Strange Posted November 21, 2015 Posted November 21, 2015 Earlier in the thread Strange stated that of course it is what we see that is true...which ignores the reality that the universe is actually more like a web of strings of galaxies 13.8 billion years old. I very much doubt he said that. If we are concerned with the metalicity of galaxies, and we are talking about current galaxies, wouldn't they all be similar to the metalicity of our galaxy Roughly - depending on the age of the galaxy and the stars in it. and NOT provide any current information based on what they look like now What they look like tells us about what galaxies were like in the past and so allows us to see the changes in galaxies over time. That allows us to develop and test models of galaxy formation. Both ways you have to use your imagination. Or, you could use scientific models.
Ophiolite Posted November 21, 2015 Posted November 21, 2015 Ophiolite, Nothing would be wrong with that. It would be accurate. However the strings of Galaxies that are currently catalogable, under that thought, are not the way we see them when we engage them with our equipment. The set of items true in the universe, under the all are currently true as 13.8 billion year old items, is not the same set of items that we see when we look at the place. There are, under the umbrella of understanding the universe as both currently existing, and as images of what used to be, two instances of every item. That which we see, and that which we imagine to have to be the case. I do not understand what you mean by the underlined phrase. The two instances you should be referring to are: 1. The galaxies as we see them today. 2. The galaxies as we understand them to be today. We can look around us and get a reasonably sound idea of what galaxies are like currently. We can look further away and see what they were like in the more remote past. This is a simple, elegant and useful notion. I don't understand why it causes you such difficulty.
tar Posted November 21, 2015 Author Posted November 21, 2015 like a scientific model is not imaginary
Strange Posted November 21, 2015 Posted November 21, 2015 like a scientific model is not imaginary Correct. It isn't. (No more than any other human activity.)
tar Posted November 21, 2015 Author Posted November 21, 2015 Strange, I don't remember your words. I asked which instance of the galaxy was true and you responded it was the instance that is seen by our equipment and logged in our catalogs of galaxies, and indicated I was silly to suggest any other instance of the galaxy was true. Ophiolite, I think it an elegant notion myself. But the two instances of each "1. The galaxies as we see them today. 2. The galaxies as we understand them to be today." are not always faithfully switched between in discussing the place. I am just asking that the two be openly referred to and not conflated. Regards TAR Strange, I don't mean we don't have thoughts. I mean you can't point to the model in your head, and tell me it goes by the rules of the universe. It absolutely does not go by the rules of universe. You can see the whole model at once, and the universe absolutely does not work that way. Regards, TAR -1
Strange Posted November 21, 2015 Posted November 21, 2015 I don't remember your words. I asked which instance of the galaxy was true and you responded it was the instance that is seen by our equipment and logged in our catalogs of galaxies, and indicated I was silly to suggest any other instance of the galaxy was true. I don't believe you. I think it an elegant notion myself. But the two instances of each "1. The galaxies as we see them today. 2. The galaxies as we understand them to be today." are not always faithfully switched between in discussing the place. I am just asking that the two be openly referred to and not conflated. Who conflates them? You seem to be the only person on the planet confused by this. I mean you can't point to the model in your head, and tell me it goes by the rules of the universe. It absolutely does not go by the rules of universe. You can see the whole model at once, and the universe absolutely does not work that way. The models are tested against observations. So to say that models do not accurately describe the universe is just not true. 1
tar Posted November 21, 2015 Author Posted November 21, 2015 (edited) how do you test your model of the galaxy against observation? The stuff you see is in some cases 100,000 year old news. And the far parts of your model will not be known for 100,000 years? The whole operation can be held in your brain, but that, by definition, is imaginary. Edited November 21, 2015 by tar
Strange Posted November 21, 2015 Posted November 21, 2015 (edited) how do you test your model of the galaxy against observation? Models make predictions. Those predictions are checked against what we see. The stuff you see is in some cases 100,000 year old news. And the far parts of your model will not be known for 100,000 years? That is insignificant in the timescales of a galaxy or a star. Edited November 21, 2015 by Strange
tar Posted November 21, 2015 Author Posted November 21, 2015 how do you know this? have you ever watched an entire galaxy for 200,000 year and not noticed any significant changes? how about the rise of civilization on Earth?
