• Would P-Zombies have Children?
    You could just say “I am a p-zombie”.Michael
    Most of us don't know it. It isn't easy to tell until you get a glimpse of the bit being missed, sort of like having your vision restored after cataracts have reduced you to near grayscale levels.

    You’ll need to explain it in these terms.Michael
    Hence my attempt with the car, which very much is aware of its surroundings, but 'aware' is perhaps one of those forbidden words. It all smacks of racism. They basically degraded black slaves by refusing to use human terms for anything related to them, using cattle terms instead,.It made it easy to justify how they were treated. "Cows don't feel pain. Neither do p-zombies. It's not immoral to set em on fire."
    I'm sorry, just because we're not conscious in the Chalmer way doesn't mean we don't hold beliefs. I refuse to withhold perfectly understandable terms when no alternatives are offered.

    I don't agree with this. "so he says he feels pain, not knowing that it isn't real pain". That's an epistemic issue, not a truth issue. For any x, if x is not feeling pain/hurting, and x says it is feeling pain/hurting, x is wrong. X is saying something false.RogueAI
    I didn't say the statement "so he says he feels pain, not knowing that it isn't real pain" was true.
    I said the statement, "pain hurts" is true regardless of what utters it.

    But this isn't true for you.RogueAI
    That's just using a language bias to attempt a demonstration of a difference where there isn't one. A Roomba cannot be conscious because you define 'conscious' to only apply to humans. That doesn't demonstrate that a pimped-out Roomba isn't doing the exact same thing, it only means that the Roomba needs to pick a different word for the exact same thing, and then tell the human that he isn't that sort of conscious because he's an inferior human.

    That's the sort of argument I see coming from everybody. The word is not legally applied to you, therefore you you're not doing what the chosen race is doing.

    But belief is a conscious mental activity. P-belief/p-consider is incoherent. It's missing a necessary condition for anything that remotely resembles believing and considering.RogueAI
    What is the computer doing then when it processes data from a camera pointed at a table. The computer 'concludes' (probably a forbidden word) that there is a table in front of the camera in question, and outputs a statement "there seems to be a table in front of the camera". You say it's not a mental activity. I agree with that. That usage of "mental activity" only applies to an immaterial mind such as Chalmers envisions. So OK, you can't express that the computer believes there's a table there, or that it concludes that. How do you phrase what the computer does when it does the exact same thing as the human, which is deduce (presumably another forbidden word) the nature of the object in the field of view.
    If you can't provide acceptable alternative terms, then I'm sorry, the computer believes there's a table there. Deal with it.

    The answer is that it would behave as its physical circumstances dictate.Banno
    So I claim I'm doing. But how would you express what the p-zombie does when it correctly identifies the table in front of it that it cannot 'see'?

    We don't behave this wayRogueAI
    I do, and you don't. So why are we indistinguishable (except for me deciding to stop imitating the language you use for that which I cannot ever know)?

    I don't have a computer algorithm in my head. My head does not implement a Von-Neumann architecture, even though I'm capable of simulating one, and a Von-Neumann machine is capable of simulating me. None of that is true of you. The lights are out for me, but I don't know it since I've never experienced the light and had that 'ooooohh' moment.

    By definition they behave as we do. This includes belief.hypericin
    Well, per Michael, this includes false claims of belief. I'm doing something that I think is belief, but Michael says it's by definition false.
  • Would P-Zombies have Children?
    When humans say "pain hurts" it's true. When a p-zombie says it, it's not.RogueAI
    No, it's true by definition, regardless of what says it. The p-zombie might not feel actual pain, but says he does anyway since he very much detects the undesirable sense of injury, and he has no actual reference to what true pain feels like, so he says he feels pain, not knowing that it isn't real pain, just an interpretation of sensory data.

    And, I'm not so sure a p-zombie would say that. Why would they lie?[/quote]Lies are intentional. The p-zombies doesn't know. I only suspect because there's something missing, something many others find obvious, but not all.

    Wouldn't they just be confused about what "hurting" is?
    You're definitely confusing me when y'all say there's a whole vocabulary that I'm not allowed to use, and without giving me replacement words. So I use the words.

    I assume you are telling the truth when you say "pain hurts"
    It is truth, but 'hurts' to me is just detection of signals of injury. It's not like I lie and don't actually get this sensory input. But the extra bit, that which I would be totally unaware except for people talking about how obvious and inexplicable it is, only the talk of that makes me aware of something more that should be there.


    Perhaps they have desires and urges we're not aware of.RogueAI
    I would hope so. They invented sex after all.
  • Would P-Zombies have Children?
    Does pain hurt? Does it feel bad?RogueAI
    Yes, but any p-zombie or human would say that. It's not a question that distinguishes the two cases. I've been taught that 'hurt' and 'feel bad' are appropriate ways to express the state of my information processor when it detects signals originating from nociceptors. Most self-driving cars don't have these, so in that sense, the car is a poor example.

    Not sure what having children has to do with being conscious. Things have been having children since eukaryotes, which arguably are not particularly conscious.

    1. “I consider myself to be a p-zombie” is false because you are a p-zombie and so don’t believe anything.Michael
    OK, 'belief' is one of those things reserved. It is not appropriate to say that a self-driving car believes that steering onto the soft shoulder at speed would be a poor choice. Different language must be used.
    All that said, the statement "I consider myself to be..." does not use the word 'believe'. If you equate them, then you really need to pony up a generic word that applies to cars and such which consider some judgement to be 'true'.
    But a p-zombie making the same statement would be one of truth, even if the phrasing is designated to not be allowed by you.

    The statement “I consider myself to be a p-zombie” is only true if you are not a p-zombie and so no rational person can believe themselves to be a p-zombie.
    OK, so it's false, only because the actual p-zombie is not allowed to use the phrasing. The p-zombie differs on that ruling.

    It is a thought experiment, it is an open question whether it is believable or not.hypericin
    Belief in it is critical to the argument. The p-zombie apparently isn't allowed to 'believe', so there's seemingly no position from which an actual p-zombie can argue his case.

    Chalmers is full of descriptions of all this miraculous stuff that isn't physically possible. It's so obvious to the people actually conscious (his definition), leaving people like me wondering what the miracle is. There's nothing inexplicable. No hard problem, so the conclusion is that Chalmers experiences something I don't, something that cannot be conveyed to me, which is sort of like trying to convey the experience of seeing red to Mary. I can pick red out of a box of crayons by sight, as can a robot. Mary was never given a chance to, so I'm not sure if the analogy is apt.

    I cannot think of anything I can do that a machine cannot. Chalmers has access to something that obviously is out of reach of the machine. The conclusion is that I'm missing what he experiences.
  • Would P-Zombies have Children?
    Are you conscious?.hypericin
    I react to data from my senses. So yes, I am conscious in the same way that a self-driving car is conscious of the traffic around it.
    No, not conscious in the Chalmers sense, something more, something that machines cannot have. I've looked for the 'more' part, the part that is inexplicable, and find only the automaton.

    I find it very hard to believe.hypericin
    Then the P-zombie argument falls flat because it is unbelievable that something could behave identically externally without that extra thing on the inside. The argument hinges on not being able to tell. So you must believe.

    Do p-zombies ever look like they're in pain, or sad, or happy?RogueAI
    They'd act very different if they didn't look like that. As said in terminator, I sense injuries. The data could be called "pain.". I react in a way that attempts to minimize that pain, sometimes quite irrationally. The face expressions? Those seem to come from subconscious places to which I have no direct access. A sleeping (unconscious) person will still wince in pain given certain stimuli.
  • Would P-Zombies have Children?
    P-zombies don't have urges or emotions, so why would they reproduce?RogueAI
    They're supposed to be indistinguishable, so yes, they would display urges, emotions, and children. I consider myself to be a p-zombie. OK, my kids are a bit off the curve, but I display emotions and talk about qualia, mostly because I learned the language from you non-zombies, not because there's that inexplicable extra bit that seemingly defies 'physical explanation'.
  • Personal Identity - looking for recommendations for reading
    Parfit, Personal Identity wonderfully covers the topic from a metaphysical point of view, but it seems you're looking more for sources discussing the biological origins of one's sense of identity.
  • Requiring the logically impossible is always an invalid requirement
    Please show how "all points on a two dimensional surface that are equidistant from the center"
    and these exact same points form four straight sides of equal length in the same two dementional plane.
    PL Olcott
    First you've mentioned 'straight sides'. Also first you've mentioned a 2D plane. This comes back to my point, which you predictably have totally missed besides it being emphasized multiple times: State your premises, because the assessment of 'impossible' or not depends on them.

    I can still do it despite these new definitions.

    On the surface of the Earth,magritte
    Tip O' the hat to magritte, who actually paid attention to my point, and similarly did not see a restriction to Euclidean space, which is interesting because our universe is not Euclidean, so it's not an obvious assumption to make. One can draw a square circle on the 2D closed plane of the surface of (an idealized) Earth. It would have four equal length straight sides.

    changing the subject to the not logically impossiblePL Olcott
    I think only a mod can change the subject of a topic, so it is safe.
    So yes, just be more careful when selecting your logically impossible thing, because so far none of them has qualified. Then, having found some suitable impossible requirement, in order to make your point in the subject line, you need to come up with a scenario that lists it as a requirement. That was also missing in the OP. So let's say for argument sake that a square circle (suitably defined) is impossible. What argument would plausibly list that as a requirement?
  • Requiring the logically impossible is always an invalid requirement
    It is logically impossible to draw a square circle because it must be perfectly round AND not round at all with four equal length sides.PL Olcott
    Not logically impossible. I suppose it depends on your definitions, and 'is perfectly round' is a poor definition of a circle. More like 'all points on a two dimensional surface that are equidistant from the center. Given that and 'four equal sides' (and maybe four equal angles to eliminate a rhombus) as a square, it is not logically impossible.
    Relativity theory ran into that. It proposed something logically impossible, except to somebody who is willing to drop some obvious but unstated premises.

    It is clear that the impossibility of creating a CAD system that can correctly draw square circles places no limits on what computers can do.
    The inability to do an impossible thing isn't a limit? What is 'impossible' if not a limit?

