame.
— noAxioms

There is a reason why they call it "Relativity". It's because of the fact of the relativity of simultaneity. Look it up if you disagree.

Are you saying that relativity does not order my parents' birth before my own? The ordering is ambiguous or nonexistent?

Yeah, that was my point. Eternalism doesn't say anything about simultaneity. It has probably been around before relativity was a thing but the lack of any absolute notion of simultaneity has been used to argue for the view.

Yes, the lack of absolute simultaneity is seriously suggestive, but not proof of any sort.

No, I say he exists. There is no current time.
— noAxioms

I'm sorry, but there are only three ways I could read your "exists". Either you're saying that Napoleon "did exist" or "will exist" or you're saying that he is currently existing. You somehow deny all of them, and want a fourth option, this "tenseless" form of exist, but I have no idea what that is.

Yes, all three reference the present. I mean exists ontologically, and eternalism does not give any ontological status to a present, so there is no present to reference.

I guess I should have referenced Socrates, not Napoleon.

I think you're confusing a preferred time with things currently existing. — Alec

Eternalism is not an assertion that all times 'currently exist'.

The argument from relativity states that there is nothing to determine that one set of simultaneous events should be preferred to any other, leading to the conclusion that none are.

No, events are still ordered if within each others' light cones. My parents were born before me, in any relativistic reference frame.

There are no privileged frames; this is known as the relativity of simultaneity.

Eternalism is not an assertion about simultaneity or preferred frames or the lack of them.

My emphasis on the word "exists". You seem to be using "exist" in the present tense.

Both are tenseless.

You don't say that Napoleon "did exist" or "will exist", you are saying that he currently exists.

No, I say he exists. There is no current time.

What do you mean by "relative terms"? And what inconsistency are you talking about? I don't understand. — Alec

Let me bold some:

...every moment is real in the same sense as the present is real. ... to treat them all as I do present objects, which is to say, that they currently exist, unless you have another idea of what it means to say that they are all "real". — Alec

There is no present, no present objects, since no reference has been specified. So you can say that Napoleon presently exists at Earth, 1815, which is a redundant way of saying Napoleon exists at Earth, 1815. But there is no 'the present', and 'currently' is meaningless without a temporal reference point. Whose present? Currently with what? Begging references to these things is going to make you declare the position irrational.

I was asking if you have an idea of what all moments being equally "real" or all "existing" could possibly mean if not that they exist in the present tense. If you cannot do so for whatever reason, then I can only conclude that your disagreement is irrational and that you don't know what you're talking about.

Napoleon exists, and he also exists in 1815, but does not exist in 1915 since the two times are not simultaneous. Paris exists, and Paris exists in France, but Paris does not exist in Japan since the two locations are not the same place. But that doesn't mean Paris doesn't exist just because the speaker is in Japan. It simply doesn't exist at that speaker's 'here' any more than Napoleon exists at your 'present'.

According to eternalism, every moment is real in the same sense as the present is real. I don't see how else I can make sense of all moments being real or equally real other than to say treat them all as I do present objects, which is to say, that they currently exist, unless you have a better idea of what it means to say that they are all "real". — Alec

Very well then, but use of relative terms to describe a non-relative concept is inevitably going to run into inconsistencies like that.

Distant places look younger because their light just reached us, which of course it was anxious to do. The more distant the objects, the older they are--isn't that the case? — Bitter Crank

Yes, the most distant objects are from the longest time ago. The CMB is the oldest thing visible. It is a wall beyond which nothing can be seen, at least not with the light to which our instruments are sensitive. The CMB is older than any galaxy.

I think the stars are what give galaxies light, so can't see them. Hence the dark ages for the first 0.4 billion years or so, sort of like our early solar system before the sun ignited. The mass is still under the process of collective gathering into one place.

Quasars are super-bright because of all the stars falling into the initial formation of the galactic black holes. That settles down after a while and there seem to be none left 'now'. The nearest one is only about 2 billion years away, and if there were quasars at age 11.7 billion years old, there might be a few that are the age of our galaxy here.

According to eternalism, every moment in the universe's history is real and as such exists simultaneously. — Alec

No, not simultaneously. Each moment is its own time (they're not simultaneous any more than each location is the same place). It's just that no particular moment is special any more than any particular location is the one correct 'here'.