Strange Posted November 21, 2015 Posted November 21, 2015 how do you know this? As this is simply an argument from ignorance, I am going to suggest you go and study the subject if you are interested. have you ever watched an entire galaxy for 200,000 year and not noticed any significant changes? Hey, guess what. We don't have to because we can look at stars and galaxies at different distances. how about the rise of civilization on Earth? How about it? How is this relevant?
tar Posted November 21, 2015 Author Posted November 21, 2015 (edited) Strange, In #24 of this thread you said, among other things indicating that you favor our view of the universe over our knowledge of how it must currently be, this... "Fairly obviously it is looking at the state of the universe now and comparing it with the state of the universe at some time in the future. As none else shares your warped view of how time works, you can be fairly certain that no one will be basing models on it." Regards, TAR There were only 5 or 6 thousand of these insignificant time periods of 200,000 years between the time the Earth formed 5,540,000,000 years ago and the time life started here 4,500,000,000 years ago. When talking about the presence of earthlike planets in a galaxy the time period our galaxy went from when it formed 10,000,000,000 years ago, and the time it was ready to form this Earth like planet was only 4,460,000,000 years. this is 22,300 times what you consider an insignificant time period, but ALL of time, that has happened so far is only 69,000 of these insignificant time periods. So 200,000 years is only insignificant on the scale of stars and galaxies if 8 hrs is insignificant on the scale of a human and her lifetime. A lot can happen in 8 hours and you can't tell much about what some 61 year old in Bulgaria is doing right now, by looking at my childhood photos. Edited November 21, 2015 by tar
Strange Posted November 21, 2015 Posted November 21, 2015 Strange, In #24 of this thread you said, among other things indicating that you favor our view of the universe over our knowledge of how it must currently be, this... "Fairly obviously it is looking at the state of the universe now and comparing it with the state of the universe at some time in the future. As none else shares your warped view of how time works, you can be fairly certain that no one will be basing models on it." Which appear to be almost the exact opposite of what you claimed. Maybe you should have looked for it first.
tar Posted November 21, 2015 Author Posted November 21, 2015 ? I thought we subsequently agreed that is was a good notion to look at the progression of galaxies of different ages to determine what the universe looks like now. It has nothing to do with what the universe will look like in the future. The best model would be to look at local stuff and figure it was something like that, everywhere, now. Looking at young galaxies just tells us how we got to this point. Does not say a thing about the future. We don't know how things are going to go. we have zero examples of 13.8002 billion year old galaxies. Those are yet to occur...anywhere.
Strange Posted November 21, 2015 Posted November 21, 2015 The best model would be to look at local stuff and figure it was something like that, everywhere, now. Gosh. I wonder why no one has thought of that. Oh, hang on. That is the basis of the paper in the OP. Looking at young galaxies just tells us how we got to this point. Does not say a thing about the future. We don't know how things are going to go. Arguments from ignorance are so boring. As I said before... Effectively, yes. Estimates like this are made based on observations of the number/density of stars, the rates at when they form, the rates at which they die, the number of planets per star, models for planetary formation given the amount of gas and different levels of metallicity, and so on. These factors can be observed now (locally) and in the past (at a distance) and from that one can model what is happening now and what might happen in the future.
tar Posted November 21, 2015 Author Posted November 21, 2015 Strange, Right. Not what you said in #24. Regards, TAR
Ophiolite Posted November 21, 2015 Posted November 21, 2015 Ophiolite, I think it an elegant notion myself. But the two instances of each "1. The galaxies as we see them today. 2. The galaxies as we understand them to be today." are not always faithfully switched between in discussing the place. I am just asking that the two be openly referred to and not conflated. I am not conscious of any instances where they are conflated in the way you suggest. The intended instance is readily identified by statement or context. Please provide a specific example where this is not the case.
tar Posted November 22, 2015 Author Posted November 22, 2015 Ophiolite, The specific example that bothers me the most is the statement "the universe is currently expanding at an accellerated pace". Perhaps you can explain to me, which sense of now that is referring to. Regards, TAR
Strange Posted November 22, 2015 Posted November 22, 2015 Doesn't the word "currently" give you a clue?
