new theory of non-expanding universe
... ratio V/D of recession velocities-to-distances for the receding galaxies, V = Zc being estimated by the redshift Z and the distance D by the apparent intensity or faintness of the stellar source. The attractive gravitational force varies inversely as the square of the distance and curves the spaceti ...
... ratio V/D of recession velocities-to-distances for the receding galaxies, V = Zc being estimated by the redshift Z and the distance D by the apparent intensity or faintness of the stellar source. The attractive gravitational force varies inversely as the square of the distance and curves the spaceti ...
Astrophysics E1. This question is about stars.
... (iii) Light from Vega is absorbed by a dust cloud between Vega and Earth. Suggest the effect, if any, this will have on determining the distance of Vega from Earth. ...
... (iii) Light from Vega is absorbed by a dust cloud between Vega and Earth. Suggest the effect, if any, this will have on determining the distance of Vega from Earth. ...
IDS 102
... This web page is designed to give everyone an idea of what our universe actually looks like. There are nine main maps on this web page, each one approximately ten to twenty times the scale of the previous one. The first map shows the nearest stars and then the other maps slowly expand out until we h ...
... This web page is designed to give everyone an idea of what our universe actually looks like. There are nine main maps on this web page, each one approximately ten to twenty times the scale of the previous one. The first map shows the nearest stars and then the other maps slowly expand out until we h ...
Ch. 23
... the next moment in time, when gravity was distinct from the other three forces, which together formed the GUT force. At the end of this era, when the strong force became distinct, a period of inflation may have caused an enormous expansion of the universe. Electroweak era: Three forces — the strong ...
... the next moment in time, when gravity was distinct from the other three forces, which together formed the GUT force. At the end of this era, when the strong force became distinct, a period of inflation may have caused an enormous expansion of the universe. Electroweak era: Three forces — the strong ...
Lecture 5
... A nebula is an interstellar cloud of dust, hydrogen gas and plasma. Originally nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way. Nebulae often form star-forming regions, such as in the Eagle Nebula. This nebula is depicted in one of NASA's most ...
... A nebula is an interstellar cloud of dust, hydrogen gas and plasma. Originally nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way. Nebulae often form star-forming regions, such as in the Eagle Nebula. This nebula is depicted in one of NASA's most ...
Slide 1
... A nebula is an interstellar cloud of dust, hydrogen gas and plasma. Originally nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way. Nebulae often form star-forming regions, such as in the Eagle Nebula. This nebula is depicted in one of NASA's most ...
... A nebula is an interstellar cloud of dust, hydrogen gas and plasma. Originally nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way. Nebulae often form star-forming regions, such as in the Eagle Nebula. This nebula is depicted in one of NASA's most ...
BAS_Paper2_TheEarliestEpochs
... (not inaccurately) deem it the “epoch of ignorance” [10; 0, pg. 234]. Using classical general ...
... (not inaccurately) deem it the “epoch of ignorance” [10; 0, pg. 234]. Using classical general ...
2 Galactic radiation fields
... and molecular gas, etc.) depends on the rate at which molecules are photodissociated and atoms are photoionized by the radiation field. – The thermal state of the gas depends on the photoionization rate, and also on the rate of a process known as photoelectric heating: the ejection of an energetic e ...
... and molecular gas, etc.) depends on the rate at which molecules are photodissociated and atoms are photoionized by the radiation field. – The thermal state of the gas depends on the photoionization rate, and also on the rate of a process known as photoelectric heating: the ejection of an energetic e ...
Early Universe and Thermal History
... During the early stages the temperature went through a large range or values (many orders of magnitude). From conventional solid state physics we know that temperature changes can produce phase transitions, and there are commonly known examples of that: ferro-magnets, water drops condensing out of f ...
... During the early stages the temperature went through a large range or values (many orders of magnitude). From conventional solid state physics we know that temperature changes can produce phase transitions, and there are commonly known examples of that: ferro-magnets, water drops condensing out of f ...
2004 Term 1 January
... performance) or soliton pulses (supposedly non-dispersing light pulses that are subject to quantum-induced timing jitter accumulation) used in fiber-optic communications. MIT's Research Laboratory of Electronics is a place where quantum aspects of electrical engineering are taken very seriously. The ...
