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Mordred last won the day on June 29 2020

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About Mordred

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  • College Major/Degree
    University of the Caribou
  • Favorite Area of Science
    cosmology and particle physics

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  1. Thanks for the link. Nice to see additional validation for the cosmological principle. Will study in more detail
  2. If a hypothetical graviton is found. (Though we would need far higher energy levels at an LHC) it would most likely be a spin two boson. We're nowhere near the technology to produce one (TeV ) energy range. Wish we could though quantizing gravity would be easily done.
  3. Sounds like a bad scene in men in black lol
  4. In essence correct the FLRW metric is however in the weak field limit so SR is still useful. The slight curvature will cause deviations at extreme ranges however is approximately flat for the shorter ranges. Past the Hubble horizon the deviations become apparent. The recessive velocity and Z scale will become more progressively non linear. ( In order to correct for this one must take into account the evolution of the matter, radiation and Lambda densities) The updated cosmocalculator has that capability see signature.
  5. Also under density wave theory involved in spiral galaxies you get some seperation of heavier elements. When those stars form from that material you will find differences in composition depending on the abundance of elements in each region
  6. You will be applying pressure to something that in cosmological observation doesn't exert pressure. This would give you the wrong equation of state for matter. Just because you can mathematically do something doesn't necessarily mean it's correct...
  7. IsThe total energy/mass density doesn't just depend on H. It also involves the mass density for matter, radiation and Lambda. Radiation and matter will stretch differently due to expansion However the mean average wavelength stretch will become equal at Z_eq. (Matter, radiation equality). Then too you must also equate the equations of state for matter and radiation to determine the actual energy density. Unfortunately someone changed this page and gave the Lambda approximation for the universe today however during matter domination or radiation dominant eras you would use the applicable equation of state. As an approximation. It is more precise to use the density of each at the Z being examined. (The scale factor can also be used as it equates and does help simplify the calculations) however option works https://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology) The critical density formula is in actuality a matter only approximation. The pressure equals zero. This isn't true for radiation or Lambda.
  8. The Omega total is default normalized to critical density of 1. The calc allows you to change this in the inputs along with H. This gives flexibility to use it with different datasets. Also allows you to change the curvature term. I'm still learning the new features so I will be comparing it to other datasets to see how accurate it is overall. (Keep in mind sometimes the number of digits on the inputs will matter on rounding errors.)
  9. The new cosmocalculator is out they had to change the host site. There is still some bugs being resolved however they increased the flexibility of the calculator http://jorrie.epizy.com/LightCone7-2017-02-08/LightCone_Ho7.html?i=1 [latex]{\scriptsize\begin{array}{|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|} \hline z&T (Gy)&R (Gly)&D_{now} (Gly)&Temp(K) \\ \hline 1.09e+3&3.72e-4&6.27e-4&4.53e+1&2.97e+3\\ \hline 3.39e+2&2.49e-3&3.95e-3&4.42e+1&9.27e+2\\ \hline 1.05e+2&1.53e-2&2.34e-2&4.20e+1&2.89e+2\\ \hline 3.20e+1&9.01e-2&1.36e-1&3.81e+1&9.00e+1\\ \hline 9.29e+0&5.22e-1&7.84e-1&3.09e+1&2.81e+1\\ \hline 2.21e+0&2.98e+0&4.37e+0&1.83e+1&8.74e+0\\ \hline 0.00e+0&1.38e+1&1.44e+1&0.00e+0&2.73e+0\\ \hline -6.88e-1&3.30e+1&1.73e+1&1.12e+1&8.49e-1\\ \hline -8.68e-1&4.79e+1&1.74e+1&1.43e+1&3.59e-1\\ \hline -9.44e-1&6.28e+1&1.74e+1&1.56e+1&1.52e-1\\ \hline -9.76e-1&7.77e+1&1.74e+1&1.61e+1&6.44e-2\\ \hline -9.90e-1&9.27e+1&1.74e+1&1.64e+1&2.73e-2\\ \hline \end{array}}[/latex] One of the bugs is setting the tex format for other columns under the column options which are too numerous to type each option down
  10. Well you can test it I finally got a new link to the updated cosmocalculator. Looks like they added a lot of flexibility to it http://jorrie.epizy.com/LightCone7-2017-02-08/LightCone_Ho7.html?i=1 They have the Omega columns now for the portion each contribute of the total density parameter and how each evolved over time. I would suggest testing your model to it. [latex]{\scriptsize\begin{array}{|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|} \hline z&T (Gy)&R (Gly)&D_{now} (Gly)&Temp(K) \\ \hline 1.09e+3&3.72e-4&6.27e-4&4.53e+1&2.97e+3\\ \hline 3.39e+2&2.49e-3&3.95e-3&4.42e+1&9.27e+2\\ \hline 1.05e+2&1.53e-2&2.34e-2&4.20e+1&2.89e+2\\ \hline 3.20e+1&9.01e-2&1.36e-1&3.81e+1&9.00e+1\\ \hline 9.29e+0&5.22e-1&7.84e-1&3.09e+1&2.81e+1\\ \hline 2.21e+0&2.98e+0&4.37e+0&1.83e+1&8.74e+0\\ \hline 0.00e+0&1.38e+1&1.44e+1&0.00e+0&2.73e+0\\ \hline -6.88e-1&3.30e+1&1.73e+1&1.12e+1&8.49e-1\\ \hline -8.68e-1&4.79e+1&1.74e+1&1.43e+1&3.59e-1\\ \hline -9.44e-1&6.28e+1&1.74e+1&1.56e+1&1.52e-1\\ \hline -9.76e-1&7.77e+1&1.74e+1&1.61e+1&6.44e-2\\ \hline -9.90e-1&9.27e+1&1.74e+1&1.64e+1&2.73e-2\\ \hline \end{array}}[/latex] There is still some bugs in the new calc that has occurred due to having to change the host site. They are still working on it
  11. Well you know the Hubble constant isn't constant. It's value changes as the universe evolves. Look at the H/H_0 column on the table in the previous thread on the first page. Now if H varies in time then applying the critical density formula it too must vary in time. Yet the cosmological constant is constant in time...so does the curvature term k.
  12. Yes we covered this in those pages. Recall that critical density is a calculated value that does not represent the actual total density. It also does not separate the three contributors to expansion. Though our universe is close to the critical density value you still have the contributions of matter, radiation and Lambda. The first two vary in contribution as the universe expands while the cosmological constant does not. On the first page I posted a specific formula to calculate the energy density as a function of Z for the former two...
  13. I see one problem the critical density has three contributors. Matter radiation and Lambda. Currently the primary contributor to expansion being Lambda. However this isn't always the case Critical density is normalized with the other three cosmological parameters a portion of the critical density. Though our universe is perfectly critically dense it's close enough for a good approximation. You need to derive which portion of critical density is due to the cosmological constant.
  14. Yes but you can no longer track them past the EH... Does the black region within the accretion disk not indicate no light signal at any spectrographic frequency ? The image used more than visible light frequencies. A neutron star isn't a true blackbody while the event horizon is as close to perfect blackbody as you can get in nature. It's quite easy to tell the difference from a neutron star from a BH lol. Are you intentionally trying to be obtuse ?
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