The Curtis-Shapley debate – two different views of
... starlight by dust in the galaxy and decided that our galaxy, and therefore possibly the universe, was like a flat lens with a diameter of 17 kiloparsecs with the Sun apparently close to its centre. Shapley’s view of the Universe He believed that out galaxy was the whole universe, that it had a diame ...
... starlight by dust in the galaxy and decided that our galaxy, and therefore possibly the universe, was like a flat lens with a diameter of 17 kiloparsecs with the Sun apparently close to its centre. Shapley’s view of the Universe He believed that out galaxy was the whole universe, that it had a diame ...
"Seeing" Dark Matter
... same for galaxy clusters as it does for smaller systems, like binary stars, the Solar System, or apples falling from trees. Either solution could deliver the additional force needed to hold a cluster together. Since Zwicky’s work, dark matter has remained a mystery. Is it real? What is it? Or is the ...
... same for galaxy clusters as it does for smaller systems, like binary stars, the Solar System, or apples falling from trees. Either solution could deliver the additional force needed to hold a cluster together. Since Zwicky’s work, dark matter has remained a mystery. Is it real? What is it? Or is the ...
Chapter 1 1. The parallax angle of Sirius is 0.377 ′′. Find the
... density distribution that varies as r−2 . Show that if the mass distribution is spherically symmetric, the mass interior to a radius is given by M (r) = kr + Mo, where k is a constant. Assuming perfectly circular motion and Newtonian gravity, show that the orbital velocity curve is given by v = (G(k ...
... density distribution that varies as r−2 . Show that if the mass distribution is spherically symmetric, the mass interior to a radius is given by M (r) = kr + Mo, where k is a constant. Assuming perfectly circular motion and Newtonian gravity, show that the orbital velocity curve is given by v = (G(k ...
has occurred over the past 14 billion years COSMIC DOWNSIZING
... them to be so close at hand! Moreover, the optical spectra of many of these galaxies showed absolutely no evidence of black hole activity; without the x-ray observations, astronomers could never have discovered the supermassive black holes lurking in their cores. This research suggests that not all ...
... them to be so close at hand! Moreover, the optical spectra of many of these galaxies showed absolutely no evidence of black hole activity; without the x-ray observations, astronomers could never have discovered the supermassive black holes lurking in their cores. This research suggests that not all ...
Astronomy
... Directions: Answer the following questions with the most correct answers. TRUE/FALSE: 1. _____ Hubble classified galaxies 2. _____ There are three main classifications of galaxies 3. _____ Elliptical galaxies have little or no star formation 4. _____ Elliptical galaxies have little or no rotation 5. ...
... Directions: Answer the following questions with the most correct answers. TRUE/FALSE: 1. _____ Hubble classified galaxies 2. _____ There are three main classifications of galaxies 3. _____ Elliptical galaxies have little or no star formation 4. _____ Elliptical galaxies have little or no rotation 5. ...
The Electric Universe by Wallace Thornhill and David Talbott
... How did the universe begin? How does it work? Where is it headed? For years, the scientific media have bombarded the public with intriguing answers to these big-picture questions. The themes are familiar even to the most casual observers of scientific commentary. Cosmologists speak confidently of th ...
... How did the universe begin? How does it work? Where is it headed? For years, the scientific media have bombarded the public with intriguing answers to these big-picture questions. The themes are familiar even to the most casual observers of scientific commentary. Cosmologists speak confidently of th ...
Stars and Galaxies
... Telescope) is used as evidence to help develop scientific theories Big Bang Dominant scientific theory about the origin of the universe Occurred ~13.7 billion years ago ...
... Telescope) is used as evidence to help develop scientific theories Big Bang Dominant scientific theory about the origin of the universe Occurred ~13.7 billion years ago ...
The universe as a whole would have continued expanding and
... itself, making it rather like the surface of the Earth. If one keeps traveling in a certain direction on the surface of the Earth, one never comes up against an impassable barrier or falls over the edge, but eventually comes back to where one started. Space, in the first Friedmann model, is just lik ...
... itself, making it rather like the surface of the Earth. If one keeps traveling in a certain direction on the surface of the Earth, one never comes up against an impassable barrier or falls over the edge, but eventually comes back to where one started. Space, in the first Friedmann model, is just lik ...
Stars and Galaxies
... Telescope) is used as evidence to help develop scientific theories Big Bang Dominant scientific theory about the origin of the universe Occurred ~13.7 billion years ago ...
... Telescope) is used as evidence to help develop scientific theories Big Bang Dominant scientific theory about the origin of the universe Occurred ~13.7 billion years ago ...
