metacogitans Posted August 2, 2014 Posted August 2, 2014 (edited) only path of least resistance. The reason an electron stays bound to a proton is because the least-negative direction is in the direction of the proton, and thus there is least resistance in the direction of the proton.Basically, what I'm thinking is, only like-charges interact with each other; positive and negative never interact with each other, and what appears to be 'attraction' between a positive and negative charge is actually just the particles staying along the path of least resistance.Would you guys say that's correct? That isn't considering gravitational attraction, which according to GR isn't attraction either, but geodesics of space-time. Although now that I think about it, a charged particle would follow a path of least resistance not only in the direction of opposite charged particles, but any mass in general (assuming mass itself is charge-less), since for any charged particle, there will be less resistance in the direction of any massive object, even if not of an opposite charge, as long as the mass is either charge-less or neutral.This could explain gravity, assuming:1. Charged particles only interact electromagnetically with particles of the same charge.2. Mass itself shields charged particles from the electromagnetic field of other same-charged particles by being between the two. One might then ask why light would be affected by gravity if gravity is just an extended effect of electromagnetism, but consider that light is itself not chargeless; photons are both positive and negative. You may ask what electromagnetic repulsion could a charged particle out in space be experiencing? But keep in mind that an electromagnetic field is infinite with dwindling intensity; even if the charged particle out in space is only experiencing a miniscule amount of electromagnetic repulsion, it will still begin accelerating in the path of least resistance; If the presence of mass is shielding the particle from electromagnetic repulsion, then the path of least resistance will tend to be in the overall direction of the mass. Since the particle is being constantly accelerated in this manner, the rate at which its velocity increases along the path of least resistance will be exponential, as is the case with gravity. Edited August 2, 2014 by metacogitans
studiot Posted August 2, 2014 Posted August 2, 2014 (edited) You are working towards Lagrangian and Hamiltonian Mechanics. But you need to think in energy terms not force terms. https://www.google.co.uk/search?hl=en-GB&source=hp&q=hamiltonian+mechanics&gbv=2&oq=Hamiltonian&gs_l=heirloom-hp.1.2.0l10.1453.3968.0.7953.11.6.0.5.5.0.125.671.0j6.6.0....0...1ac.1.34.heirloom-hp..0.11.905.0yx_xPQhI7U Edited August 2, 2014 by studiot
Sensei Posted August 2, 2014 Posted August 2, 2014 (edited) Have you heard about Positronium? http://en.wikipedia.org/wiki/Positronium or exotic atom made of antiproton-helium nucleus? http://en.wikipedia.org/wiki/Antiprotonic_helium Once electron collides with positron there is annihilation. Once antiproton collides with nucleus there is annihilation. Have you heard about "breaking radiation" Bremsstrahlung? http://en.wikipedia.org/wiki/Bremsstrahlung f.e. positive ion is attracting free electron, which is emitting photon and loses kinetic energy.. and it's slowed down, or intercepted by nucleus.. Edited August 2, 2014 by Sensei
metacogitans Posted August 3, 2014 Author Posted August 3, 2014 (edited) You are working towards Lagrangian and Hamiltonian Mechanics. But you need to think in energy terms not force terms. https://www.google.co.uk/search?hl=en-GB&source=hp&q=hamiltonian+mechanics&gbv=2&oq=Hamiltonian&gs_l=heirloom-hp.1.2.0l10.1453.3968.0.7953.11.6.0.5.5.0.125.671.0j6.6.0....0...1ac.1.34.heirloom-hp..0.11.905.0yx_xPQhI7U If that's the case, I think I'm only working towards it conceptually in my mind, and not in a written-down mathematical sense (at least not yet). Have you heard about Positronium? http://en.wikipedia.org/wiki/Positronium or exotic atom made of antiproton-helium nucleus? http://en.wikipedia.org/wiki/Antiprotonic_helium Once electron collides with positron there is annihilation. Once antiproton collides with nucleus there is annihilation. Have you heard about "breaking radiation" Bremsstrahlung? http://en.wikipedia.org/wiki/Bremsstrahlung f.e. positive ion is attracting free electron, which is emitting photon and loses kinetic energy.. and it's slowed down, or intercepted by nucleus.. I haven't heard of those particles before in particular, but that's interesting since those are the types of particles I've been tossing around hypothetically in my own head while trying to figure it all out. What do you guys think about gravity just being a byproduct of electromagnetic repulsion in the universal background, and the presence of mass dampening this electromagnetic repulsion causing the path of least resistance for a particle to tend to be in the direction of mass? Do you think that explanation holds water? Right off the bat, it would seem to help explain a few other things as well, like the mystery of dark energy. If gravity were a byproduct