tar Posted November 22, 2015 Author Posted November 22, 2015 (edited) is what we see expanding or is what we imagine expandinghow do we figure the place is expanding at all now, if every local galaxy is gravitationally bound?By using the elegant notion, we should figure that the closer stuff would give a better idea of how fast galaxies are receding from each other, compared to how fast they seemed to be receding from each other when we look at galaxies at huge distances when things were different, a long while ago. A short while ago the galaxies seem to be gravitationally bound. If the universe is homogeneous and every observer, everywhere would look out and see their local galaxies gravitationally bound, then that is evidence that the universe is no longer expanding as rapidly as it used to be expanding. What we see, after all further away, is less what the universe is like now, than what we see closer. Edited November 22, 2015 by tar
Strange Posted November 22, 2015 Posted November 22, 2015 (edited) how do we figure the place is expanding at all now, if every local galaxy is gravitationally bound? A combination of theory and observation. It is a shame you are unwilling to learn about any of this stuff, it is really fascinating. A short while ago the galaxies seem to be gravitationally bound. Did they? Which galaxies? If the universe is homogeneous and every observer, everywhere would look out and see their local galaxies gravitationally bound, then that is evidence that the universe is no longer expanding as rapidly as it used to be expanding. They would but it isn't. The fact that galaxy clusters are held together by gravity has absolutely nothing to do with the expansion of the universe. Because ... wait for it ... they are held together by gravity. Edited November 22, 2015 by Strange
tar Posted November 22, 2015 Author Posted November 22, 2015 (edited) Strange, "Did they? Which galaxies?" The local group, which I am told are gravitationally bound. These are the most recent observations we can possibly make. What the local group is doing is probably what every local group is doing. There is most likely no reason a Galaxy a couple million lys from here is not as gravitationally bound to a galaxy 4 million lyrs in that direction as it is to us. Since both us and the galaxy four million lyrs from here are 2 million lyrs from the galaxy 2 million lyrs from here. That is a galaxy in a chain of galaxies has just as much of a reason to be gravitationally bound to the next one in the chain to its left as the one in the chain to its right. And if the strings of galaxies are currently gravitationally bound to each other, and we see something different across the way through a void, it is not an indication that the void is growing in size and the strings are still stretching. The indication would be that the strings are now stable and gravitationally bound. Compared to a former time when they appeared to be receding from each other. Regards, TAR which actually would make sense in another way if the inflation of the universe happened at a very rapid pace at first, and later was just an expansion, it would make sense if it now had stabilized and gravity is taking over and pulling everything back together We wouldn't know however if the galaxy were getting smaller currently, because it still looks as big as it was 100,000 years ago. Similarly, the universe could have already expanded to its largest, already and is on its way back to a singularity, a massive black hole that will include all matter and the one growing at the Milky Way core, will merge with a nearby other black hole and so on, until there is only one. This would take a while, but we would not see it as happening as soon as it started. It takes light from far away extents of the universe many billions of years to get here. Edited November 22, 2015 by tar
Acme Posted November 22, 2015 Posted November 22, 2015 Acme, Sorry, I need to continue to spin my wheels. ... Therein lies the rub. Your concern for folks here is duly noted and your apology rejected. Good grief.
Ophiolite Posted November 22, 2015 Posted November 22, 2015 Tar, it is clear from your responses to Strange (and to others throughout the thread) that the problem is threefold: 1. You lack basic knowledge of the subject. 2. Rather than properly consider explanations given by others you appear to be stuck in a groove. 3. There is no evidence that you intend to rectify item 1. Recently, I became involved in a discussion on another forum, about a different topic and with a different user name. I was questioning a definitive statement made by one knowledgeable member. Despite repeated attempts to explain why I felt they might be incorrect all it produced was more members joining in to repeat the assertion, while seemingly missing the central point I was making. It reminded me of what you are experiencing here. I suspect that you may feel puzzled, even frustrated for our inability to understand the simple point you are making. My solution on the other forum is this: I shall study the topic in sufficient depth to either understand why I am in error, or to be able to explain why they are in error. You might want to consider the same approach.
