Delta1212 Posted December 20, 2012 Posted December 20, 2012 I'm absolutely certain that I exist, I think therefore I am. You can't build castles in the sky if you don't have your boots firmly on rock. But despite a lot of common conceptions, the goal of science isn't to build castles in the sky. It's to figure out where the heck the rock is. Taking that into consideration, planting your feet firmly anywhere is likely to impede your progress because you won't be able to look anywhere else, and since you planted your feet without knowing where the rock is, it's just as likely that you planted them on quicksand. So yes, people who want to build castles in the sky need to plant their feet first, but those people become politicians, not scientists.
ACG52 Posted December 20, 2012 Posted December 20, 2012 Here's an interesting article on the web entitled "Problems with General Relativity" It's not an article, it's simply a post by someone who has their own 'theory'.
Daniel Foreman Posted December 20, 2012 Author Posted December 20, 2012 (edited) But despite a lot of common conceptions, the goal of science isn't to build castles in the sky. It's to figure out where the heck the rock is. Taking that into consideration, planting your feet firmly anywhere is likely to impede your progress because you won't be able to look anywhere else, and since you planted your feet without knowing where the rock is, it's just as likely that you planted them on quicksand. The rock is the act of producing experiments that can be well established and tested. The sky is theories that things we can't test exist. Before you can start guessing at what you can not see, you have to establish the rock upon which it is based. As far as I am aware there's no way of testing dimensions outside of a mathematical construct. It's not an article, it's simply a post by someone who has their own 'theory'. Ok, then how about form the man himself. http://photontheory.com/Einstein/Einstein04.html there's plenty more web pages listing problems with relativity. In fact Einstein died trying to correct the problems with General Relativity with his special theory of relativity. Since then more holes have been punched into it. Apart from anything else, marrying together the standard model and the special theory of relativity is problematic at best. @ abisha If you want a great diagramming tool check out OmniGraffle for the Mac or iPad. I used the iPad version to create the image that follows. In regards to black holes at the beginning of the universe (aka the big bag) which was superceeded by inflation theory. The big bang may have been the most compact collection of matter in history, however we can not call this a black hole because the specific properties are entirely different. A black hole under it's own gravity field can not expand, it sucks everything in becoming denser and denser. The beginning of the universe started with all the matter of the universe compressed into one spot, but with the key difference that it could inflate at a constant rate. Clearly it had some kind of internal pressure that allowed it to do so, not only could light escape, it was undoubtedly forced to escape. When dealing with the beginning of the universe there's many ways of looking at things. My own idea's can be summarised in the following diagram. And I'm not trying to pass this off as fact, or well researched, right or wrong, merely a conceptual idea I've been building for a science fiction story I'm working on. Unified origin is a general term for whatever exists outside of our universe. The basic principle for this is the following: It is a completely alien entity (not living, merely a fundamental universal construct) that has it's own set of rules, framework and internal mechanics. It has no need for mass, matter, spatial dimensions, time or anything else we take for granted. Due to some kind of unknown internal mechanic this Unified Origin emits a corrupted or incomplete fragment of itself. As a consequence it's nature changes and it corrupts further. First, there is a corruption of it's own framework, this becomes our spatial dimensions, X, Y and Z Second comes a Super Force. A collection of all forces within our universe. The Super Force due to the corrupted framework can not maintain itself as a single force and begins to separate and "filter" itself through our spatial dimensions unevenly. The creates the fundamental forces, to which I am including the Higgs force, even though it has not been officalli recognised as a fundamental force. Each of these forces interact with each other. The Higgs field creates mass, gravity attracts mass together. The Higgs force