of electromagnetism, then all of the phenomenon we attribute to 'dark energy' could already be accounted for and need no further explanation. The expansion of the universe would merely be residual electromagnetic repulsion over great distances; which, despite the great distance, would still be influential on the trajectory of a particle. It readily explains the shape of our universe. Gravity explained in this way would be indistinguishable in many aspects from General Relativity; objects following a 'path of least resistance' amidst residual electromagnetic repulsion in the universal background would look and act like 'curved space-time', but in this case, the 'invisible grid of spacetime' is made of tangible ingredients we have identified. Edited August 3, 2014 by metacogitans
Bignose Posted August 3, 2014 Posted August 3, 2014 If gravity were a byproduct of electromagnetism, then all of the phenomenon we attribute to 'dark energy' could already be accounted for and need no further explanation. But gravity being part of EM is trivially falsified. EM's attraction is between opposite charges. The moon is attracted to the earth. Ergo, the moon must have the opposite charge of the earth. The earth is attracted to the sun. Ergo, the earth must have the opposite sign of the sun. It them follows that the sun and the moon must have the same sign. Yet, in EM, the same charges are repelled, but the moon is not repelled by the sun. This is just one of many, many reasons we know that gravity is not the same as EM. Many have tried to proposed this exact same idea, and none have been able to offer forth a model that agrees with observations. Until such a time -- and there very well may be a unified force description we discover some day -- the best model science has is treating gravity and EM as separate. 1
studiot Posted August 3, 2014 Posted August 3, 2014 A clear and concise refutation, Bignose +1. metacogitans, you have the germ of a good idea so I am trying to steer you in the appriate direction, because others have trod this path before. However you are trying to minimise the wrong thing, hence my reference to Hamiltonian - Lagrangian mechanics. However I'm sorry to tell you that this approach requires some advanced mathematics and I do not know of a website or book that presents it in elementary terms. Using H-M mechanics leads, amongst other things, to the Schrodinger equation.
metacogitans Posted August 4, 2014 Author Posted August 4, 2014 (edited) But gravity being part of EM is trivially falsified. EM's attraction is between opposite charges. The moon is attracted to the earth. Ergo, the moon must have the opposite charge of the earth. The earth is attracted to the sun. Ergo, the earth must have the opposite sign of the sun. It them follows that the sun and the moon must have the same sign. Yet, in EM, the same charges are repelled, but the moon is not repelled by the sun. This is just one of many, many reasons we know that gravity is not the same as EM. Many have tried to proposed this exact same idea, and none have been able to offer forth a model that agrees with observations. Until such a time -- and there very well may be a unified force description we discover some day -- the best model science has is treating gravity and EM as separate. The main idea I was trying to make with the thread was speculating whether or not 'attraction' even exists, and instead trying to explain the phenomenon of 'attraction' as a result of particles following a path of least resistance. Consider that a charge does not attract its opposite, but instead dampens its opposite - and there is only repulsion, with the phenomenon of attraction resulting from a lack of repulsion in a particular direction. When this is applied to a macroscopic scale, if we assume that mass in a sense 'blocks' residual EM repulsion (similar to how in the previous paragraph we proposed that an opposite charge dampens repulsion), then an object or particle's path of least resistance will tend to be in the direction of mass. Also, when I said that gravity was a 'byproduct of electromagnetism', I meant that the electromagnetic activities taking place at the subatomic scale give rise to gravity on the macroscopic scale. When you say the 'moon is attracted to the Earth', I am proposing that it's not 'attracted' to the Earth, but the Earth's mass shields the moon from residual electromagnetic repulsion in the universe from that direction, causing the moon to have less resistance in the direction of the Earth. metacogitans, you have the germ of a good idea so I am trying to steer you in the appriate direction, because others have trod this path before. However you are trying to minimise the wrong thing, hence my reference to Hamiltonian - Lagrangian mechanics. However I'm sorry to tell you that this approach requires some advanced mathematics and I do not know of a website or book that presents it in elementary terms. Using H-M mechanics leads, amongst other things, to the Schrodinger equation. I agree; I think the ideas I have make sense, and nothing jumps out at me as contradictory, but I think for me to get any more of an understanding, I'm going to have to learn how its expressed mathematically. I enjoy trying to work out these ideas myself a little, so I can sort of feel like I did it a little independently. I don't know if I have an original idea, but I'm having fun putting the pieces together. As for Hamiltonian Mechanics, take a swing at giving a little explanation if you feel like it. I'm reading about Lagrangian mechanics right now, and one of the things it says is "Thus, instead of thinking about particles accelerating in response to applied forces, one might think of them picking out the path with a stationary action." which is weird because I was thinking of that just the other day. Edited August 4, 2014 by metacogitans