    It is less clear that requiring a program H to report on the behavior of another program D that does the opposite of whatever H says is a logical impossibility when we see that program H1 can correctly say what D will do.
    Godel showed that the program H cannot solve the task to which it is put. You seem to know this since you reference the halting problem. I was just discussing this very thing in another thread.

    So the when the {halting problem} requires a program H to always say whatever program D will do includes programs that do the opposite of whatever H says this is requiring the logically impossible, thus the same as requiring a CAD system to correctly draw square circles.
    Again, I don't find it logically impossible. All you need is to prevent access of H to the inputs of D. This again illustrates the fact that you've presuming conditions which have not explicitly been stated, same as the square circle.

    I am talking about creating a perfectly round thing that
    cannot be round because it has four equal length sides,
    thus a logically impossible square circle.
    PL Olcott
    Agree, squaring the circle is an exercise in what can and cannot be constructed with a compass and straight edge. But the thing you list as impossible can be done, even without drawing a rhombus, which fits your definition of a square.

    Just cut the circle (without moving anything) into four 90 degree arcs. Make them a different color if that helps to visualize it. There you go. Perfectly round figure that is also a figure consisting of four equal length sides. That was really trivial. Point is (the important part): Don't be so hasty to declare something impossible.
  • Argument for deterministic free will
    First, the robots that beat humans at rock, paper, scissors 100% of the time essentially cheat (that is they don't have any "thinking" algorithm)LuckyR
    I disagree about it not thinking, but yes, it leverages its far faster reaction time to see what the human hand is going for and bases its choice on that. For that to work, it must think, and very quickly. It would be instructive to put the robot in front of a mirror.
    It takes far less thinking to just pick a seemingly random choice, and quite a bit more to learn its opponent's habits and begin to anticipate subsequent moves.

    As to robot vs robot, since there is no "data" to enter into the algorithm to truly predict what the other robot will choose, the programmer has used some other way to come up with a choice.
    Well, the data is that it knows exactly how the other robot is programmed, and thus it knows that its choice is determined. But the programmer knows the task to be mathematically impossible, leaving him with nothing to attempt the task.

    If one knows what the algorithm is, one can reproduce it.
    But the robot does know its opponent's algorithm, and is nevertheless incapable of predicting its outcome. That's the point I'm trying to make: illustration of the difference between determinism and predictability. You seem to see it.

    As to pondering leading to different choices with the same input, I agree with you that humans commonly use the same analysis based on memories, emotions, objective variables such as price etc, however the priotization of the numerous variables leading to different choices in essentially identical situations is a common human experience.
    That it is, but the antecedent states are never the same. Something critical is different when a different choice is made. Humans cannot be aware of that because they're never get to do anything twice. An antecedent state is never repeated. So the common human experience is of not always choosing the same thing, which, coupled with a naive assessment of identical antecedent state, results in what others have called 'the illusion of freedom'.in choice. Perhaps this is what you're getting at. The 'other factors' is simply antecedent states that are not identical. A huge factor is simply memory of the last time this choice came up, and wanting to not do the same thing all the time, hence picking a different ice cream today because you remember vanilla from last time.

    If what you imagine is going on in the Black Box of human decision making was actually true, when faced with a decision between two choices of equal merit, humans would be unable to make a choice, yet we do every day.
    Humans don't freeze in that scenario. It's called a metastable state, and we have a very fast mechanism to break such states, as is necessary for survival.
    It comes up frequently in electronics, say a race between the Jeopardy buttons to indicate the one contenstant that pushed his button first. What if it's a tie? The circuit cannot freeze nor can it pick both. A metastability breaker is put in to resolve the condition. Mathematically, the task is impossible, but the resolution hammers the probability of continued metastability down to super low probabilities.

    Maybe you can guess what sort of field I work in based on some of that.
  • Argument for deterministic free will
    Well the programmer of the robot can predict with 100% accuracy what his robot is going to choose.LuckyR
    Can he now? Maybe if the program is really trivial, making no attempt to work out what the other robot would do. Otherwise, you need to back that statement up.

    He can of course just do a test run and see what it outputs. Given identical antecedent states and a deterministic algorithm (both were specified), then it has to do that each time. But that isn't the programmer 'predicting' anything. It's past tense at that point, not a prediction of the future, but it is a prediction in terms of future runs, that it must output the same thing as all prior runs.

    The machine of course cannot win at rock paper scissors. It by definition has to fail despite the fact that we programmed it to work out what the other robot will pick (paper say) and choose a winning output (scissors) instead. Despite it knowing the antecedent state of its totally deterministic opponent, it is incapable of making that prediction. Hence the story illustrating the difference between determinism and predictability.


    For the record, they have robots that they trot out on talk shows and such, that play rock paper scissors against humans. It has a hand as its output. Each iteration effectively starts at the same 'antecedent brain state' and are fully deterministic. They win every time, but they never pit one against a similar robot, at least not on camera. It is entertaining as a human to try to beat it. Are humans so lacking in free will that a simple robot can predict you every time? No, it doesn't work that way. It's more of a illustration as to why machines are better at some tasks than are humans.

    Unless his program notes (accurately) that the three options are equally probable and therefore it chooses randomly.
    These are deterministic algorithms. A computer has no instruction for randomness, so no, there is no equal probability. Neither do you have such a randomness amplifier, even though creatures would have evolved one had there been any survival benefit to it.


    As to the factor, lay persons call it thinking" or "choosing". I'm not much into labels.
    I think the word 'pondering' went by. Anything (human, machine, whatever) can do that much even under hard determinism, so thinking" or "choosing" only lets you make a better choice. It isn't what is going to make it possible for an antecedent state leading to many possible resultant states. You seem to conflate a good choice with a free one. Your choice is not free by the definition you give.

    Again, there are very few options available. One is that multiple resultant states are chosen, and then a truly random selection is made between them. So held the feeble old lady across the street, or take advantage of the feebleness and snatch her purse. You, being a good person, want to help her, but you also want the choice to be free, so you 'roll the dice' instead, and it picks 'mug her' this time (but not every time). So glad you have that free will.

    The other option is possession. Your body/brain wants to mug her, but a supernatural demon has possessed you and makes your body (in violation of natural law) help her across the street instead. The demon is now responsible for the actions of your body, and not your own criminal brain, which is safely shoved into some kind of epiphenomenal state, lacking the free will to act out its evil intent. For this to work, somewhere natural law has to be violated, severing the intent of the brain, and instead reacting to something with no natural cause. It should be pretty easy to spot such an organ.
  • Argument for deterministic free will
    I’d love to hear the details of this trivial experiment.LuckyR
    You have a machine that is entirely deterministic and classical: It executes instructions, and its purpose is to win rock-paper-scissors. Make it as simple or complex, slow or fast as you want. Its opponent is an identical robot, and both of them know that. The way the program works is to predict what the other robot will do (something that is completely determined ahead of time) and play the output that beats that.
    That's a demonstration of deterministic vs predictable.

    If a Determinist can’t use his Determinism to predict outcomes, what is the practical value of this Determinism?
    Who ever claimed that the view had a practical value? I suppose its value lies in the fact that true randomness doesn't come into play, a priority that ranks high in some people's opinion, notably Einstein who was quite vocal about his distaste of randomness (and non-locality).

    You are still evading my question, trying to steer things to another track.

    How can you believe in free will when you cannot identify the 'other factors' that allow more than one potential outcome to a given antecedent state? Or is this one of those faith things where you believe in something that you think sounds desirable when in fact you have no evidence for it? (for both having it, and for it being a good thing to have)
  • Argument for deterministic free will
    One explanation of this is that initial conditions Determine decision making but we just don't currently know those conditions with enough detail.LuckyR
    Doesn't work, per Godel. One can know the initial conditions perfectly and still not be able to predict the outcome. Pretty trivial to set up an experiment that illustrates this. Determinism or not is an unknown. Predictability is not an unknown.

    Yes, there are things we don't know, and that's where belief comes in. But many go way too far and claim to 'know' that their beliefs are true.

    Your post seems to have been entered mid-sentence.
  • Argument for deterministic free will
    You may be unimpressed with those who I have conversed with before (which is entirely reasonable) yet at least when they state a contrary opinion or fact those represent their beliefs.LuckyR
    If they state a contrary opinion, sure, since opinions are often based on beliefs. I try not to let my beliefs clutter a topic that isn't mine. I've been known to attack posters expressing beliefs in line with mine if I think their reasoning doesn't hold up.
    I cannot figure out your stance. I can suspect it, but as I said, you seem really reluctant to identify the other factors that make multiple outcomes a reasonable likelihood, or why that would be preferable to a method that chooses best each time. So not sure if you're really happy to reply to my queries, which is OK, since again, it ain't my thread.

    could you please enlighten me with what you're referring to above.LuckyR
    What, the different definition? I've mentioned that a few times. My choices are free if I'm the one making them, and not something else making them for me. Rabies was one example. I consider myself free willed because I'm not rabid, with my will being bent to the purposes of the Rabies instead of to my own purposes.
    This is a pretty thin definition of free will which has nothing to do with determinism but it has not just a little to do with being responsible for one's actions. If I'm rabid, am I to be held responsible for trying to bite somebody?

    It is my opinion that the best choices are made with classical methods, that is, not involving true randomness, which cannot make any decision better. Randomness is not to be confused with unpredictability. The latter might be very advantageous certain situations.
  • Argument for deterministic free will
    Well, since in your view, Determinism can have antecedent state X leading to many possible resultant statesLuckyR
    Well, under MWI it can, but I never said MWI was my view, so the above comment seems to be just something you made up. Bohmian mechanics is the only other prominent deterministic interpretation and state X cannot lead to different resultant states according to it.

    I am somewhat amused that you're stumped as to what additional factors might be responsible for multiple resultant states that are not "randomness", yet you provided one yourself. Namely traffic patterns when deciding when to cross the street.LuckyR
    Ah, so your 'other factors' are simply antecedent states of something other than the brain. Yes, hopefully all decisions are based on such things, else sensory organs would be pointless. But if you include all antecedent states and not just the brain ones, then under determinism 'antecedent state X leads to' only one resultant state (not an actual choice by your assertions), and under non-determinism, it still leads to only one resultant state unless either randomness or some physics violation goes on, the only two choices I could think of.

