Time Travel and Warp Drives
... closed because you can return to your starting point in both space and time. It is called “timelike” because the time changes from point to point along the curve. The statement that a closed timelike curve exists is just a fancy way of saying that you have a time machine. It would seem that time tra ...
... closed because you can return to your starting point in both space and time. It is called “timelike” because the time changes from point to point along the curve. The statement that a closed timelike curve exists is just a fancy way of saying that you have a time machine. It would seem that time tra ...
Galaxy Evolution
... both a bulge and a disk with spiral arms. If a bar is present, this contains the bulge at its center and has the spiral arms departing from its extremities. IRREGULAR GALAXIES tend to resemble spiral ones, except that the bulge, the disk and the spiral arms are not regularly defined. There are also ...
... both a bulge and a disk with spiral arms. If a bar is present, this contains the bulge at its center and has the spiral arms departing from its extremities. IRREGULAR GALAXIES tend to resemble spiral ones, except that the bulge, the disk and the spiral arms are not regularly defined. There are also ...
Galaxy Evolution Encyclopedia of Astronomy & Astrophysics eaa.iop.org Mauro Giavalisco
... both a bulge and a disk with spiral arms. If a bar is present, this contains the bulge at its center and has the spiral arms departing from its extremities. IRREGULAR GALAXIES tend to resemble spiral ones, except that the bulge, the disk and the spiral arms are not regularly defined. There are also ...
... both a bulge and a disk with spiral arms. If a bar is present, this contains the bulge at its center and has the spiral arms departing from its extremities. IRREGULAR GALAXIES tend to resemble spiral ones, except that the bulge, the disk and the spiral arms are not regularly defined. There are also ...
sections 23-25 powerpoint
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
Physics and Our Universe: How It All Works
... of the universe at the most basic level and describe natural phenomena as well as the technologies that enable modern civilization. Physics is an experimental science that probes nature to discover its secrets, to re¿ne our understanding, and to explore new and useful applications. It’s also a quant ...
... of the universe at the most basic level and describe natural phenomena as well as the technologies that enable modern civilization. Physics is an experimental science that probes nature to discover its secrets, to re¿ne our understanding, and to explore new and useful applications. It’s also a quant ...
instructor notes: weeks 9/10
... Spiral galaxies are sometimes classified on the basis of the length of the spiral arms and their degree of “tightness.” However, a more universal criterion is the relative size of the central bulge, which is always largest in the Sa galaxies and smallest at Sc. van den Bergh suggested using disk to ...
... Spiral galaxies are sometimes classified on the basis of the length of the spiral arms and their degree of “tightness.” However, a more universal criterion is the relative size of the central bulge, which is always largest in the Sa galaxies and smallest at Sc. van den Bergh suggested using disk to ...
The Celestial Origin of Atoms
... lithium-7, the stars for carbon to uranium, and cosmic rays for lithium, beryllium and boron. By the 1990s, nuclear astrophysics was no longer suspended in theoretical limbo. It had ceased to be a purely speculative discipline and was becoming a science in its own right, with its own quantitative an ...
... lithium-7, the stars for carbon to uranium, and cosmic rays for lithium, beryllium and boron. By the 1990s, nuclear astrophysics was no longer suspended in theoretical limbo. It had ceased to be a purely speculative discipline and was becoming a science in its own right, with its own quantitative an ...
PDF
... Since the late 1970s it has been known that there are many more such systems than expected from our knowledge of the locally observed population. One of the first results from the Cambridge HST surveys was the identification of a strong increase with redshift in the fraction of morphologically pecul ...
... Since the late 1970s it has been known that there are many more such systems than expected from our knowledge of the locally observed population. One of the first results from the Cambridge HST surveys was the identification of a strong increase with redshift in the fraction of morphologically pecul ...
IXO as an observatory in the large telescopes era
... is generally too faint in X-rays to detect individually even with deepest Chandra exposures (e.g. Daddi et al. 2007; Alexander et al. 2008; Fiore et al. 2008). If one assumes that all members in the sample have the same hard X-ray flux, their average corresponds to an intrinsic X-ray luminosity > 10 ...
... is generally too faint in X-rays to detect individually even with deepest Chandra exposures (e.g. Daddi et al. 2007; Alexander et al. 2008; Fiore et al. 2008). If one assumes that all members in the sample have the same hard X-ray flux, their average corresponds to an intrinsic X-ray luminosity > 10 ...