Bignose Posted August 4, 2014 Posted August 4, 2014 The main idea I was trying to make with the thread was speculating whether or not 'attraction' even exists, whether you want to quibble on whether it is a push or a pull is rather immaterial here. You can dicker on word choice, but I notice that you didn't address any of the substance of my post. Namely, if what we call gravity today is an EM effect, why doesn't it obey what we know about EM today? Or, to the point, why isn't the moon repelled by the sun? Please propose a model that makes predictions that agree with observations. Again, I don't care whether you call it a pull, a push, least resistance, repulsion, attraction, or whatnot. I just want a model that agrees with what is observed.
studiot Posted August 4, 2014 Posted August 4, 2014 OK I will have a go at a Hitchhiker’s Guide to Hamiltonian-Lagrangian mechanics. If I spread too much jam on it I’m sure Bignose will apply the necessary corrections. First a mathematical observation. I assume you know some elementary calculus. So I will make the statement that every process that can be modelled mathematically by a differential equation can also be formulated as an integral equation. Now Newton’s second law is a differential equation that models the motion of a body as it travels along some trajectory or path. At any point on that path Newton’s Law provides a connection between external forces and the local conditions (at the point) by way of the time rate of change (differential coefficient), to enable us to determine the actual path traversed. I stress this equation is local ie applies individually at each point, but each individual application may be different. Now an alternative view is to ask Is there a function that if applied to the whole path will define that path for us? The answer is yes. There is such a function that we call ‘the action’. If we integrate this action function along any entire proposed path it turns out that the action integral is minimised by using the actual path traversed. This introduces our first Big Name is known as Hamilton’s principle, also called the Principle of Least Action. Now two things. Firstly proving this is the province of some advanced mathematics. Secondly deducing the actual path uses a process ( some more advanced calculus) known as the calculus of variations. I will not attempt either here. The function itself introduces our second Big Name, the Lagrangian. [math]Action = \int_{{t_1}}^{{t_2}} {Ldt} [/math] and for simple conservative fields like gravity the Lagrangian is simply the difference between the kinetic and potential energies L = K – P A parting thought in support of Bignose’ desire for agreement with real world observation. So let us start back with Newton and his law of gravitation.[math]{F_{grav}} = s\frac{{{M_1}{M_2}}}{{{r^2}}}[/math]This states that for two masses there is a force between them proportional to each mass and inversely proportional to the square of the distance between them. s is the constant of proportionality to make this an equation.After it became possible to measure this force, it was noticed that for certain objects there was an additional force in action over and above that given by the gravity equation.This was found to follow the same form (Coulombs law)[math]{F_{elec}} = t\frac{{{Q_1}{Q_2}}}{{{r^2}}}[/math]Well physicists are lazy customers and like to recycle equations rather than introduce new ones.So when magnetism was being investigated another additional force was proposed and the relationship experimentally verified by Michell in 1750.[math]{F_{mag}} = u\frac{{{P_1}{P_2}}}{{{r^2}}}[/math] A quantity known as the pole strength was introduced.Do you notice any similarity?Note I have only used some of the standard symbols for clarity of comparison.Note also that all these three are experimental results. Observations on the physical world. 1
