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Lesson 5 - What is a Black Hole? (show 30 min video) Black holes, like neutron stars were created in theory (Einstein’s theory of general relativity). A black hole is an object in space that has a gravitational field is so intense that no matter or radiation (light) can escape.
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What is a Black Hole? Because of its mass (15-20 times the mass of our sun) the star’s gravity would collapse the star into a point of singularity. Because of its mass (15-20 times the mass of our sun) the star’s gravity would collapse the star into a point of singularity. Einstein’s theory predicts that this object would have a no radius and its gravity would be infinite. Einstein’s theory predicts that this object would have a no radius and its gravity would be infinite. Impossible? Quantum physicist think so too. Impossible? Quantum physicist think so too.
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What happens In a Black Hole Leaping feet first a person would be distorted by tidal forces long before reaching even the event horizon. Leaping feet first a person would be distorted by tidal forces long before reaching even the event horizon. Tidal forces would stretch the body lengthwise while compressing it laterally – While time on your watch read differently than what your friends see. Friction from this distortion would heat the body to high temperatures
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Proof that Black Holes Exist The orbits of stars at the center of our Galaxy suggest that an extremely massive compact object sits there.
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Proof that Black Holes Exist Observations showed that a mass of about 4 million times that of the Sun is concentrated within a radius of no more than 6.25 light-hours known as “Sagittarius A“. About the diameter of Uranus' orbit around the sun. Sagittarius A is located in the middle of the star cluster at the center of our galaxy.
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Black Hole Misconceptions Black holes are not giant vacuum cleaners. They should come in all sizes. Exist anywhere in the galaxy.
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Quasar’s Quasi-stellar radio sources are the most energetic and distant members of a class of objects called active galactic nuclei (AGN). Their luminosity can be 100 times greater than the Milky Way.
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What are Quasar’s A quasar is an active black hole consuming large amounts of material in the center of a distant galaxy. They are among the brightest objects in the universe and reside in the centers of galaxies. This view, taken with infrared light, is a false-color image of a quasar-starburst tandem with the most luminous starburst ever seen in such a combination. starburst
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Quasar’s Brightness Quasars are ultra- luminous and appear star-like even though most are extremely distant. Quasars are ultra- luminous and appear star-like even though most are extremely distant. Quasar 3C 273 resides in a giant elliptical galaxy in the constellation of Virgo, its light has taken some 2.5 billion years to reach us
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Where to Find Quasar’s The Age of Quasars, it seems, is over – most quasars found are no younger then 9 byo. The Age of Quasars, it seems, is over – most quasars found are no younger then 9 byo. Rarely found are younger quasars which are believed to be created by the collision with another galaxy - re-igniting the once dormant super-massive black hole. Rarely found are younger quasars which are believed to be created by the collision with another galaxy - re-igniting the once dormant super-massive black hole. The Chandra X-ray image is of the quasar PKS 1127-145, a highly luminous source of X-rays and visible light about 10 billion light years from Earth.Chandra
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Quasar’s As the galaxies expand further apart and as the galaxy formation became less active, quasars became less common.
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Lesson 6 – Dark Matter 1933, Fritz Zwicky, found evidence of a hidden mass in clusters of galaxies. 1933, Fritz Zwicky, found evidence of a hidden mass in clusters of galaxies. Messier 81
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Dark Matter 1973, Vera Rubin & co- worker Kent Ford, studied rotational rates of distant galaxies. Concluded the orbital speeds of stars and matter that rotate around galaxies do not match that of our solar system. Stars and matter are moving at almost the same speeds.
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Dark Matter This could only occur if galaxies have a much stronger gravitational field then expected. In order to create this gravitational field their must be more mass that cannot been seen.
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Dark Matter Since we cannot see nor do we understand what this mass of matter is, it is referred to as dark matter. Dark matter is non-luminous matter that is detected only by its gravitational influence and found around the visible matter in the Universe. Map of dark matter based on the light recorded by Hubble S.T.- created by light bending its way through the universe
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What is Dark Matter Most cosmologist agree that dark matter will most likely be some type of WIMP or Weakly-Interacting-Massive-Particles that has yet to be detected with certainty. WIMP’s are even smaller then the elementary particles of the Standard Model (Supersymmetric)
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Standard Model In order of largest to smallest -Subatomic – (Proton) -Elementary particles (quark) -WIMP A proton is made of two up- quarks and one down-quark. A neutrino is produced by the decay of a neutron and would be an example of a lepton. The Standard Model of elementary particles
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Why is Quantum Mechanics Important? Quantum mechanics led to the invention of the transistor, the key ingredient for all modern electronics, laser and other medical technologies like MRI's, PET scans
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Could Antimatter be the Answer? Current theory suggest that equal amounts of matter and antimatter were created in the Big Bang at the birth of the universe 13.8 billion years ago. Within one second, however, the antimatter had all but disappeared. Antimatter is real matter and it has been demonstrated to exists –in space and in labs
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Dark Matter What ever dark matter turns out to be, current calculations figure dark matter makes up ~ 25% of the matter in the universe, while visible matter makes up ~ 5%. This leaves another ~ 70% of the universe that is still unknown.
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Fate of the Universe (2011) Nobel Prize for Physics, worth 1.5 million, led by astrophysicist Saul Perlmutter. Because all Type I supernovae explode at about the same mass, their brightness is always the same. This makes them very useful as standard candles.
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Fate of the Universe The Chandra X-Ray Observatory measured the amounts of hot gas and dark matter in 25 galaxy clusters. The Chandra X-Ray Observatory measured the amounts of hot gas and dark matter in 25 galaxy clusters. Both observations concluded: Both observations concluded:
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Universe Expanding 1 st – Expansion of the universe initially slowed down, but then shifted gears about 6 billion years ago and is now accelerating. 2 nd – The acceleration appears to be constant and not gaining strength.
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Why are we Accelerating – Cosmological Constant Gravity has long been consider the great force in the universe. In order to create spacetime, Einstein balanced the constant and attractive force of gravity within his formula with a cosmological constant.
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Albert Einstein – Cosmological Constant The cosmological constant is an anti-gravity 'vacuum' force that is constant and keeps gravity from pulling the universe in on itself - Like wind to a kite. The cosmological constant is an anti-gravity 'vacuum' force that is constant and keeps gravity from pulling the universe in on itself - Like wind to a kite.
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Albert Einstein – Cosmological Constant (’29) Hubble proves universe is expanding which means Einstein’s cosmological constant is wrong and he thought it was his biggest blunder. Modern astronomers aren’t so sure
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Dark Energy The acceleration is believed to be caused by a unknown energy – Dark Energy. Dark energy is believed to fill empty spaces (70% of the universe) and drive the acceleration of the expanding universe. This energy acted much like a cosmological constant.
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End of the Universe Scientists have long assumed that gravity must be slowing down the expansion of the universe. Based on the latest data, dark energy has taken over and is expanding us like a balloon.
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End of the Universe This energy should continue to expand our universe forever into a “Big Chill”.
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End of the Universe Universal cooling would occur as stars and galaxies get to far apart to interact and slowly lose the energies needed to recycle and stay hot. Universal cooling would occur as stars and galaxies get to far apart to interact and slowly lose the energies needed to recycle and stay hot.
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