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Thread: On conservation of energy.

  1. #1 On conservation of energy. 
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    from wikkipedia;
    "In physics, the law of conservation of energy states that the total energy of an isolated system cannot change—it is said to be conserved over time. Energy can be neither created nor destroyed, but can change form, for instance chemical energy can be converted to kinetic energy in the explosion of a stick of dynamite."

    so there are a number of conceptual issues that jump out at me. the first is an "isolated system."
    reality is a continuum and is infinite (if youd like to debate this point id be happy to).
    an "isolated" system is defined as having boundaries, which the universe does not. thus such a system(isolated) does not exist.

    now of course we can define conceptual boundaries(like a circuit, or the hydrological cycle, or a single organ system in the body or whatever), but all this does is exclude data to make conceptualizing and calculations easier - however it makes them less accurate due to the exclusion of the rest of the system.

    now, the wikki article on "isolated systems" does say that very thing "Truly isolated systems cannot exist in nature, other than possibly the universe itself"

    so in the first line of the definition of the law of conservation, it would seem there's a big hole...
    although notice the emboldened word "possibly."
    it is possible (as noted in the wikki article) to consider the universe as a whole, as an isolated system. since there is no "outside" the universe to "get" more energy from. that would satisfy the definition of isolated.
    but why would we need to get more energy in an infinite system? - there is infinite energy in an infinite system.

    going back to the beginning, the term "total energy" in the definition of the law seems misleading - it implies that infinity is a quantity.
    since infinity cannot be quantized, then there can be no "total energy."

    anyone else irked by the concepts in this law?


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    There's an absolutely finite amount of energy in the Universe. This amount of energy will never and can never change in quantity, only in form.


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    Quote Originally Posted by Daecon View Post
    There's an absolutely finite amount of energy in the Universe. This amount of energy will never and can never change in quantity, only in form.
    im struggling to understand your statement =)

    so;
    finite amount of energy.
    static quantity.
    but it can change form.

    so the amount doesnt change, but the form does.

    and can it change form an infinite amount of times? or does it eventually stop changing form?
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    Quote Originally Posted by c0sm View Post
    anyone else irked by the concepts in this law?
    I see where you are coming from, however I would also have issues with statements that 'reality is a continuum and is infinite' which appears to me to be an assumption as well (eg. an assumption based on the notion that our 'classical reality' can be extended to the entire universe (whatever form that may take).

    Of course there are many factors which have relegated the conservation of energy to the status of a law as it has proven the test of time with regards to experimental observation and associated mathematical theorems such as Noethers theorem, but again these mathematical theorems are based on assumptions such as symmetry etc.

    So in a nutshell what I am sure about is that we cannot be sure about anything in our theoretical descriptions of how the universe works. It is best to take seriously the notion that a Law or theorem is only valid until until it can be disproved. That's what makes science interesting. :-))
    Last edited by Implicate Order; October 25th, 2013 at 03:41 AM. Reason: Fixing an horrendous typo!!!!!
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    Quote Originally Posted by Implicate Order View Post
    I see were you are coming from however I would also have issues with statements that 'reality is a continuum and is infinite' which appears to me to be an assumption as well (eg. an assumption based on the notion that our 'classical reality' can be extended to the entire universe (whatever form that may take).
    i figured some might question that part which is why i parenthesized a note about it =) i also figured that it was a commonly enough accepted idea to not have to go into it further, but if you are skeptical for some reason id be happy to address it. EDIT; ive made some implications further down about the idea of infinite regression and the "unmoved mover" which are pertinent to the concept of an infinite universe.
    Quote Originally Posted by Implicate Order View Post

    Of course there are many factors which have relegated the conservation of energy to the status of a law as it has proven the test of time with regards to experimental observation and associated mathematical theorems such as Noethers theorem, but again these mathematical theorems are based on assumptions such as symmetry etc.
    one of the thing that always sticks out to me that conflicts with the the proofs of the law is the fact that we're here =) hehe.
    are you familiar with the philosophical concept of the "unmoved mover" ? its essentially about a theoretical "first cause."
    i would imagine that if there were not an "imbalance" of energy in the universe, then there would be no activity to begin with.
    it would be more efficient for "nothing" to be happening. but things happen - the big bang "happened" (or "something" happened at least), and it continues to.

    i imagine the reason it(1st law of thermodynamics) has been proven time and again is because of the metrics used - the way the experiments have been constructed. for example as i was saying about "isolated" systems; if you isolate a system, you essentially cut it off from the greater system which had previously sustained it. obviously from that point the energy will "run out."
    i feel like there is a name for the logical fallacy described above but i cant think of it at the moment...
    maybe its a false premise?
    ie; the assertion that you can have an isolated system of the type described?