Entropy?

Distant places look younger. There are no quazars nearby since they've all burned out.
Really distant galaxies don't have stars yet.

Also the rate of expansion is not constant, and I would think it would need to be in the steady state scenario you describe.

I find the idea more plausible than not. If Earth now gets clobbered by a big asteroid, it will eject tons of life into space, plenty to drops some seeds on some fertile planet somewhere. The hardest part is getting the shrapnel up to escape velocity in order to make the trip to other star systems before those stars die out. A few billion years is hardly enough to make the trip.

It just pushes the origin question to another planet. — T Clark

Indeed, it does not answer the origin question, but it opens up possibilities to the origin being in some environment that would never plausibly be found here.

Actually they make the case that some epidemics originate from extra-terrestrial material. — Wayfarer

This one seems pretty unlikely. Earth has made life its own, evolving well beyond whatever may have dropped from space. Any virus from space would not have evolved to infect terrestrial life. Epidemics are home grown I would think.

That's Newton, which at the end may be closer to nature than Relativity. — Rich

Yes, I said it was Newton. I also said that equation went unaltered by relativity. Zero force still means zero acceleration, in any frame.

All this is utterly wrong. The stay-home person is not accelerating in the frame of the rocket twin. It takes force to accelerate, and no force is being applied.
— noAxioms

I don't see how either twin knows this or how the clocks know this. Do the feel it? To the twin on Earth, it appears that he is accelerating away from the rocket. Where in the the equations does it identify which twin to choose? — Rich

F=MA.
No force means no acceleration. That's a Newton equation, and relativity didn't even need to modify that one.

The twin paradox can be illustrated with nothing but SR rules using a tag team and no acceleration and no significant masses screwing with gravity. I put one together that I think has no flaws. I can post it if you like. As I said, both subjects can be accelerating equally and yet one will age more than the other. Acceleration is not required.

The equations do not identify which twin is to be considered accelerating. Either one can be chosen since from either twin's frame of reference, it can be accelerating from the other. — Rich

The equations should be reciprocal. I don't know how you pick which one is accelerating. — Rich

All this is utterly wrong. The stay-home person is not accelerating in the frame of the rocket twin. It takes force to accelerate, and no force is being applied.
Velocity is not a frame independent property of an object, but acceleration very much is.

However, as we all know, acceleration can be felt, and therefore may be biological effects as a result of the actual real duration of acceleration. In other words, there may be real effects but independent of Relativity which assumes no privileged frame of reference. — Rich

One twin getting older than the other is not a function of acceleration. Suppose both get on a rocket, and one accelerates at so many G straight out and back, and the other furriously orbits with similar acceleration. They both experience the same acceleration but the orbiting one is much older (more proper time in his worldline) when they meet. So it is not biological effects of being under acceleration. It's not the velocity since in the frame of each, it is the other one that has all the velocity.
But one has a greater moment of acceleration, and that is the difference.

An accelerating frame of reference is privileged. Only inertial frames of reference aren't. — Agustino

Privileged means it is the one correct frame. There is no correct accelerated or inertial frame, so none is privileged. Or are you just yanking Rich's chain?

Scientific time is measurement of simultaneous events. — Rich

I know you're anti-science, but what does that statement even mean???

Agustino, I would have said that scientific time is the time in scientific equations, like velocity * time = distance. Such time is frame dependent since none of the terms above (velocity, time, or distance) is meaningful without a frame.
This is opposed to proper time which is a frame independent duration on a world-line between two events on that world-line. Experienced-time is proper time of the experiencer, or his real age.

And would you agree that if I take a man and fly him close to the speed of light he will age slower than one that remains on Earth? — Agustino

In scientific time, each man ages faster than his counterpart since for each man, it is the other that has all the velocity. Sans acceleration, they cannot ever meet but once and have a meaningful comparison of age.
In proper time, they age at the same pace, but their world lines are different lengths so if they meet, they are not the same age.

A materialist would probably answer yes, rendering the conception of the philosopher moot.

In effect, the philosopher thinks of time as transcendent. — Agustino

Have not read all the replies, but the language in the OP is summarized by that snippet. One is a materialist or a philosopher. It seems that materialism is not presented as a philosophical stance.