is the strongest force, while gravity is the weakest. In between you get the nuclear forces and electromagnetic forces. This distribution of all of this is pretty random. Whenever the Unified origin emitts a fragment of itself it either forms something self sustaining, partly self sustaining, or entirely unstable. This means while you've been reading this forum post 10,000 new universes with differing frameworks from our own have been created. Some have become stable. Some like ours are unstable and others fail to create anything and simply fall back into the unified origin. In this concept, universes are emitted, then forced to spread out and break down with enough time. They are then absorbed, which creates a minor imbalance which created a new cycle of universe birth. Again, I don't claim this is true or right or researched or experimented, this is just something I cooked up for my own science fiction work. It has no scientific method, the only hope this system has of being right is 1) by total luck and 2) by somehow stimulating some clever sods imagination to the point that they actually discover what did happen while at the same time completely disproving this concept. There's little point in creating beginning of the universe stories, until we understand everything we can about how our universe works, and then reverse engineer that knowledge back through time, and beyond. Edited December 20, 2012 by Daniel Foreman
elfmotat Posted December 20, 2012 Posted December 20, 2012 Daniel, it has become quite obvious that you'd rather argue your crackpot ideas than actually learn something. We've all been trying very hard to clear up your incredibly numerous misconceptions, but your overwhelming response has been to either treat facts like opinions or ignore them completely when it suits your cause. I took the time to write you a detailed post, and your response was to ignore large chunks and provide me with a link to a crackpot's forum post which you probably didn't even read yourself. If you had, you would have realized that the OP was torn to shreds by responses to the topic. I don't see what good it would do to continue trying to make you see reason. You're wasting my and everyone else's time which could be better spent on people who are actually willing to learn.
MigL Posted December 20, 2012 Posted December 20, 2012 Nobody is going to hand you a black hole to prove their existence to you Dan. But you say you are familiar with Ohom's Law so you've probably been exposed to Newton's gravity also. Its simple enough to get the escape velocity needed to escape from a given mass concentrated in a given radius. You may even have a C++ program for it. When this escape velocity is equivalent to the speed of light you have a black hole. Or do you think anything could travel faster and a black hole need not form ? For a mass confined to a radius such that the relation Elfmotat gave you is true, we know of no force that can resist gravitational collapse. Maybe you have an idea of a force that can, we'd be glad to hear about it. As someone once said, once you've exausted all possibilities, its time to consider the impossible Dan ( was it Mr Spock ? ). As for observational evidence of air versus black holes , they both have exactly ZERO direct observational evidence. And they have varying amounts of indirect observational evidence. The emperor may have no clothes, but I think I look damn good, even naked( so I've been told ).
swansont Posted December 20, 2012 Posted December 20, 2012 Oh I dunno, I'm sure if they wanted to prove that an orange existed, they'd just hand me an orange. The point is they are cautious because they are not absolutely certain. More likely it's that they can't just hand you a black hole. Not that you'd want to grab one. There's a pretty wide spectrum of physics that does not rely on being able to handle it or observe it with one's eyes. You mentioned radio waves somewhere. You acknowledge them but can't see them, even if you can take a radio apart, so how do you know they exist? Here's an interesting article on the web entitled "Problems with General Relativity" 1. The red shift. 2. Matter and energy not equivalent 3. Problem with the metric model 4. Cosmological issues 5. General Relativity is dimensionally incomplete 6. General relativity is mathematically incomplete 7. Complexity. http://cosmoquest.org/forum/showthread.php/15196-Problems-with-General-Relativity So it's certainly not perfect by any stretch of the imagination. This is what I mean by observations not matching the theory. The internet makes it pretty easy to find crackpots and others who reject science they don't understand.