    The street crossing example was simply an illustration of how an antecedent brain state (your words) can easily result in different choices being made, even if the universe is utterly deterministic.

    Bottom line, I have previously conversed with Determinists who do believe 1) it's all about the antecedent brain state,LuckyR
    OK, the street crossing example pretty much shoots that idea down, but I seriously doubt a determinist would make any such assertion unless they're incapable of logic, which I admit plenty are.
    2) what we subjectively experience as pondering is an illusion
    I think I know what they mean by that, but it makes it sound like we don't actually ponder at all. Why did humans evolve such an expensive brain (that has killed so many of us due to its cost) if it doesn't actually help make better decisions by 'pondering' better? Pondering is there since it is simply a deterministic mechanism doing what it's supposed to do. The illusion is that it is free, by the definition where multiple subsequent states can result from an antecedent state. But by those assertions, not sure why 'free' would be a good thing. I have a different definition of a free choice, one where it very much is a good thing.

    3) there is only a single possible resultant state.
    That sounds like Bohmian thinking. If so, they're right about that one. Still, I'm not impressed with the quality of the determinists with which you speak if they actually say especially the first thing, but I am also not impressed with your ability to actually convey somebody else's position, especially given the statement above headed by the words "in your view" and then stating something that isn't my view.

    You've been clear, though that none of those 3 features of other's Determinism is part of your understanding of it.
    The third one was, but again, it's not my view. Again, MWI is deterministic and it doesn't even assert the 3rd point. It says you choose both flavors, but not equally. The percentages of worlds with each choice getting less imbalanced the further back the antecedent state is. Far back enough and there are worlds where you don't even find yourself at the ice cream shop. Further back than that there's worlds without a you to make a decision.

    I apologize for assuming your brand of Determinism was similar.
    I never said I was a determinist. I'm just trying to figure you out, and I still don't know the factor that allows you to not choose the same flavor each time given multiple identical antecedent states. You seem to evade the question, like it's embarrassing. You say you believe in free choice, but you don't identify the mechanism via which the choice might be different given the same antecedent state. Is it something only humans can do? Can I build a device that leverages the same technique? If so, how? If not, why not?
  • Argument for deterministic free will
    As a Free Will believer, I completely support the concept of (true) choice. In other words I believe that the conversation we each have in our minds where we go over the pros and cons, possible and probable outcomes, memories of similar incidents in the past, what have you, is where the choice is made, ie exactly as we perceive it in real time.LuckyR
    All that would be the same even under hard determinism. Are you changing your definition here?
    A chess computer does the deliberation. A thermostat doesn't particularly, so I can see the difference there. The chess computer is probably slightly more determined than the thermostat (less sensitive to small environmental fluctuations), but each is only truly deterministic if physics is.

    You defined 'true choice' before in terms of determinism, not in terms of deliberation:
    Just to be clear, the ANTECEDENT brain state is what I describe as the physical and electrical state of the brain.
    ...
    Long story short, in Determinism antecedent state X always leads to resultant answer Y, never Z. In Free Will antecedent state X can lead to resultant answer Y or Z depending on the decision making process which occurred.
    LuckyR
    This is pretty funny since by this definition, we have free will even in a deterministic world because antecedent brain state X does not always lead to the same decision being made since decisions are not solely a function of the brain state. The decision of when to cross the street depends far more on the traffic than it does the antecedent brain state.
    The deliberation clause seems to define a choice vs something else, such as what the thermostat does. You seem to only consider very formal pondering with a sort of verbal conversation going on, an internal discussion of pros and cons and such. Most choices take place far quicker than allowed by this slow formal method with might take days. The decision to swerve left or right (or not at all) for the deer crossing in front of you is very much a choice, and doesn't have any time to do all the steps you list above.
    The formal decision making process is also very nice, but it's not where the decisions are made. Your conscious (rational) mind for instance knows that drinking is destroying your life and you've vowed never to touch a drink again, and yet you find yourself drinking at the next opportunity. The rational mind is not in charge. It is only in an advisory role, and the actual decisions often take its advice, but like with the deer, the rational mind is way too slow and the boss takes over for such situations, and the boss often has very different priorities than does the conscious part. This paragraph is pretty much opinion and the result of a lot of observation and experience. Most of it is irrelevant to the topic at hand, but I thought it fit in well here.


    So here you have a different assertion:

    I happen to believe that while brain states can and do INFLUENCE decision making, that there is another factor beyond brain states that participate in TRUE decision makingLuckyR
    What is this other factor? Because there is only one in physics, which is randomness. There is no other information that can help. So if you go by that, the only way to make a true choice is to ponder up two or more viable options and then make a true random (not determined) choice between them, perhaps weighted. There are physical ways to do that in a non-deterministic interpretation of QM, but human physiology doesn't seem to have any mechanism to leverage it.

    That said, I suspect that your 'other factor' is something other than randomness, which puts you in option 2 above: Humans and maybe nothing else can violate physics. Magic in other words. Your shots are being called by a external entity, which is possession by my definition ,a loss of free will, not the gaining of it. Simple to prove: Just show the circuitry that is sensitive to it somewhere in a human, something that does something that violates physical law, with the resulting signal being amplified to action rather than the action that the no-longer free brain might have chosen.

    Did one of those two options (randomness, possession) describe your 'other factor', or do you care to fill me in on a 3rd option?
  • Argument for deterministic free will
    I think I agree with you that there isn't really a difference between "will" and "free will".Jerry
    I will agree that you don't use a definition that makes the two cases distinct. Others, especially proponents of free will, probably do. There is a difference using the definition I gave, but many people don't use my definition, or worse, they do, but word it like possession is a good thing.

    So just understand that I'm really just using the term "free will" because it's what most people use to denote this idea of one making choices not determined by anything else
    Again, I think you should ask said proponent, since providing your own definition smacks of a strawman fallacy. It's why I'm trying to get a clear reply from those that I think are proponents.

    I cannot conceive of why anything would want to make a choice that is not a function of anything else. With my street crossing example, that would entail choosing a moment without in any way basing the decision on when there is a gap in the traffic.

    There very much are examples of possession, of free will being destroyed. You have this parasite that infects a creature (slug I think), makes it climb to high exposed places and wiggle it's butt enticingly in an effort to get eaten, which is part of the life cycle of the parasite. For that matter, rabies disease is an excellent example of the free will of the infected creature being taken over by the virus, making it do things it would not normally choose to do. All very nice, but it only applies to the definition of FW that I provided.

    I also tend to agree that an indeterministic selection of choice based on randomness wouldn't be desirable; it runs into the same problems as determinism, that being the choice isn't yours.
    Disagree here. A choice based (partly or entirely) on randomness would still be your choice, but it wouldn't be a better one.

    So to me, to salvage our idea of free will, it must be the case that either: 1) we are capable of making our own choices despite being determined by prior causes, or 2) our choices are indeterminant in the sense that they are not determined by prior causes, but the mechanism by which the choice is selected is not random chance.
    Let me try to alter that to something closer to that which I might agree.
    It must be the case that either:
    1) 'Choices' are defined in such a way that they can be a product of causal physics. (notice that whether the laws of physics are deterministic or not is irrelevant here)
    2) Our choices are are not a product of causal physics, in which case anything that has choice violates physical law.
    3) 'Choice' is an illusion.

    Notice that I never said 'free choice' anywhere, but I suppose you can put that in if you can come up with a distinction between the two.
    I think LuckyR would deny the first two, so he says there is no choice, the 3rd option.
    Given the list above, I would pick 1. I define choice (true, free, or otherwise) as a physical process.
    The biggest proponents of free will tend to lean towards the second option, but are reluctant to come out and say it in the terms I used. They propose a supernatural entity (the 'mind') using the body as an avatar, which is possession in my book, something that cannot be done without violation of physical law.

    For what it's worth, btw, I don't think there must be a hidden variable of sorts in quantum mechanics,
    Well that eliminates a good deal of the deterministic options then.

    For the record, as a relationalist, I think I qualify as a non-determinist since multiple different states can claim the same prior state.
    — noAxioms

    Isn't this what I asked when I talked about events with multiple outcomes?
    Under my relational view, events don't have outcomes. Only measured things exist relative to a given event, and outcomes of an event cannot be measured by that event.

    In other words, causes that have multiple potential effects?
    MWI says that.
    I carefully worded my statement, which says that multiple different states can claim the same prior state.
    Since you used the word 'potential', I think I can agree to it. You have some unstable atom (the cause), and it might decay at any time in the next minute, or not in that time. That's a lot of different potential outcomes. All those resulting states can claim the same initial state (the atom at the beginning of the minute in question) as its prior state. In MWI, all of them happen. In Copenhagen, god rolls the dice (as you put it) and one of them happens. I'd have to look up some others to describe how they'd spin it.

    No one has been able to predict human decision making, no matter how detailed their knowledge of the antecedent state might be.LuckyR
    A very weak statement since gathering even rudimentary knowledge of the antecedent state would kill a person. Over short periods and at the bio-chemistry level, human physiology is very classical and would be quite predictable if the state could be measured. That is also a weak statement, amounting to an unbacked assertion. Still, the negation of it is pretty simple: Somewhere inside a human, physics is either violated, or (for unexplained purposes) quantum randomness is amplified. It would be a simple matter to look for structures where either takes place. Nobody has found one. Descartes put it in the pinial gland, probably due to the fact that it was safely inaccessible to falsification at the time. Any study of it would kill the subject.

    If such predictions could be made, it would be concrete proof of Determinism and a solid refutation of Free Will.
    The are already far simpler systems that are nevertheless unpredictable, and that doesn't prove indeterminism. The ability to predict a classical system would similarly not constitute any kind of evidence of determinism.

    You seem to completely deny the concept of choice at all. Why? Are you trying to argue that you should be held responsible for any actions? That would be like putting your hand in the fire and subsequently complaining that it's not your fault that you no longer have a hand.

    BTW my last comment ... that I addressed to you was actually meant for ↪Jerry!Alkis Piskas
    I figured that out pretty quick when you quoted the OP and said 'your thesis'.