    (goes to lookup noethers theorem)


    Quote Originally Posted by Implicate Order View Post
    So in a nutshell what I am sure about is that we cannot be sure about anything in our theoretical descriptions of how the universe works. It is best to take seriously the notion that a Law or theorem is only valid until until it can be disproved. That's what makes science interesting. :-))
    indeed =) ive been thinking/talking lately about how words and descriptions are different from the actual nature of the things they are about....
    the word "fun" is not the same as the "thing" fun...
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    Quote Originally Posted by c0sm View Post
    fnow, the wikki article on "isolated systems" does say that very thing "Truly isolated systems cannot exist in nature, other than possibly the universe itself"
    All physics deals with idealisations. In reality, the conditions don't really apply (e.g. in your thread in electricity, Ohm's law is only an approximation because real devices don't act as perfect resistors).

    But you can make a system nearly isolated (e.g. a lot of experiments are done using a calorimeter, which is very well insulated) and you can take into account energy that leaks in and out.

    going back to the beginning, the term "total energy" in the definition of the law seems misleading - it implies that infinity is a quantity.
    Couple of points here. It is actually very difficult to define what the energy of the universe is (what it even means). Also, even if we assume we can total it all up, it may not be infinite, because the universe may not be infinite.
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    Quote Originally Posted by c0sm View Post
    i figured some might question that part which is why i parenthesized a note about it =) i also figured that it was a commonly enough accepted idea to not have to go into it further, but if you are skeptical for some reason id be happy to address it. EDIT; ive made some implications further down about the idea of infinite regression and the "unmoved mover" which are pertinent to the concept of an infinite universe.
    Ok, am looking into it now with regards to "First Cause" and the "Cosmological Argument". Thanks for the reference

    In relation to this, a valid argument as a prime mover for universal dynamics is the notion of a Big Bang to get the ball rolling but I have always wrestled with the notion of a single Big Bang for an infinite universe. This does not however apply to an infinite series of 'bounces' in an infinite universe which I am more comfortable with, but that is just an intuitive judgement on my part. One of the conceptual hurdles I am trying to overcome is the notion as you have expressed that there would be infinite energy in an infinite universe which I cannot disagree with but the reality is such that my intuition is telling me that nature doesn't work necessarily in that way. Taking this approach leads to a parsiminous conclusion but also leads to a pretty dull universe that appears to be imcompatible to that which is observed.

    Quote Originally Posted by c0sm View Post
    indeed =) ive been thinking/talking lately about how words and descriptions are different from the actual nature of the things they are about....the word "fun" is not the same as the "thing" fun...
    I agree with you entirely on this. Our language (particularly Western language) is based on a 'reductionist' viewpoint with an emphasis on 'nouns' that imply that things exist such as isolated systems and particles and so forth. This is contrary to what science is experiencing now particularly in the Quantum domain where it is all about 'verbs' such as interactions, relationships and dynamics. As David Bohms suggests, to be in a position to faithfully describe what is going on and avoid misunderstandings we need a language re-write that is holistic, dynamic and all encompassing. :-))
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    Quote Originally Posted by c0sm View Post
    indeed =) ive been thinking/talking lately about how words and descriptions are different from the actual nature of the things they are about....the word "fun" is not the same as the "thing" fun...
    You might want to read Saussure on signs: the signifier and the signified (and the [almost] arbitrary relationship between them).

    Our language (particularly Western language) is based on a 'reductionist' viewpoint with an emphasis on 'nouns' that imply that things exist such as isolated systems and particles and so forth.
    In what way does our language "emphasise nouns"? Please provide some evidence to support this.

    And how on Earth are "Western" languages (which encompasses a huge variety of unrelated and varied languages) different from "non-Western" languages (which presumably encompasses an equally large group of unrelated and different languages). Japanese has more in common with Italian than it does with Chinese, for example (and is, obviously, totally unrelated to both).

    o be in a position to faithfully describe what is going on and avoid misunderstandings we need a language re-write that is holistic, dynamic and all encompassing.
    What you need is mathematics.
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    Quote Originally Posted by Strange View Post
    . In what way does our language "emphasise nouns"? Please provide some evidence to support this.
    In some ancient languages such as Hebrew, the verb is taken as primary, and the root of almost all words in Hebrew was of verbal form. In modern Hebrew, the actual usage is similar to English in that the noun is given a primary role in its meaning. David Bohm looks at language extensively in his development of the Rheomode which was his attempt to refine language in an effort to simplify quantum theory. An in depth discussion is contained in his book "Wholeness and the Implicate Order". A brief summary is here Ideas on Language and Linguistics - F. David Peat. His investigation into language suggests that in particular Indo-European languages are highly noun oriented. Tracing the origins of this tendency is quite insightful which Bohm attributes to differences between Eastern and Western notions of measure. The Western notion is interpreted as a comparison of an object with an external standard or unit which was actually not inherent in the Ancient Greeks notion of measure which was a term used to convey a sense of inner balance eg. When something went beyond its proper measure, it meant that something was not conforming to inner harmony. The the Latin 'mederi' meaning to 'cure' is based on a root meaning 'to measure'.

