MikeAL

I don't see why we should have to assume either of this things. Do you need to assume them if geometry is Euclidean (as we used to think)? It turns out that the geometry of space and time measurements is non-Euclidean. I don't see why that implies a medium of some sort. Understood, but I am not attempting to modify gravity at all. I am suggesting that the field could be weakening due to expansion, and that evidence for such a weakening could be found in the past (as was suggested it should be). The article suggests that the expansion of the universe has not been linear, that it suddenly, based on observable masses, seemed to accelerate. I linked that reference. The idea of dark energy itself is not fully understood and is only a theory used to fill a hole in another theory. Google dictionary will tell you it is: a theoretical form of energy postulated to act in opposition to gravity and to occupy the entire universe, accounting for most of the energy in it and causing its expansion to accelerate. My suggestion when it came to looking at gravity and matter is that we should look at matter as the manifestation of the field when a certain threshold density is crossed (the curvature of space). I have also argued previously it could account for DM and thus we don't need to invoke right hand neutrinos or anything else. This led to the discussion that fields are not real in our universe but only mathematical abstractions, a fact I strongly disagree with based on the fact that they exert forces. Geometric space time may involve the changing relationship between time and distance, but somehow that rock floating by Jupiter is acted upon. Mathematics, a pure descriptor of the universe and absolutely essential for any serious study of the universe, cannot exert a force. Something is exerting the force and thus we cannot claim the field is a mathematical abstraction, but rather it is an intangible reality. That is the entirety of my argument. Can all you science guys honestly tell me that the fields that permeate our universe are simple mathematical conveniences used to answer physics questions and do not really exist? I agree that GR is an incredible theory, Einstein earned his title as genius, no doubt about it. However, there are problems with his theory at the quantum level, and when it comes to other strange areas of the universe such as DM (which accounts for a large part of the universe). When Einstein's theory overturned Newton's the proof was the 1919 solar eclipse. Up to that point the two theories made almost the same predictions. Such a tiny thing as the degree of bending or a ray of light unhinged Newton's theory in favour of Einstein's. https://www.wired.com/2009/05/dayintech-0529/ Perhaps, Einstein's theory is also, like Newton's, almost there, but these areas where we have gone into gap filling mode do give me reason for pause.

Good answer. For this to occur then we must assume one of two conditions: 1. That time and distance themselves have extra-mathematical properties attributable to them that is causing the physical effect. 2. That the interaction is occurring in a medium of some sort. Perhaps not a PB and J medium, but something.

You obviously know what you are talking about much better than I do, so it's going to take me a little while to get back to you with the specificity of answer I think you are after. But let me take a shot at it for now anyway. The universe can be described mathematically and therein lies the dilemma. We don't live in mathematics. We live in a world in which material objects materialise out of a mathematical orchestra. But they do not materialize out of a void. We limit our truths, and perhaps rightly so, to what is at some level tangible and testable, and what what is mathematically plausible. These are descriptors of reality. Not reality. It is like looking at a sonar image and asking what the image you are observing is made of. The answer can only be found by beginning with the material properties of the objects themselves. We know that there is matter and there is energy. We know for example that the mass of an atom cannot be accurately accounted for without including the binding energies. So back to this one, I would describe it as the problem of applying mathematical methodology to a substance. What precisely it is made of is anybody's guess and maybe one day we will know. However, it does manifest itself in the material from time to time, and in its observable effects (DM and DE) from time to time. A layer of reality, describable by mathematics, underlays our universe - but that layer is not mathematics. Mass does not bend spacetime because mathematics says so. Mathematics describes the fact that mass bends spacetime. But something is being bent for the effect to occur, otherwise it makes no sense. That's my take on it. No, Strange, I'm not claiming anything. I'm just pursuing a line of reasoning that originates from conventional wisdom. If that line of reasoning contradicts Einstein, then that is very interesting, but it is by no means my assertion that GR is wrong.

