© 2010 Pearson Education, Inc. Chapter 14 Dark Matter and Dark Energy.

Slides:



Advertisements
Similar presentations
FORMATION OF THE UNIVERSE Chapter 15 – 4 Part 2. Gravity and the Universe After the big bang, gravitational attraction caused the matter to form into.
Advertisements

Chapter 23: Dark Matter & The Fate Of The Universe.
Dark Matter. Either dark matter exists or we do not understand how gravity operates across galaxy-sized distances. We have many reasons to have confidence.
Possible Fate of the Universe W e already know that the universe is expanding. Only the pull of the gravitational force can slow it down. So, similar to.
Dark Matter Da yang Jacob Daeffler. What do we mean by dark matter? Material whose presence can be inferred from its effects on the motions of stars and.
Dark Matter, Dark Energy, and the Fate of the Universe.
Chapter 16 Dark Matter And The Fate Of The Universe.
Chapter 20 Dark Matter, Dark Energy, and the Fate of the Universe.
The Age of the Universe. The universe is expanding !!  The visible universe is made up of clusters of stars, held together in galaxies by their mutual.
Objectives Distinguish the different models of the universe.
1 Announcements Reading for next class: Chapters 22.6, 23 Cosmos Assignment 4, Due Wednesday, April 21, Angel Quiz Monday, April 26 Quiz 3 & Review, chapters.
© 2010 Pearson Education, Inc. Chapter 22 Dark Matter, Dark Energy, and the Fate of the Universe.
© 2010 Pearson Education, Inc. Chapter 21 Galaxy Evolution.
The Fate of The Universe. Will the universe continue expanding forever?
© 2010 Pearson Education, Inc. Chapter 20 Galaxies and the Foundation of Modern Cosmology.
ASTR100 (Spring 2008) Introduction to Astronomy The Case for Dark Matter Prof. D.C. Richardson Sections
Copyright © 2010 Pearson Education, Inc. Dark Matter and Dark Energy.
GALAXY FORMATION AND EVOLUTION - 2. DISCOVER Magazine’s 2007 Scientist of the Year David Charbonneau, of the Harvard-Smithsonian Canter for Astrophysics.
The Milky Way: How do we know what it looks like? Bryan Hill.
© 2010 Pearson Education, Inc. Chapter 19 Our Galaxy.
Announcements Starry Night Saint-Rémy: June, 1889 Van Gogh Out in the sky the great dark clouds are massing; I look far out into the pregnant night …
Dark Matter, Dark Energy, and the Fate of the Universe
© 2010 Pearson Education, Inc. Chapter 20 Galaxies and the Foundation of Modern Cosmology.
Chapter 22 Dark Matter, Dark Energy, and the Fate of the Universe
Dark Matter, Dark Energy, How Come Some People Think We Need It and Others Don’t and the Fate of the Universe.
Chapters 16 & 17 The Universe, Dark Matter, Dark Energy.
Dark Matter in Galaxies and Clusters AST 112. Matter Galaxies appear to be made up of stars, gas and dust Reasonable to think that’s the end of the story…
YSS - Intro. to Observational Astrophysics (ASTR 205) Class #13 Dark Matter, Dark Energy, and the Fate of the Universe (Chapter 16) Professor: José Maza.
Lecture 12 Astronomy /27/07. Looking Back Through Time Recall that looking at distant objects is the same as looking backwards through time The.
© 2010 Pearson Education, Inc. Chapter 21 Galaxy Evolution.
Chapter 16 Dark Matter, Dark Energy, and the Fate of the Universe.
Lecture Outline Chapter 18: Dark Matter, Dark Energy, and the Fate of the Universe © 2015 Pearson Education, Inc.
Chapter 18: Dark Matter, Dark Energy, and the Fate of the Universe
