PPT - University of Arizona
... For Thomson scattering of photons off of free electrons, assuming the gas is completely ionized and pure hydrogen Other sources of absorption opacity, if present, will contribute to ...
... For Thomson scattering of photons off of free electrons, assuming the gas is completely ionized and pure hydrogen Other sources of absorption opacity, if present, will contribute to ...
Types of Radiation
... Definition: A positively charged particle that consists of two protons and two neutrons bound together. It is emitted by an atomic nucleus undergoing radioactive decay and is identical to the nucleus of a helium atom. Because of their relatively large mass, alpha particles are the slowest and least ...
... Definition: A positively charged particle that consists of two protons and two neutrons bound together. It is emitted by an atomic nucleus undergoing radioactive decay and is identical to the nucleus of a helium atom. Because of their relatively large mass, alpha particles are the slowest and least ...
Neutron Stars and Black Holes
... awe, uncertainty, and bad science fiction •! Many people think that black holes are dangerous –! That they suck matter in like “cosmic vacuums” •! Black holes follow the same laws of gravity as everything else ...
... awe, uncertainty, and bad science fiction •! Many people think that black holes are dangerous –! That they suck matter in like “cosmic vacuums” •! Black holes follow the same laws of gravity as everything else ...
Cosmology and Astrophysics II
... neither decays nor combines easily to form heavier nuclei. So out of every 16 nucleons (2 neutrons and 14 protons), 4 of these (25%) combined into one helium-4 nucleus. One analogy is to think of helium-4 as ash, and the amount of ash that one forms when one completely burns a piece of wood is insen ...
... neither decays nor combines easily to form heavier nuclei. So out of every 16 nucleons (2 neutrons and 14 protons), 4 of these (25%) combined into one helium-4 nucleus. One analogy is to think of helium-4 as ash, and the amount of ash that one forms when one completely burns a piece of wood is insen ...
Linking Asteroids and Meteorites through Reflectance Spectroscopy
... Pulsars • Pulsars were interpreted as rotating neutron stars • Only neutron stars could rotate that fast • Strong magnetic fields can beam radiation out ...
... Pulsars • Pulsars were interpreted as rotating neutron stars • Only neutron stars could rotate that fast • Strong magnetic fields can beam radiation out ...
Stellar Evolution
... of radio energy that acts like a spinning search-light. That appear to us as a Pulsar, a source of a rhythmic radio signal first thought to be intelligent aliens! ...
... of radio energy that acts like a spinning search-light. That appear to us as a Pulsar, a source of a rhythmic radio signal first thought to be intelligent aliens! ...
Black Holes - Gresham College
... observers. [This is somewhat contentious, as the theorem violates the principle that if complete information about a physical system is known at one point in time then it should be possible to determine its state at any other time.] ...
... observers. [This is somewhat contentious, as the theorem violates the principle that if complete information about a physical system is known at one point in time then it should be possible to determine its state at any other time.] ...
ASTR 300 Stars and Stellar Systems Spring 2011
... 1. Astronomers believe that a 13 M⊙ star will end as a neutron star. What is the maximum mass of a neutron star? What happens to the rest of the mass of the original star? The maximum mass of a neutron star is thought to be between 2 and 3 solar masses – surely below 3 M⊙ . A 13 M⊙ star explodes as ...
... 1. Astronomers believe that a 13 M⊙ star will end as a neutron star. What is the maximum mass of a neutron star? What happens to the rest of the mass of the original star? The maximum mass of a neutron star is thought to be between 2 and 3 solar masses – surely below 3 M⊙ . A 13 M⊙ star explodes as ...
Lecture 3: Interstellar Dust, Radiative Transfer and Thermal Radiation
... •Mean intensity Jν, i.e. the average of Iν over all directions: ...
... •Mean intensity Jν, i.e. the average of Iν over all directions: ...
- Fermi Gamma-ray Space Telescope
... Discovered in 1965 by Arno Penzias and Robert Wilson who were working at Bell Labs ...
... Discovered in 1965 by Arno Penzias and Robert Wilson who were working at Bell Labs ...
Sample Test 22
... 1. Type II supernovae, which result from massive stars, reveal prominent hydrogen lines. They are powered by gravitational energy that is released as gravity continuously collapses the core. 2. The process by which Type II supernovae occur is not well known but is thought to begin with the conversio ...
... 1. Type II supernovae, which result from massive stars, reveal prominent hydrogen lines. They are powered by gravitational energy that is released as gravity continuously collapses the core. 2. The process by which Type II supernovae occur is not well known but is thought to begin with the conversio ...
Do not mess with time: Probing faster than light travel and
... example, think of the causal loops where at some point ones travels back in time to give to his/her past-self the numbers associated to some lottery. Several solutions have been proposed for such paradoxes (see e.g. for a detailed discussion Ref. 1) we shall here focus on the so called Hawking’s chr ...
... example, think of the causal loops where at some point ones travels back in time to give to his/her past-self the numbers associated to some lottery. Several solutions have been proposed for such paradoxes (see e.g. for a detailed discussion Ref. 1) we shall here focus on the so called Hawking’s chr ...
ppt - damtp
... There is a big difference between this orbifold and the usual Euclidean orbifold: any momentum around the circle becomes infinitely blue shifted and turns this simple singularity into a general curvature singularity. The Milne singularity is unstable. It may still be possible to go through the singu ...
