Our Universe—Infinite and Eternal: Its Physics
... the nitty gritty of a topic might find a first reading difficult. However, the first reading should give the reader the essentials of the needed background so that a second reading should proceed more easily and give a fuller understanding of what is being presented. The only topic so far in this part of ...
... the nitty gritty of a topic might find a first reading difficult. However, the first reading should give the reader the essentials of the needed background so that a second reading should proceed more easily and give a fuller understanding of what is being presented. The only topic so far in this part of ...
Astronomy and the Bible
... The popular theory is that stars form from vast clouds of gas and dust through gravitational contraction. Because of heat pressure gas and dust clouds will expand, NOT contract. “The complete birth of a star has never been observed. The principles of physics demand some special conditions for st ...
... The popular theory is that stars form from vast clouds of gas and dust through gravitational contraction. Because of heat pressure gas and dust clouds will expand, NOT contract. “The complete birth of a star has never been observed. The principles of physics demand some special conditions for st ...
Minimal modifications of the primordial power spectrum from an
... M can be considered a minimal model for short distance effects since, in an expanding spacetime, the adiabatic vacuum is the closest analogue to the usual Minkowski vacuum. Indeed, any other choice of the initial state will produce larger effects unless the amplitudes to find pairs of adiabatic quan ...
... M can be considered a minimal model for short distance effects since, in an expanding spacetime, the adiabatic vacuum is the closest analogue to the usual Minkowski vacuum. Indeed, any other choice of the initial state will produce larger effects unless the amplitudes to find pairs of adiabatic quan ...
Library PDF - Fort Wayne Astronomical Society
... Meteor Observing Guide by Mark Davis of the North American Meteor Network Observe The Herschel Objects, Astronomical League Seeing The Sky, 100 projects, activities & explorations in Astronomy by Fred Schaaf Sky Facts With Myths And Legends Of The Sky by Mary Esther Cary Sharp Skyguide, A field guid ...
... Meteor Observing Guide by Mark Davis of the North American Meteor Network Observe The Herschel Objects, Astronomical League Seeing The Sky, 100 projects, activities & explorations in Astronomy by Fred Schaaf Sky Facts With Myths And Legends Of The Sky by Mary Esther Cary Sharp Skyguide, A field guid ...
In fla tio n
... For inflation to work: need short-term cosmological constant, i.e., need particles with negative pressure. ...
... For inflation to work: need short-term cosmological constant, i.e., need particles with negative pressure. ...
Spiral Galaxy - Purdue Physics
... understand our Universe from t = 0 to 13.8 billion years We only have one Universe although some models include speculation about connections to other Universes Elementary Particle Physics – Fundamental building blocks and forces Cosmology – Understanding the history and evolution of the Universe, l ...
... understand our Universe from t = 0 to 13.8 billion years We only have one Universe although some models include speculation about connections to other Universes Elementary Particle Physics – Fundamental building blocks and forces Cosmology – Understanding the history and evolution of the Universe, l ...
www.astro.caltech.edu
... While the majority of detected GRBs originate from massive stars, a smaller subset sees to have a completely different physical cause (Figure 2). The host galaxies of short-duration GRBs (those whose gamma-ray emission lasts for 2 seconds or less) observed with Keck have been localized to a complete ...
... While the majority of detected GRBs originate from massive stars, a smaller subset sees to have a completely different physical cause (Figure 2). The host galaxies of short-duration GRBs (those whose gamma-ray emission lasts for 2 seconds or less) observed with Keck have been localized to a complete ...
slides
... – Light from regions of the universe beyond that has not reached us yet, so we cannot see them. – This part of the universe where light had time to reach us is called “the observable universe” – As the universe ages, we will be able to see more distant parts of the universe. ...
... – Light from regions of the universe beyond that has not reached us yet, so we cannot see them. – This part of the universe where light had time to reach us is called “the observable universe” – As the universe ages, we will be able to see more distant parts of the universe. ...
