I>clicker quiz #20 Which of the following statements is FALSE? A.Black holes emit Hawking radiation which can be characterized as black-body radiation.

Slides:



Advertisements
Similar presentations
E4 Cosmology. Newton’s Universe Infinite (in space and time) Static.
Advertisements

Olber’s paradox Why isn't the night sky as uniformly bright as the surface of the Sun? If the Universe has infinitely many stars, then it should be uniformly.
Origin & Evolution of the Universe
Objectives: 1. relate the cosmological principle to isotropy and homgeneity of the universe. 2. understand how Hubble’s law is used to map the universe,
When Galaxies Collide. It is not uncommon for galaxies to gravitationally interact with each other, and even collide!
Chapter 26: Cosmology Why is the sky dark? The expanding universe Beginning of the universe: The Big Bang Cosmic microwave background The early universe.
LET’S PLAY JEOPARDY!! Big BangBlack Hole Key Players Evidence Mixed Q $100 Q $200 Q $300 Q $400 Q $500 Q $100 Q $200 Q $300 Q $400 Q $500 Final JeopardyJeopardy.
The Fate of the Universe. The cosmological principle The simplest universes is: Homogenous – the same everywhere you go Isotropic – the same in all directions.
Newton’s Hypothesis The universe is infinite, static and uniform. Proven to be incorrect by Olber’s Paradox. Olber theorised that if this was correct then.
The Expanding Universe Except for a few nearby galaxies (like Andromeda), all the galaxies are seen to be moving away from us Generally, the recession.
Objectives Distinguish the different models of the universe.
Cosmology Past, present and future of the universe Is space flat or curved? Where is the center? What lies beyond our limit of vision? What is the universe.
Lecture 23 Models with Cosmological Constant ASTR 340 Fall 2006 Dennis Papadopoulos Chapter 11 Problems Due 12/5/06.
The Birth Of Our Universe The Big Bang And Inflation
Cosmology Astronomy 315 Professor Lee Carkner Lecture 22 "In the beginning the Universe was created. This has made a lot of people very angry and been.
No Structure on Largest Scales (Galaxies distributed fairly uniformly)‏ Surprising given structure on smaller scales Cosmological Principle: Universe is.
Galaxies What is a galaxy? How many stars are there in an average galaxy? About how many galaxies are there in the universe? What is the name of our galaxy?
Review for Exam 3.
The Big Bang Astrophysics Lesson 18. Learning Objectives To know:-  What is the big bang theory  What is the evidence supporting it including:-  Cosmological.
Chapter 26: Cosmology How big is the universe? How long has it been around and how long will it last?
Why is the sky dark at night? Distant galaxies are receding from us with a speed proportional to distance.
Please press “1” to test your transmitter.
The Standard Model of Cosmology Chad A. Middleton, Ph.D. Mesa State College October 11, 2007 “The most incomprehensible thing about the world is that it.
Pop-quiz #21 Which of the following statements is TRUE? A.Black holes can emit particles and thereby lose mass — this is called Hawking radiation B.John.
Cosmology: The Study of the Universe as a Whole Physics 360 Geol 360 Astronomy John Swez.
Midterm exam: date: March 17, 2006, 8:15 a.m. date: March 17, 2006, 8:15 a.m. location: Conrad Naber Hall location: Conrad Naber Hall bring pocket calculator.
Standard Cosmology.
Astronomy Topic 4 Revision Booster. Milky way facts 200 billion stars 250 million years to orbit One of a group of about 30 galaxies (The local group)
Cosmology The Origin and Future of the Universe Part I Olbers’ Paradox.
COSMOLOGY SL - summary. STRUCTURES Structure  Solar system  Galaxy  Local group  Cluster  Super-cluster Cosmological principle  Homogeneity – no.
Expansion of the Universe Natural consequence of the basic field equations of the General Theory of Relativity (GTR) When GTR was first developed in the.
Astrophysics Cosmology - the study of the nature of the universe.
Introduction to Cosmology. Types of Universes If you were to make a universe, would you give it a finite size, or make it infinite? In a finite universe,
Cosmology and extragalactic astronomy Mat Page Mullard Space Science Lab, UCL 3. Cosmological concepts and Olbers’ paradox.
I>clicker Quiz #14 Which of the following statements is TRUE? A.Hubble’s discovery that most distant galaxies are receding from us tells us that we are.
The Fate of the Universe
2 pt 3 pt 4 pt 5pt 1 pt 2 pt 3 pt 4 pt 5 pt 1 pt 2pt 3 pt 4pt 5 pt 1pt 2pt 3 pt 4 pt 5 pt 1 pt 2 pt 3 pt 4pt 5 pt 1pt.
The Tully-Fisher Relation A relation between the rotation speed of a spiral galaxy and its luminosity The more mass a galaxy has  the brighter it is 
Big Bang Theory – A History 1927: Belgian priest Georges Lemaître proposes that the universe began with the explosion of a "primeval atom". Einstein develops.
Hubble’s galaxy classes Spheroid Dominates Disk Dominates.
The Big Bang: what happened, and when did it happen?
10B The Big Bang Where do we come from, where are we going?
HUBBLE’S LAW Edwin Hubble Hubble’s Law “the farther away a galaxy is from its observer, the faster it appears to be moving away from the observer”
Week 9 (11/13) – Quiz #22 Which of the following statements is TRUE? A.Inflation is the astronomical term used to describe the transformation our bellies.
The Expanding Universe. The Hubble Law The Hubble constant H o is one of the most important numbers in cosmology because it may be used to estimate the.
Our Universe. The universe is everything that exists including all matter and energy The universe is 13.7 billion years old. No one knows if the universe.
Questions From Reading Activity? IB Assessment Statements  Olbers’ Paradox E.4.1.Describe Newton’s model of the universe. E.4.2.Explain Olbers’paradox.
To do: Run through the ppt on Big Bang and Cosmology (resources.faulkes-telescope.com > GCSE Astronomy > Class Exercises > Cosmology Complete the following.
Cosmology (Chapter 14) NASA. Student Learning Objectives Describe the Big Bang theory Analyze possible fates of our universe.
Cosmology -- the Origin and Structure of the Universe Cosmological Principle – the Universe appears the same from all directions. There is no preferred.
The Expanding Universe
Dec 8, 2003Astronomy 100 Fall 2003 Last Homework is due Friday– 11:50 am Honor credit– need to have those papers this week! Estimated grades are posted.
Announcements Final exam is Monday, May 9, at 7:30 am. –Students with last names A-K go to 225 CB. –Students with last names L-Z go to 300 CB. –All students.
Homework for today was WORKBOOK EXERCISE: “Expansion of the Universe” (pg in workbook)
ASTR 113 – 003 Spring 2006 Lecture 12 April 19, 2006 Review (Ch4-5): the Foundation Galaxy (Ch 25-27) Cosmology (Ch28-29) Introduction To Modern Astronomy.
The Fate of the Universe. The fate depends on the rate of expansion and the density Density greater than critical value – gravity will halt expansion.
Milky Way Galaxy. Galaxy A group of stars, dust and gases held together by gravity. 170 billion galaxies in the universe 200 billion stars in a galaxy.
Discovering the Universe Eighth Edition Discovering the Universe Eighth Edition Neil F. Comins William J. Kaufmann III CHAPTER 18 Cosmology Cosmology.
Image of the day Turn in cosmology questions!.
© 2017 Pearson Education, Inc.
Big Bang Theory.
Alternative to Big Bang theory: Steady State Cosmology
Ch. 14 Cosmology (or “The Whole Enchilada”)
Pop-quiz #9 Which of the following statements is TRUE?
Expansion of the Universe
Pop-quiz #5 Which of the following statements is FALSE?
i>clicker Quiz #12 Which of the following statements is FALSE?
Pop-quiz #1 Which of the following statements is TRUE:
Absorption lines of a galaxy shift toward the blue end of the spectrum when it moves toward Earth. The lines shift to the red end of the spectrum when.
Cosmology.
Presentation transcript:

i>clicker quiz #20 Which of the following statements is FALSE? A.Black holes emit Hawking radiation which can be characterized as black-body radiation with a temperature that is proportional to the black hole ’ s mass B.The radius of the event horizon (Schwarzschild radius) of a black hole, the region over which it can trap light, is proportional to the black hole ’ s mass C.“ A black hole has no hair ” is a statement that describes the loss of identity of matter when it is swallowed by a black hole D.The gravitational field of a black hole extends out to an infinite distance

i>clicker quiz #21 Which of the following statements is FALSE? A.Radio jets and lobes are lit up by synchrotron radiation produced by charged particles moving along spiral paths in a magnetic field B.The typical mass of a super-massive black hole that powers the nucleus of a quasar is about five million times the mass of our Sun C.The light-emitting region of a typical quasar is roughly comparable in size to our Solar System D.Quasars and AGNs can be 100 to 1000 times more luminous than our Milky Way galaxy E.Most galaxies have massive black holes at their centers

Expansion of the Universe Natural consequence of the basic field equations of the General Theory of Relativity (GTR) When GTR was first developed in the 1920s, everyone thought the Universe was static Albert Einstein ’ s static solution: He arbitrarily introduced a cosmological constant Λ (later called it his “ greatest blunder ” ) Edwin Hubble ’ s observations of receding galaxies led to the discovery that the Universe is expanding Hubble ’ s law: v = H 0 d — where H 0 ~ 70 km/s/Mpc (Hubble constant)