metacogitans Posted August 4, 2014 Author Posted August 4, 2014 (edited) whether you want to quibble on whether it is a push or a pull is rather immaterial here. You can dicker on word choice, but I notice that you didn't address any of the substance of my post.Namely, if what we call gravity today is an EM effect, why doesn't it obey what we know about EM today? Or, to the point, why isn't the moon repelled by the sun? Simple - the laws governing a dynamic system will give the dynamic system a different appearance at different scales. I think that the EM you're referring to is an older classical perspective where everything is rotating around each other in perfect circles with positives and negatives. You are thinking of how the broader picture should appear linearly when you should think of it as exponential. Please propose a model that makes predictions that agree with observations. Again, I don't care whether you call it a pull, a push, least resistance, repulsion, attraction, or whatnot. I just want a model that agrees with what is observed. In my mind, this proposed model seems to be even more consistent with observations since the inconsistencies in the current model are absent, but again, I'm just making speculations; I'm coming to you guys for the actual answers. This subject matter has been discussed, debated, picked apart and analyzed over and over throughout history, and you guys are the experts when it comes to that, so I'm defering to you. Edited August 4, 2014 by metacogitans
Bignose Posted August 5, 2014 Posted August 5, 2014 (edited) ...and you guys are the experts when it comes to that, so I'm defering to you. No, not really. Because the experts know that gravity is an attractive force not a repulsion, and is not the same as EM. You are thinking of how the broader picture should appear linearly when you should think of it as exponential. So you're saying [math]f_{gravity \ and \ EM}=\exp(something)?[/math]. what is that 'something'? You need to show me that this model makes better predictions than the models we have today. And this is not the functional form we see today which makes supremely accurate predictions. Here is an easy one: using your model of gravity/EM, please show the math for a geostationary orbit. Edited August 5, 2014 by Bignose
metacogitans Posted August 5, 2014 Author Posted August 5, 2014 OK I will have a go at a Hitchhiker’s Guide to Hamiltonian-Lagrangian mechanics. If I spread too much jam on it I’m sure Bignose will apply the necessary corrections. First a mathematical observation. I assume you know some elementary calculus. So I will make the statement that every process that can be modelled mathematically by a differential equation can also be formulated as an integral equation. Now Newton’s second law is a differential equation that models the motion of a body as it travels along some trajectory or path. At any point on that path Newton’s Law provides a connection between external forces and the local conditions (at the point) by way of the time rate of change (differential coefficient), to enable us to determine the actual path traversed. I stress this equation is local ie applies individually at each point, but each individual application may be different. Now an alternative view is to ask Is there a function that if applied to the whole path will define that path for us? The answer is yes. There is such a function that we call ‘the action’. If we integrate this action function along any entire proposed path it turns out that the action integral is minimised by using the actual path traversed. This introduces our first Big Name is known as Hamilton’s principle, also called the Principle of Least Action. Now two things. Firstly proving this is the province of some advanced mathematics. Secondly deducing the actual path uses a process ( some more advanced calculus) known as the calculus of variations. I will not attempt either here. The function itself introduces our second Big Name, the Lagrangian. [math]Action = \int_{{t_1}}^{{t_2}} {Ldt} [/math] and for simple conservative fields like gravity the Lagrangian is simply the difference between the kinetic and potential energies L = K – P A parting thought in support of Bignose’ desire for agreement with real world observation. So let us start back with Newton and his law of gravitation. [math]{F_{grav}} = s\frac{{{M_1}{M_2}}}{{{r^2}}}[/math] This states that for two masses there is a force between them proportional to each mass and inversely proportional to the square of the distance between them. s is the constant of proportionality to make this an equation. After it became possible to measure this force, it was noticed that for certain objects there was an additional force in action over and above that given by the gravity equation. This was found to follow the same form (Coulombs law) [math]{F_{elec}} = t\frac{{{Q_1}{Q_2}}}{{{r^2}}}[/math] Well physicists are lazy customers and like to recycle equations rather than introduce new ones. So when magnetism was being investigated another additional force was proposed and the relationship experimentally verified by Michell in 1750. [math]{F_{mag}} = u\frac{{{P_1}{P_2}}}{{{r^2}}}[/math] A quantity known as the pole strength was introduced. Do you notice any similarity? Note I have only used some of the standard symbols for clarity of comparison. Note also that all these three are experimental results. Observations on the physical world. Thank you for that, I need to digest that for a while; I'm basically trying to jump into intermediate physics and calculus when the last math class I took was pre-calc in high school 7 years ago
