
Introduction to Observational Cosmology
... 1. Averaged over sufficiently large scales, the universe is nearly homogeneous and isotropic (=cosmological principle) 2. The universe, i.e. space itself, is expanding so that the distance D between any pairs of widely separated points increases as dD/dt~D (=Hubble law) 3. (?) the universe expanded ...
... 1. Averaged over sufficiently large scales, the universe is nearly homogeneous and isotropic (=cosmological principle) 2. The universe, i.e. space itself, is expanding so that the distance D between any pairs of widely separated points increases as dD/dt~D (=Hubble law) 3. (?) the universe expanded ...
Astronomy Chapter 17 – Galaxies A. Main Ideas 1. Discovering
... parallax to measure such large distances because the angle by which the galaxy’s position changes as we move around the Sun is too small to be measured. Astronomers use the method of standard candles to measure the distance to distant galaxies. Using the inverse-square law and the known luminosity o ...
... parallax to measure such large distances because the angle by which the galaxy’s position changes as we move around the Sun is too small to be measured. Astronomers use the method of standard candles to measure the distance to distant galaxies. Using the inverse-square law and the known luminosity o ...
Unit 1: The Foundations of Astronomy
... 1. Science builds upon itself over time. As new evidence arises and we acquire new understandings, old theories are revised or replaced by new ones. 2. Early astronomers tracked the motion of objects in the sky and used that information to describe the universe. 3. Mathematical tools and the use of ...
... 1. Science builds upon itself over time. As new evidence arises and we acquire new understandings, old theories are revised or replaced by new ones. 2. Early astronomers tracked the motion of objects in the sky and used that information to describe the universe. 3. Mathematical tools and the use of ...
PHY 375 - DePaul University
... We will use the full relativistic Doppler effect formula to avoid faster than light recession velocity (but see posted lecture notes about why this step angers theoreticians, especially because faster than light motions are not a problem in general relativity; in fact, the preference is to keep dist ...
... We will use the full relativistic Doppler effect formula to avoid faster than light recession velocity (but see posted lecture notes about why this step angers theoreticians, especially because faster than light motions are not a problem in general relativity; in fact, the preference is to keep dist ...
A new view of galaxy evolution
... This dark matter, furthermore, is thought to formed up until the 1980s. make up the bulk of the matter within galaxies. The other idea, based on Cold Dark Matter This has many implications beyond simply the cosmology, is that galaxies form through the idea that the light we see from galaxies is just ...
... This dark matter, furthermore, is thought to formed up until the 1980s. make up the bulk of the matter within galaxies. The other idea, based on Cold Dark Matter This has many implications beyond simply the cosmology, is that galaxies form through the idea that the light we see from galaxies is just ...
Astronomy, Astrophysics, and Cosmology
... Apparent position in sky of more distant stars changes so slowly that proper motion can’t be detected with even most patient observation However + rate of approach or recession of star in line of sight can be measured much more accurately than its ⊥ motion to line of sight Technique uses familiar pr ...
... Apparent position in sky of more distant stars changes so slowly that proper motion can’t be detected with even most patient observation However + rate of approach or recession of star in line of sight can be measured much more accurately than its ⊥ motion to line of sight Technique uses familiar pr ...
2 Particle Interaction with Matter
... Depending on the particle type, the particle energy and the material some processes dominate, other do not occur. For instance only charged particles will interact with electrons of the atoms and produce ionisation, etc.! ...
... Depending on the particle type, the particle energy and the material some processes dominate, other do not occur. For instance only charged particles will interact with electrons of the atoms and produce ionisation, etc.! ...
Answering the Fermi Paradox - Acceleration Studies Foundation
... the incomplete "random and contingent" neo-Darwinian view of change ("life does not engender progress in generalized functional complexity, except in rare circumstances, and then only by chance"). In other words, they don't presently think about universal change developmentally, but rather only evol ...
... the incomplete "random and contingent" neo-Darwinian view of change ("life does not engender progress in generalized functional complexity, except in rare circumstances, and then only by chance"). In other words, they don't presently think about universal change developmentally, but rather only evol ...