    Over time European language evolved to where prevailing notions of measure were no longer seen as forms of harmony or inner balance but rather as external truths about reality. Far different to the Ancient Greeks concept where 'Man is a measure of all things'. While the origin still survives in some contexts, the word measure is now routinely come to denote a process of comparison with an external standard. This has further evolved with the Western Societies development of science and technology (dependent on measure) whereas in the East , the main emphasis has gone towards religion and philosophy. Interestingly in the East, the immeasurable (that which cannot be named, described or understood through any form of reason) is regarded as the primary reality, whereas that which can be understood and measured is an insight created by man.

    The Wests development of external measure as a basis for science and technology flowed into its language with the notion that everything can be localised, divided and categorised. Eg. That everything is ultimately constituted out of fundamental particles. The Western language is very subject-verb oriented. For example "It is raining" where "It" takes on a seperate existence. A more accurate description would be "Rain is going on" etc etc..........

    It really is quite interesting and I can see where our language may run into difficulties.

    What you need is mathematics.
    True. I am out of my depth here. That's why without mathematics, the only tool I have to try to understand how this universe works is through common language. The language of mathematics however is concise and leaves little room for confusion, but again there is a skill in interpreting how well the theoretical construct of maths actually applies to real world situations which I would say the only a few can master. :-))
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    Quote Originally Posted by Implicate Order View Post
    In some ancient languages such as Hebrew, the verb is taken as primary, and the root of almost all words in Hebrew was of verbal form.
    Interesting. I don't know much about Semitic languages; I have never heard this before. I know that words are based on triliteral roots from which most nouns, verbs and adjectives are formed. I have never heard that all or most words were verbal. Do you have a reference for this?

    In modern Hebrew, the actual usage is similar to English in that the noun is given a primary role in its meaning. David Bohm looks at language extensively in his development of the Rheomode which was his attempt to refine language in an effort to simplify quantum theory. An in depth discussion is contained in his book "Wholeness and the Implicate Order". A brief summary is here Ideas on Language and Linguistics - F. David Peat. His investigation into language suggests that in particular Indo-European languages are highly noun oriented. Tracing the origins of this tendency is quite insightful which Bohm attributes to differences between Eastern and Western notions of measure.
    Maybe physicists should leave linguistics to the linguists. I don't know anything about Bohm's ideas (and it is not something that sounds interesting enough to invest any time in) but from your description it sounds like a version of the (largely discredited) Sapir-Whorf hypothesis.
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by c0sm View Post
    fnow, the wikki article on "isolated systems" does say that very thing "Truly isolated systems cannot exist in nature, other than possibly the universe itself"
    All physics deals with idealisations. In reality, the conditions don't really apply (e.g. in your thread in electricity, Ohm's law is only an approximation because real devices don't act as perfect resistors).

    But you can make a system nearly isolated (e.g. a lot of experiments are done using a calorimeter, which is very well insulated) and you can take into account energy that leaks in and out.
    indeed idealizations are all we have since they are the only perspective available - the subjective, first person, conceptual perspective. (how we conceptualize things as opposed to how they "are" - and assuming there is an exclusive difference? ...)

    i suppose my intention is to work from the angle of making this less isolated. because doing that will give a better approximation than trying to make them more isolated. essentially to consider more factors. i often feel like my conceptual understanding of things in the world is stifled by the "specialization" of the various fields of science. (i realize there is value in the specialization as well)
    Quote Originally Posted by Strange View Post
    Quote Originally Posted by c0sm View Post
    going back to the beginning, the term "total energy" in the definition of the law seems misleading - it implies that infinity is a quantity.
    Couple of points here. It is actually very difficult to define what the energy of the universe is (what it even means). Also, even if we assume we can total it all up, it may not be infinite, because the universe may not be infinite.
    indeed again! i spend a fair bit of time pondering what energy "is" - although not so much about consider how much of "it" there "is" anymore. i feel like im comfortable with the concept of an infinite universe at this point (and thus infinite energy)
    i cant conceive of the universe not being infinite, because if it were finite - it would have a border, and borders are composed of and "inside" and an "outside".
    an "edge" of the universe would imply an "outside" of the universe. but that means that "outside" the universe is "somewhere" specific - giving it dimension.

    /ponder

    OH and im stoked to have sparked a bit of conversation about language - one of my favorite topics! (reading a bit about sassure now - reminds me of alan watts)
    =)
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    Quote Originally Posted by Strange View Post
    Interesting. I don't know much about Semitic languages; I have never heard this before. I know that words are based on triliteral roots from which most nouns, verbs and adjectives are formed. I have never heard that all or most words were verbal. Do you have a reference for this?
    It's a bit of a slog but here you go. Biblical Hebrew - Wikipedia, the free encyclopedia. Refer to the section on Phonology.