J.C.MacSwell Posted December 21, 2012 Posted December 21, 2012 (edited) As for observational evidence of air versus black holes , they both have exactly ZERO direct observational evidence. And they have varying amounts of indirect observational evidence. The emperor may have no clothes, but I think I look damn good, even naked( so I've been told ). Neither I nor ACG were debating that, but thank you all the same. You can always claim, correctly at some level, that nothing is direct. Nice, though, to see you admit the "indirect" varies. I hope that last part did not refer to black holes... ...if it's about higher dimensions we are skeptical...but back on topic... Edited December 21, 2012 by J.C.MacSwell
Daniel Foreman Posted December 21, 2012 Author Posted December 21, 2012 Nobody is going to hand you a black hole to prove their existence to you Dan. lol, I should hope not! I'd rather like to continue living! As someone once said, once you've exausted all possibilities, its time to consider the impossible Dan ( was it Mr Spock ? ). Sherlock Holmes. "when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" I prefer Occam's Razor, the principle states "Entities should not be multiplied unnecessarily" When you start having to add additional dimensions to your mathematics to make it work I'd say it's probably wrong. It also states that bad theories are those theories which make too many assumptions. Just because we see a dark blob in the middle of a photograph, people immediately start saying BLACK HOLE! It kinda looks like gods cappuccino to me, he's just added the chocolate and given it a swirl. Can anyone tell me what that white blob is in the middle? Would a black hole have a white core? Seems unlikely to me! No sorry, doesn't do it for me. But if people want to use this as evidence for it then they are welcome to believe it if they want too, just don't ask me too. Daniel, it has become quite obvious that you'd rather argue your crackpot ideas than actually learn something. We've all been trying very hard to clear up your incredibly numerous misconceptions, but your overwhelming response has been to either treat facts like opinions or ignore them completely when it suits your cause http://www.nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-lecture.pdf Einstein himself wrote the above document it is hosted on nobelprize.org, is that legitimate enough for you? It's well known that Einstein sadly went to his grave never fixing all the problems with General Relativity, and that General Relativity nor Special theory of relativity can married with the Standard Model. this is why there's so much work going into the unified theory.
StringJunky Posted December 21, 2012 Posted December 21, 2012 (edited) It kinda looks like gods cappuccino to me, he's just added the chocolate and given it a swirl. Can anyone tell me what that white blob is in the middle? Would a black hole have a white core? Seems unlikely to me! No sorry, doesn't do it for me. But if people want to use this as evidence for it then they are welcome to believe it if they want too, just don't ask me too.. It's in-falling super-hot gases surrounding the blackhole. Your incredulity is getting tiresome. Nobody here is obligated to convince you.or even cares. The only thing that matters is that we give information to the best of knowledge and if you choke on it that's not our problem...nature doesn't have to make sense to you in order to be true. The truth is you don't have the basics under your belt so things like 'time-dilation' and 'black holes' are too exotic and out of your reach at the moment to comprehend properly. If you are really bothered, you need to start reading properly from proper science books by proper scientists in your fields of interest. If you ask I'm sure you'll be pointed to good resources. Edited December 21, 2012 by StringJunky
ACG52 Posted December 21, 2012 Posted December 21, 2012 Dan, your POV appears to be, 'if I don't like it, it can't be so. Nahh nahh nahh..."
ajb Posted December 21, 2012 Posted December 21, 2012 Can't GR's singularities be correct for black holes but incorrect for the big bang (or just before it) because this is where the problems I've seen aired seem to lie? Both represent situations in which we have extreme curvature, in fact general relativity says infinite curvature. General relativity breaks down here and one expects quantum effects to regulate these infinities. In short, the details of the big bang singularity and the physics near the centre of a black hole require a quantum theory of gravity. As far as I am aware there's no way of testing dimensions outside of a mathematical construct. Their are ways of doing this, I briefly suggested some things earlier. One very direct test is to examine Coulomb's law; the force is proportional to r^{d-1} and so one could look for deviations from 3 dimensions. There has been an examination of neutrino oscillation to put bounds on the size of large extra dimensions [1]. The possibility of seeing narrow Regge-excitations of particles at the LHC, as well as black hole production was examined in [2]. The extra dimensions could manifest themselves as missing energy. KK gravity and the LHC was discuss in [3]. And so on... References [1] P. A. N. Machado, H. Nunokawa, R. Zukanovich Funchal, Testing for Large Extra Dimensions with Neutrino Oscillations, Phys.Rev.D84:013003,2011 [2] Antoniadis, Ignatios; Arkani-Hamed, Nima; Dimopoulos, Savas; Dvali, Gia, New dimensions at a millimeter to a fermi and superstrings at a TeV, Physics Letters B, Volume 436, Issue 3-4, p. 257-263. [3] Xiao-Zhou, Li; Peng-Fei, Duan; Wen-Gan, Ma; Ren-You, Zhang; Lei, Guo, WWZ/γ production in the large extra dimensions model at the LHC and ILC, Physical Review D, vol. 86, Issue 9, id. 095008 (2012) A black hole under it's own gravity field can not expand, it sucks everything in becoming denser and denser. I don't follow exactly what you mean. Classically we have the Second Law of black hole thermodynamics, which states that the area of the event horizon is never decreasing. This is true for massive black holes where the loss of mass due to Hawking radiation is tiny. As mass falls into a black hole it grows.