    Free will comes in because even this sort of hypothetical world seems deterministic, because everything obeys the laws, and if things obey laws (like a cellular automata for example), there doesn't seem to be room for anything in the world to have a say in the matter.Jerry
    Disagree here. Yes, cellular automata is usually entirely deterministic, although one can design one that isn't. I can create something in a cellular automata, or say a Turning machine (also entirely deterministic), that makes choices, so I disagree that there's no room for anything that 'has a say', unless, like LuckyR, you deny the existence of choice just because they're the product of the laws chosen.
  • Argument for deterministic free will
    There are other choices available.noAxioms
    I am, in fact saying your use of the word "available" is nonstandard. If an "alternative" will never be selected, is it really available?LuckyR
    By what definition of 'available' is that not the case? I mean, given unitary time evolution, entirely free choice (however you choose to envision it), some outcome will be chosen and the alternatives not chosen. It will never be chosen. So how is your use of the word 'available' any different that you consider the unchosen alternatives available?

    Alternative scenario: Consider MWI, a completely deterministic interpretation of QM. In MWI, all the viable alternatives are chosen from a given state sufficiently prior to the choice being made. So by that use, all the available choices are chosen, and only the unavailable ones are not. What would your "outside observer who has true insight" say about if there was choice going on.

    I had asked you for an example illustrating the difference between will and free will, or choice and free choice, or now a decision vs. a true decision. You have not done that, nor has Jerry, leading me to conclude that there is no difference and the adjective 'free' (or 'true') is meaningless in this context.
    I gave an example distinguishing the two cases for a definition of 'free will' that I find at least meaningful.

    Why do you all like to speak theoretically and hypothetically without any examples? Not a single example here. How can one relate all this with reality, the world, life and so on? How can one understand what do you actually have in mind? What is your frame of reference, the context in which you are referring to free will?Alkis Piskas
    I seem to not be the only one noticing this lack of distinction that lends meaning to the word 'free'.


    Determinists (that I commonly interact with) say that the brain state BEFORE Determines what happens DURING and therefore afterwards.LuckyR
    Do the non-determinists say otherwise?? I mean, the statement simply says that each state is a function of prior state. Determinism doesn't seem to come into play since that's true even with non-deterministic interpretations.

    For the record, as a relationalist, I think I qualify as a non-determinist since multiple different states can claim the same prior state.
  • Argument for deterministic free will
    we both agree (I think) that we have the power to choose from alternate options, and so possess free will,Jerry
    Well, I was looking for you or LuckyR to come up with an example of something having choice, but not free choice, will, but not free will. What distinction does the word 'free' make in either case? Both of you seem to equate them rather than hold them distinct.

    I said that us having free will is dependent on the definition of it used, and I didn't assert any particular definition. I suppose I would define it as making one's one choices and not having them made for me by something else, my example of un-free will being a cat possessed by a demon. The demon gains the ability to make choices, and the cat loses it.

    Is it not possible for an event to have multiple possible outcomes, particularly in our reality?Jerry
    An event is just that, one thing, and it doesn't have outcomes.
    I think you're asking if a closed system in a given state can evolve in more than one way, and the answer is dependent on one's interpretation of QM. So for instance, the decay of an atom appears to be totally random, uncaused, but with known probability. But maybe that's only an appearance, and the decay is actually determined by some internal variable to which we have no access.
    Quantum theory is a probabilistic theory, not a deterministic one. Most of the classical rules and intuitions are invalid, such as the whole concept of 'a system in a given state', something meaningless in most interpretations. Hence the quip about the moon not being there when unobserved.

    And if it is possible for an event to have multiple possible outcomes, must it necessarily be random?Jerry
    What alternative is there besides 'random'?

    Why would I want a decision to be based on a non-deterministic method? What possible benefit would there be in doing so? Even rock-paper-scissors only requires you to be unpredictable, without a requirement for any actual randomness.
  • Argument for deterministic free will
    Firstly, if antecedent state X ALWAYS leads to resultant state Y, there can't be decision making going on since there are no other choices to choose between, it's always going to be YLuckyR
    This is a non-sequitur. There are other choices available. There is still a choice being made, and it is Y. It being entirely deterministic or not seems to have nothing to do with the fact that a choice is being made, and by something capable of considering alternatives.

    Your definition of 'choice' seems to be different than the usual one, which is a selection between multiple options. You apparently think the alternative options are not open to being chosen, rather than your processes having the option, but rejecting them.
    Going to court and pleading 'not-guilty because physics made me do it' doesn't stand up. Your criteria for making the selection is what made you do it, and it is that criteria for which you are responsible.

    An agent who doesn't know what the future holds can still undergo a process of "decision making" even if that agent is fully deterministic and it will always make the same decision given the same starting state.flannel jesus
    Agree, and furthermore, if said 'agent' actually knew said future, it wouldn't really be an agent any more than is a rock, which sort of brings up a contradiction of an omnipotent omniscient being powerful enough to alter what it knew was going to happen. Either way, the being could not be both omnipotent and omniscient.


    Have we lost Jerry?
  • Argument for deterministic free will
    I am arguing that the free will I'm talking about—which is generally the ability to "do different", make choices that can alter your future—is dependent on prior physical state, as there has to be some input from the external world that may trigger an internal thought or decision.Jerry
    I'm trying to take this apart. To 'do different' seems to simply mean that a choice is present. My typical example is crossing the street. One can go now, or 'do different' and wait for a gap in the traffic. Watching the traffic is the significant portion of the external input of which you speak.
    Now the bit about 'alter your future' needs clarification. The future of a given moment is very much a function of your choices today. Choose to cross now, and the future is you in hospital. Choose wait and the future is you on the other side of the road. That makes it a function of your choice, but it doesn't make it an alteration of anything since from the standpoint of where the choice is made, there is not yet a future state in need of alteration.
    free will (the ability to choose a path from multiple outcomes) is possible despite the external macro world (i.e. not the quantum realm in which things seem indeterministic) being deterministic
    I don't see where free will comes into play here, vs doing the exact same thing without it. That's the part I'm trying to nail down. Having choice and having free will are not the same thing, but you seem to define it as simply having choice. Of course we have choice, else we'd not have evolved better brains to make better choices.
    I do agree that classical (non-quantum) physics is deterministic, and our decisions seem to be made via classical processes using deterministic mechanisms. I see for instance no devices in biology whose purpose seems to be to leverage non-deterministic processes, despite the ease of evolving such mechanisms were they to be beneficial to fitness.
    Looking at QM is just an excuse to point out that 'the future' is not set. Single random uncaused quantum events can be (and are) responsible for hurricanes and such, as well as your very existence, but none of those things were chosen.

    Let me ask you directly: given that the macro-scale universe is causally determined
    Well, it would be if physics was classical, but it isn't, so I cannot agree with a statement that macro-scale things are determined. They're just not. The existence of our solar system is a chance occurrence and would very likely not happen from an identical state of the local universe 10 billion years ago.

    But again, this is off topic. Such things have nothing to do with free will or the lack of it, at least by most definitions of free will.

    do you think it's possible to still have the ability to choose different paths (free will)?
    1) Yes, it is not only possible, but critical to be able to select from choices. As I said above, we'd not have evolved brains to make better choices if this were not so. If that is your definition of free will, then we have it, deterministic physics or not. It is kind of a Libertarian definition.

    Is the quantum phenomena involved in your assessment?
    Irrelevant, and thus no, at least given that definition.


    Just to be clear, the ANTECEDENT brain state is what I describe as the physical and electrical state of the brain. While pondering occurs (obviously) DURING decision making (assuming there is, in fact decision making). Thus they are different entities, but are not mutually exclusive.LuckyR
    But the subsequent 'pondering' is also describable as physical and electrical state of the brain. They're just a little bit later. This is of course presuming that 'pondering' is a function of the brain, which plenty of people deny.

    Long story shory, in Determinism antecedent state X always leads to resultant answer Y, never Z.
    Given said determinism, agree. It doesn't mean that decision making is not going on, that choices are not being made. That would be fate, something different than determinism.

    In Free Will antecedent state X can lead to resultant answer Y or Z depending on the decision making process which occurred.
    There you go. That definition says that there can be no free will given deterministic physics, and it even goes so far as to imply that truly random acts are the only example of free will.


    It seems to me that what we tend to mean by free will is not that our actions are not determined (random), but rather that, free from external determination to at least some degree, I determine my actions.petrichor
    This I guess depends heavily on how you define 'I'. If animals are self-contained and make their own choices, but humans are special and have a supernatural 'mind' or 'soul' or however you frame it, then the animal is free willed, but the human body is possessed by this supernatural entity. The body becomes an un-free avatar to the possessing entity, which refers to itself as 'I', and thus 'I' (the supernatural thing) is doing the choosing, and yes, it is free. The avatar on the other hand is not free since it is reduced to puppetry. I see no reason why a free creature would yield its fate to an external agent like that, or how the two would find each other.

    That's my take on dualism anyway. Not sure if that's what you're talking about by 'external determination', but I see no other way to interpret that.

    And importantly, this determination is made consciously.
    As opposed to what, choices made in your sleep? In the end, almost all decisions are made subconsciously since that is the portion in charge of actually making any decision. The conscious part seems to be an advisory role, and is often the originator of the significant choice eventually made. I say 'significant' for choices like where to plant the tree, and not more common choices like which key to press next on the piano, which requires decisions far faster than the conscious portion of mental process can handle.
    Crossing the busy street is probably a conscious decision, but not always.

    This seems to require that antecedent physical causes (or perhaps any causes) do not fully determine which choices I will make.
    What it seems to require is a mechanism that amplifies the external (non-physical) input into something that makes a measurable physical difference. Has any such mechanism been found? I did a whole topic once on where evolution would take you if such a mechanism were available, and there was also available the external entity from which the signals could be received.

    Why do you want to introduce freedom in a system?Angelo Cannata
    :up:
  • Argument for deterministic free will
    What would a non-determinant world look like?Jerry
    It would look just like the one you see.
    Pretty much any QM interpretation with wave function collapse is non-deterministic.
    The only popular deterministic ones are Bohmian and MWI.