tar Posted November 22, 2015 Author Posted November 22, 2015 (edited) Ophiolite, Thank you, but on your number one, my basic lack of knowledge on the subject I have a philosophical objection. Nobody knows or can know what the universe is doing now. All we have is our best guess model. We CANNOT check it. Not me, not you, not the brightest minds we have. It is too darn big and too long lived and too "out of our reach". So we all suffer from a basic lack of knowledge on the subject. The subject being the current state of the universe. What I do suffer from by myself, is a lack of respect for the stance of anyone who feels their model is better and more complete than the place itself. And to this, in both religion and science, I say that my view of the place is based on my access to the place, which is exactly the same access as you, or a priest or a scientist has. If I don't have knowledge of, or do not agree with the model that is conventionally held or if I see an inconsistency in the model and speak to it, we are talking about the model, not the thing the model is of. You, are of the opinion that the proper course of action is to submit to the judgement of the experts because they have already thought these things through and know the answers. That I have no weight to fight with the big dogs. Perhaps. But I need my model of the world to be consistent and workable, same as everybody else has that need. I cannot hold someone else's model, that does not work. The universe will continue to work exactly as it is working whether we are among the first of many many Earths, or the only Earth, or the last to emerge among a million that have emerged around the universe. We are unlikely to know which is the case by the end of our lives. The models of the experts will not be exactly like the current model, by 2017. The universe will not have changed as much as the model of it will have changed by that time. Well actually the universe will have changed more than the model, since the universe is way more complex and way bigger than the model, but the idea is, what I know about the model and what I know about the place are two different thoughts. Regards, TAR that is, we have my model, your model, Strange's model, the standard model (which changes as new measurements and ideas are added and equations modified) and we have probably about as many interpretations of the standard model, as there are minds that dabble in it But we only have one instance of reality and to that we all have equal access not total access equal access what is probably the most crucial consideration to my point is that I have very little access to your model, and total access to my own this works the other way around as well and through convention we can have access to a common model, but that does not directly address the lack of access to someone else's model, nor the collective limitations to total access to the whole place that we ALL have Edited November 22, 2015 by tar
Strange Posted November 22, 2015 Posted November 22, 2015 This entire post is just a confirmation of your ignorance. Nobody knows or can know what the universe is doing now. We can know. All we have is our best guess model. They are not guesses. You really ought to find out a tiny bit about how science works. We CANNOT check it. Of course it can be checked. That is what makes it science. (As opposed to the uninformed "philosophy" of some random guy on the Internet. So we all suffer from a basic lack of knowledge on the subject. Not "we all". Just you. What I do suffer from by myself, is a lack of respect for the stance of anyone who feels their model is better and more complete than the place itself. Does anyone think that? Why even say it? And to this, in both religion and science, I say that my view of the place is based on my access to the place, which is exactly the same access as you, or a priest or a scientist has. Scientists have far better access. Apart from the technological tools (optical and radio telescopes, satellites, etc.) they have a good understanding of the underlying physics and chemistry, well-tested models for the evolution of the universe, the lifecycles of stars and galaxies, etc. You have nothing. (Except a "philosophy".) If I don't have knowledge of, or do not agree with the model that is conventionally held or if I see an inconsistency in the model and speak to it, we are talking about the model, not the thing the model is of. You cannot see an inconsistency in the model because you don't have a friggin clue what the model says. You, are of the opinion that the proper course of action is to submit to the judgement of the experts because they have already thought these things through and know the answers. That I have no weight to fight with the big dogs. I don't know what your area of expertise is, so lets try this analogy. Imagine you are building a house. Your architect comes up with a design which is both practical, aesthetically pleasing and meets all necessary building regulations/codes. Your structural engineer calculates (using models!) the sizes of the beams needed, the loading on the roof, etc. The project manager works out the number of people, the scheduling of resources and so on to meet the timescales. You are quite happy with all this. Then some random guy walks in the door, looks at all the plans and sweeps them on the floor. "I know nothing about building but I have a philosophy. These people are just guessing. I'll build your house in a week for one tenth of the price." Who do you believe: the experts who have done the calculations. Or some idiot with a "philosophy"? Perhaps. But I need my model of the world to be consistent and workable, same as everybody else has that need. I cannot hold someone else's model, that does not work. You don't have a model. And you don't have the knowledge or skills to evaluate the scientific models. I think I will put you back on ignore. I find it too depressing that people can be so proud of their ignorance and so desperate to hang on to it. 2
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