Cosmology in the Bible
... Jeremiah 10:12; 51:15; and Zechariah 12:1. Job 37:18 appears to be a twelfth verse. However, the word used for “heavens” or “skies” is shehaqîm which refers to the clouds of fine particles (of water or dust) that are located in Earth’s atmosphere,8 not the shamayim, the heavens of the astronomical u ...
... Jeremiah 10:12; 51:15; and Zechariah 12:1. Job 37:18 appears to be a twelfth verse. However, the word used for “heavens” or “skies” is shehaqîm which refers to the clouds of fine particles (of water or dust) that are located in Earth’s atmosphere,8 not the shamayim, the heavens of the astronomical u ...
Astroparticle physics A.M. van den Berg () O. Scholten
... If (t=0) > 1 the Universe would have recollapsed at once If (t=0) < 1 the Universe would have cooled very quickly HORIZON PROBLEM Regions on the CMB sky separated by more than 1o had no time to interact, yet their temperature is the same to 100 ppm What is needed An initial condition of the Univer ...
... If (t=0) > 1 the Universe would have recollapsed at once If (t=0) < 1 the Universe would have cooled very quickly HORIZON PROBLEM Regions on the CMB sky separated by more than 1o had no time to interact, yet their temperature is the same to 100 ppm What is needed An initial condition of the Univer ...
(S. Lloyd 2001) - Digilander
... the number of elementary operations that can be performed using gravitational energy is exactly equal to the number that can be performed using the energy in matter. Including the number of operations that can have been performed by gravitational energy (however one might accomplish such a feat!) th ...
... the number of elementary operations that can be performed using gravitational energy is exactly equal to the number that can be performed using the energy in matter. Including the number of operations that can have been performed by gravitational energy (however one might accomplish such a feat!) th ...
RobinCollins_CPiS_Ca..
... of fine-tuning is that of the Cosmic Microwave Background Radiation (CMB). The CMB is microwave radiation that permeates space. It was caused by the big bang. ...
... of fine-tuning is that of the Cosmic Microwave Background Radiation (CMB). The CMB is microwave radiation that permeates space. It was caused by the big bang. ...
powerpoint - Physics @ IUPUI
... • A group at the University of Minnesota discovered a void a BILLION light years across! • This is something we just cannot explain currently as we expect them to be 50-200 million light years in size. ...
... • A group at the University of Minnesota discovered a void a BILLION light years across! • This is something we just cannot explain currently as we expect them to be 50-200 million light years in size. ...
Heic0116: EMBARGOED UNTIL: 20:00 (CET) WEDNESDAY 05
... the first time. Images and spectra of a MACHO microlens – a nearby dwarf star that gravitationally focuses light from a star in another galaxy - were taken by the NASA/ESA Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope. The result is a strong confirmation of the ...
... the first time. Images and spectra of a MACHO microlens – a nearby dwarf star that gravitationally focuses light from a star in another galaxy - were taken by the NASA/ESA Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope. The result is a strong confirmation of the ...
What Lies Beyond
... The Brightness, Luminosity, and Motions of the Stars Apparent magnitude is a measure of the amount of light received from a celestial object This measure contrasts with luminosity – the rate at which electromagnetic energy is emitted from a celestial object Proper motion is the term for the a ...
... The Brightness, Luminosity, and Motions of the Stars Apparent magnitude is a measure of the amount of light received from a celestial object This measure contrasts with luminosity – the rate at which electromagnetic energy is emitted from a celestial object Proper motion is the term for the a ...
Early Universe Cosmology Advanced String School 2014 Puri, India
... fall into this category. Their energy density simply scales inversely to the volume of a given region of space, ρ ∝ a−3 , as expected. • Relativistic particles/radiation, w = 13 . The energy density of radiation or a gas of relativistic particles scales as a−4 . This means that in an expanding unive ...
... fall into this category. Their energy density simply scales inversely to the volume of a given region of space, ρ ∝ a−3 , as expected. • Relativistic particles/radiation, w = 13 . The energy density of radiation or a gas of relativistic particles scales as a−4 . This means that in an expanding unive ...
Survey of Astrophysics A110 Cosmology
... origin of the Universe, at some point matter must be created. [Only one atom would have to be created in a cubic cm of space every million billion years (1015 years)]. • In its purest form, the Steady State Theory is not consistent with observations of the Universe. For example, we now know that the ...
... origin of the Universe, at some point matter must be created. [Only one atom would have to be created in a cubic cm of space every million billion years (1015 years)]. • In its purest form, the Steady State Theory is not consistent with observations of the Universe. For example, we now know that the ...
