Mordred

I don't think you realize that the LCDM model already predicts that the Universe will have less uniformity as the Universe expands. Same goes with greater entropy. These details are already considered in the model. Large scale structure formation and void size increase is an obvious consequence. But consider this, the main thermodynamic player today isn't matter or radiation distribution. The main player is the cosmological constant itself which is uniform. We're now in the Lambda dominant era. The less dense matter and radiation becomes the greater influence the cosmological constant has. This is one of the reasons why the homogeneous and isotropic ideal gas laws still work today. We may have to change the scale at which one can consider the Universe uniform but those terms already involve scaling. So in your last post you haven't stated anything that isn't already considered. Granted I might have missed something in your lengthy post The equation I posted is a reflection of how matter, radiation and the cosmological energy/density evolved over time. They don't evolve at the same rate. I've already explained we don't naturally assume uniformity. It always amazes me that more often than not the ones declaring a model is wrong. More often than not, never studied the model in the first place. They never look at the math, they never see how interconnected one model is with other theories. Nor have they ever picked up an introductory text book but instead make their determination based upon pop media videos, and literature. For example do you know the formula for entropy in Cosmology applications? Do you know what the thermodynamic properties of an adiabatic and isentropic fluid is ? Are you familiar with the term thermal equilibrium? The reason I ask these questions is that they directly relate to entropy density. Judging from above your under the assumption that the arrow of time itself is the determining factor. Along with expansion. Yes they are involved but certainly not the full story. Let's take for example during the Planck epock the Universe is in thermal equilibrium. No particles can be distinguished from photons and antiphotons. What is the entropy value in that state?

Why would you think there is a preferred frame for all? There isn't that is the whole point behind the term homogeneous and isotropic expansion. No matter where your located or direction you look in you will see the same curvature constant Here maybe the raisin bread analogy may help. http://www.astronomy.ohio-state.edu/~ryden/ast162_9/notes38.html

You keep thinking there is a paradox simply due to lack of your knowledge. That's really a bad habit You keep thinking curvature has a preffered frame. No matter what location or direction you fire the light beam it will curve the same amount. That follows the geometry of a homogeneous and isotropic expansion. If you think about what we OBSERVE via light paths. How can it not match what we observe for expansion? It's impossible not to match. You cannot observe a location without following the light path influence due to expansion

In all honesty you will never understand unless you understand how the thermodynamics work. You keep basing your assertions on visual limitation. That's not how this works. Every major equation in the FLRW metric has thermodynamic correlations. We can measure and test those trends over time quite well. Measurements of the CMB gives us an extremely wide view snapshot of the cosmological principle. It's highly uniform. Which was well predicted long before it was discovered. This is the aspect your overlooking. Much of the thermodynamic properties including big bang nucleosynthesis was predicted well before they were confirmed. You might not understand it but the equations do make highly accurate predictions that match observational evidence. That's without needing a large 3d snapshot of now. The only question is will you take the time to understand it or will you continue to deny that the metrics works due to not understanding how they work? The other aspect ppl ignore is the cosmological principle wasn't merely assumed to be correct. There was billions of dollars of research performed over several decades of measurements to confirm the cosmological principle. The truly neat part is using supercomputers we can test our known theories and run a simulation. http://www.cfa.harva...du/news/2014-10 http://www.illustris-project.org/ this simulation tested the LCDM model to an extremely high degree, including producing the types of galaxies we observe today. How would you explain that degree of accuracy if our metrics were wrong? Or for that matter all the predictions that LCDM made prior to observation evidence such as the correct % of elements in the CMB. Keep in mind the FLRW metric also employs the Einstein field equations.