studiot Posted August 5, 2014 Posted August 5, 2014 (edited) Thank you for that, I need to digest that for a while; Come back and ask questions about it when you like, I agree it's a lot to digest. If you can begin to make sense of it we can talk about the lagrangian formulation necessary to cope with electric forces. Edited August 5, 2014 by studiot
metacogitans Posted August 5, 2014 Author Posted August 5, 2014 (edited) No, not really. Because the experts know that gravity is an attractive force not a repulsion, and is not the same as EM. So you're saying [math]f_{gravity \ and \ EM}=\exp(something)?[/math]. what is that 'something'? You need to show me that this model makes better predictions than the models we have today. And this is not the functional form we see today which makes supremely accurate predictions. Here is an easy one: using your model of gravity/EM, please show the math for a geostationary orbit. I'll try to; Although even if I managed to with my very limited knowledge of mathematics, I have a suspicion it'd end up looking a lot like the GR field equation, since I think the 'residual repulsion' I was talking about would just be a variant of the cosmological constant. I think maybe what I would be doing is re-writing the cosmological constant in the equation so that it's no longer a constant, but dynamic - and a product of electromagnetism. Edited August 5, 2014 by metacogitans
Bignose Posted August 5, 2014 Posted August 5, 2014 I'll try to; Although even if I managed to with my very limited knowledge of mathematics, I have a suspicion it'd end up looking a lot like the GR field equation, since I think the 'residual repulsion' I was talking about would just be a variant of the cosmological constant. I think maybe what I would be doing is re-writing the cosmological constant in the equation so that it's no longer a constant, but dynamic - and a product of electromagnetism. I think you are getting way ahead of yourself. Using the accepted version of gravity today, I can write the math that describes a geostationary orbit very straightforwardly. No reason to invoke GR or cosmological constant or anything like that. I am asking you to do the same thing treating gravity as EM as you've claimed. No need to expand to cosmological scales if you can't even describe the local ones. I am hoping that you will clear up my question that I've asked several times now as to if gravity was EM based, why the sun doesn't repel the moon. Again, I don't care if you call it a push, a pull, an attraction, a repulsion, or so on. We know that things with opposite charges behave differently than things with same charges. If gravity was EM based -- and thus objects would have charges -- it doesn't fit what we see. This needs to be remedied before your idea goes any further. I have very little interest in an idea that doesn't match what we see. 1
metacogitans Posted August 9, 2014 Author Posted August 9, 2014 (edited) I think you are getting way ahead of yourself. Using the accepted version of gravity today, I can write the math that describes a geostationary orbit very straightforwardly. No reason to invoke GR or cosmological constant or anything like that. I am asking you to do the same thing treating gravity as EM as you've claimed. No need to expand to cosmological scales if you can't even describe the local ones. I am hoping that you will clear up my question that I've asked several times now as to if gravity was EM based, why the sun doesn't repel the moon. Again, I don't care if you call it a push, a pull, an attraction, a repulsion, or so on. We know that things with opposite charges behave differently than things with same charges. If gravity was EM based -- and thus objects would have charges -- it doesn't fit what we see. This needs to be remedied before your idea goes any further. I have very little interest in an idea that doesn't match what we see. But you can't explain the shape of the universe with your math without assuming things like "dark energy" and "dark matter"; with gravity explained as a result of net repulsion in the universe, the shape of our universe and the trajectory of the everything in it just so happens to be conveniently explained in the math. The cosmological constant, the background radiation, would be written as dampened by mass; if you imagine the background radiation as the residual electromagnetic field from everything in the universe propagating through space, and imagine it being blocked by, say, a planet or a star - then the path of least resistance for objects around the planet or the star is going to tend to be in that direction. The cosmological constant is already in the GR field equation; I guess a good question should be "does GR already do what I intend?" ...Okay, reading right now that the cosmological constant in GR was bunk. So why do they still use GR for gravity? And no one has come up with another theory of gravity since then? That's good news. That would also give some new insight into particle physics; if we know how things got their shape so far, we know more about what events need to have taken place during the big-bang for them to have got the way they are now, and we can also throw out 'dark energy and dark matter' if