FURTHER COSMOLOGY Book page T H E M A K E U P O F T H E U N I V E R S E

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "FURTHER COSMOLOGY Book page T H E M A K E U P O F T H E U N I V E R S E"

Transcription

1 FURTHER COSMOLOGY Book page T H E M A K E U P O F T H E U N I V E R S E

2 COSMOLOGICAL PRINCIPLE Is the Universe isotropic or homogeneous? There is no place in the Universe that would be considered as the source of the Big Bang it expanded identical everywhere

3 ISOTROPY Assume Universe looks the same in every direction Not true on small scale Large scale: it looks the same in all direction Imagine: You are standing at the edge of the Universe Looking outward there would be a limited number of galaxies sending photons to us Looking inward, there would be an immense number of galaxies to send photon

4 EDGE OF THE UNIVERSE The two situations would appear different Isotropy says that this isn t the case

5 HOMOGENEITY Matter is uniformly spread in space Not true on small scale On large scale: average density of matter is about the same in all places in the Universe

6 Isotropy and homogeneity only considered in scales of millions of ly

7 EVIDENCE FOR COSMOLOGICAL PRINCIPLE Cosmic microwave background radiation CMB is the image of photons emitted from the early Universe Isotropy and homogeneity are seen in its random appearance APM Galaxy survey image: there is no special region or place that is different from any other

8 EINSTEIN AND SPECIAL RELATIVITY Einstein showed that Matter can only distort space time in one of three ways: 4rth dimension is time complex to visualize use impact of 3 rd dimension on a flat surface

9 POSITIVELY CURVED SPACE Spherical space of finite size Ω 0 > 1 By travelling through the Universe you could return to the original position in space time

10 NEGATIVELY CURVED Shape of a saddle of infinite size Ω 0 < 1 You would never return to the same point in space time

11 SURFACE REMAINS FLAT Shape remains flat of infinite size Ω 0 = 1 You would never return to the same point in space time

12 CRITICAL DENSITY ρ c Critical density is important Needed to determine what will happen to the Universe It is difficult to measure density We don t know how much there is Existence of dark matter

13 FATE OF THE UNIVERSE The critical density is the average density of matter required for the Universe to just halt its expansion, but only after an infinite time The Universe could be open, closed or flat

14 CLOSED UNIVERSE (POSITIVELY CURVED) Density of Universe is such that gravity will stop Universe from expanding It will cause Universe to contract Leads to big crunch Creation process could start again

15 OPEN UNIVERSE (NEGATIVELY SHAPED SADDLE) Gravity is too weak to stop Universe from expanding for ever

16 FLAT UNIVERSE Density is at critical value Universe will only start to contract after an infinite amount of time Ω 0 = 1

17 CRITICAL DENSITY ρ c - appears to be no greater than 10 particles per m 3 Research suggest that the average density is very close to this value ρ c for Universe ~ kgm 3

18 BUT IMPLICATIONS Rate of expansion has been slowing down Data from supernova type1a suggests that Universe may actually be undergoing an accelerated expansion caused by dark energy

19 FINDING A VALUE FOR ρ c Hubble s Law states the Imagine a speed of the galaxy as homogeneous sphere of radius r v = H 0 R and density ρ A galaxy of mass M will be moving away with speed v from the center of an imaginative sphere

20 TE=KE+PE TOTAL ENERGY OF GALAXY TE = 1 2 mv2 GMm R Mass of sphere ρ = M V M = ρv = 4 3 πr3 ρ TE = 1 2 m(h 0R) 2 G m4 3 πr3 ρ TE = 1 2 m H 0 2 R πmgρr2 R Galaxy will continue to move providing it has enough energy TE becomes positive

21 LET THE LIMIT OF TE=0 1 2 m H 0 2 R 2 = 4 3 πmgρr2 H 0 = Hubble constant G = Newton s gravitational constant

22 POSSIBLE DEVELOPMENT OF THE UNIVERSE Flat Universe ρ = ρ c Open Universe ρ < ρ c Closed Universe ρ > ρ c No gravity, ρ = 0 Accelerating Universe

23 DENSITY PARAMETER Ω 0 Open Universe ρ < ρ c Flat Universe ρ = ρ c Closed Universe ρ > ρ c Ratio of actual matter in Universe ρ to critical density ρ c is called the density parameter Ω 0 Ω 0 = ρ ρ c

24 4 th POSSIBILITY An accelerated Universe might be explained by dark energy This is an increasing likely prospect Hypothetical dark energy outweighs the gravitational effect of baryonic and dark matter

25 COSMIC SCALE FACTOR R Wavelength of emitted radiation will always be in accordance with the cosmic scale factor R Z = λ λ = R R 0 1 where z is the ratio b/w λ and R = cosmic scale factor, which would have changed from R 0 to R Assuming Black Body retains its shape during expansion T 1 R and T 1 λ Since λ R Cosmological Redshift λ of the emitted radiation is lengthened due to the expansion of the Universe