Introduction: The Night Sky
... neutron star is about 50% more massive than Sun, but is only 20 km across basically a gigantic atomic nucleus: protons and electrons have combined to form neutrons in extreme cases even this may not be stable, and a black hole is formed instead ...
... neutron star is about 50% more massive than Sun, but is only 20 km across basically a gigantic atomic nucleus: protons and electrons have combined to form neutrons in extreme cases even this may not be stable, and a black hole is formed instead ...
Module 5 Modelling the universe - Pearson Schools and FE Colleges
... towards themselves than the regions where the density is very low. Given enough time, these areas will very gradually become more dense, and the density will rise at an ever increasing rate until some of the gases in the area become hot enough to glow. This means that they can be detected through te ...
... towards themselves than the regions where the density is very low. Given enough time, these areas will very gradually become more dense, and the density will rise at an ever increasing rate until some of the gases in the area become hot enough to glow. This means that they can be detected through te ...
Dark energy from quantum gravity
... interpretations which agree on the basic postulates up to small modifications. The quality of the interpretations and the number of them point to an unsolved problem. What is so special with nature on small scales? However philosophical, the question likely needs more insight before finding a theory ...
... interpretations which agree on the basic postulates up to small modifications. The quality of the interpretations and the number of them point to an unsolved problem. What is so special with nature on small scales? However philosophical, the question likely needs more insight before finding a theory ...
Get ready for quiz # 7
... 14.6 The Mass of the Milky Way Galaxy The orbital speed of an object depends only on the amount of mass between it and the galactic center. ...
... 14.6 The Mass of the Milky Way Galaxy The orbital speed of an object depends only on the amount of mass between it and the galactic center. ...
Document
... does now and hasn’t changed. The trouble is that the night sky would be completely lit up because of the billions of stars, but it’s not, so… The “Big Bang” theory This theory states that the universe started off with an explosion and everything has been moving away ever since. There are two main pi ...
... does now and hasn’t changed. The trouble is that the night sky would be completely lit up because of the billions of stars, but it’s not, so… The “Big Bang” theory This theory states that the universe started off with an explosion and everything has been moving away ever since. There are two main pi ...
As far as - Sangeeta Malhotra
... distances of all galaxies thanks to a dramatic drop-off in the ultraviolet spectrum of hydrogen known as the “Lyman break.” At such extreme distances, this spectral feature redshifts into the wavelength range ACS can detect. We see about 50 Lyman-break galaxies between redshifts of 4 and 7. And beca ...
... distances of all galaxies thanks to a dramatic drop-off in the ultraviolet spectrum of hydrogen known as the “Lyman break.” At such extreme distances, this spectral feature redshifts into the wavelength range ACS can detect. We see about 50 Lyman-break galaxies between redshifts of 4 and 7. And beca ...
Document
... for the formation of molecular clouds, the birth places of stars, which makes studying the distribution of HI and its evolution crucial for our understanding of various aspects of star formation. We know that shortly after the Big Bang, the initially hot plasma cools down as the Universe expands and ...
... for the formation of molecular clouds, the birth places of stars, which makes studying the distribution of HI and its evolution crucial for our understanding of various aspects of star formation. We know that shortly after the Big Bang, the initially hot plasma cools down as the Universe expands and ...
Big Bang
The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution. The model accounts for the fact that the universe expanded from a very high density and high temperature state, and offers a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background, large scale structure, and Hubble's Law. If the known laws of physics are extrapolated beyond where they are valid, there is a singularity. Modern measurements place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe. After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, and later simple atoms. Giant clouds of these primordial elements later coalesced through gravity to form stars and galaxies.Since Georges Lemaître first noted, in 1927, that an expanding universe might be traced back in time to an originating single point, scientists have built on his idea of cosmic expansion. While the scientific community was once divided between supporters of two different expanding universe theories, the Big Bang and the Steady State theory, accumulated empirical evidence provides strong support for the former. In 1929, from analysis of galactic redshifts, Edwin Hubble concluded that galaxies are drifting apart, important observational evidence consistent with the hypothesis of an expanding universe. In 1965, the cosmic microwave background radiation was discovered, which was crucial evidence in favor of the Big Bang model, since that theory predicted the existence of background radiation throughout the universe before it was discovered. More recently, measurements of the redshifts of supernovae indicate that the expansion of the universe is accelerating, an observation attributed to dark energy's existence. The known physical laws of nature can be used to calculate the characteristics of the universe in detail back in time to an initial state of extreme density and temperature.