here - Oxford Astrophysics
... (D-branes, fluxes, strings,...) These regions are separated by certain field configurations called domain walls. Calling these regions different “universes” is a matter of linguistic convenience. This situation is very similar to a piece of glass separating two different local environments, such as ...
... (D-branes, fluxes, strings,...) These regions are separated by certain field configurations called domain walls. Calling these regions different “universes” is a matter of linguistic convenience. This situation is very similar to a piece of glass separating two different local environments, such as ...
Section 6 The Expanding Universe The Doppler Effect
... microwave background (CMB). It is an irony that it was Hoyle who coined the name that would come to be applied to Lemaître’s theory, referring to it as ‘this big bang idea’ in derision during a 1950 BBC radio broadcast. For a while support was split between these two theories. Eventually, the observ ...
... microwave background (CMB). It is an irony that it was Hoyle who coined the name that would come to be applied to Lemaître’s theory, referring to it as ‘this big bang idea’ in derision during a 1950 BBC radio broadcast. For a while support was split between these two theories. Eventually, the observ ...
Word version of Episode 704
... If you live in a big city, find a way to get into the country where the city lights don’t pollute the night sky with unwanted light. You need to know the direction of north. Pop out in the day at mid-day, turn your back to the Sun and so face north. Or use a compass. Make a note of any useful landma ...
... If you live in a big city, find a way to get into the country where the city lights don’t pollute the night sky with unwanted light. You need to know the direction of north. Pop out in the day at mid-day, turn your back to the Sun and so face north. Or use a compass. Make a note of any useful landma ...
Our galaxy is the centre of the universe, `quantized` redshifts show
... other only if our viewing location is less than a million light years from the centre. The odds for the Earth having such a unique position in the cosmos by accident are less than one in a trillion. Since big bang theorists presuppose the cosmos has naturalistic origins and cannot have a unique cent ...
... other only if our viewing location is less than a million light years from the centre. The odds for the Earth having such a unique position in the cosmos by accident are less than one in a trillion. Since big bang theorists presuppose the cosmos has naturalistic origins and cannot have a unique cent ...
OGU - What`s Out Tonight?
... Even this is too much to imagine for most of us, so lets really bring it down to size. If our Milky Way Galaxy were just one inch across, which is the size of a quarter, the Andromeda Galaxy would be a mere 23 inches away, and the Universe would stretch for 2 miles in every direction. ...
... Even this is too much to imagine for most of us, so lets really bring it down to size. If our Milky Way Galaxy were just one inch across, which is the size of a quarter, the Andromeda Galaxy would be a mere 23 inches away, and the Universe would stretch for 2 miles in every direction. ...
CH. 7 - science1d
... conversation with someone living near these stars, just saying hello to each other would require more than 8.5 years. That is how long it would take the radio signal, moving at the same speed as light, to travel to the Centauri system and back again to Earth. As we continue our voyage out farther th ...
... conversation with someone living near these stars, just saying hello to each other would require more than 8.5 years. That is how long it would take the radio signal, moving at the same speed as light, to travel to the Centauri system and back again to Earth. As we continue our voyage out farther th ...
Galaxy Hunters Article, Cosmology Information, First Star Facts
... universe was pitch-black and contained mostly hydrogen and helium with a smattering of lithium. During the past few years, together with his colleagues Michael L. Norman of the University of California, San Diego, and Greg L. Bryan of Oxford University, Abel has created supercomputer simulations tha ...
... universe was pitch-black and contained mostly hydrogen and helium with a smattering of lithium. During the past few years, together with his colleagues Michael L. Norman of the University of California, San Diego, and Greg L. Bryan of Oxford University, Abel has created supercomputer simulations tha ...
reading the mind of god!
... the energy of empry space. Who would of thought of that? In fact, it was Nicola Tesla, 70 or so years ago, who wrote about invisible energy, the energy of nothing. And now our latest satellite, the WMAP satellite, has confirmed it. 73% of the universe is made oUt of dark energy, and 23% is made out ...
... the energy of empry space. Who would of thought of that? In fact, it was Nicola Tesla, 70 or so years ago, who wrote about invisible energy, the energy of nothing. And now our latest satellite, the WMAP satellite, has confirmed it. 73% of the universe is made oUt of dark energy, and 23% is made out ...