    Maybe physicists should leave linguistics to the linguists. I don't know anything about Bohm's ideas (and it is not something that sounds interesting enough to invest any time in) but from your description it sounds like a version of the (largely discredited) Sapir-Whorf hypothesis.
    Ouch...poor old Bohm. He did have a hard time appealing to the mainstream view......but then again Bohr also had simmilar issues with language that can be read in "Reflections on Bohr" by Paul McEvoy. These darned physicists, they should just stick to their patch......... or is that just what a reductionist would say?
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    [QUOTE=c0sm;477055]
    Quote Originally Posted by Strange View Post
    OH and im stoked to have sparked a bit of conversation about language - one of my favorite topics! (reading a bit about sassure now - reminds me of alan watts)
    =)
    You troublemaker. Now see what you've done!!!!!!!/TIC :-))
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    Quote Originally Posted by c0sm View Post
    i cant conceive of the universe not being infinite, because if it were finite - it would have a border, and borders are composed of and "inside" and an "outside".
    Not necessarily. As a 2D analogy, consider the surface of a sphere: it has a finite area but no boundaries. This can be (and is) extended to 3D space.
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    Quote Originally Posted by Implicate Order View Post
    It's a bit of a slog but here you go. Biblical Hebrew - Wikipedia, the free encyclopedia. Refer to the section on Phonology.
    The Phonology section says a lot about phonology (which is interesting enough) but doesn't appear to say anything about the pre-eminence of verbs.

    These darned physicists, they should just stick to their patch......... or is that just what a reductionist would say?
    I wouldn't mind them talking about language if they had studied linguistics. But (again, just based on your description here) it doesn't appear they have.

    Physicists have a bit of a reputation for thinking they are experts on any field: xkcd: Physicists
    (I don't know if it is deserved.)
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    Quote Originally Posted by Strange View Post
    Quote Originally Posted by c0sm View Post
    i cant conceive of the universe not being infinite, because if it were finite - it would have a border, and borders are composed of and "inside" and an "outside".
    Not necessarily. As a 2D analogy, consider the surface of a sphere: it has a finite area but no boundaries. This can be (and is) extended to 3D space.
    interesting! im having difficulty conceptualizing a 2D "sphere"... i suppose the surface of a 3D sphere has a finite area, though it's impossible to calculate exactly isnt it? we only calculate to an arbitrary decimal place - because of the nature of pi?

    and a 3D sphere would have boundaries, it has an inside and an outside - though i dont know about a 2D "sphere" - not sure if that's possible? i know they do some funny things with math and simulated environments though... but that might be a good example of an over-isolated system, excluding important "real" factors.

    so im not sure about how you mean that boundless finite areas can be (and are) extended into 3D space... ?
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    Quote Originally Posted by c0sm View Post
    interesting! im having difficulty conceptualizing a 2D "sphere"... i suppose the surface of a 3D sphere has a finite area, though it's impossible to calculate exactly isnt it? we only calculate to an arbitrary decimal place - because of the nature of pi?
    Sorry, I meant the surface is 2D, not the sphere (although, to mathematicians a 3D sphere is actually a 2D object!)

    And yes, the surface has a finite area. (If the area is, say, 10 cm2 then it is exactly known so I'm not sure why you think it can't be nor why you think that is relevant)

    In exactly the same way, 3D space can be "curved back on itself" so it has a finite volume but no boundaries.
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    Quote Originally Posted by Strange View Post
    Sorry, I meant the surface is 2D, not the sphere (although, to mathematicians a 3D sphere is actually a 2D object!)
    mind=blown =)

    i think i get what your saying about the surface - you can travel left/right//up/down so its 2D. and you could say, for example, that something traveled "to the left" for an infinite amount of time, and map that motion to a circular object.
    or to get more complicated i travel "left" for a distance of 2 - then "up" for a distance of 2. that motion could be "mapped" to a sphere which had a "size"(circumference) of 1, and i would conceptually move around it twice in one direction, then around it twice again in a direction perpendicular to the first.

    is this kinda what you mean by saying "to mathematicians a sphere is 2D" ?
    Quote Originally Posted by Strange View Post
    And yes, the surface has a finite area. (If the area is, say, 10 cm2 then it is exactly known so I'm not sure why you think it can't be nor why you think that is relevant)

    In exactly the same way, 3D space can be "curved back on itself" so it has a finite volume but no boundaries.
    i might be okay with the assertion that a given surface area is finite - i was saying that the exact size cant be know functionally, theoretically it could, but actual measurements are approximations. and, in the case of spheres and circles, doesnt the nature of pi make even exact theoretical calculations impossible? since you just have to calculate to an arbitrary decimal of pi?

    though you may be right that this is not relevant at all.... (it may not even be correct - im such a laymen) =)

    now, i know ive heard that 3D space can curve back in on itself.... but that's a big load to swallow... =D
    im willing to accept the possibility, but what im interested in is how to conceptualize such a dynamic.