And my point is that it doesn't matter. Sure, a simulation of Paris is not the same as Paris. That is why it's called a simulation. But that doesn't affect the fact that we do not know if the Paris we know is one or the other. Apart from that, I don't see your point. — Alec

It apparently does matter if you give meaning to the distinction between the Paris we know being real or a simulation. If a thing cannot be a simulation (only be simulated), then the Paris we know is not one. It only then doesn't matter since there is no distinction between the two cases because there are not two cases.

Evidence of this lack of distinction is that it is impossible to do a "I'm in a simulation" test armed with only subjective knowledge, no matter how inaccurate the simulation.

Note I did give a distinction there. Given non-subjective knowledge, there is a distinction since there is suddenly existence of information from outside the universe. It isn't really a simulation then anymore, but just a sub-process within a larger universe. So for instance, if God created this universe and communicates in any way (imparts state inconsistent with the physics), then the universe is not really a universe, but just a sub-process/object (not a simulation), part of a larger universe containing the full explanation of all empirical data including the said communication.

And again, I must stress that you move away from talk about the self. The simulation argument deals more with the world we are in rather than ourselves and I feel like ignoring that would lead to more confusion than not.

No self needed here. Paris has a library with books describing different physics than the physics of the Paris being inaccurately simulated. That's inconsistent. Such inconsistencies are detectable.

It indeed cannot be exact, and yes, it works fine that way. I suppose our universe could be simulated down to the quantum level, but not on any simulating equipment that I can envision. It seems unnecessary unless there is a quantum amplifier (like the one that kills Schrodinger's cat) that needs to be simulated. Biology seems not to have them, nor does electronics for the most part. History cannot be reproduced, but a functional world of sorts can be simulated. It would work. A transistor for instance has very simulatable macroscopic behavior, and I've actually worked with transistor simulations which are cheaper to test than real chips. But transistors rely on quantum effects to function. They wouldn't work without that. Doesn't matter: The simulation does not simulate at the quantum level. It simply simulates it as a macroscopic switch with this and that delay, threshold, and EM noise. The neuro-chemical nature of brain cells seem to have similar macroscopic function. The simulation need not be more detailed than that.
— noAxioms

Didn't know you were implying quantum phenomena here by the use of "macroscopic".

Never said that. I said macroscopic rules will usually do unless the simulation needs a quantum amplifier, which cannot be simulated properly with a macroscopic simulation.

I must first start off by saying that my knowledge of physics is only basic (some Pop Sci. Books and a rough knowledge of the history), but I do not see how quantum phenomena cannot in principle be simulated.

It can be, but not with simulator running macroscopic rules, and not even in principle if predictable results are expected, since quantum events are not predicable.

Indeed, aren't some physicists already simulating quantum phenomenon in their research?
I can imagine it is impractical sure but not impossible.

Sure they do, but those simulations do not predict unpredictable events like when the atom will decay. The simulations necessarily have randomness built into them, something not particularly needed at the macroscopic level.

In addition, we should not imagine that the world running a simulation of our physics needs to run on the same rules. That was the point of what I said earlier. The ancestor world can run on an entirely different set of laws, one that makes the simulation of the quantum more practically feasible.

That's right, but it wouldn't be an ancestor simulation then, but merely a dumbed down fictional virtual reality.

However, the simulation would still run on the same fundamental principles of computation that we have for our own computers.

No, that cannot be. The nature of our universe is not one that can be accurately simulated on the principles on which our computers operate. I cannot even figure out how to express the position and state of the most trivial particle given unlimited computing resources. An accurate simulation of us would require something fundamentally different I would think.

And that is the key point in all this. In order to demonstrate that something cannot in principle be simulated, it must not be able to run on a computer. Computers, as far as I can tell, are digital, they run on binary, they use an algorithm and are finite.

OK, so we can simulate Paris, at least on a macroscopic level. Anything that can be put in a box. Hard to put Paris in a box since it has continuous interaction with its neighbors, but perhaps the whole Earth with pared down simulation of celestial activity which is pretty easy to predict most times.
A simpler case is a locked room. The whole simulation can be confined to that. I assert that barring information inconsistent with the simulation, it is impossible for the simulated thing to distinguish reality from the simulation. If it were possible, it would be a simulation of a different reality, and thus the distinction would be in error.