My feeling was that fields are not abstract devices for the purpose of calculation, but rather actual intangible properties of our universe. It seems there is one big field, teased apart for the purpose of measurement and because of its predictable independent behaviours into smaller threads of fields such as gravitational or electromagnetic or strong or weak forces or any one of the tiny particle ones. Looking for the moment at a field as an actual rather than abstract entity and applying the definitions set by science, and I will just quote you here for a second: Could we not suggest that, when a magnet bends the magnetic field, that the magnetic field itself is doing work on the magnet? (Newtonian) or that because different strength magnets are capable of bending the magnetic field to different extents that the field itself is resistive of the change (inertial implies mass and velocity and so we enter into a loop with too strict a definition) - and that this resistance to change of form (I want to now call it inertial) therefore suggests mass. Under such a definition, mass thus would stand independent of the particles of the field and reside as a property of the field itself.

Very insightful, and a bit over my head as well. Let me ask though, why the fixation of attributing mass only to particles? Particles arise as fluctuations of their fields right? If we condense energy, particles pop out. http://www.askamathematician.com/2010/01/q-is-it-true-that-all-matter-is-simply-condensed-energy/ Why not ascribe mass to energy before it even becomes a particle? A particle to me seems a bit like a Schwarzchild radius in the fact that it represents a type of event horizon beyond which energy transforms itself into a differently recognizable object (or more measurable form of energy). But the sudden emergence of the particle with mass should not preclude mass existing in the energy from which it was created.

Some other factor, but not gravity? How can you be so sure? I'm not looking at just one piece of data. The gravity is a field (no pun intended) that you chose to explore when discussing a potential diminuition of fields in general, which seems reasonable based on simple extrapolations of the physics. The fact is our current understanding of gravity is not complete and seems to be showing a lot of problems. We keep adding bits to the existing theory to try and make it better (dark energy, dark matter), but at some point, the theory simply needs to be gutted and reworked. The same site, NASA, also suggests: A last possibility is that Einstein's theory of gravity is not correct. That would not only affect the expansion of the universe, but it would also affect the way that normal matter in galaxies and clusters of galaxies behaved. This fact would provide a way to decide if the solution to the dark energy problem is a new gravity theory or not: we could observe how galaxies come together in clusters. But if it does turn out that a new theory of gravity is needed, what kind of theory would it be? How could it correctly describe the motion of the bodies in the Solar System, as Einstein's theory is known to do, and still give us the different prediction for the universe that we need? There are candidate theories, but none are compelling. So the mystery continues. Hi Mordred, I can see that you are very well informed in your field, so you probably have a better handle on this than me, but I have just run across an article on discrepancies between different ways of measuring Hubbles Constant, and I thought of particular note was this quote: “Do we really know what makes up all of the radiation in the Big Bang?” wonders Freedman. “Is there a new kind of particle we aren’t accounting for? Or are dark energy’s or dark matter’s properties changing over time? Over the next few years, researchers like Freedman will be trying to poke holes in how each method conducts its analysis -- before possibly invoking a revised model of cosmology. https://science.nasa.gov/science-news/news-articles/hubbles-contentious-constant-news

We could look at the an answer to this by visiting the NASA site. Then came 1998 and the Hubble Space Telescope (HST) observations of very distant supernovae that showed that, a long time ago, the universe was actually expanding more slowly than it is today. https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy Does this not suggest a stronger gravitational attraction?

You haven't told me the direction of expansion of the hole, only the outer walls. A bit jumpy there, Strange. I just explained the logic to you. It is not an alternative to GR at all. GR tell us that at the time of the Big Bang there must have been infinite density in a tiny space, and that it is the point that time started. You can check out the maths on it for yourself if you like. A field density change would fit right in there I would think.

No. Yes.