    i might also just argue that space isnt a real "thing" its the relationship between real things... like time, its an abstract//arbitrary measurement.
    i dont know how to conceive of a relationship that curves back onto itself....
    Last edited by c0sm; October 25th, 2013 at 05:05 PM. Reason: terrible grammer
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    Quote Originally Posted by c0sm View Post
    i think i get what your saying about the surface - you can travel left/right//up/down so its 2D. and you could say, for example, that something traveled "to the left" for an infinite amount of time, and map that motion to a circular object.
    or to get more complicated i travel "left" for a distance of 2 - then "up" for a distance of 2. that motion could be "mapped" to a sphere which had a "size"(circumference) of 1, and i would conceptually move around it twice in one direction, then around it twice again in a direction perpendicular to the first.
    Exactly. You can go north-south or east-west on the surface of the Earth - in other words you can define every location by its latitude and longitude. But (and this is the important bit) you can visit every location on Earth: the area is finite.

    is this kinda what you mean by saying "to mathematicians a sphere is 2D" ?
    That is more to do with the fact that mathematicians define a sphere by its surface whereas we mere mortals think of it as a volume.

    i might be okay with the assertion that a given surface area is finite - i was saying that the exact size cant be know functionally, theoretically it could, but actual measurements are approximations. and, in the case of spheres and circles, doesnt the nature of pi make even exact theoretical calculations impossible? since you just have to calculate to an arbitrary decimal of pi?
    Well, I suppose you never measure anything perfectly. You can only approximate a second, a metre, a kilogram, etc. Surface area is no different.

    now, i know ive heard that 3D space can curve back in on itself.... but that's a big load to swallow... =D
    im willing to accept the possibility, but what im interested in is how to conceptualize such a dynamic.
    You either need to think of some way of extending the analogy of a 2D surface to 3D or get to grips with the math.

    i might also just argue that space isnt a real "thing" its the relationship between real things...
    Exactly right.

    i dont know how to conceive of a relationship that curves back onto itself....
    I don't how to conceive of a relationship that doesn't! (joking)

    We are used to thinking of the ground in front of our house being flat so it is hard to conceive of the Earth as being round.

    We are used to thinking of the distance between things as being straight lines, so it is hard to conceive that they might be curved. But they are (this is what we perceive as gravity, for example).
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    Quote Originally Posted by Strange View Post
    Exactly. You can go north-south or east-west on the surface of the Earth - in other words you can define every location by its latitude and longitude. But (and this is the important bit) you can visit every location on Earth: the area is finite.
    but! you cant visit every temporal location on earth =D its also possible to argue that if i start in location A, move to location B, and then back to A - that even though im back at A it will be a different A than before. even if you stand still @ location A it changes through time. "stillness" and "motion" are relative terms arent they? (im still in relation to the ground below me, but the ground is moving in relation to the ground on mars)
    this i think it what i was saying about isolating systems - it confuses the picture in ways by obfuscating important data.

    i think im trying to argue that we talk about finite concepts, but that they are actually part of a wider infinite context.

    ...im about to go for a hike and i think i'll be pondering the relationship of space and time.... =D

    Quote Originally Posted by Strange View Post
    You either need to think of some way of extending the analogy of a 2D surface to 3D or get to grips with the math.
    i'll have to ponder that one....
    Quote Originally Posted by Strange View Post
    We are used to thinking of the ground in front of our house being flat so it is hard to conceive of the Earth as being round.

    We are used to thinking of the distance between things as being straight lines, so it is hard to conceive that they might be curved. But they are (this is what we perceive as gravity, for example).
    well i can conceptualize the curvature of the earth (especially because i live on the coast and frequently look over the horizon) but it is more difficult to conceptualize the "space" between the earth and the sun as being curved.
    maybe that will go on the same pondering list as the 2D -> 3D mapping. =)

    i feel a bit like we've strayed from the disputed point though about the nature of the universe being finite or infinite... at least im not sure how curved space would be relevant to that...
    even if space curved into itself, and we had a sort of "mobius-strip" universe, we would still have infinite time. right?
    even if time was cyclic, we would still have an infinite number of cycles?

    *goes for a walk in the forest* =)
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    Quote Originally Posted by c0sm View Post
    its also possible to argue that if i start in location A, move to location B, and then back to A - that even though im back at A it will be a different A than before.
    It will be the same A but at a different time. Which brings us back to why we need four dimensions to describe the universe: 3 spatial an one time.

    i feel a bit like we've strayed from the disputed point though about the nature of the universe being finite or infinite... at least im not sure how curved space would be relevant to that...
    even if space curved into itself, and we had a sort of "mobius-strip" universe, we would still have infinite time. right?
    even if time was cyclic, we would still have an infinite number of cycles?
    We might or we might not.

    The universe might be spatially finite or it might not. The universe might be eternal or it might not. There is no necessary connection between these.

    And note that the universe could have a beginning but still be eternal (i.e. have no end).