You mentioned infinity, which is something that our ideal computer cannot simulate,due to its limitations.

Hence the need for a box. The box confines some of the infinities.

Other examples of phenomena which cannot be simulated are continuity and true randomness.

That is an interesting point. Does randomness need to be true? I think so, since if it was not true randomness, it would be predictable, and that conflicts with QM. It would not be a simulation of our reality. If it is a macroscopic simulation, I don't think randomness is needed at all, true or otherwise.

There are computers with true randomness. It just requires a small randomness device, and they probably fit on a chip. Not so hard.

I've seen 3-body simulations that had poor continuity implementation. The objects seemed to always gain energy. So point taken again.

Unless the intelligent race is somehow able to tap into the infinity and create the ultimate computer, then we can safely assume that their simulations are limited (thus excluding the infinitely small and the infinitely big). And the same goes for true randomness, as computers are necessarily deterministic.

That the running-on-the-same-rules point. Said super-race might have physics that effortlessly let them do infinities in their computations, but again, they would not be running an ancestor simulation by simulating us here.

However, the problem with these possibilities, when I was thinking about them, was that it was impossible for us to know whether or not they were true. Unless we are able to go to the ends of the universe, then we cannot determine if there really is an end to space or not.

Not too hard to know that. People didn't know where the Earth ended either, nobody having visited the edge. Then they found out it had a geometery with no edge and the problem went away. The geometry of the universe has no edge, and no center (not in space at least). There is no vantage from which there are stars only on one side and not the other.

Sorry for slow reply. Been busy and I wanted to not post this until I reviewed it a couple times.

I believe there are a couple of assumptions that you've made that I've pointed out below. I am not sure what you mean by dualism though, if you consider BIV to require it. As far as I can tell BIV works perfectly fine with most positions about the mind. — Alec

I don't consider BIV to require it. There is a mind, and it has zero access to the nature of itself or reality, so it can trust no knowledge. I am discounting that scenario from my discussion.

A more dualistic BIV scenario is a very immersive video game. You are Lara Croft in Tomb Raider, and so convinced of it that you forget you're something else. But you can tell: Lara's head is empty and contains no mechanism for thought and experience, which is served by the 'immaterial' player. The physics of Tomb Raider is obviously not deterministic, so no simulation of Lara physics will result in her acting like she does with the player component.

This statement presumes that the simulation is the simulated.
— noAxioms
Okay, then we are not sure if we are talking about something simulated when we are talking about the world we live in. Whichever way you word it, the fact is that we still have no clue.

Don't know how to explain it better. The simulation is of a real thing. The simulation is not the thing, and thus at no point are we in a simulation, be we simulated or not. So my stance is that we cannot be a simulation. If a simulation is run and it is not perfect (does not simulate what was intended), then the simulation is just of something else with different physics, but the simulated thing is still not a simulation.

It perhaps comes down to a language quibble, but one I feel is important. I can be simulated in principle, but I cannot be a simulation. Running a simulation is not an ontological act any more than the running of a 'real' universe. All it does is execute a simulation process.

Your possibility tries to undermine the simulation scenario just as much as the first two possibilities do. That's just how it is.

Yea, I guess it does. It seems that my position is not just another possibility, but it debunks the whole argument. The argument works from the presumption that the states universe are things (objects??) that happen or are executed, which I find absurd.

The simulation's macroscopic rules don't necessarily have to be the same as the rules in the world of the simulation.

Agree, but is it an 'ancestor simulation' as described by the OP if the simulation is of a different world that the one running the simulation? Conway's Game of Life is a simulation, but not one of our physics. No structure in that game can detect that it is in a simulation because no structure is actually in one. They are being simulated, but are not simulations. See what I'm saying?

And even if the simulation world's rule do mimic the macroscopic rules, there is no requirement that it has to be an exact representation.