The considerations you've posted amount to not understanding how the FLRW metric works. The FLRW metric takes into consideration time dilation and observer influences. Due to being a homogeneous and isotropic metric though time dilation isn't a problem. You need a mass density gradiant at a point in time for time dilation. So even though the past the Universe is denser. There isn't a time dilation. As far as observer is concerned the FLRW metric uses a fundamental observer in a commoving coordinate system. A fundamental observer is one in which the average energy/density is the same as the average energy/density of his present. Ie not in a gravity well. Cosmology doesn't base all its data on distance measurements. A large portion of determining expansion etc lies in measuring the thermodynamic properties at a given time period and applying the ideal gas laws. Everyone that hasn't truly studied the metric tends to assume we determine expansion strictly by redshift. This is wrong. The truth is we always look for correlating evidence in multiple theories (thermodynamic, particle physics, distance measurements, GR etc) to determine the dynamics of our universe and how it evolves. If say the thermodynamic data doesn't match the distance measurements etc we know something is wrong. For example this formula determines the rate of expansion at any given time period. You can see the ideal gas laws applications in the terms under the square root. [latex]H_z=H_o\sqrt{\Omega_m(1+z)^3+\Omega_{rad}(1+z)^4+\Omega_{\Lambda}}[/latex] Your right that we can't see a 3d slice of now but we can see how the Universe evolves over time. As its consistent over 13 billion years it's highly unlikely to change its trends anytime soon

Along with the other posts. I've already stated expansion is related to curvature via the critical density formula. (Though the cosmological constant confuses this aspect). Prior to the discovery of the cosmological constant a negative curved universe has insufficient mass to stop expansion so would expand forever. A flat universe would expand but would eventually slow down and start to collapse. However is also infinite A positive curved universe would also gradually collapse but is finite (again there is no edge, Remember the geometry of a sphere). If the cosmological constant remains constant the Universe will never collapse.

The reason the paper shows the metrics for 2d to 3d to 4d. Is to teach the metrics involved as well as assist in understanding 4 dimensional curvature. Which in itself is extremely difficult to visualize It is not saying we live in a 2d universe. We obviously live in a 4d universe. If one simply tried using a 4d coordinate system without understanding the 2d and 3d coordinates. They would have an extremely difficult time.

Multiverse theories don't mean our universe is finite. You can devide an infinite universe an infinite number of times and each universe would still be infinite

Lets put it this way. One of the methods we used to determine our geometry was to look for distortions in the CMB measurements. As the thermodynamic properties determine our overall geometry and affects light paths. Those distortions become apparent when you have curvature. As we see an extremely small distortion we can tell our universe is flat. (The CMB is all around us so you can't look in one direction to see the entire CMB you must measure every direction and orientation) That's a highly accurate way of describing the problem. Prior to WMAP you would be amazed at the number of geometry shapes were theorized to describe the Universe. Donut, torus, saddle, klien Gordon bottle etc. The WMAP and Planck data eliminated hundreds of models that were running around. I recall being on Space.com back when it had a forum in the 80s arguing alternative geometry models. Lol Minkowsii metric was the big thing back then. Now it's not so practical except as introductory to GR. Lol the quintessence and MOND arguments were extreme (Ps yes I'm old but not that old I started studying cosmology when I was in my teens. Right after Allen Guth proposed inflation) Just a side note if the Planck datasets continue in the direction it's going the number of viable inflation models will reduce to 7 out of 76. The preference to observation being single scalar to low kinetic term models @David the above should indicate that science is a process of elimination. Most ideas presented on speculation have been presented before (if feasible) and already eliminated. Granted most speculative ideas on a forum aren't even feasible.

If you study the article you will note how thermodynamics, mainly energy/density works with geometry. I think the difficulty you might be having is thinking the curvature is on a particular orientation. It isn't you will have the same curvature regardless of direction. Remember the cosmological principle. There is no preferred direction or location. Homogeneous and isotropic. So yes the Universe geometry is also involved in expansion, The light rays path is a consequence of the geometry. We don't need to adjust our thinking on this aspect as the energy/density relations used in expansion already determine the null geodesic aspects via the Einstein field equations for the path of light. (As I know you aren't strong on the EFE equations you'll have to accept my word on that). Trying to explain the principle of least action and spacetime hydrodynamic relations with the FLRW metric is an extremely lengthy and math intense subject. Far more than can be done in a forum

Try reading the articles I wrote first. Pay attention to the detail on light paths The curvature is part of the FLRW metric. Each scenario is part of the equations. However the Universe is so dang big it is tricky to isolate a precise curvature constant. It's taken over 50 years of data to fine tune the value we have today. You keep expecting exact answers that's rarely the case on cosmological scales. The universe is so big it's highly possible we may never know if it's finite or infinite. Not with 100% certainty Think of a flea sitting on a beachball from its view point the ball is flat. Could very well be the same case for the curvature. We could be in such a small portion that all measurements give the appearance of flat

