What is Cosmological: Definition and 432 Discussions

Cosmology (from Greek κόσμος, kosmos "world" and -λογία, -logia "study of") is a branch of astronomy concerned with the studies of the origin and evolution of the universe, from the Big Bang to today and on into the future. It is the scientific study of the origin, evolution, and eventual fate of the universe. Physical cosmology is the scientific study of the universe's origin, its large-scale structures and dynamics, and its ultimate fate, as well as the laws of science that govern these areas.The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, and in 1731 taken up in Latin by German philosopher Christian Wolff, in Cosmologia Generalis.Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation myths and eschatology.
Physical cosmology is studied by scientists, such as astronomers and physicists, as well as philosophers, such as metaphysicians, philosophers of physics, and philosophers of space and time. Because of this shared scope with philosophy, theories in physical cosmology may include both scientific and non-scientific propositions, and may depend upon assumptions that cannot be tested. Cosmology differs from astronomy in that the former is concerned with the Universe as a whole while the latter deals with individual celestial objects. Modern physical cosmology is dominated by the Big Bang theory, which attempts to bring together observational astronomy and particle physics; more specifically, a standard parameterization of the Big Bang with dark matter and dark energy, known as the Lambda-CDM model.
Theoretical astrophysicist David N. Spergel has described cosmology as a "historical science" because "when we look out in space, we look back in time" due to the finite nature of the speed of light.

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  1. wolram

    Quantum cosmological origin of universe

    http://arxiv.org/abs/gr-qc/0504123 Quantum Cosmological Origin of Universes Authors: V.N. Pervushin, V.A. Zinchuk Comments: 25 pages, 2 figures, Invited talk at the XXXIX PNPI Winter School on Nuclear Particle Physics and XI St.Petersburg School on Theoretical Physics (St.Petersburg...
  2. wolram

    Cosmological constant and Dark energy

    http://arxiv.org/abs/astro-ph/0504416 Authors: Mustapha Ishak (Princeton University) Comments: 10 pages, 5 figures Associated with the cosmic acceleration are the old and new cosmological constant problems, recently put into the more general context of the dark energy problem. In...
  3. wolram

    Detecting Initial Singularity with Cosmological Tests - Szydlowski et al.

    http://rainman.astro.uiuc.edu/coffeepap_Friday.html astro-ph/0504464 Title: Can the initial singularity be detected by cosmological tests? Authors: Marek Szydlowski, Wlodzimierz Godlowski, Adam Krawiec, Jacek Golbiak Comments: 30 pages, 7 figures In the present paper...
  4. C

    Cosmological Questions and Their Degenerate Answers

    There are many qusetions in science & cosmology which have degerate answers some of them are as follows: 1. In the presence of matter space get curved so massive particles as well as light photons do not move along stright line. Now one could always assume that photons also carry...
  5. M

    Bad Science and the Anthropic Cosmological Principle

    "Bad Science" and the Anthropic Cosmological Principle Many observers have noted that the physical laws, parameters and constants of our cosmos appear to be remarkably "fine tuned" in accordance with our existence. There are a number of suggestions that if certain parameters were to be...
  6. Garth

    Another possible crisis for the standard cosmological model?

    Another possible crisis for the standard cosmological model? An old quasar in a young dark energy-dominated universe? Perhaps the universe is older than it is normally thought to be? (for example: Freely Coasting Model?) Garth
  7. Math Is Hard

    Cosmological argument (from contingency)

    My teacher presented us with this version of the cosmological argument: 1. Something is contingent. 2. If something is contingent, its ultimate cause is either self-caused, uncaused, itself merely contingent, or a necessary being. 3. Its ultimate cause is either self-caused, uncaused...
  8. M

    Cosmological vs Doppler redshift

    generic redshift is characterised (defined) by z = (L-L0)/L0 where L is the wavelength at time of absorption (detection), and L0 was the wavelength at time of emission. for Doppler redshift z = v/c for small (non-relativistic) values of v. assuming the universe is expanding, I've read...
  9. T

    Cosmological Principle: Finite or Finiteless Universe?

    The Cosmological Principle says that the universe is homogenous and isotropic. Doesn't this imply that our universe cannot be in finite size, but is finiteless? If it has a boundary, how can then the cosmological principle still be true for those heavenly bodies residing at the boundary of the...
  10. S

    Relativity & Quantum Field Theory: Explaining Cosmological Constant

    Can anyone explain the relation between quantum field theory and relativity. I mean the "cosmological constant". Tanks a lot.
  11. C

    Cosmological relativity theories

    If a galaxy is 1 billion light year far from us and if for us big bang did happen 13 billion years ago then when it did happen for that galaxy ? Pure guess will predict the answer 12 billion years, but what the observer on that galaxy will say about us ? will not he predict that we are...
  12. Garth

    The Twin Paradox Revisited: A Local Case Study

    There have been plenty of posts about the Twin Paradox. I don't think this version has been aired before except in my post #47 on the "Is Age Relative" thread. The Twin Paradox in a closed universe. If cosmic expansion slows down and reverses it would become hypothetically possible to...
  13. turbo

    Newly revised paper on zero point energy and cosmological constant

    Here is a fellow who is working on the cosmological constant problem. He is working with the standard model and has taken a different approach than mine, but has arrived at a similar understanding of the ZPE fields. In empty space, the ZPE fields are self-moderating and non-gravitating, but in...
  14. marcus

    Olaf Dreyer: the Cosmological Constant paradox

    http://arxiv.org/hep-th/0409048 this is a 4-page paper. the cosmological constant problem is the worst prediction in the history of physics---conventional Quantum Field Theory predicts a vacuum energy which is 123 orders of magnitude off: wrong by a factor or 10123 why is this? it should...
  15. L

    Cosmological Red Shift: What Is It & How Does It Relate to Gravity?