immortal Posted December 21, 2012 Posted December 21, 2012 So ultimately I don't square my day to day observations with the idea of this of higher dimensional space because apart from anything I can not see them. One might point out that I can't see radio waves, or even the air around me either. But the difference is that I can detect these things, and they are pretty obviously operating within the usual 3 dimensions. If extra dimensions exist then they must be small. http://www.sciencedaily.com/releases/2001/02/010213070804.htm
DarkStar8 Posted December 26, 2012 Posted December 26, 2012 (edited) Below is a view from a spaceship moving in a forward direction And below is a view of a fractal like generated Spacetime zooming in to smaller scales, moving in the direction of 'in' Einstein never said Time was the forth dimension. He said Spacetime is 4D. It is not 3D+t, only 4D.In another thread I suggested that scale has direction of 'IN' and 'OUT', where you can apply the laws of motion in a *similar manner. Yes compactify Spacetime and Time slows but I suggested it is scale that is the direction in which the Spacetime is being dragged. Well that's what I think. Scale is like one face of a 4D hyper cube. You can't turn it unless you turn Spacetime inside out... Although perhaps that's exactly what a blackhole is. I can except being wrong if someone can give me a convincing reason for my apparent error of judgement. I'm listening... * similar manner not the same, for we would need a different type of yard stick that is fractal in nature. This bit makes my head hurt, but obviously all momentum in any direction must have a 'speed' limit. Edited December 26, 2012 by DarkStar8 1
MigL Posted December 29, 2012 Posted December 29, 2012 Here's my take on black holes, Daniel... I sometimes find it hard to believe that some events or processes that are readily believed on one scale, all of a sudden become incredulous at a totally different scale. Consider the elementary quantum particle, the electron. It is, in effect, considered a point particle and has no dimensions. It has a weight equivalence of 511meV and a theoretical radius of exactly zero. So what happens to a test weight as we approach the electron ? According to the inverse square law of Newtonian gravity, when the separation approaches zero, the force experienced by the test mass will tend to infinity. It doesen’t matter if the electron’s weight were twice as much, or one hundred times, or a billion times or even equivalent to ten solar masses; The force at zero separation would still be infinite. That sounds very much like the singularity of a black hole to me. Now we know that quantum effects modify this situation to rid us of the infinities. For one thing the Heisenberg Uncertainty Principle makes a separation of near zero impossible because the electron would then have an almost exact position and so its momentum, ie energy, would swing wildly. At exactly zero separation, the left side of the Heisenberg inequality would always be zero, no matter what the momentum or energy, and so the product could never be greater than or equal to Planck’s constant. The infinity, or more specifically the proliferation of virtual particle ( gravitons in this case ) interactions at very close ranges would need to be removed by a mathematical trick ( my bias is showing ) known as renormalization, as is currently done with the similar , inverse square, Coulomb interaction in QED. What we need to get rid of the infinite gravitational force felt at zero separation, is then, a quantum gravity model. It would get rid of the infinity at the singular electron and at the singularity of a black hole, by modifying the behaviour at zero separation, or, eliminating the singular nature of both elementary particles and black holes. Both modern attempts at a quantum gravity theory, which both predict gravitons and allow for renormalization, have their own solution to the problem. Superstring/M-theory uses strings of finite, but non-zero, size ( separation or radius of the inverse square interaction cannot go to zero ), while loop quantum gravity places restrictions on how finely space-time can be subdivided ( space-time is actually a quantised field and there is no background ). DISCLAIMER: Of course there is a difference. For some reason nature throws up a censorship curtain around a black hole, but not the electron, known as an event horizon, to keep the rest of the universe from knowing what goes on inside, so I hedge my bets and say that there could very well be a singularity at the centre of a black hole. So even after we get a working theory of quantum gravity, we’ll never be able to actually verify whether there is a singularity at the centre of a black hole or not. 1