The Fate of the Universe
Chapter 22 Dark Matter, Dark Energy, and the Fate of the Universe.
Chapter 12 Space Exploration. Section 12.1 page 428 Explaining the Early Universe GALAXY – collection of stars, planets, gas and dust held together by.
Hubble’s galaxy classes Spheroid Dominates Disk Dominates.
Space and Unsolved Mysteries. Black Holes Form from the death of a very large star ( more than 25 solar masses). A supernova occurs followed by a black.
1 The Milky Way Galaxy We live on the quiet outskirts of a galaxy of approximately 100 Billion stars. This galaxy, the Milky Way, is roughly disk-shaped.
Chapter 12 Space Exploration. Section 12.1 page 428 Explaining the Early Universe GALAXY – collection of stars, planets, gas and dust held together by.
What does our galaxy look like?
The Universe. Galaxies are believed to have formed from mergers of smaller galaxies and star clusters. Galaxy Formation and Evolution.
25-4: Galaxies Use the following PowerPoint to take notes on the final section of the chapter. Upon completion work with your partner to answer the Self.
Fate of the Universe 1)Fate of the Universe 2)Shape of the Universe 3)Large Scale Structure November 25, 2002 Final Exam will be held in Ruby Diamond Auditorium.
Chapter 12 Space Exploration. Section 12.1 page 428 Explaining the Early Universe GALAXY – collection of stars, planets, gas and dust held together by.
© 2010 Pearson Education, Inc. Galaxies. © 2010 Pearson Education, Inc. Hubble Deep Field Our deepest images of the universe show a great variety of galaxies,
HOMEWORK: PAGE 381 # 1, 5, 7, UNSOLVED MYSTERIES.
Yale Summer Class: Observational Astronomy. Class #13 Dark Matter, Dark Energy, and the Fate of the Universe Professor: José Maza July 6, 2009 Professor:
© 2010 Pearson Education, Inc. Dark Universe: Dark Matter Dark Energy and the Fate of the Universe.
Unit 2 - Cosmology Part 1: Stars Part 2: Galaxies Part 3: Origin and Evolution of the Universe.
Key Areas covered Evidence for the expanding Universe We can estimate the mass of a galaxy by the orbital speed of stars within it Evidence for dark matter.
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.
The Milky Way Galaxy. What are each of these?
Chapter 20 Cosmology. Hubble Ultra Deep Field Galaxies and Cosmology A galaxy’s age, its distance, and the age of the universe are all closely related.
The Universe, Dark Matter, Dark Energy. What do we actually know about the Universe? 3° K background Age = ±0.021 Billion Years Pattern of the galaxies.
Dark Matter, Dark Energy, and the Fate of the Universe.
Wormholes. The simplest example The r = 2m singularity is more complicated than previously mentioned… Has solution (the Schwarzschild metric):
Important Stuff (Section 001)
Solar system Orbital motions AQA SPACE PHYSICS PHYSICS ONLY Red shift
Milky Way Orbits of stars in the Milky Way Rotation curves
The Cosmic Perspective
dark matter and the Fate of the Universe
FORMATION OF THE UNIVERSE
Key Areas covered Evidence for the expanding Universe
Dark Matter, Dark Energy, and the Fate of the Universe
FORMATION OF THE UNIVERSE
Homework #10 is due Wednesday, April 25, 9:00 pm. Review session Wednesday, April 25, 7:15 pm.
Chapter 15 – Stars, Galaxies and the Universe
Chapter 16 Dark Matter, Dark Energy, & The Fate of the Universe
Solar system Orbital motions AQA SPACE PHYSICS PHYSICS ONLY Red shift
Presentation transcript:

© 2010 Pearson Education, Inc. Chapter 14 Dark Matter and Dark Energy

© 2010 Pearson Education, Inc. What do we mean by dark matter and dark energy?

© 2010 Pearson Education, Inc. Dark Matter: An undetected form of mass that emits little or no light, but whose existence we infer from its gravitational influence Dark Energy: An unknown form of energy that seems to be the source of a repulsive force causing the expansion of the universe to accelerate Unseen Influences

© 2010 Pearson Education, Inc. “Ordinary” matter: ~ 4.4% –Ordinary matter inside stars:~ 0.6% –Ordinary matter outside stars:~ 3.8% Dark matter: ~ 23% Dark energy~ 73% Contents of Universe

© 2010 Pearson Education, Inc. What is the evidence for dark matter in galaxies?

© 2010 Pearson Education, Inc. We measure the mass of the solar system using the orbits of planets: orbital period average distance For circles: orbital velocity orbital radius

© 2010 Pearson Education, Inc. Rotation curve A plot of orbital velocity versus orbital radius The solar system’s rotation curve declines because the Sun has almost all the mass.

© 2010 Pearson Education, Inc. Who has the largest orbital velocity? A, B, or C?

© 2010 Pearson Education, Inc. Who has the largest orbital velocity? A, B, or C? Answer: C

© 2010 Pearson Education, Inc. The rotation curve of a merry-go- round rises with radius.

© 2010 Pearson Education, Inc. The rotation curve of the Milky Way stays flat with distance. Mass must be more spread out than in the solar system.

© 2010 Pearson Education, Inc. Mass in the Milky Way is spread out over a larger region than its stars. Most of the Milky Way’s mass seems to be dark matter!

© 2010 Pearson Education, Inc. Mass within the Sun’s orbit: 1.0  M Sun Total mass: ~10 12 M Sun

© 2010 Pearson Education, Inc. The visible portion of a galaxy lies deep in the heart of a large halo of dark matter.

© 2010 Pearson Education, Inc. Spiral galaxies all tend to have flat rotation curves, indicating large amounts of dark matter.

© 2010 Pearson Education, Inc. Does dark matter really exist? Insert TCP 6e Figure unannotated

© 2010 Pearson Education, Inc. Our Options 1.Dark matter really exists, and we are observing the effects of its gravitational attraction. 2.Something is wrong with our understanding of gravity, causing us to mistakenly infer the existence of dark matter.

© 2010 Pearson Education, Inc. Our Options 1.Dark matter really exists, and we are observing the effects of its gravitational attraction. 2.Something is wrong with our understanding of gravity, causing us to mistakenly infer the existence of dark matter. Because gravity is so well tested, most astronomers prefer option #1.

© 2010 Pearson Education, Inc. What is the role of dark matter in galaxy formation?

© 2010 Pearson Education, Inc. Gravity of dark matter is what caused protogalactic clouds to contract early in time.

© 2010 Pearson Education, Inc. Dark matter is still pulling things together. After correcting for Hubble’s law, we can see that galaxies are flowing toward the densest regions of space.

© 2010 Pearson Education, Inc. What are the largest structures in the universe?

© 2010 Pearson Education, Inc. Maps of galaxy positions reveal extremely large structures: superclusters and voids.

© 2010 Pearson Education, Inc. Models show that gravity of dark matter pulls mass into denser regions—the universe grows lumpier with time. Time in billions of years Size of expanding box in millions of light-years

© 2010 Pearson Education, Inc. Models show that gravity of dark matter pulls mass into denser regions—universe grows lumpier with time.

© 2010 Pearson Education, Inc. Will the universe continue expanding forever?

© 2010 Pearson Education, Inc. Does the universe have enough kinetic energy to escape its own gravitational pull?

© 2010 Pearson Education, Inc. The fate of the universe depends on the amount of dark matter.

© 2010 Pearson Education, Inc. Since the amount of dark matter is ~25% of the critical density, we expect the expansion of the universe to overcome its gravitational pull.

© 2010 Pearson Education, Inc. In fact, the expansion appears to be speeding up! Dark energy?

© 2010 Pearson Education, Inc. Estimated age depends on the amount of both dark matter and dark energy.

© 2010 Pearson Education, Inc. Is the expansion of the universe accelerating?

© 2010 Pearson Education, Inc. The brightness of distant white dwarf supernovae tells us how much the universe has expanded since they exploded. Insert TCP 6e Figure 20.14

© 2010 Pearson Education, Inc. An accelerating universe best fits the supernova data.