    My personal preference (on Tuesdays) is for a universe that is spatially finite but infinite in age and eternal. But there is zero evidence for (or against) this.
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    Quote Originally Posted by c0sm View Post
    now, i know ive heard that 3D space can curve back in on itself.... but that's a big load to swallow... =D
    im willing to accept the possibility, but what im interested in is how to conceptualize such a dynamic.
    The other way of thinking of it is the "PacMan Universe" - if you go far enough to the left, you end up at the extreme right etc.
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    So on my walk i was thinking about curved space and it occurred to me that; the only way to know that something is curved, or even to perceive it as curved, is by comparing it to something straight.
    so what is the straight frame of reference which could be used to contrast curvature of space? does time curve as well? (... i know of the phenomenon called "time dialation")

    *scratches chin"

    Quote Originally Posted by Strange View Post
    Quote Originally Posted by c0sm View Post
    its also possible to argue that if i start in location A, move to location B, and then back to A - that even though im back at A it will be a different A than before.
    It will be the same A but at a different time. Which brings us back to why we need four dimensions to describe the universe: 3 spatial an one time.
    it occurrs to me that the spacial and temporal location is a relative definition here. if i move from 1st st. to 2nd st, then back. i will be @ 1st street, where i started, but the earth will have rotated in a number of ways and then of course you can add solar and galactic motion. so in a way being @ 1st st is a different "absoulte" location (if there could be such a thing).
    and the time too is relative, maybe i start @ 1st st and its 12pm and i get back to 1st st @ 1pm. "different" time, yet both times will be "now" from current perspective. i could start by saying "now" im @ 1st st. and then when i left and came back, i could say the same thing...

    i was also pondering the relationship of space and time on my walk =)
    Quote Originally Posted by Strange View Post
    Quote Originally Posted by c0sm View Post
    i feel a bit like we've strayed from the disputed point though about the nature of the universe being finite or infinite... at least im not sure how curved space would be relevant to that...
    even if space curved into itself, and we had a sort of "mobius-strip" universe, we would still have infinite time. right?
    even if time was cyclic, we would still have an infinite number of cycles?
    We might or we might not.

    The universe might be spatially finite or it might not. The universe might be eternal or it might not. There is no necessary connection between these.

    And note that the universe could have a beginning but still be eternal (i.e. have no end).

    My personal preference (on Tuesdays) is for a universe that is spatially finite but infinite in age and eternal. But there is zero evidence for (or against) this.
    now that just seems like a big stick in my eye =D
    im gonna start with the assertion that the universe could have a beginning and not have an end...(time-wise, right?)
    start and end are relational terms. so if the universe had a beginning, it would seem to be after another universes end - how could you define when the beginning was without referencing the end of something else?
    now maybe you are asserting that there was "nothing" before the universe? but it seems quite absurd to think that something could "happen" when there is nothing.
    as i understand since there is activity now, there must have always been. (did i bring up the philosophical idea of the "unmoved mover" or the problem of infinite regression, in this thread?)

    about the exclusivity of finite/infinite space and finite/infinite time; i suspect they would be necessarily connected. firstly for the reason that, as i understand, all things are connected - not in some hippy-dippy new age kinda way, but in the sense that reality, as a whole, can be considered as one system.
    this is like talking about cartesian dualism.... if there is to be interaction between things, they must be part of the same system. if they dont interact they effectively dont exist in relation to one another.

    i feel like im starting to repeat myself but, if the universe were spacially finite, what is beyond the border? and, if the universe is temporally finite, what is before/after? (really the same question i suppose)
    since definitions are relative, that is, they are exemplified by their contrast to their opposite, then you cant have 1 without the other.

    beginning of A is the end of Z, end of A is the beginning of B. round and round =)

    oh yea and on the "pac-man" universe (laugh) thats basically what im saying here ^
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    Quote Originally Posted by c0sm View Post
    So on my walk i was thinking about curved space and it occurred to me that; the only way to know that something is curved, or even to perceive it as curved, is by comparing it to something straight.
    Right. And there are various ways of doing that. For example, if you measure the angles of a large enough triangle on the surface of the Earth the angles will add up to less than 180, telling you the surface is curved. There are various other things you can do.

    so what is the straight frame of reference which could be used to contrast curvature of space? does time curve as well? (... i know of the phenomenon called "time dialation")
    What is actually curved is space-time. This produces, for example, the effects we perceive as gravity. It also means that the time taken for light to travel past a massive object is sllghtly greater than if the object were not there. And so on.

