JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 It was a reply to this: "I use an equals sign...is this not math?" I'm not quite sure what the error/fallacy here is, but saying that the can (or spacetime) equals zero because it is empty is just meaningless. (Even if it contains an equals sign.) Empty doesnt mean a zero value to you in most realms? If i say a gas can is empty what Im telling you is that there is no gas...a can of beans being empty means no beans...space-time being empty means no mass...And if space-time gets its values from anything other than the properties of mass, then GR is blown for me... imagining space-time without mass is like imagining mass without space-time...its hard to imagine mass without any volume... I cant believe yall let the fellow in the "Infinity Hypothetis" blog start out by saying... Empty space has a value of 1 now mass has a value of 1... In empty space, we give mass a value of 1? Its not empty space anymore if we change the value of mass to 1...
Mordred Posted January 18, 2015 Posted January 18, 2015 (edited) I think your getting lost again. Let's try this angle. The Scwartzchild metric starts with a flat geometry. Essentially massless. No deformations due to mass/energy. (Vacuum) Then we place mass on this manifold. This then causes the deformity. That's how classic SR uses the coordinate system..Minkowkii So lets switch coordinate systems to field theory. Let's set that previous coordinate system to reflect the minimal energy per volume. This is called zero point energy. QMs minimal vacuum. Based on the Heisenburg uncertainty principle the minimal energy of that metric above is [latex] e=\frac{1}{2}hv[/latex]. This energy is essentially virtual particle/anti particle pairs popping in and annihilating. Now in first scenario the metric does such a good job predicting GR influences such as gravity that it is an excellent approximation. The second set even though it sounds more accurate its still an approximations. ( most models are just good approximations) Neither one is incorrect nor is either one. more accurate Both are accurate in terms of the model. In the latter case you can normalize a positive energy density and set the value at zero. That's one thing about differential geometry. You define the relations. You can choose to set any positive or negative property with a value of zero. By the way QM treats all vacuums as having at least zero point energy. http://en.m.wikipedia.org/wiki/Zero-point_energy Edited January 18, 2015 by Mordred
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 Nice...but real quick, Empty space has how much mass in it? anyone? after awhile, arguing questions like this is ridiculous...
Mordred Posted January 18, 2015 Posted January 18, 2015 (edited) No clue but the average critical density of our universe is [latex]1.87*10^{-29} grams/m^3[/latex] Edited January 18, 2015 by Mordred
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 Just started in on Quantum Field Theory and after thinking about GR in terms of waves and curves, now theyre going to turn it into particles? What is the quanta for space-time? No clue but the average critical density of our universe is[latex]1.87*10^{-29} grams/m^3[/latex] You have no clue what empty means? Youll never stop playing this game..."containing nothing; not filled or occupied."So...if youre referring to spacetime as empty, it cannot contain anything...not even energy... Whats the density with no mass? lemme guess....1
Mordred Posted January 18, 2015 Posted January 18, 2015 (edited) I think you missed the point of E=1/2hv The critical density value I gave you is all the major energy matter contributors (dark energy ,photons,radiation,dark matter etc) average of the universe You just got into an explanation that virtual particles pop in and out of spacetime. Empty in QM isn't empty neither is it in field theory. Particularly since you didn't specify a volume Energy has a mass equivalents. E=mc^2. Photons have no rest mass but they have a mass equivalence due to their kinetic energy. Virtual particles often come in the form of photons/anti photon pairs. So even photons can generate gravity. So can a gravity wave. Edited January 18, 2015 by Mordred
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 Oh yeah? Diffeomorphism says different...he told me to say hello General convariance seems to agree with me.. what is hv? I dont know what h nor v stand for...
Mordred Posted January 18, 2015 Posted January 18, 2015 (edited) Did he also tell you that energy and momentum can also generate gravity lol say hi back been awhile V is frequency h is the planck constant Edited January 18, 2015 by Mordred
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 (edited) when you say energy, you dont have to say momentum...ive been doing it all along...all you need is mass and energy...and if they are equal, then all you need is one or the other to cover all gravitational influences...I assumed these things could create gravity...I find it strange that you asked me what volume my massless space is...why would space have a volume if there were no mass or energy? Wouldnt you need to successfully merge GR and QFT to talk about them relating to each other? Are there particle/anti-particle pairs in GR? I do not think so Energy equals half of the product of momentum times the plank constant?Man, can you give me the terms involved here? And what terms or form does the resulting energy have? joules? I know that momentum is mass times velocity, but if mass is in grams and velocity is in meters per second,...does that make the final terms for momentum? gram meters per second? gm/s? Edited January 18, 2015 by JohnSSM
Mordred Posted January 18, 2015 Posted January 18, 2015 (edited) How many times have you heard me say space is geometric volume. According to QMs zero point energy it's never empty. You didn't catch my edit. V is frequency in QM. Edited January 18, 2015 by Mordred
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 A billion times...I aint talking bout QM...i was talking bout GR And when it finally sinks in that space-time is only "there" because the properties of mass define it with geometry, in no medium other than motion and time with no form...then yall try to tell me it can be empty..IF space-time has vacuum energy, i should really know...cuz thats all it takes to revive my space foam thoery... Consider a fisher price bubble blowing kit...there is no bubble before you blow...