    What is the cosmological red shift? I've seen it before and couldn't figure out what exactly it was. All I know is that it has something to do with the effects of gravity and how it relates to photon frequency.
  16. turbo

    Virtual particles and cosmological expansion

    I re-read parts of "Genius" by James Gleick earlier today after visiting a web-site that discussed steady-state cosmology. Apparently, Feinman felt that the creation and obliteration of virtual particles (diagramed by equivalent waves moving BOTH forward and backward in time) supported the idea...
  17. H

    Nature of the cosmological constant

    If one adds a scalar to the Hilbert action without considering any matter fields, S = \int {d^nx {\sqrt -g} (R - 2 \Lambda) one gets the Einstein equations as: R_{\mu \nu} - \frac{1}{2} R g_{\mu \nu} + \Lambda g_{\mu \nu} = 0 Now, one can take T_{\mu \nu} = -...
  18. V

    Multiverse Cosmological Models

    There is much confusion and mystery surrounding the Multiverse Theory. At present there is a wide range of different Multiverse Theories, which this paper does a good job in giving the basic concept behind the different variations Multiverse cosmological models
  19. I

    Cosmological Expansion: Exploring Expansion Force Beyond Big Bang Theory

    At the risk of further muddying up the epicycling, let me offer a wild speculation concerning the expansion force. At the close of the infaltion epoch assumed by its advocates to have been at 10^-35 (superscript negative 35) seconds after time zero of the big bang, the universe is believed...
  20. wolram

    Cosmological constant problem

    http://members.aon.at/chakalov/Thiemann.html From: Dimi Chakalov <dimi@chakalov.net> To: Thomas Thiemann <tthiemann@perimeterinstitute.ca> Cc: <odreyer@perimeterinstitute.ca>, <fotini@perimeterinstitute.ca>, <dgottesman@perimeterinstitute.ca>, <hburton@perimeterinstitute.ca>...
  21. A

    Thermal Decay of the Cosmological Constant into Black Holes

    A great new paper showed up today, elucidating the gist of the subject mentioned above... the idea seems to be novel to me, so i thought it was more than worth being brought up to your attention :) http://arxiv.org/abs/hep-th/0311011 I can't say much about it, since i quite frankly...
  22. A

    Understanding the Cosmological Constant Problem

    I do realize that this is an enormous problem in science today (string theory included), but after reading some related material, i have a question i'd like you guys, if possible, to answer... There are two problems with the cc: Why is it so small and why is the cc the same order of...
  23. marcus

    Quantizing speeds with the cosmological constant

    a new paper by Girelli and Livine http://arxiv.org/gr-qc/0311032 4 pages
  24. R

    Is the Cosmological Constant a Result of Spacetime's Tendency to Be Flat?

    I started this thread in theory development again no reponse so I moved it here. Is it Cosmological or Universal Constant? Another related thought concerning the Cosmological Constant. Just as space time, dimensional space and time, is a characteristic of matter and formed as matter formed...
  25. F

    Einstein's Cosmological Constant

    recently i heard a prominent english physicist using 70 as his value for ecc. what value do you like and where did you get it from?
  26. N

    Does the Cosmological Constant Exist?

    is that cosmological constant exist??
  27. marcus

    The cosmological redshift is not the result of a Lorentz transformation

    We have a theoretical issue here. There is a misconception floating around PF about the relation of the cosmological redshift to present and past recession velocity. If a redshift is Doppler in origin then in the context of Special Relativity one has Einstein's correction of the Doppler...
  28. marcus

    3pi/Lambda = area of cosmological horizon

    It just turns out that the dark energy density &Lambda; or cosmological constant is of such a size that 3pi/&Lambda; = the surface area of the observable universe Smolin calls the surface of the observable universe "the cosmological horizon" and treats it in the same paragraphs with black...
  29. marcus

    Cosmological redshift: how much energy has gone missing?

    In the cosmol. redshift thread (Q) asked [[I would like to hear some interpretations of this phenomenon, especially in regards to what happens to the energy of photons in cosmological redshift – where do YOU think it goes? Is it lost or is it conserved?]] It is clear that a whole lot of...
  30. Q

    Cosmological Redshift: Exploring Photon Energy Loss or Conservation

    I would like to hear some interpretations of this phenomenon, especially in regards to what happens to the energy of photons in cosmological redshift – where do YOU think it goes? Is it lost or is it conserved?
  31. Loren Booda

    Radius of cosmological mass-energy symmetry?

    Starting at the microscopic entities we observe in our immediate neighborhood outward, then tracing mass-energy evolution from the universal horizon inward, can we determine where processes of both coincide in intermediate space? Our own Planck regions, quarks, protons, atoms, planets, stars...
  32. M

    Exploring the Popular Cosmological Model of Our Universe

    I just recently read an article from Scientific American (May 2003 issue and on their website here). I'm curious to know if the theories in the article are, in fact, how many theoretical physicists feel about our universe. Essentially, the article claims that "the simplest and most popular...
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