michel123456 Posted December 30, 2012 Posted December 30, 2012 (edited) Below is a view from a spaceship moving in a forward direction And below is a view of a fractal like generated Spacetime zooming in to smaller scales, moving in the direction of 'in' Einstein never said Time was the forth dimension. He said Spacetime is 4D. It is not 3D+t, only 4D.In another thread I suggested that scale has direction of 'IN' and 'OUT', where you can apply the laws of motion in a *similar manner. Yes compactify Spacetime and Time slows but I suggested it is scale that is the direction in which the Spacetime is being dragged. Well that's what I think. Scale is like one face of a 4D hyper cube. You can't turn it unless you turn Spacetime inside out... Although perhaps that's exactly what a blackhole is. I can except being wrong if someone can give me a convincing reason for my apparent error of judgement. I'm listening... * similar manner not the same, for we would need a different type of yard stick that is fractal in nature. This bit makes my head hurt, but obviously all momentum in any direction must have a 'speed' limit. Great pictures. I live with that in Autocad on an everyday basis. No need for fractals. Zoom and Scale commands have exactly the same effect on my display screen. Except that zoom has no effect on the objects while scale has an effect: scale changes the absolute dimensions, zoom not. But still, if I change the metric in CAD, by setting for example that meters become millimeters, then again scale may have no effect. IOW if I set the change in metric equal to the scale factor, zoom & scale have exactly the same effect. As for the rest of your post, I suppose I should agree. My position is that distance is the exact same thing as time (with the opposite sign). That is not much different than yours. But that's all speculation. --------------------------------------------------------- Here's my take on black holes, Daniel... I sometimes find it hard to believe that some events or processes that are readily believed on one scale, all of a sudden become incredulous at a totally different scale. Consider the elementary quantum particle, the electron. It is, in effect, considered a point particle and has no dimensions. It has a weight equivalence of 511meV and a theoretical radius of exactly zero. So what happens to a test weight as we approach the electron ? According to the inverse square law of Newtonian gravity, when the separation approaches zero, the force experienced by the test mass will tend to infinity. It doesen’t matter if the electron’s weight were twice as much, or one hundred times, or a billion times or even equivalent to ten solar masses; The force at zero separation would still be infinite. That sounds very much like the singularity of a black hole to me. Now we know that quantum effects modify this situation to rid us of the infinities. For one thing the Heisenberg Uncertainty Principle makes a separation of near zero impossible because the electron would then have an almost exact position and so its momentum, ie energy, would swing wildly. At exactly zero separation, the left side of the Heisenberg inequality would always be zero, no matter what the momentum or energy, and so the product could never be greater than or equal to Planck’s constant. The infinity, or more specifically the proliferation of virtual particle ( gravitons in this case ) interactions at very close ranges would need to be removed by a mathematical trick ( my bias is showing ) known as renormalization, as is currently done with the similar , inverse square, Coulomb interaction in QED. What we need to get rid of the infinite gravitational force felt at zero separation, is then, a quantum gravity model. It would get rid of the infinity at the singular electron and at the singularity of a black hole, by modifying the behaviour at zero separation, or, eliminating the singular nature of both elementary particles and black holes. Both modern attempts at a quantum gravity theory, which both predict gravitons and allow for renormalization, have their own solution to the problem. Superstring/M-theory uses strings of finite, but non-zero, size ( separation or radius of the inverse square interaction cannot go to zero ), while loop quantum gravity places restrictions on how finely space-time can be subdivided ( space-time is actually a quantised field and there is no background ). DISCLAIMER: Of course there is a difference. For some reason nature throws up a censorship curtain around a black hole, but not the electron, known as an event