The Milky Way at Different Wavelengths
... Owing to the strong obscuration by interstellar dust the light is primarily from stars within a few thousand light-years of the Sun, nearby on the scale of the Milky Way, which has a diameter on the order of 100,000 light years. Nebulosity from hot, low-density gas is widespread in the image. Dark p ...
... Owing to the strong obscuration by interstellar dust the light is primarily from stars within a few thousand light-years of the Sun, nearby on the scale of the Milky Way, which has a diameter on the order of 100,000 light years. Nebulosity from hot, low-density gas is widespread in the image. Dark p ...
dark matter. - Gordon State College
... • If the Big Bang did occur and the universe is expanding, the light emitted at the instant of the Big Bang would have been redshifted so much that it would appear as microwave signals if we received them today. • Arno Penzias and Robert Wilson observed these signals in 1964, which became known as t ...
... • If the Big Bang did occur and the universe is expanding, the light emitted at the instant of the Big Bang would have been redshifted so much that it would appear as microwave signals if we received them today. • Arno Penzias and Robert Wilson observed these signals in 1964, which became known as t ...
In Search of the Dark Matter in the Universe
... and galaxies were the only matter in the universe, the universe would expand forever. We neglected here the amount of matter in form of planets, since they contribute not more than a few percent of the mass of a star. However, it came as a surprise when Vera Rubin and her team found out in the 1970 ...
... and galaxies were the only matter in the universe, the universe would expand forever. We neglected here the amount of matter in form of planets, since they contribute not more than a few percent of the mass of a star. However, it came as a surprise when Vera Rubin and her team found out in the 1970 ...
Discovery of radio afterglow from most distant cosmic explosion
... • We have detected the radio afterglow of GRB 090324 at z=8.3 • The best-fit broad-band afterglow model is a quasi-spherical (θj>12o), hyper-energetic (1052 erg) explosion in a constant, low density (n=1 cm-3) medium. • GRB 050904 (z=6.26) was also hyper-energetic but it exploded into a high density ...
... • We have detected the radio afterglow of GRB 090324 at z=8.3 • The best-fit broad-band afterglow model is a quasi-spherical (θj>12o), hyper-energetic (1052 erg) explosion in a constant, low density (n=1 cm-3) medium. • GRB 050904 (z=6.26) was also hyper-energetic but it exploded into a high density ...
6 The mysterious universe
... twenty‐first century, than we did 400 years ago when people were arguing about whether the Earth or the sun was the centre of the universe? 11 Given that the Earth is such a tiny speck, would you expect to find other, similar planets in the universe? If so, where would you expect to find them? ...
... twenty‐first century, than we did 400 years ago when people were arguing about whether the Earth or the sun was the centre of the universe? 11 Given that the Earth is such a tiny speck, would you expect to find other, similar planets in the universe? If so, where would you expect to find them? ...
Effects of Gravitation
... energy/matter density of the universe important for acceleration, its makeup was determined by the early thermal history of the universe. Speculation on the nature of the matter in the universe was, of course, determined by the micro-physics of the period. Although the nature of the cosmic distribut ...
... energy/matter density of the universe important for acceleration, its makeup was determined by the early thermal history of the universe. Speculation on the nature of the matter in the universe was, of course, determined by the micro-physics of the period. Although the nature of the cosmic distribut ...
Powerpoint slides
... The large spiral galaxy in this image is about 50 times farther than the Andromeda Galaxy. On the scale of our CD-filled universe, this is about 400 feet from our own Milky Way CD. Your volunteer would have to stand in the parking lot to model this to scale. What about the smaller galaxy in the lowe ...
... The large spiral galaxy in this image is about 50 times farther than the Andromeda Galaxy. On the scale of our CD-filled universe, this is about 400 feet from our own Milky Way CD. Your volunteer would have to stand in the parking lot to model this to scale. What about the smaller galaxy in the lowe ...
A search for ultra-high-energy gamma rays at the South Pole
... Detection of high-energy cosmic and gamma rays is rather complicated. Because of the very low flux above 100 terraelectronvolts (approximately 1 per square meter per year), a very large area detector is required, and one must make use of the fact that both the cosmic and gamma rays generate cascades ...