It indeed cannot be exact, and yes, it works fine that way. I suppose our universe could be simulated down to the quantum level, but not on any simulating equipment that I can envision. It seems unnecessary unless there is a quantum amplifier (like the one that kills Schrodinger's cat) that needs to be simulated. Biology seems not to have them, nor does electronics for the most part. History cannot be reproduced, but a functional world of sorts can be simulated. It would work. A transistor for instance has very simulatable macroscopic behavior, and I've actually worked with transistor simulations which are cheaper to test than real chips. But transistors rely on quantum effects to function. They wouldn't work without that. Doesn't matter: The simulation does not simulate at the quantum level. It simply simulates it as a macroscopic switch with this and that delay, threshold, and EM noise. The neuro-chemical nature of brain cells seem to have similar macroscopic function. The simulation need not be more detailed than that.

So I have a hard time with the assertion that the simulation could be so good that we can't know we're in one.
— noAxioms

I have to correct my own comment there. If the simulation is so 'imperfect' or size-limited, then it is simply a different thing being simulated. The thing can know it is not in a simulation. It simply exists in a small limited simpler universe.

The true universe (the world that isn't simulated) does not necessarily have to be infinite either.

A true universe I would say, or 'ours'. I speak repeatedly of other universes (say the Conway GoL one) in this post. There is our universe, but I don't think ours is any more or less true than another. Perhaps we need a more concrete definition of 'universe'.

As for determining if the universe is infinite and therefore not a simulation, I am not sure what kind of experiment could be done to even determine such a fact anyways (though I am open to hearing proposals), so it seems like we're lost there too.

My solution solves this problem. Can't be a simulation because things are not simulations (by definition), even if simulated.

Never said you assumed BIVs. I merely used the case of BIVs to demonstrate what I think is a wild assumption with your approach. — Alec

My assumption is no dualism, not necessarily true, but hardly a wild assumption. I consider BIV to be dualism, essentially a mind being fed lies about its true nature.

As far as I see it, the only way for your argument to undermine the simulation argument to work is for you to somehow point out some feature or element about the nature of our understanding of the world (or our experience of it) that cannot in principle be replicated by a computer program.

I'm not undermining the argument. I'm listing additional possibilities than the three listed. I have no problem with a computer program simulating consciousness.

If it can be, then we cannot ascertain whether or not we are looking at a simulation when talking about the world we live in.

This statement presumes that the simulation is the simulated. Not sure if I've driven home the difference. The simulation is a tool for yielding information to the simulator (the creator of the simulation). So if say a human set up and ran a simulation of a bat, the running of the simulation would behave like a bat, but would not impart the human with knowledge of what it is like to be a bat. Meanwhile, the bat in the simulation would know what it is like to be a bat, whether or not the simulation is actually run or not.

Hope this helps.

Of course, this sort of discovery seems as likely as the discovery that there is a feature of our experience that is impossible to replicate, whether by a BIV, or demon, or a vivid dream scenario. Now you may not be alone in thinking this. I believe this is the sort of suggestion made in the "Answering the Skeptic" thread, but as for my own take on it I find it to be a bit too extraordinary for my own liking.

Hence my disclaimer/presumption about experience being essentially a macroscopic physical process. If it isn't, not sure if such simulation is possible, so I'm considering only the case where it is.

Your example deals with a conscious person, but again, I must point out that the simulation argument (as well as the BIV argument) is more about the world we find ourselves in rather than who we are.

The simulation runs on macroscopic rules, and suddenly the simulated guy starts doing non-macroscopic experiments in his simulated lab and the simulation cannot handle that. He'd be able to tell. So the simulation has to be good enough to mimic even that, and at that point I have a hard time agreeing that it is possible even in principle.
Likewise, the simulation needs to be confined somehow, limiting resources. An infinite universe cannot be fully simulated even macroscopically. The simulated guy would possibly notice that he is in the center of a finite place, just like we were centuries ago. So I have a hard time with the assertion that the simulation could be so good that we can't know we're in one.

Well if the odds are not 50/50, then what are they? — XanderTheGrey

You've not defined the problem. The odds of having the best poker hand at a given time is 1/number-of-players, and that does not equate to the odds of winning the hand, but it helps.

What are the odds that the Cubs win the last world Series? Point of view matters a lot in answering a question like that, hence my asking for a problem definition, but I cannot think of a way to word it where the odds work out to 50/50.

You might say we would have to calculate the odds by examining all things that could effect the outcome of the situation; even things that manipulate time and space, and in this case the things that could effect the situation to go in any direction or arive at any outcome are infinite.