horizon, to keep the rest of the universe from knowing what goes on inside, so I hedge my bets and say that there could very well be a singularity at the centre of a black hole. So even after we get a working theory of quantum gravity, we’ll never be able to actually verify whether there is a singularity at the centre of a black hole or not. (bolded mine-great post!) Yes. A similar remark is made by Brian Green's "Elegant Universe". i'll dig to find the exact quote. --------------- My edition is in modern Greek language. the remark is in the beginning of chapter 13. Found this from here on the web Chapter 13: Black Holes: A String/M-Theory PerspectiveGreene makes an unlikely comparison between black holes and elementary particles. Both, he says, have an internal structure that physicists have yet to identify. It has recently been suggested that an even greater similarity exists: perhaps black holes are actually huge elementary particles. After all, Einstein set no minimum limit on the mass of a black hole. Therefore, if we crushed a chunk of matter into ever-smaller black holes, the result would be an object no different from an elementary particle. This is because both are defined by their mass, force charges, and spin. This the quote: (...)Black Holes and Elementary Particles At first sight it's hard to imagine any two things more radically different than black holes and elementary particles. We usually picture black holes as the most gargantuan of heavenly bodies, whereas elementary particles are the most minute specks of matter. But the research of a number of physicists during the late 1960s and early 1970s, including Demetrios Christodoulou, Werner Israel, Richard Price, Brandon Carter, Roy Kerr, David Robinson, Hawking, and Penrose, showed that black holes and elementary particles are perhaps not as different as one might think. These physicists found increasingly persuasive evidence for what John Wheeler has summarized by the statement "black holes have no hair." By this, Wheeler meant that except for a small number of distinguishing features, all black holes appear to be alike. The distinguishing features? One, of course, is the black hole's mass. What are the others? Research has revealed that they are the electric and certain other force charges a black hole can carry, as well as the rate at which it spins. And that's it. Any two black holes with the same mass, force charges, and spin are completely identical. Black holes do not have fancy "hairdos"—that is, other intrinsic traits —that distinguish one from another. This should ring a loud bell. Recall that it is precisely such properties—mass, force charges, and spin—that distinguish one elementary particle from another. The similarity of the defining traits has led a number of physicists over the years to the strange speculation that black holes might actually be gigantic elementary particles. In fact, according to Einstein's theory, there is no minimum mass for a black hole. If we crush a chunk of matter of any mass to a small enough size, a straightforward application of general relativity shows that it will become a black hole. (The lighter the mass, the smaller we must crush it.) And so, we can imagine a thought experiment in which we start with ever-lighter blobs of matter, crush them into ever-smaller black holes, and compare the properties of the resulting black holes with the properties of elementary particles. Wheeler's no-hair statement leads us to conclude that for small enough masses the black holes we form in this manner will look very much like elementary particles. Both will look like tiny bundles characterized completely by their mass, force charges, and spin. But there is a catch. Astrophysical black holes, with (...) B.Greene the Elegant Universe Chapter 13. Edited December 30, 2012 by michel123456
MigL Posted December 30, 2012 Posted December 30, 2012 Did you read my disclaimer ? If an elementary particle were truly of a singular nature, then it should have a finite size, event horizon about it just as a black hole singularity does. Since it doesn't, we cannot asssume it is singular ( I believe Hawking and Penrose proved a naked singularity cannot exist ).
ajb Posted December 31, 2012 Posted December 31, 2012 I believe Hawking and Penrose proved a naked singularity cannot exist. Penrose conjectured the Cosmic Censorship Hypothesis, which states that singularities are always hidden behind event horizons. This has not been proved conclusively in the context of general relativity. There are technicalities and physical assumptions to be made. But so far it looks like any "physically reasonable" space-time will obey the hypothesis.