the effects those were invented to explain turn out to be included in an explanation for gravity. Am I just late to the 'punch'? I mean, they're able to keep spacecraft in orbit travelling several thousand meters per second around the Earth, they've got to know gravity fairly well. So: background radiation forms a 'medium' consisting of repulsive waves of energy; these repulsive waves are blocked/absorbed by matter, giving rise to the phenomenon of gravity. Taking a look at Einstein's Field Equation: Nothing looks as though it needs to be changed except for the cosmological constant (lambda) and the metric tensor which need to be entirely re-written.The cosmological constant will have to be given as an average; and the metric tensor, oh boy, I do not have a clue.. could sure use a knowledge of higher calculus right now. I'm about to make a diagram explaining how I think the cosmological constant would have an average value found for it Edited August 9, 2014 by metacogitans
metacogitans Posted August 9, 2014 Author Posted August 9, 2014 (edited) Forgive the size: The arrows represent background radiation influencing the particle; the 3 arrows above the 'massive object' represent background radiation traveling in the direction of the particle on the other side of the 'massive object' - the space between the dashed lines indicates that background radiation is being blocked/dampened from the direction of the other side of the massive object. Edited August 9, 2014 by metacogitans
Strange Posted August 9, 2014 Posted August 9, 2014 This looks like "push gravity" which was falsified centuries ago. People do keep trying to add new ad-hoc excuses to try and make it work though.
metacogitans Posted August 9, 2014 Author Posted August 9, 2014 This looks like "push gravity" which was falsified centuries ago. People do keep trying to add new ad-hoc excuses to try and make it work though. How was it falsified?
Strange Posted August 9, 2014 Posted August 9, 2014 How was it falsified? http://en.wikipedia.org/wiki/Le_Sage%27s_theory_of_gravitation http://www.thescienceforum.com/physics/30064-why-push-gravity-does-not-work.html Even if it could reproduce Newtonian gravity, it seems very unlikely it could be forced to match GR.
metacogitans Posted August 9, 2014 Author Posted August 9, 2014 (edited) http://en.wikipedia.org/wiki/Le_Sage%27s_theory_of_gravitation http://www.thescienceforum.com/physics/30064-why-push-gravity-does-not-work.html Even if it could reproduce Newtonian gravity, it seems very unlikely it could be forced to match GR. GR itself is an inverse push-gravity theory; without the cosmological constant, the field equation in GR as written would lead to a universe that contracted in upon itself - Einstein included the cosmological constant in his field equation hoping it would resolve this; the cosmological constant worked as a residual repulsive force in the universal background stopping gravity from causing the contents of the universe from contracting in upon themselves - it later turned out that he was wrong. For 60 years it was simply left out of the equation; in the 1990s, it was eventually given an estimated value for GR based on measurements of the universal background radiation. Basically, Einstein himself had to include some hypothetical 'pushing force' in his equations for them to make sense, without knowing if such a force existed or not. I am simply assuming that the same 'pushing force' is responsible for gravity in the first place - which if it is, accounts for the expansion of space without the need for 'dark energy'. Edited August 9, 2014 by metacogitans
studiot Posted August 9, 2014 Posted August 9, 2014 This very recent book contains an interesting history and discussion of the various versions of General Relativity, including the introduction, retirement and resurgence of the cosmological constant. http://www.amazon.co.uk/Perfect-Theory-Century-Geniuses-Relativity/dp/1408703106/ref=sr_1_5?s=books&ie=UTF8&qid=1407610640&sr=1-5&keywords=general+relativity
Strange Posted August 9, 2014 Posted August 9, 2014 (edited) GR itself is an inverse push-gravity theory; without the cosmological constant, the field equation in GR as written would lead to a universe that contracted in upon itself - Einstein included the cosmological constant in his field equation hoping it would resolve this; the cosmological constant worked as a residual repulsive force in the universal background stopping gravity from causing the contents of the universe from contracting in upon themselves - it later turned out that he was wrong. For 60 years it was simply left out of the equation; in the 1990s, it was eventually given an estimated value for GR based on measurements of the universal background radiation. Basically, Einstein himself had to include some hypothetical 'pushing force' in his equations for them to make sense, without knowing if such a force existed or not. I am simply assuming that the same 'pushing force' is responsible for gravity in the first place - which if it is, accounts for the expansion of space without the need for 'dark energy'. That is horribly confused and garbled. Eisntein included