    However, on cosmological scales it appears that the universe is flat (as near as we can measure) which could imply it is infinite. Or it could imply a finite topology which is curved back on itself but is geometrically flat (I believe a torus [doughnut-shape] can fulfil this requirement, for example).

    it occurrs to me that the spacial and temporal location is a relative definition here.
    It is always relative. There is no zero-point, no reference we can use to make it absolute.

    i was also pondering the relationship of space and time on my walk =)
    Appropriate.

    im gonna start with the assertion that the universe could have a beginning and not have an end...(time-wise, right?)
    start and end are relational terms. so if the universe had a beginning, it would seem to be after another universes end - how could you define when the beginning was without referencing the end of something else?
    now maybe you are asserting that there was "nothing" before the universe? but it seems quite absurd to think that something could "happen" when there is nothing.
    as i understand since there is activity now, there must have always been. (did i bring up the philosophical idea of the "unmoved mover" or the problem of infinite regression, in this thread?)
    This seems like an argument from incredulity: "I can't image there being nothing before the universe therefore there must have been something".

    I can't imagine there being nothing either. Or that the universe could have created from nothing. But if it were to turn out that the evidence supported that, I would accept it with a shrug. I can't visualise curved space-time but I am not going to reject it for that reason. The universe doesn't depend on our ability to imagine it.
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    Quote Originally Posted by c0sm View Post
    So on my walk i was thinking about curved space and it occurred to me that; the only way to know that something is curved, or even to perceive it as curved, is by comparing it to something straight
    In differential geometry, the notion of curvature is defined via parallel transport of a vector around an infinitesimal closed curve on the manifold in question. Consider this :



    Start at the point on the lower left and draw a vector which is tangent to the curved surface; now transport that vector along some closed curved in such a way that it always remains tangent to the surface at each and every point ( "rolling without slipping" ). Once you return to the original starting point you will find that the resulting vector is not the same as the original vector you started with - it will point into a different direction, as in the above illustration. The failure of the original vector to coincide with the final vector is a measure of the curvature of the surface along the chosen curve. On a completely flat surface, both vectors will precisely align, i.e. there is no curvature at all.

    does time curve as well?
    Yes it does - this manifests itself as gravitational time dilation.

    i was also pondering the relationship of space and time on my walk =)
    That relationship is given by the solutions of the Einstein field equations.

    how could you define when the beginning was without referencing the end of something else?
    It's much like the North Pole on Earth - if you stand at the North Pole, then no matter where you turn, you will always face South. Likewise in space-time : if you "stand" at the Big Bang, then all other events will be in your future. This defines the beginning.
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    Quote Originally Posted by c0sm View Post
    i feel a bit like we've strayed from the disputed point though about the nature of the universe being finite or infinite


    To further compound the problem of a finite or infinite universe we need to consider the interpretation we are using in our definition of an infinite universe. This thread had predominantly been discussing forms of geommertrical expression a finite or infinite universe can take. Relativistic physics, quantum physics, cosmological physics, unified physics and computational physics all have a variety of potential forms a finite or infinite universe could take ranging from geommetrical expressions to multiverses to holographics. For example our discussion so far regarding big bang cosmology can principly be attributed to Lemaitre, Einstein and Friedman stemming from General Relativity and explores finite and infinite universes in the context of a single universe. The mathematics used in this explanation has been simplified through the adoption of assunptions such as the Cosmological Principle to make the mathematical analysis of this interpretation tractable.

    Cosmological physics inserts additional assumptions into the mix such as notions of an early inflationary period of expansion through Gamows work to solve the horizon problem. While initially dealing with a single universe, Quantum field theorists and the work of Alan Guth on inflation through the inflaton field takes of an inflationary mutiverse. Now the definition of infinity also encapsulates the notion of a finite or infinite realm of additional universes to consider. String theorists then plunge into additional dimensions, vibrating strings plus a few brains in a multiverse to further compound what a finite or infinite universe may be like.

    But hey, it doesn't stop there. Cyclic multiverses, cosmological anthropics, information theory and the holographic principle, brain fart 1, brain fart 2.....an answer to your question seems to be getting out of reach. Not only that, whatever strand of investigation you decide to take, you must remember to be consistent in its interpretation as you might just, I say might just find you blow it in one of your standard assumptions which is incompatible with the interpretation you are taking in dealing with the universe at large. Oh, and by the way e
    ach of these interpretations apply different mathematical principles so make sure you choose the right one for in doing so it will probably commit most of your life.

    Not to let that put you off at all in your search for answers/TIC :-))

    PS I hope you enjoyed your hike today cOsm. A great way for the mind to sift the wheat from the chaff.
    Last edited by Implicate Order; October 26th, 2013 at 08:13 AM.
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    Quote Originally Posted by Implicate Order View Post
    Cosmological physics inserts additional assumptions into the mix such as notions of an early inflationary period
    Please, please, please do not use the word "assumption". It is really annoying. It either demonstrates some ignorance of science (which is excusable) or is used (by some people, I don't mean you) to denigrate science ("pfft, it just a load of assumptions").