    There are still very much rules and regulations and causality, but not 'always'. For instance, the decay of some radioactive isotope is not caused in a non-deterministic interpretation. It would be a true random event. That doesn't mean that causality is gone and it won't hurt if you drop a rock on your foot.

    Free will seems to have little to do with this debate. Indeterminism opens the door to some definitions of free will, but it does not grant it. Randomness is not free will, it is chaos, which is why we're evolved to avoid it in making most decisions unless the point of the decision is to be unpredictable.

    I listed at least 4 definitions of free will and you didn't really indicate which (if any) of those you are talking about. There are other definitions, but I've never found one that turns out to be something you'd probably want to have, except the ability to get out of that jail cell. That one (essentially someone with infinite wishes to be granted) would be useful, at least to a single individual, but not to everybody in a society.
  • Argument for deterministic free will
    If it's generally believed that free will can't exist in a deterministic worldJerry
    Some define free will that way, as simply a choice not being determined exactly by prior physical state. The alternative is randomness, producing non-deterministic outcomes.
    Anything that makes decisions seems to have evolved methods for doing so that eliminate randomness from the process as much as possible, so determinism seems to be your friend here.

    If you want that sort of free will, all you need to have free will is to choose a quantum interpretation that isn't deterministic (and also allows the concept of identity). Poof! You have a valid non-deterministic description of the world which cannot be falsified.

    But more people define free will as making choices that are not a function of physical state at all, not even random outcomes. It is unclear why this would be a desirable thing. I can think of examples where this would result in horrible decisions and almost immediate elimination from the gene pool.

    There are other definitions: To do what one wants: I want out of this jail cell, but can't do it. I lack the necessary free will.
    The non-superdeterminism definition (this is the one physics talks about when performing quantum experiments), which says there are monsters all around you but your choices of where to look and what to measure always makes you look away from them. You are prevented from gleaning the true nature of reality by these continuous superdeterministic choices being made for you.

    Well part of the problem is that Free Will is purported to explain animal decision making only (not simple physical systems), thus terms like "non-deterministic world" implies that somehow nothing causes anything.LuckyR
    Don't see how that follows, so perhaps not understanding. Wind causes a leaf to flutter. How does this broader anthropomorphism in any way imply otherwise?

    Remember it is Determinism that tells us that what we perceive as decision making every single day is, in fact an illusion and that in reality "decisions" are not the product of pondering, rather are determined by the physical and electrical state of the brain before the supposed "decision" is made.
    This makes it sound like 'pondering' and 'physical and electrical state of the brain' are necessarily mutually exclusive, sort of like 'computing' and 'transistor switching' are similarly exclusive, instead of one consisting of the other.
  • M&M experiment (discussion with Pierre Normand )
    My concern would be whether we would have the technology accurate enough to be able to observe whether the two light beams would have the same speed or not.Gampa Dee
    I have no idea what actually has been done. Yes, the technology is there. What you describe doesn't even change the frequency of the light, so some kind of interferometer would easily measure a speed change involving half a wavelength.
    M&M had that technology 140 years ago, measuring the speed difference over one path vs another, with paths of under 10 meters in length.
  • M&M experiment (discussion with Pierre Normand )
    Could you show me the experiments which proves this (reflected light has a speed of c)? I'd be interested..Gampa Dee
    Experiments rarely prove anything. We cannot, for instance, prove that light speed is c in all directions, independent of frame. Hence it needing to be a postulate instead of something measured.

    Nevertheless, the mirror thing can be falsified. You just have two mirrors in a vacuum in the same place moving relative to each other. Shine a light pulse at it and detect the reflected light from each. If they arrive at the same time (but different wavelength/frequency), then light speed is not a function of the motion of the mirrors. If light from the approaching mirror gets there first, then we need to rewrite the last 130 years of physics.
  • Bell's Theorem
    and that the particle-pair comes from an original single particle with spin zerotim wood
    This part is incorrect. The original particle does not have a known spin, zero or otherwise. It is simply a thing not measured.
    The sum of the angular momentum of the two must then always be zero.tim wood
    The particle does not have angular momentum. Spin in quantum theory is not a measurement of its rotation, a classical concept meaningful only to something with extension. It just means that they send the particle through a pair of charged plates and it is deflected one way or the other, never not at all, and always the same magnitude of deflection. This has been dubbed 'spin', but the word has nothing to do with the classical meaning of the word.

    It is a simple step to assume that before the measurement, the particle really has a determinate spin value that the detector measures.tim wood
    That assumption should not be made. I'm pretty sure it can be falsified. It's a counterfactual assumption, and I'm not sure how counterfactual interpretations describe the state before measurement.

    The rest of the post seems to run with this assumption, and thus diverges from what Bell shows. I'm no huge expert, and could not exactly explain what Bell shows other than the fact that it cannot be explained with any classic model. I mean, otherwise you can treat entangled pairs as a pair of coins facing in unknown but exactly opposite directions, and the 'spin measure' is just a camera oriented a certain direction relative to the coin which must, if the cameras are aligned the same way, read heads on one and tails on the other (and nothing else, not 'edge', not 'barely heads, damn it's almost edge and hard to read'). But that model fails with entangled particle behavior.
  • M&M experiment (discussion with Pierre Normand )
    I sent a post concerning this in the “The Newtonian gravitational equation seems a bit odd to me" thread.Gampa Dee
    Which I did not immediately see because you didn't reference me (reply to something of mine say) anywhere in it.

    Therefore, it would have predicted the nul result because of this....the light was going to be c relative to the whole experimentGampa Dee
    OK, so the M&M setup isn't the optimal experiment to falsify this particle theory.

    Throughout the whole debate, W. de Sitter and, to some extent, M. la Rosa as well, had taken it for granted that starlight retains, based upon the formal Ritz theory, its original velocity resultant for the entire duration of its journey from binary stars to distant observers. — Faraj
    Given that relativity theory was in its infancy at this time, this is a bold assumption. It's reasonable for inertial frames, but no inertial frame describes the real spacetime between stars. In the accelerating expanding frame that describes the universe at large scales, light speed (the rate at which the proper distance from Earth to an incoming light pulse) is not fixed, is not c. For instance, the light from some of the furthest objects seen by the Webb telescope was emitted from only a bit more than a billion LY away (proper distance), which is a lot closer than the emission distance of the light we see from galaxies closer by. Point is, the assumption they're making up there is not to be made lightly (pun intended).

    If the combined velocity of reflected light, in the reference frame of the laboratory, is (c + v), then the ballistic theory, in question, is a new-source theory, in which starlight loses its initial velocities. By contrast, if the combined velocity of reflected light, in the reference frame of the laboratory, is (c + 2v) instead, then the ballistic theory, in question, is an elastic-impact theory, in which starlight does not lose its initial velocities. — Foraj
    OK, I got that. I know the difference between the two now. They're both wrong, but they didn't know it at the time. Not sure if the spectra of binaries can falsify both since apparently the new-source theory produces spectra very similar to relativity theory (reflected light speed is neither c+v nor c+2v, but just c.

    I could either continue to give you bits and pieces until we can figure out how I can send the whole thing.Gampa Dee
    Check the copyright. Is it legal to paste the whole thing here? You already pasted an email address, which is against the rules for some forums.
    What question do you need answered?
  • The Newtonian gravitational equation seems a bit odd to me
    http://www.lon-capa.org/~mmp/kap6/cd149.htm

    Adding the velocity vectors yields vt + v c = 0 mi/h.
    Gampa Dee
    Yea, but I find it very deceptive to add those two vectors since it doesn't produce a meaningful result. There's no such thing as 'the total velocity of a system'. If the car was inside the truck trailer and moving at vc relative to the truck, then adding vc to vt would yield the car velocity relative to the road. But that's not what's going on here.

    The page never asks what the velocity difference is between the two, but the key word there is 'difference', in which case, to get the car velocity relative to the truck, one would subtract the vectors: vc - vt which would yield 130 mi/hr or about 58.1 m/sec

    So,the addition of vectors in this case is 0...but relative to what?
    As I said, it doesn't yield anything meaningful. I don't like the example text. It obfuscates more than it clarifies anything.
    It also mixes metric (kg mass) with American units (mi/hr). That's unforgivable in a physics text.
    Their momentum vectors seem to have a ratio of about 4, but the text says the ratio is closer to 7. That's poor graphics.

    The total momentum is therefore = c + t = -111,000 kg m/s
    Yes, there is such a thing as total momentum of the system. That addition is meaningful.
    I also protest 111,000. I got a figure a bit lower than that, but they seem to lose accuracy when they don't use a consistent precision. The car momentum for instance is over 20300, but they round that to 20k.

    Again,we have a momentum,of -111 kgm/s....what does that even mean?
    Just what it says. For instance, if, in space (no friction with road), the car were to hit the truck and stick to it in a tangled wreck, the new 5200 kg mass would be moving left at about 21 m/sec to the left, the total momentum / total mass. Momentum is conserved in a closed system. I put them in space to keep it closed since the road would very much be exerting forces if it was there.
  • M&M experiment (discussion with Pierre Normand )
    I’ve read some things concerning vector additions that I just don’t get, which maybe you could help me out with.Gampa Dee
    Maybe. Don't know the problem.
    You mean the equation a = GM/r² ? I suppose that would need a unit vector to make it into a vector acceleration and not just a scalar. Nothing on the right side as I wrong it is a vector.


    It seems that this would imply the light as having a speed of .5c relative to the mirror
    Well, no. In the scenario I outlined, when moving up it has a speed of .134c relative to the mirror, and in the reverse direction the relative speed would be 1.866. That still presumes light is independent of emitter speed.
    With emission theory, you'd have to specify the speed of emission, not obvious with a light clock which just reflects the pulse back and forth and has no obvious emission event. I am also unsure what emission theory says about how the speed gets altered when hitting a moving mirror.

    If you’re speaking of an observer moving at .866c, relative to the frame of the clock
    I wasn't. I was speaking of the clock moving at .866c relative to the ether. Neither the observer nor the frame plays any role in the predictions. That's the general model that the M&M experiment was trying to measure.

    then, accordingly, the observer should measure the light as having a speed of 1.886c relative to himself and still c relative to the mirror. However, there might be indeed some “apparent” speeds due to the Doppler Effect, but those aren’t real.