... performance) or soliton pulses (supposedly non-dispersing light pulses that are subject to quantum-induced timing jitter accumulation) used in fiber-optic communications. MIT's Research Laboratory of Electronics is a place where quantum aspects of electrical engineering are taken very seriously. The ...
Lecture 9
... The yields of D, 3 He, 4 He, 6 Li, and 7 Li are sensitive to the baryon-to-photon ratio, η. Since we know the photon density from CMB, we can constrain the baryon density by comparing the predictions of BBN computer codes to the observed density of especially deuterium but also helium and lithium. A ...
... The yields of D, 3 He, 4 He, 6 Li, and 7 Li are sensitive to the baryon-to-photon ratio, η. Since we know the photon density from CMB, we can constrain the baryon density by comparing the predictions of BBN computer codes to the observed density of especially deuterium but also helium and lithium. A ...
Chapter 31 - The Galaxy & Universe
... 1. The outcome of the Universe depends on the amount (density) of material in it. a) Less than critical density (10-26 kg/m3) results in open Universe. ...
... 1. The outcome of the Universe depends on the amount (density) of material in it. a) Less than critical density (10-26 kg/m3) results in open Universe. ...
Great Discoveries in Astronomy and Astrophysics 171.112
... Doing and understanding the homework is important to get the most out of the class and to prepare yourself for the exams. It should not take too long to complete. Homework is due at the assigned time. Greatly reduced credit, if any, will be given for late homework. It is OK to consult with others on ...
... Doing and understanding the homework is important to get the most out of the class and to prepare yourself for the exams. It should not take too long to complete. Homework is due at the assigned time. Greatly reduced credit, if any, will be given for late homework. It is OK to consult with others on ...
(the factor f star in the Drake equation. Recall it
... After that, the electromagnetic radiation did not interact strongly with the matter any more and it remained in the universe from that time. The discovery by radio astronomers of this ‘cosmic ray background’ electromagnetic radiation is one of the experimental reasons that we believe this story. ...
... After that, the electromagnetic radiation did not interact strongly with the matter any more and it remained in the universe from that time. The discovery by radio astronomers of this ‘cosmic ray background’ electromagnetic radiation is one of the experimental reasons that we believe this story. ...
Quasars and Active Galaxies
... • “Steady State”: As galaxies move apart from each other, new atoms are spontaneously created in empty space. These atoms coalesce to form new galaxies. The average density of the universe doesn’t change over time. There was no hot early universe. Quasars were the first evidence that the universe wa ...
... • “Steady State”: As galaxies move apart from each other, new atoms are spontaneously created in empty space. These atoms coalesce to form new galaxies. The average density of the universe doesn’t change over time. There was no hot early universe. Quasars were the first evidence that the universe wa ...
Slides - Events - Tata Institute of Fundamental Research
... acquired ANY significant knowledge about the physical universe, its content and its long term evolution. In particular, the theories of relativity and dynamics (including QM) as well as the theory of gravity were developed assuming an EMPTY universe. ...
... acquired ANY significant knowledge about the physical universe, its content and its long term evolution. In particular, the theories of relativity and dynamics (including QM) as well as the theory of gravity were developed assuming an EMPTY universe. ...
Lecture 29 - Empyrean Quest Publishers
... Harlow Shapley 1917--We are not at the center of the disk. Globular clusters orbit galactic center, sun 2/3rds way out. He used proper motions of Cepheids-->Distance (11 stars). Shapley-Curtis debate 1920--Nebulae are within our island universe (Shapley). Nebulae may be other galaxies (Curtis). Edwi ...
... Harlow Shapley 1917--We are not at the center of the disk. Globular clusters orbit galactic center, sun 2/3rds way out. He used proper motions of Cepheids-->Distance (11 stars). Shapley-Curtis debate 1920--Nebulae are within our island universe (Shapley). Nebulae may be other galaxies (Curtis). Edwi ...
powerpoint file
... The Universe originated in an explosion called the “Big Bang”. Everything started out 13.7 billion years ago with “zero” size and “infinite” temperature. Since then, it has been expanding and cooling. Now its temperature is 2.735 K. While the temperature was still high enough — at age 2 to 30 minute ...
... The Universe originated in an explosion called the “Big Bang”. Everything started out 13.7 billion years ago with “zero” size and “infinite” temperature. Since then, it has been expanding and cooling. Now its temperature is 2.735 K. While the temperature was still high enough — at age 2 to 30 minute ...
ppt format
... back in the 1920s, astronomers started classifying spectra into classes based primarily on the prominence of the H-beta Balmer absorption line. Those with most prominent H-beta were called class “A”, next “B” etc, up to O. ...