    Inflation is a hypothesis proposed to explain certain observations. It is not clear that it is necessary (Steinhardt, one of the developers of the idea is not longer happy with it, for example). More work required.
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    Quote Originally Posted by Strange View Post
    Please, please, please do not use the word "assumption". It is really annoying. It either demonstrates some ignorance of science (which is excusable) or is used (by some people, I don't mean you) to denigrate science ("pfft, it just a load of assumptions"). Inflation is a hypothesis proposed to explain certain observations. It is not clear that it is necessary (Steinhardt, one of the developers of the idea is not longer happy with it, for example). More work required.
    *extends olive branch*.....Yeah, I concede, it was just me getting petty and frustrated with the processes used by mainstream science to answer questions relating to fundamental truths. Being a lover of science as you probably are as well as evidenced by your 12, 000 posts on the matter in this forum, I am batting for science, but just baffled at the moment in where it is all heading. What irks me in this matter is the roundings, renormalisations, assumptions, hypothesis etc. etc. that is taken to get there that in principle are fine in the search for a parsimionous solution, but in application may be just compounding the issue. c0sm in his introduction to this thread posted a very welcomed and refreshing tack in querying some of the purported fundamental truths......... anyway *rant over*. I reckon I need to take a hike as well........ Sorry Strange for the tone of my posts. It's not you.......it's me :-))
    Last edited by Implicate Order; October 27th, 2013 at 12:05 PM.
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    Quote Originally Posted by Implicate Order View Post
    Yeah, I concede, it was just me getting petty and frustrated with the processes used by manstream science to answer questions relating to fundamental truths.
    Science doesn't address "fundamental truths". That is the domain of science, philosophy and similar wastes of time.
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    Quote Originally Posted by Strange View Post
    Science doesn't address "fundamental truths". That is the domain of science, philosophy and similar wastes of time.
    I wouldn't say philosophy was a waste of time, I believe philosophy is useful for coming up with answers to questions of why whereas science answers questions of how.

    I'd go so far as to say than some philosophical subjects, such as ethics, are vitally important to Human civilization.

    Even logic is a philosophical discipline, and I'm sure we'd all agree that logic is crucial for scientific understanding.
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    Quote Originally Posted by Daecon View Post
    I'd go so far as to say than some philosophical subjects, such as ethics, are vitally important to Human civilization.

    Even logic is a philosophical discipline, and I'm sure we'd all agree that logic is crucial for scientific understanding.
    I agree completely with this. But there is an awful lot of philosophy that seems pretty pointless (including searching for fundamental truth).
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    Originally posted by Strange:

    The universe doesn't depend on our ability to imagine it.
    The above statement is very much a lynchpin, in my opinion. We are a part of the very system which we are attempting to observe, which denies us the ability to truly have 'an arm's length' perspective. 'Infinity' and 'nothing' are concepts that we have devised which is truly remarkable given that both are purely mind exercises which we cannot actually demonstrate.

    I find it rather intriguing that a species of finite duration is capable of such dynamic conceptualization that we may hypothesis a universe that has always existed just as easily as we may hypothesis a universe that arose from ... where was that again?
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    Quote Originally Posted by scheherazade View Post
    Originally posted by Strange:

    The universe doesn't depend on our ability to imagine it.
    The above statement is very much a lynchpin, in my opinion. We are a part of the very system which we are attempting to observe, which denies us the ability to truly have 'an arm's length' perspective. 'Infinity' and 'nothing' are concepts that we have devised which is truly remarkable given that both are purely mind exercises which we cannot actually demonstrate.

    I find it rather intriguing that a species of finite duration is capable of such dynamic conceptualization that we may hypothesis a universe that has always existed just as easily as we may hypothesis a universe that arose from ... where was that again?
    But to be on the safe side you have to take the broadest definition available of what the "universe" is. Several anthropic theories such as The Many Minds Interpretation of Quantum Mechanics, the Holographic Universe and Biocentrism for example do depend on our ability to imagine it, as what is manifest from these theories is a perceived reality comprising spacetime, physical laws and mass-energy. The universe under these these proposals is deeper still necessitating the broadest possible form of definition such as the sum total of everything that exists.

    Addendum: Guys I am not picking bones here and I agree with your statements but there is a subtlety here in definition I am arguing that appears to be creating problems with many of the competing unification theories. This lack of attention to the detail is giving breath to what I would regard as mere 'philosophical theories' as opposed to theories of 'scientific substance'.

    What I find interesting is that in many senses some branches of theoretical science is really starting to take the place of some of the counterpoint views that historically was the domain of the philosopher.

    I take it for granted that possibly all of these more esoteric theories are going to go the way of the dodo, however I can't help feel that an investigative approach taken from a more patient and mathematically complex holistic viewpoint as opposed to a perpetual drilling down viewpoint using simplification assumptions would avoid fragmentation (seen through the large number of competetive alternate theories emerging that are likely to end in dead-ends). With ever increasing numbers of competetive theories available in seaarch of a Theory of Everything, it is going to be difficult to decide which to seriously invest in. Upon reaching a dead-end you then need to determine which alternative to consider but more importantly from what point to progress from. I can't help but feel it is all going to end in tears. :-))
    Last edited by Implicate Order; October 28th, 2013 at 06:49 AM.
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