Mordred Posted January 18, 2015 Posted January 18, 2015 The space foam is a descriptive once used to describe the quantum fluctuations of the quantum oscillator in QM. GR doesn't have space foam. This is where the debate is space smooth or lumpy came into play . Side note the process I described leads to 120 orders of magnitude to much energy. So either QMs quantum oscillator is wrong or something unknown is suppressing the energy. It's why you don't see it mentioned much anymore
Strange Posted January 18, 2015 Posted January 18, 2015 Empty doesnt mean a zero value to you in most realms? But you need to be precise about what is "zero". So you can say the mass of beans is 0g (or the mass of the universe 0kg). But that doesn't mean you can say that "the can = zero" (or that spacetime = zero). The latter makes no sense.
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 If space-time is only a set of coordinates, its not really like a can at all...and it makes little obvious sense to say that space-time is anything...I was pretty sure it was just an illusion created by the properties of mass...gravity? motion? not real...im comfy with that now and shall not let it go until i find more info...But to try to understand, are yall saying that the energy it takes to support the field of spacetime, with or without mass within it, can be considered a source of gravity within that space-time that creates no curves? So, empty space does have an energy value, and that energy value effects the geometry of empty space-time? and you could consider that energy value to be relative to a mass value without having mass?IS that how you get empty space with an energy value1 that equates to a mass value1 and creates gravity in empty space?
ajb Posted January 18, 2015 Posted January 18, 2015 I get that...but gravitational waves are created by the properties of mass...IF we have empty space, where would gravitational waves come from? The space-time the gravitational waves are propagating in can be a vacuum. There are some exact solutions to the field equations of this form.
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 So, the gluon field could be the energy source for space-time...just as I thought The space-time the gravitational waves are propagating in can be a vacuum. There are some exact solutions to the field equations of this form. In that case, what energy is causing the gravitational waves...?
ajb Posted January 18, 2015 Posted January 18, 2015 Nice...but real quick, Empty space has how much mass in it? anyone? after awhile, arguing questions like this is ridiculous... The usually thing would be to put mass and energy equal using E=mc^2 and then looks at the energies that I listed. S0 this notion is not always well defined.
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 IS it fair to think of gravity waves like areas of accelerating or decelerating gravity which propagate into space?
ajb Posted January 18, 2015 Posted January 18, 2015 (edited) In that case, what energy is causing the gravitational waves...? In real situations one source of gravitation waves are coalescing black holes. You can probabily treat these as points provided you are not too close to them. The point is that these waves do not need any media to propagate, they really are little ripples in the space-time geometry. IS it fair to think of gravity waves like areas of accelerating or decelerating gravity which propagate into space? The usual way is to think of local stretching and compression of space. Edited January 18, 2015 by ajb
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 The usually thing would be to put mass and energy equal using E=mc^2 and then looks at the energies that I listed. S0 this notion is not always well defined. IS it ever possible to give E and m zero values? Like actually 0? Would that just represent no space time as opposed to empty space time? In real situations one source of gravitation waves are coalescing black holes. You can probabily treat these as points provided you are not too close to them. The point is that these waves do not need any media to propagate, they really are little ripples in the space-time geometry. The usual way is to think of local stretching and compression of space. This whole time, ive been talking about empty space... What im hearing is, even when there is no mass or energy put into spacetime from an outside source...ie...spacetime with NO added mass or energy...it still has energy which can be considered mass and create gravity...
ajb Posted January 18, 2015 Posted January 18, 2015 IS it ever possible to give E and m zero values? Like actually 0? Would that just represent no space time as opposed to empty space time? The ADM mass of Minkowski space-time is zero. (So are the other masses). This is not considered as 'no space-time'.
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 Im still trying hard to take in Minkowski space..Still trying to grasp what vectors, scalars and tensors are...im pretty lost on the subject right now I dont really understand Euclidean space either...
swansont Posted January 18, 2015 Posted January 18, 2015 I have no idea how that applies to this conversation...Im just trying to find the logic of giving something which is empty, a value which is based on whats inside it... Like, an empty can of beans is said to have no beans...you dont claim to give it bean values because the can is made of something...and in the point of spacetime, there is no can as far as I know...there are only beans which create the shape of the can...no beans? no shape? no value, no can... If you are counting the number of beans that makes sense. N is the number of beans, and N=0 (or N=23, or whatever) spacetime value=0 makes no sense unless you can tell me what spacetime value=1 means, or some other arbitrary values. If it's counting, then a number suffices. If it's a relationship of some sort, it needs to be an equation.
Strange Posted January 18, 2015 Posted January 18, 2015 Still trying to grasp what vectors, scalars and tensors are...im pretty lost on the subject right now You are trying to understand something that I think requires several years of postgraduate study. Asking ad-hoc questions on a forum and reading a few articles is not going to get you up to speed quickly. I dont really understand Euclidean space either... This is just what we learn in school: 3 different dimensions at right angles to each other - space divided up into cubic grid.
JohnSSM Posted January 18, 2015 Author Posted January 18, 2015 If you are counting the number of beans that makes sense. N is the number of beans, and N=0 (or N=23, or whatever) spacetime value=0 makes no sense unless you can tell me what spacetime value=1 means, or some other arbitrary values. If it's counting, then a number suffices. If it's a relationship of some sort, it needs to be an equation. I do agree...and the equation needs terms doesnt it? But it was never space-time equals 0 or 1...its been mass and energy...i have mentioned space-time being empty...but is there anyway to define space-time values without regarding matter and energy? If there is zero mass and zero energy, I would say that space-time is empty of mass and energy, and to give it any value at that point seems strange...but i am still grasping...
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