Abstract - UChicago High Energy Physics
... (BAU) remains one of the greatest puzzles of cosmology. As was pointed out by Sakharov, any model that explains BAU has to satisfy three conditions: (1) baryon number non-conservation, (2) C and CP violations, and (3) departure from thermal equilibrium [1]. In fact, many of the early Universe proble ...
... (BAU) remains one of the greatest puzzles of cosmology. As was pointed out by Sakharov, any model that explains BAU has to satisfy three conditions: (1) baryon number non-conservation, (2) C and CP violations, and (3) departure from thermal equilibrium [1]. In fact, many of the early Universe proble ...
Exploring the Most Bizarre Ideas in Cosmology Astronomers
... 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, "empty" spac ...
... 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, "empty" spac ...
Durham Research Online
... unlikely, and is very unlikely to have a significant effect on direct detection experiments. Key words: cosmology: theory, dark matter – Galaxy: structure, disc – methods: numerical ...
... unlikely, and is very unlikely to have a significant effect on direct detection experiments. Key words: cosmology: theory, dark matter – Galaxy: structure, disc – methods: numerical ...
Lecture notes 18: Galaxies and galaxy clusters
... At scales larger than 100 Mpc the galaxies (matter) seems evenly distributed. Gravitational lenses and dark matter. Galactic cluster dynamics show that there is a great amount of dark matter: there is not enough luminous matter, even when considering the very hot intergalactic gas clouds, to bind ga ...
... At scales larger than 100 Mpc the galaxies (matter) seems evenly distributed. Gravitational lenses and dark matter. Galactic cluster dynamics show that there is a great amount of dark matter: there is not enough luminous matter, even when considering the very hot intergalactic gas clouds, to bind ga ...
P7 Further Physics : Observing the Universe
... eclipses of the Sun and Moon, apparent motion of planets and stars. Difference between solar and sidereal day. ...
... eclipses of the Sun and Moon, apparent motion of planets and stars. Difference between solar and sidereal day. ...
normal and active - FirstLight Astro
... ✴ we are larger than most spirals but there are some 4x bigger, 10x more luminous ✴ ellipticals have a huge range, from 1% our size ➙ 5x bigger than us ...
... ✴ we are larger than most spirals but there are some 4x bigger, 10x more luminous ✴ ellipticals have a huge range, from 1% our size ➙ 5x bigger than us ...
Introduction to Cosmology - Experimental Elementary Particle
... year is approximately equal to 3.2 × 107 s. In cosmological context, a year is frequently an inconveniently short period of time, so cosmologists frequently use gigayears (Gyr), equal to 109 yr, or 3.2 × 1016 s. For example, the age of the Earth is more conveniently written as 4.6 Gyr than as 1.5 × ...
... year is approximately equal to 3.2 × 107 s. In cosmological context, a year is frequently an inconveniently short period of time, so cosmologists frequently use gigayears (Gyr), equal to 109 yr, or 3.2 × 1016 s. For example, the age of the Earth is more conveniently written as 4.6 Gyr than as 1.5 × ...
Cosmological Consequences of Topological Defects
... the limit of large number N of coupled scalar fields, approaches the so-called ‘ideal’ model (in terms of its potential to lead to network frustration). By using the results of the largest and most accurate three-dimensional field theory simulations of domain wall networks with junctions, we find co ...
... the limit of large number N of coupled scalar fields, approaches the so-called ‘ideal’ model (in terms of its potential to lead to network frustration). By using the results of the largest and most accurate three-dimensional field theory simulations of domain wall networks with junctions, we find co ...
Galaxies
... arms are wound, with “a” being most tightly wound. The Andromeda Galaxy is an Sb. • Elliptical galaxies are denoted by “E”, with a number from 0-7 indicating how circular it appears. An example of this would be M87, which is an E0 galaxy. • Irregulars, such as the Small Magellanic Cloud, are denoted ...
... arms are wound, with “a” being most tightly wound. The Andromeda Galaxy is an Sb. • Elliptical galaxies are denoted by “E”, with a number from 0-7 indicating how circular it appears. An example of this would be M87, which is an E0 galaxy. • Irregulars, such as the Small Magellanic Cloud, are denoted ...