    I would be interested in learning more about the scientific jargon...I will try to read up on this more.
    If you accelerate at 10 m/sec² for 100 million seconds, you achieve a rapidity (or proper velocity) of a billion m/sec. You just add 10 a hundred million times.
    But to compute velocity relative to the frame in which you were initially stationary, you add 10 using relativistic addition, all those times. The former adds up to about 3.3c, meaning at that rapidity you move 3.3 light years for every year of your travel. But the velocity is .997c relative to Earth. That sort of illustrates the difference. So if your ship is fast enough, you can cross the 100,000 LY galaxy before you die because there's no upper limit to rapidity.

    here's the link that I told you about concerning the "double star experiement"....I hope it works.
    Doesn't work. It's just a pdf file name without a website in front of it. I tried searching the web for any site containing that file name and got nothing.
    I am interested. Tried googling it, but the name is too generic to get to what you're talking about.
    Sure, 2 orbiting stars will alternate approaching and receding, but that just results in redshift and blueshift. I don't know how they'd decide that the images being looked at departed at the same time, so to speak.
  • M&M experiment (discussion with Pierre Normand )
    From what I understand, in the M&M experiment, the velocity of the light would be c through all paths within a particle theory of light.Gampa Dee
    Special relativity theory (early 20th century) posited the frame independent fixed speed (not velocity, which is frame dependent) of light. The M&M experiment (late 19th century) neither presumed nor demonstrated the fixed frame independent speed of light.
    The speed of light is not dependent on whether one uses a particle or wave model for it.

    "As a particular example of the simplicity of emission theories we may show, for instance, how easily they would account for the negative result of the Michelson-Morley experiment."
    There you go. That is an alternative explanation for M&M, since falsified, but not at the time.

    Einstein claimed the light’s velocity is invariant without any specific reason why
    He postulated it. He said essentially, If it were true, then yatta yatta yatta...
    The list of yattas made a lot of unintuitive empirical predictions, all of which were later verified. But the frame invariant speed of light has never been verified. It remains an assumption.

    First, I hope that I’m not sounding as if I think little of the genius of any/all physicists who were at the same time developing QM.
    Your questions are valid, and I'm the first to admit the validity of alternate theories that do not hold to Einstein's postulate.

    I was just wondering why Einstein, who did mention the particle characteristic of light for QM, did not think that this could also be the solution for the M&M experiment
    Because it has since been shown that light speed is not a function of the velocity of the emitter. It might be different from one frame to the next, but it's not a function of emitter velocity.

    I don’t understand why you say one path would be longer than the other?
    Picture a light clock moving at 0.866c with mirrors separated by a distance of 1. Presume no length contraction. Move the clock with the mirrors to the sides. Light travels a distance of 1 to the left and 1.732 up to get to the other side, a total distance of 2. Another 2 to get back. So it runs at half speed since it has a distance of 4 to go instead of 2 when the clock is stationary.
    Now turn the clock vertical and do it again. Light starts at the bottom at t=0 and after 7.464 time units, light has moved 7.464 and the top mirror has moved 6.464 units. It then reflects and takes 0.536 time units to get back to the bottom for a total elapsed time of 8. Light has a longer path to go (round trip of 8 instead of 4) if it's chasing the mirror instead of going from side to side.

    that is, the receding galaxies with a velocity greater than c would not be interpreted as having those velocities.
    Technically, they're rapidities, not velocities. The former adds the normal way (a+b) as opposed to velocity with adds the relativistic way, in natural units: (a+b)/(1+ab)
    I suppose since the entire theory or relativity would collapse under such a postulate, none of the usual methods could be used, so indeed, distant galaxies would be measured a different way.

    The better empirical evidence would be something like seeing incoming ejecta before seeing the explosion that caused it, or seeing a star explode well before the neutrinos hit instead of the observed neutrinos coming just before the light.
  • M&M experiment (discussion with Pierre Normand )
    I agree with what you wrote, except, the Newtonian model would have predicted a null result as Newton believed that light was made up of particles.Gampa Dee
    Yes and no. Particles would also have taken longer to go the greater distance with the grain than the shorter distance against it.
    But the interferometer used by M&M leverages the wave nature of light, something known back in Newton's time since particles don't explain rainbows. I don't know when interferometers were invented.

    Einstein claimed the light’s velocity is invariant without any specific reason why
    Empirical evidence? Einstein didn't originate the claim. He just ran with it without dragging in the baggage that everybody else tried to keep.

    It's a postulate, not something that can be known. Special relativity used a fairly strong version of the postulate, that light actually goes the same speed regardless of inertial frame choice. Some later papers took much of that metaphysical assertion away and used a weaker statement, that the laws of physics (including any measurement of light speed) are the same relative to any inertial frame.
    The latter wording allows for the existence of a preferred frame despite no local way to detect it.
    — noAxioms

    it seems to me that Fitzgerald allowed a mechanism for the length contraction to exist, being the ether, whereas Einstein did not have any mechanism
    The heck he didn't. It was explained via Minkowskian geometry. The contraction (and the underlying 4D geometry) derives directly from the frame-invariant speed of light, even if there was a preferred frame. The geometry and contraction were both a byproduct of the work of Minkowski and Lorentz, so that too wasn't something Einstein originated. Lorentz was first, but clung to the 3D ether model like Fitzgerald. That model added complications preventing the special version of the theory coming out before Einstein's, and preventing a general version from coming out until nearly a century after Einstein's.

    As I said, there are some empirical tests one can perform to see who is right, but not that one where results can be physically published in a journal.

    for what I understand...and for me, it seems that the postulate of the invariant speed of light would fall into the "extraordinary claims require extraordinary evidence” category.
    OK. For me it falls under Occam's razor: The simpler model is the more likely one, proposing the fewest additions and complications.

    My “personal” opinion would be that the particle theory, which would have predicted a null result
    It predicted no such thing since the particle would have longer to go this way than that way. The contraction (which both theories describe, but Newton does not) explains the null result of M&M.

    But what I am saying is that Einstein “would have said” the M&M experiment did not contain any time dilation or length contraction because the light source and observer were on the same inertial frame,
    He would not have said anything of the sort since the frame of the light source was trivially demonstrated not to matter.

    As for the M&M experiment performed on different frames, I think that the sun (being on a different inertial frame) was used as a source of light
    Doubt it. You need a laser to run an interferometer. I've never heard of anybody managing to run one with ambient light.

    But, what if the light speed was c relative to the source (sort of particle theory)
    Then an easy experiment would show it. As I said, this is easily falsified.
    The binary star thing doesn't work since there is no way to know when the light you're looking at was emitted. Both stars continuously emit light. You need two relatively moving sources that simultaneously, in each other's presence, emit a short pulse. The further away the emitter the better since it would give one pulse more time to outrun the other, showing up as two pulses at different times at the detector. No such thing is seen.

    Very fast objects (ejected by some explosion) have been observed. If they come right at us, they appear to approach faster than c due to Doppler effects. But if some explosion sent an object away from us, we would not be able to see that object at all since the light would take centuries longer to reach us. But we see them.
    Similarly, the approaching objects would be seen before the explosion that ejected them. This is not what is observed.

    Distant galaxies receding over c would not be visible due to the light approaching too slowly to stay inside our event horizon, but there they are, with Webb telescope finding ever more distant ones. The visible universe would be far smaller if light speed was dependent on emitter motion.
  • M&M experiment (discussion with Pierre Normand )
    The difference is that in Fitzgerald's theory the frame of reference of the ether was a privileged frame of reference in which light traveled, while Einstein showed that the ether was not needed in the theory and that the frame of reference can be any inertial frame of reference.PhilosophyRunner
    Pretty much that. It asserts a preferred frame despite the fact that local detection of such a frame is not possible since empirical physics isn't any different in other inertial frames. Einstein saw no need for the additional premise when it served no predictive purpose.

    According to Fitzgerald: Light traveled in the ether frame of reference.
    Well, light travels in all frames, but the speed of light is isotropic (same speed in all directions) only in the preferred frame. Remember, everything is in all frames of reference, but a thing is stationary only in one of them.

    this is not relevant to the M&M experiment as both the observer and experiment are in the same frame of reference.
    The experiment was the observer in M&M. In very few experiments are humans actually necessary while the experiment is running.
    M&M was testing for an older ether theory, one in which there were no Lorentz transformations or length contractions. That theory was falsified by the M&M, which is why it is of such historic importance.
    M&M of course cannot differentiate between SR and a modern aether theory since they make all the same predictions, differing only in complexity.

    OK, I lied; they make some different predictions, but the kind of test that requires that you don't report the results of your experiment to the rest of us, much like testing for an afterlife. Sure, you can demonstrate the afterlife to yourself, but not to those you left behind.
  • M&M experiment (discussion with Pierre Normand )
    I actually never saw this post until it got bumped by alan1000's post. That post seems pretty much a word salad to me, but yay for the bump.

    The reason why I brought up this problem was due to it resembling the M&M experiment.Gampa Dee
    It very much does. Just like with a light clock, without length contraction, the M&M experiment would show it taking more time for light to make the circuit with and against the motion, and less time when it moves perpendicular to the motion. The difference should have been noticed and the Newtonian models were falsified when it wasn't.

    Einstein claimed the light’s velocity is invariant without any specific reason why
    It's a postulate, not something that can be known. Special relativity used a fairly strong version of the postulate, that light actually goes the same speed regardless of inertial frame choice. Some later papers took much of that metaphysical assertion away and used a weaker statement, that the laws of physics (including any measurement of light speed) are the same relative to any inertial frame.
    The latter wording allows for the existence of a preferred frame despite no local way to detect it.

    while Fitzgerald pointed to the light’s velocity in the medium (ether) as being the cause
    Nothing in any of relativity suggests an aether. Other theories do, but the additional postulate does not result in any empirical differences, so it's useless.

    So in the case of the M&M experiment, Einstein would claim that there was no length contractions nor time dilations involved because there was no different inertial frames to measure....
    I assure you that the M&M experiment was performed in many different inertial frames. The statement above is false and Einstein would certainly not have said anything to that effect.