Schutz A First Course in General Relativity(Second Edition).
... on gravitational radiation is more detailed than usual at this level because the observation of gravitational waves may be one of the most significant developments in astronomy in the next decade. The chapter on spherical stars includes, besides the usual material, a useful family of exact compressi ...
... on gravitational radiation is more detailed than usual at this level because the observation of gravitational waves may be one of the most significant developments in astronomy in the next decade. The chapter on spherical stars includes, besides the usual material, a useful family of exact compressi ...
David AJ Seargent
... to be common sense. Not only must we somehow get our heads around vast expanses of space and incredible depths of time, but we are also confronted with seemingly contradictory notion such as a vacuum which nevertheless appears to be filled with vast amounts of energy, particles which are also waves, ...
... to be common sense. Not only must we somehow get our heads around vast expanses of space and incredible depths of time, but we are also confronted with seemingly contradictory notion such as a vacuum which nevertheless appears to be filled with vast amounts of energy, particles which are also waves, ...
uWaterloo LaTeX Thesis Template
... of 0.11cm2 /V.s at 12.8V/µm electric field for a-Se has been calculated, which is consistent with the previously reported results. Another aspect of a detector which is critical in high frame rate imaging applications is temporal performance (lag and ghosting). In this study, the time dependence of ...
... of 0.11cm2 /V.s at 12.8V/µm electric field for a-Se has been calculated, which is consistent with the previously reported results. Another aspect of a detector which is critical in high frame rate imaging applications is temporal performance (lag and ghosting). In this study, the time dependence of ...
Type Ia supernovae as stellar endpoints and cosmological tools
... 17 over normal matter, and 3 over dark matter (which, despite the name, is probably unrelated). But, because dark energy is so dilute (1 m3 contains the energy equivalent to a few atoms of hydrogen), its effects can only be seen on vast scales. We must compare supernovae across ~10 Gyr of cosmic tim ...
... 17 over normal matter, and 3 over dark matter (which, despite the name, is probably unrelated). But, because dark energy is so dilute (1 m3 contains the energy equivalent to a few atoms of hydrogen), its effects can only be seen on vast scales. We must compare supernovae across ~10 Gyr of cosmic tim ...
1 The Hubble Story (10:56)
... “dark ages”, the time shortly after the big bang when the first stars reheated the cold, dim universe. Some may be the farthest ever seen, existing when the universe was just 400 million years old. 0.4.8 The expansion of the Universe Several groups of astronomers have used Hubble to observe a specia ...
... “dark ages”, the time shortly after the big bang when the first stars reheated the cold, dim universe. Some may be the farthest ever seen, existing when the universe was just 400 million years old. 0.4.8 The expansion of the Universe Several groups of astronomers have used Hubble to observe a specia ...
Nonuniversal features of turbulent systems
... fluids and plasmas at all scales - from the blood flow in the human body, via the Earth’s atmosphere to the remnants of supernovas at astrophysical scales. Despite its frequent occurrence, constructing a theory of turbulent motion, which provides reliable quantitative predictions, represents one of ...
... fluids and plasmas at all scales - from the blood flow in the human body, via the Earth’s atmosphere to the remnants of supernovas at astrophysical scales. Despite its frequent occurrence, constructing a theory of turbulent motion, which provides reliable quantitative predictions, represents one of ...
Doctoral Thesis Cosmic-Ray Physics with the Pierre Auger
... The origin and nature of the cosmic rays with the highest energies is one of the most enigmatic questions in physics. These particles are measured indirectly due to the observation of extensive air showers developing in the Earth’s atmosphere. Currently the largest and most advanced experiment desig ...
... The origin and nature of the cosmic rays with the highest energies is one of the most enigmatic questions in physics. These particles are measured indirectly due to the observation of extensive air showers developing in the Earth’s atmosphere. Currently the largest and most advanced experiment desig ...
Exploring Neutral Hydrogen and Galaxy Evolution with the SKA
... The COSMOS H I Large Extragalactic Survey (CHILES) is an ongoing 1000 hour program designed to take advantage of the upgraded capabilities on the Karl G. Jansky Very Large Array (VLA). The upgrade enables continuous redshift coverage for H I in emission from z = 0 − 0.5, doubling the look-back time ...
