Key Topics Astronomy Unit
... • After the big bang, the universe expanded quickly, and continues to expand, and cooled enough for atoms to form. • Gravity pulled the atoms together into gas clouds that eventually became stars, which comprise young galaxies. ...
... • After the big bang, the universe expanded quickly, and continues to expand, and cooled enough for atoms to form. • Gravity pulled the atoms together into gas clouds that eventually became stars, which comprise young galaxies. ...
Electromagnetic spectrum - Purdue Physics
... Energies of radio wave ‘photons’ are very low and quantized nature of EM radiation at these frequencies is not noticeable. ...
... Energies of radio wave ‘photons’ are very low and quantized nature of EM radiation at these frequencies is not noticeable. ...
1.1 Fundamental Observers
... If the first term in (1.12) does not dominate, the particle will be moving with a substantial fraction of c, and so it is relativistic. Baryons — make up the familiar matter of our universe. By baryons we mean primarily protons and neutrons, the only stable elementary particles made up of quarks (tw ...
... If the first term in (1.12) does not dominate, the particle will be moving with a substantial fraction of c, and so it is relativistic. Baryons — make up the familiar matter of our universe. By baryons we mean primarily protons and neutrons, the only stable elementary particles made up of quarks (tw ...
Paradigm Shifts in Cosmology
... force so that its effect on the expansion rate is only deceleration. In order to accelerate the expansion, a sort of repulsive force, namely, something that exerts anti-gravity is needed. What we can readily think of is Einstein s cosmological constant. The vacuum energy that caused inflation is al ...
... force so that its effect on the expansion rate is only deceleration. In order to accelerate the expansion, a sort of repulsive force, namely, something that exerts anti-gravity is needed. What we can readily think of is Einstein s cosmological constant. The vacuum energy that caused inflation is al ...
Hubblecast 70: Peering around cosmic corners Visual notes 00:00
... As a result, this massive object, or rather the curved space around it produced by its gravity, acts like a lens; a gravitational lens that deflects light into our telescopes that would have otherwise never made it there. ...
... As a result, this massive object, or rather the curved space around it produced by its gravity, acts like a lens; a gravitational lens that deflects light into our telescopes that would have otherwise never made it there. ...
Authentification of Einstein`s Static Universe of 1917
... the redshift increases in proportion to the increase of distance of the light source from us. Photons approaching the Milky Way might balance, or even outweigh this redshift effect. Therefore they are even blueshifted, as is the case with the Virgo cluster including the Andromeda galaxy. Photons dep ...
... the redshift increases in proportion to the increase of distance of the light source from us. Photons approaching the Milky Way might balance, or even outweigh this redshift effect. Therefore they are even blueshifted, as is the case with the Virgo cluster including the Andromeda galaxy. Photons dep ...
Chapter 18 - the Universe Begins
... existence, the Universe had expanded and cooled sufficiently for matter to be able to exist. (Interestingly, slightly more matter than anti-matter was formed, so that most of the matter we detect now is not anti-matter.) By the first second after the Big Bang, the fundamental particles of matter had ...
... existence, the Universe had expanded and cooled sufficiently for matter to be able to exist. (Interestingly, slightly more matter than anti-matter was formed, so that most of the matter we detect now is not anti-matter.) By the first second after the Big Bang, the fundamental particles of matter had ...
Chapter 34: Cosmology FYI 1. Radar Ranging 2. Triangulation idea
... model of the universe explain? *1. The “expanding” universe. (the red shift) 2. The “age” of the universe. *3. The abundance of hydrogen (75%), helium (24%), and other elements. (process of particle formation) *4. The microwave radiation (3K). (even in black space, started with the big bang) 5. The ...
... model of the universe explain? *1. The “expanding” universe. (the red shift) 2. The “age” of the universe. *3. The abundance of hydrogen (75%), helium (24%), and other elements. (process of particle formation) *4. The microwave radiation (3K). (even in black space, started with the big bang) 5. The ...
PHYS 390 Lecture 36 - The first microsecond 36 - 1 Lecture 36
... Given that protons have a lifetime of at least 1031 years, this ratio has had the same value for much of the history of the universe; that is: [baryon number density] ~ R -3 [photon number density ] ~ T 3 ~ R -3, so the ratio is independent of the length scale factor R. What about today's anti-baryo ...
... Given that protons have a lifetime of at least 1031 years, this ratio has had the same value for much of the history of the universe; that is: [baryon number density] ~ R -3 [photon number density ] ~ T 3 ~ R -3, so the ratio is independent of the length scale factor R. What about today's anti-baryo ...
summary lecture
... These both yield the Planck length, Lp. Any black hole smaller than this could have its singularity outside its event horizon. That wouldn’t make sense, so L is the smallest possible black hole we can describe with both QM and GR, our current theory of gravity. ...
... These both yield the Planck length, Lp. Any black hole smaller than this could have its singularity outside its event horizon. That wouldn’t make sense, so L is the smallest possible black hole we can describe with both QM and GR, our current theory of gravity. ...
Invited Talks at Major Meetings Andreas Albrecht Updated 8/31
... Parameters in Cosmology, Les Arcs January 1998 30. New paradigms in active structure formation CAPCC 98, CERN, June 1998 31. Cosmology with a time varying speed of light Cosmo-98, Asilomar 1998 32. Cosmology with a time varying speed of light 19th Texas meeting on relativistic Astrophysics Paris, De ...