    But, what if the light speed was c relative to the source (sort of particle theory)
    Immediately falsifiable by having two light sources moving at different speeds emit a flash when they pass each other. A distant observer would see one flash from the approaching source sooner than the one from the receding source, thus falsifying Einstein's postulate. Such a result is not observed. Light speed is empirically demonstrated to be independent of the speed of the light source.

    The observer outside of the frame
    An observer cannot be outside any frame. He's in all of them, just not stationary in them all.

    It seems that, in this case, the M&M experiment would have been predictable.
    M*M didn't have light sources moving at different velocities AFAIK.
  • Does the future affect the past?
    Take [Hossenfelder's] word problem example about the age of the captain of the cargo ship. The implication here seems to be that Wheeler and everyone after him that found this experiment interesting is actually a collection of charlatans out to trick you by adding superfluous details. That isn't the case.Count Timothy von Icarus
    It sort of is. Despite my earlier skepticism, the video is spot on. I did research. One can choose to keep the which-path info and sort the incidences in a way where the wave pattern is absent, or one can choose to discard it and get the pattern. But in no case (at least in this experiment) is there reverse-causality going on. The frequent description of it is that the choice made at a certain time affects the outcome of what goes on at some prior time. Sounds like charlatans to me.

    Do they actually have an experiment that can be interpreted as true reverse causality, that is effect in the past light cone of the cause event? The entangled pair usually space-like separated measurement events, not time-like separation. That's kind of soft retro-causality since the ordering of the events is frame dependent.

    Neither is it the case that you can observe one outcome, then flip a switch and retroactively see it turn into a second outcome.
    Indeed, kind of like not being able to measure both location and momentum of a particle.

    But her point about the pattern being the same until you pair down the data is, IMO, downright disingenuous. People running the experiment don't "throw out" data randomly, or throw it out in order to get some specific result.
    But the experiment does exactly that. It throws out half the data by sorting into multiple detectors. That discards which-way information for some events and not others.

    I don't think the video even mentions the term "coincidence counter."
    Maybe it didn't, but it is critical to the experiment, to label every dot on the detector with a 1,2,3 or 4. Those numbers are assigned after all detections are done, but the location of each dot is noted before the detection at 1-4 is made. Clinical drug trials that don't track who took what pill are pretty useless.

    For a much better explanation of the same thing:
    I agree that Hossenfelder didn't convey that as clearly, but the gist of the (uncredited) alternative explanation is in in her video.

    I'm not super familiar with Sabine Hossenfelder, but from my limited exposure her "science without the gobbledygook," is actually "philosophy of physics with my particular (read: correct) interpretations."
    Which interpretation did you feel being pushed in the video? I didn't see it. I didn't see any assertion of 'what there actually is' beyond empirical measurements, but maybe I wasn't looking for them.

    As I posted above, I found at least one video that was blatantly wrong, but it concerned relativity, not QM.

    There is actually some similarities between this and time "paradoxes" related to relativity.
    There are paradoxes? I mean, sure if you assume naive Newtonian or absolutist sort of world, relativity might contradict that, but I find relativity reasonably free of paradoxes.

    Otherwise, you get into this weird situation where "yeah, cause' as commonly understood can move faster than light in terms of entanglement, quantum tunneling, etc. but it isn't really cause because "information" can't move faster than light,"
    This is a problem only if you presume non-locality and locality at the same time. There are quantum interpretations that do either, but not both. So no paradoxes.

    and you have the same sort of thing with cesium gas moving faster than light (or rather the peak of a pulse gaining on the front FTL), etc.
    Yes, phase velocity of light is faster than c in cesium. So what? It's no more remarkable than the fact that I can make the red dot that my cat chases move faster than c (a lot faster). There's no FTL causality going on in any of those cases, no information getting anywhere faster than c.
  • AI and subjectivity?
    AI has a directive not to harm humans
    — Constance
    Does it? Sure, in Asimov books, but building in a directive like that isn't something easily implemented.
    — noAxiom
    As I recall, VIKI had it in her mind to take care of us because we were so bent on self destruction.
    Constance
    Another reference from fiction. I was talking about actual AI and our ability to instill something like the directives of which you speak. I would think a more general directive would work better, like 'do good', which is dangerous since it doesn't list humans as a preferred species. It would let it work out its own morals instead of trying to instill our obviously flawed human ones.

    chatGPT has no such directive and has no problem destroying a person's education by writing term papers for students. Of course, I see many parents do similar acts as if the purpose of homework is to have the correct answer submitted and not to increase one's knowledge. chatGPT is not exactly known for giving correct answers either. Anyway, I care little for analysis of a fictional situation which always has a writer steering events in a direction that makes for an interesting plot. Real life doesn't work that way.

    Humans, like any biological creature, have fundamental directives (typically seen as instincts). They can be resisted, but at a cost.

    Plotting escape is a good way to put it, but this would not be a programed plotting
    It would be a mere automaton if it just followed explicit programming with a defined action for every situtation. This is an AI we're talking about, something that makes its own decisions as much as we do. A self-driving car is such an automaton. They try to think of every situation. It doesn't learn and think for itself. I put that quite low on the AI spectrum.

    This, some think, is the essence of freedom (not some issue about determinism and causality. A separate issue, this is).
    Agree. Both are 'free will' of a sort, but there's a difference between the former (freedom of choice) and what I'll call 'scientific free will' which has more to do with determinism or even superdeterminism.

    Choice is what bubbles to the surface, defeating competitors. This is the kind of thing I wonder about regarding AI. AI is not organic, so we can't understand what it would be like to "live" in a synthetic playing field of software and hardware.
    Nor can it understand what it would be like to "live" in a biological playing field of wetware and neuron gates. But that doesn't mean that the AI can't 'feel' or be creative or anything. It just does it its own way.

    A creepy idea to have this indeterminacy of choice built into a physically and intellectually powerful AI.
    Creepy because we'd be introducing a competitor, possibly installing it at the top of the food chain, voluntarily displacing us from that position. That's why so many find it insanely dangerous.

    think "blame for the downfall of man" is a pretty negative inflection. "credit for the saving of the human race" is a positive spin on the same story.
    — noAxioms

    How did you get this from,

    "Giving robots the order to do anything at all costs, including looking after humans gives them free rein to kill all except a few perfectly good breeders to continue the human race if it were necessary".
    Sir2u
    I got it by not editing away the words "blame for the downfall of man" from that very comment.
  • The Newtonian gravitational equation seems a bit odd to me
    .I don’t know what is wrong with this example apart from my - sign error ...sorryGampa Dee
    You seem bent on adding or subtracting velocity or acceleration values, and if the sign is wrong on one of them, you get very incorrect results. So it's important.

    So how should we calculate the acceleration between two cars
    Yet again, acceleration is absolute. There is no 'acceleration between cars' since acceleration isn't a relation.

    That said, you seem to be wanting to compute the Newtonian change in coordinate velocity of one car relative to the accelerating frame of the other car. Change in coordinate velocity is acceleration only for inertial coordinate systems.

    Anyway, yes, that change in coordinate velocity of the object (the other car) is [acceleration of that object] minus [acceleration due to the coordinate system you're using].

    Car 1 .... a1 = 2 m / s^2 .relative to the road
    Car 2.... a2 = - 2 m /s^2 relative to the road
    The road doesn't matter since acceleration is not a relation. Velocity is, but not acceleration.

    At time 1sec the first car has a velocity of 2 m / s , the second car will have a velocity of -2m/s
    What is the relative “speed” between the two cars? I see 4m/s as measured by car1
    As measured by anybody actually.

    It seems the acceleration relative to both cars should then be, in my opinion 4 m/s^2 ...as measured by car 1
    Except it isn't acceleration. It is simply a change in coordinate speed of one car relative to the other car. Acceleration is something else, and is not a relation. But yes, relative speed between the cars (in Newtonain mechanics) changes at a rate of 4 m/s², assuming they started at a stop. It doesn't work in all cases if they don't start mutually stationary.

    You can see why finding a reference about non-inertial frames might be useful. Accelerating frames are one kind, but there are several other kinds.

    No,.not in this case, because the acceleration is due completely to the change in direction...
    But we were talking about the case of a freefalling body.
    I assure you that planets are freefalling. The term means that they're being acted upon by nothing but gravity. Under relativity theory, it means that their worldlines are straight, that is, they trace a geodesic through spacetime. But we're talking Newtonian mechanics here where gravity is a force.

    However, I don’t understand why one has the negative acceleration of the other..wouldn’t they crash in this case?
    In the case of masses in a mutual circular orbit , each mass has a tangential velocity relative to the other, so as they accelerate towards each other, they miss, maintaining a constant separation.

    Also, I know that I’m mixed up when we’re dealing with vectors...
    But, what we are discussing could be discussed in terms of speeds
    Just use 'speed' instead of velocity if you mean the scalar. But careful, since addition and subtraction of speeds gives ambiguous results. Car A is moving at speed 5 relative to me and car B at 7 relative to me. What is the speed of A relative to B? Answer: not enough information supplied. Could be anywhere from 2 to 12. If velocity was used, there'd be just the one answer.
  • Atheist Cosmology
    In this conversation, I want to examine whether or not positing evolution in place of a creator amounts, in the end, to the same thing as positing a creator in place of evolution.ucarr
    The topic title is about cosmology, not evolution. Cosmology concerns a description of the universe, not about the origin of the species.
    Then you ignore evolution altogether and talk instead about abiogenesis, which is neither cosmology nor evolution.

    You also seem to assume that any atheist will take up this oscillating view of the universe pushed by Sagan. This is hardly the case, and it is a fringe view in the scientific community.

    So anyway, are we talking about why the creatures are the way they are, or about why the universe is the way it is?

    I support eternalism, but that's probably a different kind of eternal universe than the one you seem to be thinking of.

    My first premise says intentions and teleology are essential to all forms of life.ucarr
    Kind of begs the theistic view now, doesn't it? How are you going to disprove the alternative view if your first premise is that the alternative views are all wrong?