Galaxies
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
Quantum Theory Cannot Hurt You
... As a science writer I am constantly amazed by how much stranger science is than science fiction, how much more incredible the Universe is than anything we could possibly have invented. Despite this, however, very few of the extraordinary discoveries of the past century seem to have trickled through ...
... As a science writer I am constantly amazed by how much stranger science is than science fiction, how much more incredible the Universe is than anything we could possibly have invented. Despite this, however, very few of the extraordinary discoveries of the past century seem to have trickled through ...
Document
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
... The Universe is filled with these star systems which themselves cluster together into larger systems. ...
P1 topic 3 - WordPress.com
... *b While the origin of stars is well understood, there is still much debate about the origin of the Universe. Two major theories about the origin of the Universe are the Big Bang and the Steady State theories. Some evidence supports both theories. Other evidence supports only one theory. By consider ...
... *b While the origin of stars is well understood, there is still much debate about the origin of the Universe. Two major theories about the origin of the Universe are the Big Bang and the Steady State theories. Some evidence supports both theories. Other evidence supports only one theory. By consider ...
cp violation and the origins of matter
... mass-energy associated with stars, galaxies, etc. The larger value comes from various measurements of large scale structure, especially measurements of the potential associated with gravitating (but not necessarily visible) mass-energy. The discrepancy between these numbers suggests that the majorit ...
... mass-energy associated with stars, galaxies, etc. The larger value comes from various measurements of large scale structure, especially measurements of the potential associated with gravitating (but not necessarily visible) mass-energy. The discrepancy between these numbers suggests that the majorit ...
arXiv:astro-ph/9701131v1 18 Jan 1997
... evolution of planets, stars, stellar populations, galaxies, and the universe itself over time scales which greatly exceed the current age of the universe. Our discussion starts with new stellar evolution calculations which follow the future evolution of the low mass (M type) stars that dominate the ...
... evolution of planets, stars, stellar populations, galaxies, and the universe itself over time scales which greatly exceed the current age of the universe. Our discussion starts with new stellar evolution calculations which follow the future evolution of the low mass (M type) stars that dominate the ...
Chapter 19 Stars Galaxies and the Universe
... Eventually, the gas becomes so hot that it begins to react. These reactions produce energy, which keeps the new star from collapsing more. The second, and longest, stage of a star’s life cycle is the main sequence star. During this stage, hydrogen in the center of the star reacts to form helium. Thi ...
... Eventually, the gas becomes so hot that it begins to react. These reactions produce energy, which keeps the new star from collapsing more. The second, and longest, stage of a star’s life cycle is the main sequence star. During this stage, hydrogen in the center of the star reacts to form helium. Thi ...
Physical cosmology
Physical cosmology is the study of the largest-scale structures and dynamics of the Universe and is concerned with fundamental questions about its origin, structure, evolution, and ultimate fate. For most of human history, it was a branch of metaphysics and religion. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed us to understand those physical laws.Physical cosmology, as it is now understood, began with the development in 1915 of Albert Einstein's general theory of relativity, followed by major observational discoveries in the 1920s: first, Edwin Hubble discovered that the universe contains a huge number of external galaxies beyond our own Milky Way; then, work by Vesto Slipher and others showed that the universe is expanding. These advances made it possible to speculate about the origin of the universe, and allowed the establishment of the Big Bang Theory, by Georges Lemaitre, as the leading cosmological model. A few researchers still advocate a handful of alternative cosmologies; however, most cosmologists agree that the Big Bang theory explains the observations better.Dramatic advances in observational cosmology since the 1990s, including the cosmic microwave background, distant supernovae and galaxy redshift surveys, have led to the development of a standard model of cosmology. This model requires the universe to contain large amounts of dark matter and dark energy whose nature is currently not well understood, but the model gives detailed predictions that are in excellent agreement with many diverse observations.Cosmology draws heavily on the work of many disparate areas of research in theoretical and applied physics. Areas relevant to cosmology include particle physics experiments and theory, theoretical and observational astrophysics, general relativity, quantum mechanics, and plasma physics.