The curvature time of transit is based on a paper from the South pole observatory. There was an arxiv paper on it around two years back. Nothing is ever conclusive in physics. So don't expect any conclusive answers. The WMAP and Planck data papers support the flat case. As far as the latter question is that there is always a margin of error in any complex analysis. Yes the light beam could theoretically return to Earth in the positive curvature case. However it will never do so due to rate of expansion. Here is a low math article on geometry. http://cosmology101.wikidot.com/universe-geometry Page 2 http://cosmology101.wikidot.com/geometry-flrw-metric/

Particle creation not decay

No there are some geometric shapes that have no edge that are finite one example is the 3 torus or a sphere. If you have a positive curvature constant however slight the Universe will be finite. However that curvature constant also means light beams will not travel "straight" but will travel with the curvature.(null geodesic) So with our measured curvature constant if you shot a laser that laser will follow the curvature (so will any craft). If you stop expansion it would take roughly 880 billion years to arrive back at its point of origin. However our universe is also extremely flat which implies an infinite universe. The measurement uncertainty favors the flat case but doesn't discount the positive curvature case It's a tricky concept to grasp but straight isn't straight in curved spacetime

Yeah your right I had forgotten that the sum of total energy of the decayed products must be less than or equal to the rest mass of the decaying particle. For others reading. [latex]Mc^2=\sum_{products}(mc^2+E_k)[/latex]

It's total energy that's involved [latex]E^2=(pc)^2+(m_oc^2)^2[/latex] A particle can only decay into particles that have less total energy. For example the LHC smashes protons and yet can cause decays of particles such as the Higgs boson which has a higher rest mass than the protons themselves. It does this via the total energy gain via accelerating the particle to near light speed. here is the various conservation laws involved http://en.wikipedia....ge_conservation http://en.wikipedia....rticle_physics) http://en.wikipedia....i/Lepton_number http://en.wikipedia....ki/Weak_isospin These two free articles will help. Though they are lengthy the first article gives a good coverage of the decay rules http://arxiv.org/abs/0810.3328 A Simple Introduction to Particle Physics Part 2 is here http://arxiv.org/abs/0908.1395

No particle decay doesn't require a substructure. Particles can decay into less massive particles but must obey several conservation rules such as conservation of Lepton, charge, etc. It's incorrect to think that the particles that are involved in the decay are part of the particle itself. The muon isn't composed of the particles it can decay into

Wow I've studied a lot of different model ideas but this is the first time I've encountered this proposal. Guess it goes to show no matter how much you study or learn there is always something new..

How you can have the illusion of moving without moving due to cells composing and decomposing? I've been studying physics for nearly 30 years. I would have absolutely no idea how you would describe the above mathematically... At least not as written. Are you describing all forms of movement or a specific dynamic? Replace cell with particle, and use terminology such as particles decay and created you might have more success.

Physics is about modelling interactions of cause and effect. For example the laws of thermodynamics. If you raise the temperature you raise the pressure etc. The purpose of the laws of physics is to model change. You change interaction a you cause influence b. The robustness of a model comes in its observational and experimental evidence. There are very few fundamental first principles that are considered laws. Any model regardless of how robust is continuously reexamined in different ways. It's not something that's written in some magical universal storage area. It's simply how the dynamics of the universe works

Your question itself is foolish.

The laws of the universe is located within the dynamics of the universe. It's not written in words but is written in cause and effect Next question

http://arxiv.org/abs/1104.5499 :''Black hole Accretion Disk'' -Handy article on accretion disk measurements provides a technical compilation of measurements involving the disk itself. The article covers in extreme detail The accretion disk

It does in one sense. A bh can only handle so much incoming matter. The accretion disk can only handle so much. Some of the mass/energy gets radiated away via the accretion jets.

yeah yeah rub it in, remind me sometime I hate graveyard shift... particularly since I'm doing lab tests every half hour grrr