History of the 2.7 K Temperature Prior to Penzias and Wilson
... Way, and corresponds to an energy density in interstellar space of about 1 eVcm −3 (10 −12 erg cm −3 ). This is comparable with the energy density of starlight, the turbulent kinetic energy density of the interstellar gas and, as we shall see later, the energy density of the interstellar magnetic fi ...
... Way, and corresponds to an energy density in interstellar space of about 1 eVcm −3 (10 −12 erg cm −3 ). This is comparable with the energy density of starlight, the turbulent kinetic energy density of the interstellar gas and, as we shall see later, the energy density of the interstellar magnetic fi ...
P1 09 Red Shift - Animated Science
... Some people think that Penzias and Wilson’s discovery of cosmic microwave background radiation was just lucky. Others disagree. What do you think? Give reasons for your answer. ...
... Some people think that Penzias and Wilson’s discovery of cosmic microwave background radiation was just lucky. Others disagree. What do you think? Give reasons for your answer. ...
Name - MIT
... 33) What happens if the density of the universe is above the critical density? A) the universe will stop expanding and start contracting B) the universe will continue expanding C) the universe will start forming more supernovas D) the universe will start forming more stars E) the universe will start ...
... 33) What happens if the density of the universe is above the critical density? A) the universe will stop expanding and start contracting B) the universe will continue expanding C) the universe will start forming more supernovas D) the universe will start forming more stars E) the universe will start ...
Invited Review The Beginning and Evolution of the Universe
... Early work on explaining the astrophysically observed abundances of elements assumed that they were a consequence of rapid thermal equilibrium reactions and that a rapidly falling temperature froze the equilibrium abundances. Tolman, Suzuki, von Weizsäcker, and others in the 1920s and 1930s argued t ...
... Early work on explaining the astrophysically observed abundances of elements assumed that they were a consequence of rapid thermal equilibrium reactions and that a rapidly falling temperature froze the equilibrium abundances. Tolman, Suzuki, von Weizsäcker, and others in the 1920s and 1930s argued t ...
Name - MIT
... A) only in spiral galaxies B) only in elliptical galaxies C) only in quasars D) only in black holes E) everywhere in the universe 23) The presence of what spectral type of stars is evidence that star formation has occurred within the last 100,000,000 years in the disk of a spiral galaxy? A) K and M. ...
... A) only in spiral galaxies B) only in elliptical galaxies C) only in quasars D) only in black holes E) everywhere in the universe 23) The presence of what spectral type of stars is evidence that star formation has occurred within the last 100,000,000 years in the disk of a spiral galaxy? A) K and M. ...
Name
... 29) Why should you be able to determine the distance to a star with a spectral type of G2 in our galaxy? A) All G2 stars are at same distance to Earth B) The period of their variability is proportional to their distance from Earth C) G2 stars have similar luminosities to our Sun, which can be used t ...
... 29) Why should you be able to determine the distance to a star with a spectral type of G2 in our galaxy? A) All G2 stars are at same distance to Earth B) The period of their variability is proportional to their distance from Earth C) G2 stars have similar luminosities to our Sun, which can be used t ...
Full text in PDF form
... Here we have a Machian definition of the gravitational cross section for a mass m. It is given by the product of its gravitational radius Gm/c2 times the size of the Universe R. Since the size of the Universe R is of the order of its gravitational radius GMu/c2, where Mu is he mass of the Universe, ...
... Here we have a Machian definition of the gravitational cross section for a mass m. It is given by the product of its gravitational radius Gm/c2 times the size of the Universe R. Since the size of the Universe R is of the order of its gravitational radius GMu/c2, where Mu is he mass of the Universe, ...
Advanced Topics in Cosmology: A Pedagogical Introduction
... universe decreases as T ∝ t−1/2 . As the universe expands, a time will come when (t = teq , a = aeq and z = zeq , say) the matter energy density will be comparable to radiation energy density. For the parameters described above, (1 + zeq ) = ΩN R /ΩR ≃ 4 × 104 ΩDM h2 . At lower redshifts, matter wil ...
... universe decreases as T ∝ t−1/2 . As the universe expands, a time will come when (t = teq , a = aeq and z = zeq , say) the matter energy density will be comparable to radiation energy density. For the parameters described above, (1 + zeq ) = ΩN R /ΩR ≃ 4 × 104 ΩDM h2 . At lower redshifts, matter wil ...
The Search for Dark Matter
... If dark matter is so esoteric, one might wonder why there is such a massive effort to discover its nature at all. Yet, physicists often cite “What is dark matter?” as one of the most important open questions in physics today. There are two reasons that physicists are working so hard to find this elu ...