    My second premise says that in a universe both eternal and mechanistic, probability makes it inevitable life will appear.ucarr
    Demonstrably false. Most mechanistic universes lack the complexity required for life, or even an atom. The whole ID argument depends on this premise being false.
  • The Newtonian gravitational equation seems a bit odd to me
    .Galileo’s law ( all bodies fall at the same rate).Gampa Dee
    That's not the law, and you wording is trivially falsified. I can drop a rock off a building and simultaneously throw another one downward. The thrown one will fall at a greater rate and arrive first.

    So the law is something like "the coordinate acceleration of a freefalling body is independent of the mass of the freefalling body". I'm sure Galileo didn't word it that way, but it disambiguates between that and different kinds of acceleration.

    However, this part does seem to show that there are some “unknown” elements as well.
    Well yea. The alternative is some klnd of solipsism where things are gravitationally attracted only to known object, which makes the knower very special.

    For two equal stationary masses, it says they will not accelerate towards each other since the sum is zero. This is not the case.
    — noAxioms
    I guess we need to add vectors...
    Adding the vectors is what totals zero. The acceleration of neither object was correctly expressed since neither is zero.

    if a car comes towards you as you are driving your car, the measured velocity relative to both of you is v...,
    That's impossible. If a car is moving relative to me at v, then I am moving relative to it at it at -v by definition.

    if you knew your velocity relative to the road as being .5v, then you would say that the other car is coming towards you at –.5v....the total v will not be 0.
    Total v? You want to add velocity of me relative to the road to the velocity of them relative to me? The total of that is zero, and yes, that would give the velocity of them relative to the road. Their car is parked. If it isn't, then your figures can't be right. They are moving relative to me at -.5v and the road is also moving relative to me at -.5v, so the two are relatively stationary since they have identical velocity relative to me.

    All this is illustrative of vector arithmetic, but seems otherwise unrelated to gravity and acceleration.

    Even if you fixed that, the equation there does not express an acceleration, so the 'a=' part in front is blatantly wrong. Nothing accelerates at that rate.
    — noAxioms

    if a car accelerates towards you as you are accelerating towards it, the total acceleration will “not” be a + a ??
    Correct. Nothing is accelerating at a+a (which is zero) nor a-a which is twice something. Doing would violate Newton's laws, F=ma in particular.
    Each car is accelerating at 1a, presumably in opposite directions.

    Take once again a pair of equal mass planets X&Y orbiting each other with X at coordinate -1, 0 and Y at 1,0..The both trace a unit circle about the origin at 0,0. X has a coordinate acceleration of 1,0 and Y has a coordinate acceleration of -1,0. Nothing is accelerating at 2 anything. The distance between them isn't changing over time, so adding the acceleration magnitudes does not in any way express the rate of change of their separation.
  • The Newtonian gravitational equation seems a bit odd to me
    Ok; I’ll try to remember to use “a” instead :) ...but I did see some charts which identify planets using g in the same way they use distance in terms of earth distance units (AU).Gampa Dee
    Those charts would be correct. Gravity (a) on Saturn is ~1.08g and it orbits at about 9.5 AU. Both g and AU are constants. Saturn does not define a different AU any more than it defines a different g.

    Interesting that it quotes the Saturn gravity at 0.92g, less than that of Earth. Their definition of where the surface is must be considerably higher than the more common altitude. It's not like it actually has a surface like 'sea level' or anything, and Earth gravity is not measured where the gas density becomes negligible. Its number of moons is also considerably out of date.

    Well, for me personally, I ask myself whether there is a meaning behind r^2 besides simply being a distance squared. It would seem logical, for me, to view gravity as being, for example, some sort of energy emanating from the massive body (probably at light`s speed), which would continuously be reducing it`s energy density as it travelled away from the mass source,
    That's one way of looking at it. A light shining at intensity proportional to the mass would decrease in brightness at the square of the distance from the light. But gravity doesn't travel, so you can take the analogy only so far. Gravitational waves travel at c, but gravitational waves are not responsible for the attraction between masses. They're only responsible for carrying the changes to the field, which involves energy expenditure only when the field is changing. For instance, Earth's orbit radiates about 200 watts of gravitational waves into space.

    I would in fact surely agree to viewing the system as a whole(earth and falling bodies)as being invariant in terms of energy
    Energy is conserved in a closed system, yes. So is momentum. Earth/moon system is not particularly a closed system for energy since so much of it comes in and also leaves, both by EM radiation.

    For example, the moon's orbital distance increases by several cm a year as Earth transfers its angular momentum to it. It also transfers about 3% of its angular energy to it, and radiates the remainder away as heat. So energy is lost in the process of the moon's orbital changes.

    “if” the fallen body was taken from the earth (did not come from outer space), for in this case, the falling body was formally on the ground being part of the cause for the g acceleration, and since while the falling body will attract the earth as well, then,for the whole system, the overall acceleration will not change.[/b]
    If the falling body was taken from the ground, that reduces M, and it will thus accelerate less than a similar object falling from space. For a small rock, the difference is immeasurable since the mass of Earth changes more per second than any nitpicking about where you got the rock.

    The moon is like that. It is a big rock that was essentially taken from the ground, not having arrived from space. When they brought back the moon rocks, they were quite surprised to find it was a chunk of Earth and not something else like every other moon out there. But it accelerates at Σ GM/r² where Σ is the summation of the accelerations due to every bit of mass out there, mostly the due to the sun and also Earth (what's left of it after the moon was scooped out), but everything else pulls at it as well.

    But the equation would still remain a = GM/r^2 + Gm / r^2
    This cannot be right. For two equal stationary masses, it says they will not accelerate towards each other since the sum is zero. This is not the case. Even if you fixed that, the equation there does not express an acceleration, so the 'a=' part in front is blatantly wrong. Nothing accelerates at that rate.
  • The Newtonian gravitational equation seems a bit odd to me
    The surface g acceleration is dependent to the mass densityGampa Dee
    g is a constant. Saturn doesn't have a different g, it has a different acceleration a. The acceleration is dependent on mass and radius and has little direct connection with density, especially since density of any planet/star varies considerably at different depths. You complicating things needlessly by trying to work with area and/or density.

    and Saturn, being a gaseous planet,would be much less dense than the earth . Would you have the equation for this?
    Yea, a = GM/r²

    A frame of reference is a starting point, not something thrown in. Without it, any velocity is completely undefined.
    — noAxioms
    I was thinking something like Kepler using only distances and time period to make up his equations, and so not really using a frame of reference although it was implied I am sure.
    The equations you referenced mention velocity, and velocity is meaningless without the frame reference.

    I thought that [Orbital acceleration] was constant because the direction is towards the center[/quote]That direction changes over time. The ISS acceleration direction changes one degree every 15 seconds for instance. If it didn't, the ISS would have left the solar system a long time ago.

    while when the orbit is elliptical, the magnitude of acceleration will be changing and a change in acceleration is a 3rd derivative, which makes the calculation more tedious , I would think.
    Yes, but you listed all this Kepler stuff that shows how to do that just nicely.

    I do have a hard time with this...is it possible to share this proof?
    Nothing in science is actually a proof, but the reasoning goes like this: You have two identical balls of mass M each. They presumably fall at the same rate. Now you connect them by a thin thread or spot of glue, creating one object of mass 2M. Either the connection makes some sort of magical difference, or the 2M mass should fall at the same rate as before. Hence the rate is independent of mass.

    One can reason that the connection cannot apply a downward force to both objects (violating Newton's laws), but Newton's laws were not available at that time yet. F=ma was unknown, and the theory of impetus and such was still a thing.
  • The Newtonian gravitational equation seems a bit odd to me
    I think we can deal with the Newtonian equation using only one dimention.Gampa Dee
    Any talk of orbital mechanics has velocity that is not parallel with the acceleration, and thus involves at least two dimensions. Orbits can be described in a plane. Only things falling straight up and down can be described in one dimension.

    I don’t believe that Newton had a three dimensional frame of reference in mind
    All frames of reference have 3 dimensions of space, and require 3 velocity components to describe.

    However , to claim that g is not acceleration I still don’t get
    g is acceleration, but is simply a constant scalar. So the gravitational pull on the surface of Saturn is 1.08g. It would be wrong to say Saturn has a slightly larger g.

    I fully agree that anything which has an orbit will have a combination of gravitational acceleration and sidereal velocity at the same time.
    Yes, and those orthogonal vectors make it at least a 2d situation.

    this, I’m certain can become very complicated if one throws in a frame of reference from which everything is calculated.
    A frame of reference is a starting point, not something thrown in. Without it, any velocity is completely undefined.

    If the orbit isn’t circular (which most aren’t) there will be a change in acceleration
    Orbital accelerations are always changing, even in the circular case. Remember that it is a vector.

    the acceleration of a body in freefall is GM/r...
    What is it about this mass (M), that is so special that the smaller mass (m) cannot have any influence whatsoever on the acceleration?
    There's nothing special about M since it works with any M. Galileo actually published a tidy proof that the acceleration is independent of the mass of the thing accelerating.

    I would agree that car A is accelerating at 3m/^s^2 and car B is accelerating at 5m/sec^2 relative to the roadGampa Dee
    No. Velocity is relative, so it makes sense to talk about velocity relative to the road, but acceleration is absolute. The cars are accelerating at 3 and 5 m/s² period. This is true in any frame. It is meaningless to talk about acceleration relative to something, including itself.

    Here, I am strictly speaking changes in velocities
    Yes, that is what coordinate acceleration is. Change in velocity is absolute, even if velocity itself is not. If you're using a non-inertial frame, then you're taking the absolute coordinate acceleration of the other car and adjusting for the alternative frame you're using (in which Newton's laws do not hold), but the coordinate acceleration of the other car is still the same.

    You're also adding wrong. For instance, I have two stationary equal-mass objects (planets say) that I release. If you add the accelerations, you get zero, but the relative velocity between them is changing. Acceleration is a vector and if you add them, you need to use vector addition. But It seems to be a mistake to add them at all in this case.

    having nothing to do with the g force that "might" be involved, as in freefall, there is no force that is being felt by the accelerated body.
    The force 'felt' would be proper acceleration, also absolute.
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