altergnostic Posted December 31, 2012 Posted December 31, 2012 Time is not a spatial dimension, it was introduced via ct, which is a spatial dimension decomposed into a motion © and the duration of that motion. It is also subtracted from x y z in Minkowski's metric. So yes, time is only measured with the motion of matter (or, more precisely, with a change of state of matter/energy) and there's no evidence that it is a physical property of space in itself. Actually, x=ct was always a distance within the 3 spatial dimensions. By that token, we can insert as many dimensions as we like in our metric. For exemple, you could add a fifth dimension from a length composed of ct squared or any other secondary measurement of space. ct is a length in xyz but it can be analised as a separate dimension. We can make measurements of t using x/c (which is basically the way a light-clock would operate). A pendulum swings x at v during a specific interval t, a radioactive atom changes it's energy state between specific regular intervals, and so forth. Time is only measured by the periodic change of state (position, energy, direction, etc) of something. And these are changes that are described in 3D, over subsequent intervals. I think even more to the point is that the universe is not 3D, it just is. We developed this euclidean graph because we can relate the spatial coordinates of anything to some origin with no more than 3 axis. But the world has no axis, these are not physical things, but geometrical abstract constructs. In reality, what we have is stuff related to other stuff, and spatial coordinates is a description of one such relation. Any talk of more than 3 spatial dimensions to describe where the force of gravity dissipates to is nonsense. No other dimensions are possible outside the former 3 because the former 3 are not physical to start with and already include all that surrounds us. It is like using 3D to describe a volume and then postulating imaginary sides because the volume doesn't fit the weight like we want it to. Hell, we can't even detect or measure dimensions, only lengths and distances, and you can always assign any dimension to x, y, z or any composition of the three, but you can't assign extra dimensions to undetected physical properties that you wish were there.
michel123456 Posted January 1, 2013 Posted January 1, 2013 Time is not a spatial dimension, it was introduced via ct, which is a spatial dimension decomposed into a motion © and the duration of that motion. It is also subtracted from x y z in Minkowski's metric. So yes, time is only measured with the motion of matter (or, more precisely, with a change of state of matter/energy) and there's no evidence that it is a physical property of space in itself. Actually, x=ct was always a distance within the 3 spatial dimensions. By that token, we can insert as many dimensions as we like in our metric. For exemple, you could add a fifth dimension from a length composed of ct squared or any other secondary measurement of space. ct is a length in xyz but it can be analised as a separate dimension. We can make measurements of t using x/c (which is basically the way a light-clock would operate). A pendulum swings x at v during a specific interval t, a radioactive atom changes it's energy state between specific regular intervals, and so forth. Time is only measured by the periodic change of state (position, energy, direction, etc) of something. And these are changes that are described in 3D, over subsequent intervals. I think even more to the point is that the universe is not 3D, it just is. We developed this euclidean graph because we can relate the spatial coordinates of anything to some origin with no more than 3 axis. But the world has no axis, these are not physical things, but geometrical abstract constructs. In reality, what we have is stuff related to other stuff, and spatial coordinates is a description of one such relation. Any talk of more than 3 spatial dimensions to describe where the force of gravity dissipates to is nonsense. No other dimensions are possible outside the former 3 because the former 3 are not physical to start with and already include all that surrounds us. It is like using 3D to describe a volume and then postulating imaginary sides because the volume doesn't fit the weight like we want it to. Hell, we can't even detect or measure dimensions, only lengths and distances, and you can always assign any dimension to x, y, z or any composition of the three, but you can't assign extra dimensions to undetected physical properties that you wish were there. Most generally i disagree. You wrote: So yes, time is only measured with the motion of matter (or, more precisely, with a change of state of matter/energy) In my view motion is not a change of state of matter/energy. Motion is a way to conserve energy. What you describe is change of motion aka acceleration.
krash661 Posted August 10, 2013 Posted August 10, 2013 (edited) humanity knows of six dimensions. two below us and three above. Edited August 11, 2013 by krash661 -1
krash661 Posted August 11, 2013 Posted August 11, 2013 (edited) hilarious, another negative point, lol typical. i do not understand this site, and i think i had enough of it. Edited August 11, 2013 by krash661 -1
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