... If dark matter is so esoteric, one might wonder why there is such a massive effort to discover its nature at all. Yet, physicists often cite “What is dark matter?” as one of the most important open questions in physics today. There are two reasons that physicists are working so hard to find this elu ...
Response to Gary Hoge on Whether the Earth can be the Center of
... every direction as seen from any other galaxy, too. This, as we have seen, was Friedmann’s second assumption. We have no scientific evidence for, or against, this assumption. We believe it only on grounds of modesty: it would be most remarkable if the universe looked the same in every direction arou ...
... every direction as seen from any other galaxy, too. This, as we have seen, was Friedmann’s second assumption. We have no scientific evidence for, or against, this assumption. We believe it only on grounds of modesty: it would be most remarkable if the universe looked the same in every direction arou ...
Generation of Cosmological Perturbations by a First
... phase to a broken phase is of strongly first-order. However a very important issue of cosmology has been left out of arguments: One has to explain how and why the universe has attained the large scale inhomogeneities of matter distribution such as superclusters of galaxies. 9 ) This problem must be ...
... phase to a broken phase is of strongly first-order. However a very important issue of cosmology has been left out of arguments: One has to explain how and why the universe has attained the large scale inhomogeneities of matter distribution such as superclusters of galaxies. 9 ) This problem must be ...
My Favorite Universe
... rotation has the effect of Àattening the system. This general Àattening is also seen in galaxies. In the Milky Way, for example, some stars reveal the skeleton of the sphere that originally existed, but the galaxy has Àattened out. Earth, too, is slightly bigger at the equator than at the poles, bec ...
... rotation has the effect of Àattening the system. This general Àattening is also seen in galaxies. In the Milky Way, for example, some stars reveal the skeleton of the sphere that originally existed, but the galaxy has Àattened out. Earth, too, is slightly bigger at the equator than at the poles, bec ...
16. Hubble`s Law and Dark Matter
... 16.1 Dark Matter in the Universe • Galaxy mass measurements show that galaxies need between 3 and 10 times more mass than can be observed to explain their rotation curves. • The discrepancy is even larger in galaxy clusters, which need 10 to 100 times more mass. The total needed is more than the su ...
... 16.1 Dark Matter in the Universe • Galaxy mass measurements show that galaxies need between 3 and 10 times more mass than can be observed to explain their rotation curves. • The discrepancy is even larger in galaxy clusters, which need 10 to 100 times more mass. The total needed is more than the su ...
© Taganov I
... studies [1-5] termed Hydro-Gravitational-Dynamics (HGD). Standard cold-dark-matter hierarchicalclustering (CDMHC) cosmological models neglect critically important HGD concepts such as viscosity1, diffusion2, turbulence3, fossil turbulence4 and fossil turbulence waves5, and should be abandoned [6-10] ...
... studies [1-5] termed Hydro-Gravitational-Dynamics (HGD). Standard cold-dark-matter hierarchicalclustering (CDMHC) cosmological models neglect critically important HGD concepts such as viscosity1, diffusion2, turbulence3, fossil turbulence4 and fossil turbulence waves5, and should be abandoned [6-10] ...
Big Bang
The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution. The model accounts for the fact that the universe expanded from a very high density and high temperature state, and offers a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background, large scale structure, and Hubble's Law. If the known laws of physics are extrapolated beyond where they are valid, there is a singularity. Modern measurements place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe. After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, and later simple atoms. Giant clouds of these primordial elements later coalesced through gravity to form stars and galaxies.Since Georges Lemaître first noted, in 1927, that an expanding universe might be traced back in time to an originating single point, scientists have built on his idea of cosmic expansion. While the scientific community was once divided between supporters of two different expanding universe theories, the Big Bang and the Steady State theory, accumulated empirical evidence provides strong support for the former. In 1929, from analysis of galactic redshifts, Edwin Hubble concluded that galaxies are drifting apart, important observational evidence consistent with the hypothesis of an expanding universe. In 1965, the cosmic microwave background radiation was discovered, which was crucial evidence in favor of the Big Bang model, since that theory predicted the existence of background radiation throughout the universe before it was discovered. More recently, measurements of the redshifts of supernovae indicate that the expansion of the universe is accelerating, an observation attributed to dark energy's existence. The known physical laws of nature can be used to calculate the characteristics of the universe in detail back in time to an initial state of extreme density and temperature.