Odds calculations are usually an epistemological issue. In the case of a poker hand, the presumption is that the order of the cards in the deck is sufficiently unknown as to be considered functionally random.

I do not know when exactly I took this stance, but yes. I think of it this way; in the bigger picture, considering an infinite time span, infinite space, matter & energy; a being somewhere could win a in gambling every single time it plays(lets say several times a day) for 90 years of its 100 year life. Thats event is a possibility. — XanderTheGrey

OK, no argument with it being a possibility. It is the expressing of the odds of this possible situation as 50/50 that I didn't understand. If you are beginning to question doing so, then I approve.

The problem is, once we start applying your reasoning to things in general, then it seems to amount to us saying that the experiences that we have of an external world cannot be replicated by a simulation or otherwise. That'd be extraordinary indeed, if we can somehow prove definitively that we cannot be brains in vats or living in a vivid dream world. Unfortunately, I think it's more likely that that isn't the case, hence the persistence of skepticism. — Alec

My reasoning assumes no BIV, a separate thing that experiences a sensory stream that is not the same sort of thing that is the experiencer. It assumes (and does not assert) that consciousness is just a physical process, no more. If this is not true, then all rules are off concerning whether a simulation of anything can exist at all.

So given my assumption, it is easily proven that a perfect simulation of some actual state of the universe (say a chosen person) is impossible. But an imperfect one is not, say simulated as a neural-chemical body with a finite world to inhabit. This simulation, being finite and imperfect, would have a different history than the real person who is being modeled, but the simulated person would be conscious (again, given the assumption of consciousness is a physical process, and for the most part, not a quantum process). If the simulation took a scan of my body as part of the initial state, then the simulated person would not know it was not me, but might quickly figure it out if the finite nature of the world is at all obvious.

Now the main part of my point: The simulation need not run at all for the simulated person to be conscious. All that is needed is the initial definition of state and the definition of how the simulation is to proceed from that state. This is what I meant by the fact that 3+3 is equal to 6 even if the arithmetic is not actually performed by some mechanism.

Or that a one in 1million, 1billion, or 1trillion year winning streak dosen't happen to me. — XanderTheGrey

That winning streak happens or it doesn't. 50/50, right? Or am I misunderstanding your stance that you stood by since you were 7?

I think the simulation argument is less about us and more about the world we live in. — Alec

Granted. I must reword then.

This whole set of logic presupposes that what things are is the instantiation, or execution, of whatever physics makes defines. But a simulation of thing X is not an instance of X. X already exists (is defined, and the definition is enough), and the simulation simply imparts some truth about X to whatever is executing the simulation.

That said, there is another presupposition that IS about us and not just things: That what we are is just a physical thing/process and not in need of some immaterial experiencer of the thing X, simulated or otherwise. I agree with that assumption, but it is still an assumption. This sort of groups under item 1: An ancestor simulation is not possible because a simulation of an ancestor is not a full simulation of that ancestor unless there is a way to grant the immaterial experiencer to the simulation. Something like that.

Possibility 5 then: The real world (the one running the simulation) is not a human civilization at all, but a much higher tech thing which can execute simulations of trivial things like a human civilization at will. The simulation need not be a simulation of its native underlying reality. I don't think that scenario is covered in any of your options.
My possibility 4 stands in such a scenario: Such a simulation is not the creation of this reality, but merely an analysis tool to learn about the already-defined reality.

The simulation argument:

1. The fraction of human-level civilizations that reach a posthuman stage (that is, one capable of running high-fidelity ancestor simulations) is very close to zero, or
2. The fraction of posthuman civilizations that are interested in running ancestor-simulations is very close to zero, or
3. The fraction of all people with our kind of experiences that are living in a simulation is very close to one — Michael

If there are more Sims than there are non-Sims then we're more likely to be Sims. — Michael

This whole set of logic presupposes that what we are is the instantiation, or execution, of whatever physics makes us up. But a simulation of thing X is not an instance of X. X already exists (is defined, and the definition is enough), and the simulation simply imparts some truth about X to whatever is executing the simulation.
So the list above leaves off the 4th possibility: that what we are is not the execution of the steps. Is 3+3 not equal to 6 until something performs that arithmetic? There are arguments for both sides of that debate, so I will not present it as truth, just a 4th option.