... Parameters in Cosmology, Les Arcs January 1998 30. New paradigms in active structure formation CAPCC 98, CERN, June 1998 31. Cosmology with a time varying speed of light Cosmo-98, Asilomar 1998 32. Cosmology with a time varying speed of light 19th Texas meeting on relativistic Astrophysics Paris, De ...
A Proposed Explanation of Dark Matter within General
... quantity that composed of two independent parts : a material part which is the average stress-energy tensor and a geometrical part which represents a non-zero ground state curvature which can be determined from the shape of the universe (as shown in other papers mentioned in the introduction but not ...
... quantity that composed of two independent parts : a material part which is the average stress-energy tensor and a geometrical part which represents a non-zero ground state curvature which can be determined from the shape of the universe (as shown in other papers mentioned in the introduction but not ...
Exploring the Helium Reionization Era
... Ironically, the period immediately after Recombination is referred to as the Dark Ages. Although the universe was transparent to light, this period was dark because no discrete sources of light yet existed. Insufficient time had elapsed to form stars and galaxies. A visitor to this period would only ...
... Ironically, the period immediately after Recombination is referred to as the Dark Ages. Although the universe was transparent to light, this period was dark because no discrete sources of light yet existed. Insufficient time had elapsed to form stars and galaxies. A visitor to this period would only ...
Which model predicts the youngest age for the universe today?
... – Space has stretched since they gave off their light ...
... – Space has stretched since they gave off their light ...
Chapter 12 - Our Place in the Universe
... evidence that the Universe has evolved from an initial uniform, hot dense state comes from the existence of the cosmic microwave background. further evidence comes from cosmological red-shift Hubble’s Law is v = Hod; Galaxies further away are moving faster 1/Ho gives an estimate of the expan ...
... evidence that the Universe has evolved from an initial uniform, hot dense state comes from the existence of the cosmic microwave background. further evidence comes from cosmological red-shift Hubble’s Law is v = Hod; Galaxies further away are moving faster 1/Ho gives an estimate of the expan ...
Galaxies - Edublogs
... Step 1: Move decimal place to 1st digit 2.99800000 Step 2: Count number of places. Exponent of 8, written as 108 Step 3: Delete zeros & rewrite 2.998 x108 m/s ...
... Step 1: Move decimal place to 1st digit 2.99800000 Step 2: Count number of places. Exponent of 8, written as 108 Step 3: Delete zeros & rewrite 2.998 x108 m/s ...
static universe - St John Brebeuf
... What is the ultimate fate of our universe? A Big Crunch? A Big Freeze? A Big Rip? or a Big Bounce? Measurements made by WMAP or the Wilkinson Microwave Anisotropy Probe favor a Big Freeze. But until a deeper understanding of dark energy is established, the other three still cannot be totally ignored ...
... What is the ultimate fate of our universe? A Big Crunch? A Big Freeze? A Big Rip? or a Big Bounce? Measurements made by WMAP or the Wilkinson Microwave Anisotropy Probe favor a Big Freeze. But until a deeper understanding of dark energy is established, the other three still cannot be totally ignored ...
1 - UCSC Physics - University of California, Santa Cruz
... Globular Cluster stars in the Milky Way, then estimated to be 16±3 Gyr, was higher than the expansion age of the universe, which for a critical density (Ωm = 1) universe is 9±2 Gyr (with the Hubble parameter h=0.72±0.07). But when the data from the Hipparcos astrometric satellite became available in ...
... Globular Cluster stars in the Milky Way, then estimated to be 16±3 Gyr, was higher than the expansion age of the universe, which for a critical density (Ωm = 1) universe is 9±2 Gyr (with the Hubble parameter h=0.72±0.07). But when the data from the Hipparcos astrometric satellite became available in ...
Histroy of Cosmology - Physics & Astronomy
... George Gamow (1904-1968) • Suggested a test to see which theory was most likely. • If universe was created in an explosion the current temperature of that explosion should be about 3 Kelvin. • Look for background radiation of the temperature. • Where do you look? http://www.colorado.edu/physics/Web ...
... George Gamow (1904-1968) • Suggested a test to see which theory was most likely. • If universe was created in an explosion the current temperature of that explosion should be about 3 Kelvin. • Look for background radiation of the temperature. • Where do you look? http://www.colorado.edu/physics/Web ...
Cosmological Constant
... First Cosmological Observation: The night sky is dark! (Olbers’ Paradox) Every line of sight would eventually hit a star in an infinite and eternal Universe and the sky would be always bright Number of stars increases by r2 for each shell brightness decreases by r2 for each shell Brightness p ...
... First Cosmological Observation: The night sky is dark! (Olbers’ Paradox) Every line of sight would eventually hit a star in an infinite and eternal Universe and the sky would be always bright Number of stars increases by r2 for each shell brightness decreases by r2 for each shell Brightness p ...
The intermediate scale anisotropy
... The observation of the large scale CR anisotropy is in agreement with the other experiments and provides useful data to constrain diffusion models. The 300 GeV - 3 TeV large-scale data form ARGO-YBj may provide essential informations about the local and galactic magnetic field. The observation of th ...
... The observation of the large scale CR anisotropy is in agreement with the other experiments and provides useful data to constrain diffusion models. The 300 GeV - 3 TeV large-scale data form ARGO-YBj may provide essential informations about the local and galactic magnetic field. The observation of th ...
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.