the cosmological constant because the equations of GR show that the universe should expand or contract (depending on density) and, at the time, the universe was assumed to be static. When it was found that the universe was expanding, the comsological constant was removed. It was later reinstated to account for accelerating expansion. The comsological constant is an energy density (hence the term "dark energy") and has a positive pressure. None of this has anything to do with gravity (other than both are described by GR). And certainly not any magical push gravity. Gravity is due to the local curvature of spacetime due to the presence of mass (no pushing involved). Expansion is what happens with a homogenous mass distribution (which is approximately true on very large scales). No pushing is required for expansion. Edited August 9, 2014 by Strange
metacogitans Posted August 9, 2014 Author Posted August 9, 2014 (edited) That is horribly confused and garbled. Eisntein included the cosmological constant because the equations of GR show that the universe should expand or contract (depending on density) and, at the time, the universe was assumed to be static. When it was found that the universe was expanding, the comsological constant was removed. It was later reinstated to account for accelerating expansion. The comsological constant is an energy density (hence the term "dark energy") and has a positive pressure. None of this has anything to do with gravity (other than both are described by GR). And certainly not any magical push gravity. Gravity is due to the local curvature of spacetime due to the presence of mass (no pushing involved). Expansion is what happens with a homogenous mass distribution (which is approximately true on very large scales). No pushing is required for expansion. All the GR field equations explain without the cosmological constant is gravitational attraction. Just a few weeks ago I watched a 2 hour long tutorial video explaining each piece of the Einstein field equation in detail. giving a full explanation of the math behind each piece. The equation consists of the gravitational constant, the speed of light, and a few tensors and scalars - it says nothing about whether the universe should expand or contract, but given that gravity is an attractive force, one would assume that, if it was the only thing contributing to the universal shape of 'space-time', it would cause contraction. And mass is what causes gravity; curvature of spacetime is a mathematical description of it. You could describe the path of any charged particle through a magnetic field and call it 'curved space-time' - the concept of 'spacetime' arises out of necessity since you can't measure time without distance/space or distance/space without time - hence, they are paired together. The real mystery if why gravity wells curve the path of light. Whether the universe is expanding or not and whether that expansion is accelerating is still a matter of debate, although I do not disagree with the possibility whatsoever; it seems to be the general consensus of the scientific community - but I'm not going to shut out other possibilities for the sake of wishful thinking - I'm going to keep thinking and considering other possibilities until it is absolutely proven one way or the other (hence the name metacogitans - 'thinking about thinking'). Now, for the 'repulsive element' which is necessary to explain the broader shape of our universe, try just using electromagnetism. Residual electromagnetic radiation is what the universal background radiation is. Then, if we assume that there is ONLY the existence of a 'repulsive element', and re-write the equation so that the tensors and scalars for curved space-time are found by approximating the extent that a massive body shields other objects in its gravity well from residual radiation, we could perhaps account for the alleged phenomenon of 'expansion' in the universe without 'dark energy'. I want to do it but I need to know how to use tensors which I don't; I'm going to have to research it. Using electromagnetism as the source of gravity, particles subject to gravity are really only following their electromagnetic path of least resistance - there tends to be less resistance in the direction of a massive body. Edited August 9, 2014 by metacogitans
Strange Posted August 9, 2014 Posted August 9, 2014 All the GR field equations explain without the cosmological constant is gravitational attraction. Just a few weeks ago I watched a 2 hour long tutorial video explaining each piece of the Einstein field equation in detail. giving a full explanation of the math behind each piece. The equation consists of the gravitational constant, the speed of light, and a few tensors and scalars - it says nothing about whether the universe should expand or contract, but given that gravity is an attractive force, one would assume that, if it was the only thing contributing to the universal shape of 'space-time', it would cause contraction. Nope. The FLRW solution to the Einstein Field Equations requires that space expands or contracts (unless the density is balanced just-so).
Recommended Posts