... The COSMOS H I Large Extragalactic Survey (CHILES) is an ongoing 1000 hour program designed to take advantage of the upgraded capabilities on the Karl G. Jansky Very Large Array (VLA). The upgrade enables continuous redshift coverage for H I in emission from z = 0 − 0.5, doubling the look-back time ...
Astrophysics for Physicists.
... Sciences as well as our Joint Astronomy and Astrophysics Programme. I must have taught this course to more than half a dozen batches. Over the years, several excellent textbooks suitable for use in one-semester courses on particle physics and solid state physics have been written. The situation with ...
... Sciences as well as our Joint Astronomy and Astrophysics Programme. I must have taught this course to more than half a dozen batches. Over the years, several excellent textbooks suitable for use in one-semester courses on particle physics and solid state physics have been written. The situation with ...
Plotting the Rotation Curve of M31
... Measure the peak frequencies of the hydrogen spectra. Is this part of the galaxy approaching us or moving away from us? Answer: the spectra show higher frequencies than the rest value (1420.406 MHz) which indicates they are blueshifted and that they were taken from the approaching limb of M31. Your ...
... Measure the peak frequencies of the hydrogen spectra. Is this part of the galaxy approaching us or moving away from us? Answer: the spectra show higher frequencies than the rest value (1420.406 MHz) which indicates they are blueshifted and that they were taken from the approaching limb of M31. Your ...
The redshift of extragalactic nebulae
... extragalactic nebula, as well as the methods that have been used for research into them. In particular, the so-called redshift of extragalactic nebulae is discussed in detail. Various theories that have been advanced to explain this important phenomenon are briefly discussed. Finally it is indicated ...
... extragalactic nebula, as well as the methods that have been used for research into them. In particular, the so-called redshift of extragalactic nebulae is discussed in detail. Various theories that have been advanced to explain this important phenomenon are briefly discussed. Finally it is indicated ...
The Swift satellite lives up to its name, revealing cosmic
... signatures were apparent; most famously in GRB 030329 (Hjorth et al. 2003; Stanek et al. 2003). This provided proof of the origin of at least some long GRBs in the core collapse of very massive stars which have lost their outer hydrogen layers, allowing the GRB to escape without being smothered by a ...
... signatures were apparent; most famously in GRB 030329 (Hjorth et al. 2003; Stanek et al. 2003). This provided proof of the origin of at least some long GRBs in the core collapse of very massive stars which have lost their outer hydrogen layers, allowing the GRB to escape without being smothered by a ...
Dark energy
In physical cosmology and astronomy, dark energy is an unknown form of energy which is hypothesized to permeate all of space, tending to accelerate the expansion of the universe. Dark energy is the most accepted hypothesis to explain the observations since the 1990s indicating that the universe is expanding at an accelerating rate. Assuming that the standard model of cosmology is correct, the best current measurements indicate that dark energy contributes 68.3% of the total energy in the present-day observable universe. The mass–energy of dark matter and ordinary matter contribute 26.8% and 4.9%, respectively, and other components such as neutrinos and photons contribute a very small amount. Again on a mass–energy equivalence basis, the density of dark energy (6.91 × 10−27 kg/m3) is very low, much less than the density of ordinary matter or dark matter within galaxies. However, it comes to dominate the mass–energy of the universe because it is uniform across space.Two proposed forms for dark energy are the cosmological constant, a constant energy density filling space homogeneously, and scalar fields such as quintessence or moduli, dynamic quantities whose energy density can vary in time and space. Contributions from scalar fields that are constant in space are usually also included in the cosmological constant. The cosmological constant can be formulated to be equivalent to vacuum energy. Scalar fields that do change in space can be difficult to distinguish from a cosmological constant because the change may be extremely slow.High-precision measurements of the expansion of the universe are required to understand how the expansion rate changes over time and space. In general relativity, the evolution of the expansion rate is parameterized by the cosmological equation of state (the relationship between temperature, pressure, and combined matter, energy, and vacuum energy density for any region of space). Measuring the equation of state for dark energy is one of the biggest efforts in observational cosmology today.Adding the cosmological constant to cosmology's standard FLRW metric leads to the Lambda-CDM model, which has been referred to as the ""standard model of cosmology"" because of its precise agreement with observations. Dark energy has been used as a crucial ingredient in a recent attempt to formulate a cyclic model for the universe.