... There is a big difference between this orbifold and the usual Euclidean orbifold: any momentum around the circle becomes infinitely blue shifted and turns this simple singularity into a general curvature singularity. The Milne singularity is unstable. It may still be possible to go through the singu ...
General Relativity, Black Holes and Quantum Field Theory in curved
... by a self-gravitating droplet. Although the issue of a smeared distance might not be the only fingerprint of the quantum geometry, these models explicitly reveal its importance. For instance, at Planckian scales where the central singularity is replaced by a black hole remnant (droplet) the metric ha ...
... by a self-gravitating droplet. Although the issue of a smeared distance might not be the only fingerprint of the quantum geometry, these models explicitly reveal its importance. For instance, at Planckian scales where the central singularity is replaced by a black hole remnant (droplet) the metric ha ...
Radiation from the Big Bang—4 Nov • Four most important
... Amount of radiation depends on emissivity. Shine light on a surface. Emissivity = fraction of light absorbed. (The rest is reflected.) – Emissivity = 1 for a black surface – Emissivity = 0 for a mirror ...
... Amount of radiation depends on emissivity. Shine light on a surface. Emissivity = fraction of light absorbed. (The rest is reflected.) – Emissivity = 1 for a black surface – Emissivity = 0 for a mirror ...
N-Body Simulations of Star Clusters with IMBH
... This object could form an inter- mediatemass black hole which creates the X-ray ...
... This object could form an inter- mediatemass black hole which creates the X-ray ...
Nature`s Book Keeping System
... coupled. The (multi-dimensional) Schrödinger equations resulting from this can now be handled by standard methods in mathematical physics. The Fock space solution may seem to be something altogether different. Here, we do not talk of fields, but of states with arbitrary numbers of elementary partic ...
... coupled. The (multi-dimensional) Schrödinger equations resulting from this can now be handled by standard methods in mathematical physics. The Fock space solution may seem to be something altogether different. Here, we do not talk of fields, but of states with arbitrary numbers of elementary partic ...
8.4 White Dwarfs
... The visual image of a black hole is one of a dark spot in space with no radiation emitted. Any radiation falling on the black hole is not reflected but rather absorbed, and starlight from behind the black hole is lensed. So even though no radiation escapes a black hole, its mass can be detected by ...
... The visual image of a black hole is one of a dark spot in space with no radiation emitted. Any radiation falling on the black hole is not reflected but rather absorbed, and starlight from behind the black hole is lensed. So even though no radiation escapes a black hole, its mass can be detected by ...
Russell County Schools Non-Traditional Instructional Expectations
... infinite density and infinitely small dimensions, it simply means that we are missing some vital insight. This last happened in physics in the 1930’s, when we faced the fundamental paradox concerning atomic structure. At that time, it was recognized that electrons moved in table orbits about nuclei ...
... infinite density and infinitely small dimensions, it simply means that we are missing some vital insight. This last happened in physics in the 1930’s, when we faced the fundamental paradox concerning atomic structure. At that time, it was recognized that electrons moved in table orbits about nuclei ...
File.
... SPEAKING AT THE 142nd SESSION OF THE CERN COUNCIL TODAY, THE ORGANIZATION´S DIRECTOR GENERAL ROBERT AYMAR ANNOUNCED THAT THE LARGE HADRON COLLIDER (LHC) WILL START UP IN MAY 2008, TAKING THE FIRST STEPS TOWARDS STUDYING PHYSICS AT A NEW HIGH-ENERGY FRONTIER ...
... SPEAKING AT THE 142nd SESSION OF THE CERN COUNCIL TODAY, THE ORGANIZATION´S DIRECTOR GENERAL ROBERT AYMAR ANNOUNCED THAT THE LARGE HADRON COLLIDER (LHC) WILL START UP IN MAY 2008, TAKING THE FIRST STEPS TOWARDS STUDYING PHYSICS AT A NEW HIGH-ENERGY FRONTIER ...
Hawking radiation
Hawking radiation is black body radiation that is predicted to be released by black holes, due to quantum effects near the event horizon. It is named after the physicist Stephen Hawking, who provided a theoretical argument for its existence in 1974, and sometimes also after Jacob Bekenstein, who predicted that black holes should have a finite, non-zero temperature and entropy.Hawking's work followed his visit to Moscow in 1973 where the Soviet scientists Yakov Zeldovich and Alexei Starobinsky showed him that, according to the quantum mechanical uncertainty principle, rotating black holes should create and emit particles. Hawking radiation reduces the mass and energy of black holes and is therefore also known as black hole evaporation. Because of this, black holes that lose more mass than they gain through other means are expected to shrink and ultimately vanish. Micro black holes are predicted to be larger net emitters of radiation than larger black holes and should shrink and dissipate faster.In September 2010, a signal that is closely related to black hole Hawking radiation (see analog gravity) was claimed to have been observed in a laboratory experiment involving optical light pulses. However, the results remain unverified and debatable. Other projects have been launched to look for this radiation within the framework of analog gravity. In June 2008, NASA launched the Fermi space telescope, which is searching for the terminal gamma-ray flashes expected from evaporating primordial black holes. In the event that speculative large extra dimension theories are correct, CERN's Large Hadron Collider may be able to create micro black holes and observe their evaporation.