OK, let's play with gravity for a second. According to the proposition of weakening field strength because of universal inflation we would expect that the ability of mass to curve space around it lessens as space itself expands. Perhaps imperceptibly so on the scale by which we can measure. If we backtrack through time, however, we get the ability of mass to bend space (and slow time but lets keep it simple) increasing backward through time, until a very small mass can bend a huge amount of space. This seems to fit, at least in broad strokes, with suggestions around the big bang, does it not? Infinitely tiny yet somehow containing the entire universe, time not existing in any appreciable way.

At the risk of talking in circles or at cross purposes, do we not consider charge as the ability of a particle to alter the existing electric field- which is said to permeate the entire universe? Perhaps the underlying question I am asking is: how can we consider this existing universal field to be immutable given all that we know about everything else in said universe?

This is a local phenomenon. Perhaps it is only proportionally the same. How do you know it is absolutely the same? I don't think you can. How do you know the entire field that it is operating in has not weakened? Let me put it a different way. If I have an electromagnetic field in a box, then is it not possible that this field can be manipulated to generate a certain maximal calculable amount of electromagnetic force? If I enlarge the box, the total force that can be generated with this field surely does not increase, therefore it must become weaker per unit area. If this does not happen with the universe, then I wonder why?

What do you mean by this Strange? Of course I am considering the larger volume. I find the last sentence particularly thought provoking. It raises another interesting facet.

Hey, Studiot, when you say the field strength is low in interstellar space, you are referring to the distance between the objects. When Swansont said none of the variables changed, again, same thing. Same with Strange. I think you are both missing my point. The relationship between the physical components will not change, granted, but the intensity of the field, which is an all-universal permeating field should decrease, just like adjusting the light intensity on your monitor. It should reduce because of the larger volume that is now being encompassed. For this not to happen would surely imply the field is a space-time independent phenomenon, and not beholden to the rules governing the universe - ie not really generated from within our universe at all.

I don't think it's a red shift question. Stuidot points out that it does happen if we consider Gauss' law: So, back to the question, isn't there an inherent contradiction between an expanding universe and an undiminished field strength?

Hey Strange, I think that the idea of a global field as merely a representation of a local effect is not quite accurate. I understand that you are saying the pertubation of the field is the strength, and that's fair enough, but as the universe expands, so too must the accommodating field. As there is no new energy entering the system (forget about Hawking for a moment), then the current field, unless it is independent of time and space itself, must stretch - unless other energy inside the universe is collapsing to be converted to the field. The total force that the field is capable of generating must therefore remain constant. If the universe is expanding, and total potential force cannot increase, then it must become diffuse, thus the local effects should decrease.

I have a small question that has been teasing me of late. If the universe is expanding, and total energy can neither be created nor destroyed, and every inch of the universe is a field (eg magnetic field), then why doesn't field strength weaken as the universe expands?

Oh my goodness. E = mc2 Mass can be converted to energy. If mass is converted to energy it is no longer mass. Mass is described by its effect on gravity. Less mass means less gravity. As the universe expands it continues to cool. As the temperature drops thermal radiation is lost from your rock. Thermal radiation is a type of energy. The loss of thermal energy from matter therefore reduces mass. This leads to a reduction in gravity. Hawking Radiation suggests that even black holes will evaporate as they lose energy in the form of radiation. An evaporated black hole has less gravity than one that is not evaporated. If it can happen to a black hole, I guess it can happen to your rock too. Can we move on now?

How much gravity does a massless object have? Do I really need to walk you through this step by step?

It was you that brought up the cold dark rock in outer space, not me. I have directed you to ideas on how entropy may affect it, but you don't want to listen to them or to the ideas laid out in the Heat Death of the universe, so I'm not sure how I can help you further with this idea. My idea is about gravity alone being the force of Dark Matter, not the mechanism by which cold dark rocks in outerspace lose heat energy to the universe. I think you forgot about heat. If you are determined to play games with me then let me ask you another question. What is the mass of a photon?

BOOM !