... Detection of high-energy cosmic and gamma rays is rather complicated. Because of the very low flux above 100 terraelectronvolts (approximately 1 per square meter per year), a very large area detector is required, and one must make use of the fact that both the cosmic and gamma rays generate cascades ...
Survey of Astrophysics A110 Cosmology
... observations of the Universe. For example, we now know that the Universe has many more quasars and active galactic nuclei as we look out to larger and larger distances from the Milky Way. Since we are looking further and further into the past this implies that the Universe is not constant --- it evo ...
... observations of the Universe. For example, we now know that the Universe has many more quasars and active galactic nuclei as we look out to larger and larger distances from the Milky Way. Since we are looking further and further into the past this implies that the Universe is not constant --- it evo ...
Paper
... Recently, information about the early universe has been flooding in from bigger and better telescopes on the earth's surface and a host of space telescopes covering spectral bands previously unobservable, all with spectacular resolution. It is becoming clear that structure existed much earlier and a ...
... Recently, information about the early universe has been flooding in from bigger and better telescopes on the earth's surface and a host of space telescopes covering spectral bands previously unobservable, all with spectacular resolution. It is becoming clear that structure existed much earlier and a ...
The Electric Universe by Wallace Thornhill and David Talbott
... confidently of the Big Bang that set the clock ticking and the universe on its course 13.7 billion years ago. This is a universe filled with black holes, dark matter, dark energy, and other incomprehensible objects and forces, all with one thing in common: they remain unseen and inaccessible under k ...
... confidently of the Big Bang that set the clock ticking and the universe on its course 13.7 billion years ago. This is a universe filled with black holes, dark matter, dark energy, and other incomprehensible objects and forces, all with one thing in common: they remain unseen and inaccessible under k ...
The origin of elements For life we need some complexity, and
... • However, any nuclei that form at this stage (e.g., deuterium, via p + n → d + γ) are immediately split by high-energy photons (via d + γ → p + n). • When the universe is much older than the lifetime of a neutron in free space (∼ 103 s, at which point the temperature is around 4 × 108 K), any remai ...
... • However, any nuclei that form at this stage (e.g., deuterium, via p + n → d + γ) are immediately split by high-energy photons (via d + γ → p + n). • When the universe is much older than the lifetime of a neutron in free space (∼ 103 s, at which point the temperature is around 4 × 108 K), any remai ...
Telescopes
... • Note the units: mag/square arcsecond is a surface brightness. • The sky is very bright past 1 micron because of thermal radiation. • This makes it difficult to observe at near and mid-infrared wavelengths. • Because the sky is so bright at infrared wavelengths, infrared astronomers are often given ...
... • Note the units: mag/square arcsecond is a surface brightness. • The sky is very bright past 1 micron because of thermal radiation. • This makes it difficult to observe at near and mid-infrared wavelengths. • Because the sky is so bright at infrared wavelengths, infrared astronomers are often given ...
Invited Review The Beginning and Evolution of the Universe
... the “Copernican” cosmological principle by Milne (1933). Peebles (1993; § 3) has reviewed the strong observational evidence for large-scale statistical isotropy; observational tests of homogeneity are not as straightforward. Einstein knew that the stars in the Milky Way moved rather slowly and decid ...
... the “Copernican” cosmological principle by Milne (1933). Peebles (1993; § 3) has reviewed the strong observational evidence for large-scale statistical isotropy; observational tests of homogeneity are not as straightforward. Einstein knew that the stars in the Milky Way moved rather slowly and decid ...
Test 4 Review
... appears to be going more and more slowly as it approaches the event horizon. This is called a gravitational redshift – it is not due to motion, but to the large gravitational fields present. The probe itself, however, does not experience any such shifts; time would appear normal to anyone inside. ...
... appears to be going more and more slowly as it approaches the event horizon. This is called a gravitational redshift – it is not due to motion, but to the large gravitational fields present. The probe itself, however, does not experience any such shifts; time would appear normal to anyone inside. ...
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.