... back in the 1920s, astronomers started classifying spectra into classes based primarily on the prominence of the H-beta Balmer absorption line. Those with most prominent H-beta were called class “A”, next “B” etc, up to O. ...
E:\2012-2013\SSU\PHS 207spring 2013\3rd test 4
... stars much older than 10 billion years and that others are 2nd and 3rd generation stars that could NOT have developed in just 10 billion years ...
... stars much older than 10 billion years and that others are 2nd and 3rd generation stars that could NOT have developed in just 10 billion years ...
Cosmic microwave background
The cosmic microwave background (CMB) is the thermal radiation left over from the time of recombination in Big Bang cosmology. In older literature, the CMB is also variously known as cosmic microwave background radiation (CMBR) or ""relic radiation."" The CMB is a cosmic background radiation that is fundamental to observational cosmology because it is the oldest light in the universe, dating to the epoch of recombination. With a traditional optical telescope, the space between stars and galaxies (the background) is completely dark. However, a sufficiently sensitive radio telescope shows a faint background glow, almost exactly the same in all directions, that is not associated with any star, galaxy, or other object. This glow is strongest in the microwave region of the radio spectrum. The accidental discovery of CMB in 1964 by American radio astronomers Arno Penzias and Robert Wilson was the culmination of work initiated in the 1940s, and earned the discoverers the 1978 Nobel Prize.The CMB is a snapshot of the oldest light in our Universe, imprinted on the sky when the Universe was just 380,000 years old. It shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future structure: the stars and galaxies of today.The CMB is well explained as radiation left over from an early stage in the development of the universe, and its discovery is considered a landmark test of the Big Bang model of the universe. When the universe was young, before the formation of stars and planets, it was denser, much hotter, and filled with a uniform glow from a white-hot fog of hydrogen plasma. As the universe expanded, both the plasma and the radiation filling it grew cooler. When the universe cooled enough, protons and electrons combined to form neutral atoms. These atoms could no longer absorb the thermal radiation, and so the universe became transparent instead of being an opaque fog. Cosmologists refer to the time period when neutral atoms first formed as the recombination epoch, and the event shortly afterwards when photons started to travel freely through space rather than constantly being scattered by electrons and protons in plasma is referred to as photon decoupling. The photons that existed at the time of photon decoupling have been propagating ever since, though growing fainter and less energetic, since the expansion of space causes their wavelength to increase over time (and wavelength is inversely proportional to energy according to Planck's relation). This is the source of the alternative term relic radiation. The surface of last scattering refers to the set of points in space at the right distance from us so that we are now receiving photons originally emitted from those points at the time of photon decoupling.Precise measurements of the CMB are critical to cosmology, since any proposed model of the universe must explain this radiation. The CMB has a thermal black body spectrum at a temperature of 7000272548000000000♠2.72548±0.00057 K. The spectral radiance dEν/dν peaks at 160.2 GHz, in the microwave range of frequencies. (Alternatively if spectral radiance is defined as dEλ/dλ then the peak wavelength is 1.063 mm.) The glow is very nearly uniform in all directions, but the tiny residual variations show a very specific pattern, the same as that expected of a fairly uniformly distributed hot gas that has expanded to the current size of the universe. In particular, the spectral radiance at different angles of observation in the sky contains small anisotropies, or irregularities, which vary with the size of the region examined. They have been measured in detail, and match what would be expected if small thermal variations, generated by quantum fluctuations of matter in a very tiny space, had expanded to the size of the observable universe we see today. This is a very active field of study, with scientists seeking both better data (for example, the Planck spacecraft) and better interpretations of the initial conditions of expansion. Although many different processes might produce the general form of a black body spectrum, no model other than the Big Bang has yet explained the fluctuations. As a result, most cosmologists consider the Big Bang model of the universe to be the best explanation for the CMB.The high degree of uniformity throughout the observable universe and its faint but measured anisotropy lend strong support for the Big Bang model in general and the ΛCDM (""Lambda Cold Dark Matter"") model in particular. Moreover, the fluctuations are coherent on angular scales that are larger than the apparent cosmological horizon at recombination. Either such coherence is acausally fine-tuned, or cosmic inflation occurred.