No. It is your claim, you have the burden of proof. Have any science said that mass disappears over time? Once again, I direct you to the link on the heat death of the universe. https://en.wikipedia.org/wiki/Heat_death_of_the_universe "Proposals about the final state of the universe depend on the assumptions made about its ultimate fate, and these assumptions have varied considerably over the late 20th century and early 21st century. In a hypothesized "open" or "flat" universe that continues expanding indefinitely, a heat death is expected to occur.[1] If the cosmological constant is zero, the universe will approach absolute zero temperature over a very long timescale. However, if the cosmological constant is positive, as appears to be the case in recent observations, the temperature will asymptote to a non-zero, positive value and the universe will approach a state of maximum entropy.[8] The "heat death" situation could be avoided if there is a method or mechanism to regenerate hydrogen atoms from radiation, dark energy or other sources in order to avoid a gradual running down of the universe due to the conversion of matter into energy and heavier elements in stellar processes.[9][10] " So let me ask you a question. What happens to mass when matter is converted into energy?

I have been turning over some ideas for a while and have come up with the following which could be useful ontologically. It have gone to effort to make it simpler than my previous attempt, and to correct any obvious errors I came upon. We know the universe is expanding at an accelerating rate and the acceleration is ubiquitous throughout the universe. We know matter doesn't seem to undergo this same spreading. Such a uniform acceleration of expansion brings is typical of the forces a wave would exert as its wavelength increased. Fig 1. In a sine wave both the trough and the crest undergo expansive geometric forces, causing a shift in wavelength as they propagate. The arrows indicate the direction of the forces at that part of the wave. Fig 2. I would like to ascribe this wave function to the curvature of space-time. Note there is a +1 and -1 reflecting the degree of curvature. Superimposed onto this wave is the universal plane. This is where matter exists. The value of the gravity along this line corresponds to the value of the sine wave at that point. As the wave lengthens, the universal plane is stretched. Fig 3. If we make the curvature of space where 'gravity' occurs -1, then by convention +1 would become a curvature of space that is 'anti-gravitational'. In these areas of anti-gravity, matter cannot exist. It will only exist where the gravity is between the value range of 0 and -1. I wish to denote the area of the trough where the gravity is between 0 and -1 as Mike's Gravity (A), to differentiate it from the gravity intrinsic to matter. The crest we can simply call B. Fig 4. Because matter has its own intrinsic gravity different to Mike's gravity (A), it will act to curve space in this region further. This will cause trough walls in A to close together. B has not such gravity and does not clump, however the shape is affected by the change in the trough. B would represent areas of no matter. In our universe this would correspond with intergalactic space. Mikes gravity A, which is separate from the intrinsic gravity of matter could be considered Dark Matter. This is the unaccounted for gravity that I was describing in my Dark Matter OP. The space in the crests could be argued to display the properties of Dark Energy. This structure approximates what we see when we look at the Cosmic Web, which shows the relationships between galaxies and intergalactic space (below). Of course the wave I have described is not an exact duplicate of what we see. For example the wave I have drawn is a 2D representation and the images have a 3D shape. My wave is also simplified as no attempt at describing interference patterns created by matter with gravity moving independently has occurred. Just so we are clear, I am not saying THIS IS IT! I am offering the idea for discussion.

In that case the answer is entropy. If you would like to quarrel it, there are a lot of scientists I'm sure would take you on.

The atoms in the rock are bonded and stretch and contract (jostle) relative to each other. The electronic bonds in adjacent atoms are pushed this way and that, in and out. This pulsing vibration affects the distance of the electron from its nucleus creating energy changes within the atom. The atom seeks to settle the jostling down by emitting energy. "With emission, the molecule can start in various populated vibrational states, and finishes in the electronic ground state in one of many populated vibrational levels. The emission spectrum is more complicated than the absorption spectrum of the same molecule because there are more changes in vibrational energy level." It's not about mass and gravity, I am trying to answer a question you are pursuing about the entropy. I don't claim to be an expert in vibronics.