Hubble ’ s Law

Nature of the Universal Expansion Hubble ’ s law implies the Universe is expanding uniformly Expansion of Universe can be thought of as the expansion of space itself Observed redshift of distant galaxies — wavelength of photons “ stretched ” by the expansion of space Not everything is expanding — if it were, we couldn ’ t detect the expansion since our rulers would be expanding in proportion to everything else in the Universe

i>clicker quiz #22 Which of the following statements most accurately describes what happens when I HOLD A PIECE OF CHALK IN MY HAND ? A.A gravitational force and an electromagnetic force are canceling each other B.Only a gravitational force is acting on the piece of chalk C.Only an electromagnetic force is acting on the piece of chalk D.A gravitational force and a strong nuclear force are canceling each other

The Big Bang Reverse extrapolation of Universal expansion → There must have been an instant of infinite density and temperature → The BIG BANG! Phrase “ Big Bang ” was derisively coined by Fred Hoyle, but the name stuck! It was not like an explosion: it happened everywhere! Universe has a finite age: t ~ 1 / H 0 We are not allowed to ask the question: What happened before the Big Bang?

The Future of the Universe Is the expansion slowing down (i.e., decelerating) because of the mutual gravitational attraction of all the matter in the Universe? …….or……. Is the expansion speeding up (i.e., accelerating) because of a repulsive anti-gravity force (analogous to Einstein ’ s cosmological constant Λ? One of the most exciting developments of the last decade is the discovery that the Universal expansion rate is actually ACCELERATING!

i>clicker quiz #23 Which of the following statements is TRUE? A.Hubble ’ s discovery that most distant galaxies are receding from us tells us that we are at the center of the Universe B.The Universe started with the Big Bang and will end in the Big Crunch C.The expansion rate of the Universe is speeding up because of a repulsive anti-gravity force D.The Andromeda galaxy is moving away from the Milky Way galaxy as a result of the expansion of the Universe

Dark Matter and Dark Energy Critical density of matter needed to barely halt the Universe ’ s expansion: ρ crit ~ g/cm 3 Most of the matter in the Universe is DARK — total density of matter in the Universe ρ may or may not be equal to this critical density: Ω matter ≡ ρ / ρ crit How much DARK ENERGY (anti-gravity) is present in the Universe? Determination of Ω matter and Ω Λ are major goals / achievements of modern cosmology Methods:  Density/dynamics of galaxies in the Universe  Geometrical properties of the Universe  Expansion rate in the Universe ’ s past  Search for dark matter particles / physical origin of dark energy

Olbers ’ Paradox: Why is the Night Sky Dark? Assume uniform and infinite distribution of stars — night sky should be infinitely bright(!), but is observed to be dark Paradox phrased by Olbers in 1823, though already well known for about a hundred years at the time Stars are distributed over a finite volume (our Galaxy, for example) but the argument can be extended to the distribution of individual galaxies Can absorption by dust in galaxies solve the paradox? NO! Dust would heat up and glow as a black body radiator Universe has finite age t → observable Universe has a horizon at a finite distance ct — this is the most important factor in solving Olbers ’ Paradox!

Alternative to Big Bang theory: Steady State Cosmology Cosmological Principle: Universe is homogenous and isotropic — the same everywhere in space Perfect Cosmological Principle: Universe is the same at all times also — our Universe probably does not obey the Perfect Cosmological Principle Steady State theory proposed as alternative to Big Bang by Bondi, Gold, & Hoyle in 1940s — a theory is based on Perfect Cosmological Principle Requires that galaxies constantly be created at the expense of energy out of the so-called C-field Not widely believed — discovery of the Cosmic Microwave Background Radiation is considered definitive evidence against Steady State cosmology

Cosmic Microwave Background Radiation (CMBR) Relic of the Big Bang ( “ afterglow ” of initial fireball) predicted in late 1940s Discovered by Penzias & Wilson in 1965 — they won the Nobel Prize for this discovery CMBR studied in detail by satellites (COBE, WMAP) Radiation comes from era of decoupling of matter and radiation in the early Universe (~300,000 years old) when neutral H atoms first formed

i>clicker quiz #24 Which of the following statements is TRUE? A.Black holes emit Hawking radiation which can be characterized as black-body radiation with a temperature that is proportional to the black hole ’ s mass B.The radius of the event horizon (Schwarzschild radius) of a black hole, the region over which it can trap light, is inversely proportional to the black hole ’ s mass C.“ A black hole has no hair ” is a statement that describes the loss of identity of matter when it is swallowed by a black hole D.The gravitational field of a black hole only extends out to an finite distance, its Schwarzschild radius