26 EVIDENCE FOR DARK MATTER fg

27 SUPPOSE v 2 = GM R a star of mass m is near the center of a spiral galaxy of total mass M The average density of the galaxy is ρ Star moves in circular orbit with orbital velocity v and radius R

28 CENTRAL BULB Assume the central bulb is spherical v 2 = GM R = G 4 3 πr3 ρ v 2 = 4 3 GρπR2 R v = 4 3 Gρπ R Hence v = constant R

29 ASSUME STAR IN ARMS OF GALAXY If the star is in the less populated areas of the arms of a galaxy, the galaxy would behave as if the total mass was concentrated at its center Stars would be free to move with nothing impede their orbits v 2 = GM R and v 1 R

30 SPEED OF STARS IN ARM: v 1 R When plotting rotational velocity against the distance from center of galaxy, we would expect to see rapidly increasing line that changes to decaying at the edge of the hub

31 EXPECTATION VS OBSERVATION By increasing speed from redshifts a different, much higher curve is observed Stars far out into the region beyond the arms move at same speeds as stars inside the galaxy

32 EXPLANATION Dark matter forms a halo around the outer rim of a galaxy Matter is not luminous or baryonic and emits no radiation

33 DARK MATTER HALO When the halo with dark matter is added to the curve, it almost fits the observed data

34 OTHER EVIDENCE Velocity of galaxies orbiting each other in clusters They emit far less light than suggested by their velocities WRT their mass

35 GRAVITATIONAL LENSING Radiation passing through a cluster of galaxies becomes much more distorted than expected due to the luminous mass of the cluster This is observable from Quasars

36 X-RAY IMAGES X-ray images of elliptical galaxies show halos of hot gas extending well outside the galaxy To be bound to the galaxy, galaxy must have mass far greater than observed Up to 90% of galaxies is assumed to be dark matter

37 WHAT IS DARK MATTER? Nobody knows

38 CANDIDATES FOR DARK MATTER MACHO s Massive compact halo objects - black holes - neutron stars - small stars such as brown dwarfs Compact stars at the end of their lives with high density Detected by gravitational lensing Not sufficient to provide amount of dark matter in cgrahamphysics.com Universe 2016

39 WIMP S Weakly interacting massive particles They are subatomic particles - non baryonic - they pass through baryonic matter with very little effect - massive does not mean big, but rather they have mass, also very small mass To make up dark matter, there would need to be an cgrahamphysics.com unimaginable 2016 amount of them

40 MORE WIMP S 1998 neutrinos with very little mass were discovered other hypothetical particles are called axions and neutralinos They have not been discovered experimentally Dark matter research in CERN

41 DARK ENERGY Unknown force causing galaxies to move further apart and stretching the fabric of space faster

42 ESA S PLANCK MISSION 68% of the Universe consists of dark energy 26.8% is dark matter 4.9% is ordinary matter

43 DATA FROM SUPERNOVA Supernova dimmer than Suggested expected explanation: They are further away than expected They must be speeding Dark energy is a up rather than slowing down property of space As universe expands so does dark energy Dark energy comes into existence with more space

44 ANISTROPIES IN CMB According to Big Bang Theory First ~300000years of Universe atoms could not exist Matter distributed as ionized plasma Photons trapped in fog that hid early times of Universe s history Universe expanded Density and temperature dropped Nucleus and electrons could combine to form atoms Epoch of recombination Now photon could escape CMB is the record of these at the moment of their escape

45 BLACK BODY SPECTRUM Multiple scattering of photons resulted in BB spectrum Had temperature ~ 3000K They were undergoing cosmological redshift to longer λ during their ~ 13 billion journey Now detected in microwave region at temperature of 2.725K In agreement with Big Bang prediction

46 DEFINITION ANISOTROPY Although radiation is almost perfectly isotropic, observations show slightly variations in temperature Temperature fluctuations with direction are called anisotropies

47 FLUCTUATIONS.. Fluctuations in temperature correspond to regions of slightly different densities Slightly shorter λ in direction of constellation Leo (hotter) In opposite direction radiation is slightly cooler Fluctuations in density developed later into galaxies and galaxy clusters

48 EVIDENCE FROM CMB ANISOTROPIES.. may require to rethink the theory Lack of symmetry in average temperatures in opposite hemispheres in sky suggest Universe may not be isotropic There is also a cold spot extending over a patch of sky

49 HUBBLE CONSTANT The Hubble constant is now ~ 67.15kms 1 Mpc 1 Significantly less Age of Universe billion of years New orbiting telescopes will provide new additional data NASA/ESA Euclid mission James Webb space telescope

Moment of beginning of space-time about 13.7 billion years ago. The time at which all the material and energy in the expanding Universe was coincident

Moment of beginning of space-time about 13.7 billion years ago. The time at which all the material and energy in the expanding Universe was coincident Big Bang Moment of beginning of space-time about 13.7 billion years ago The time at which all the material and energy in the expanding Universe was coincident Only moment in the history of the Universe

More information

If there is an edge to the universe, we should be able to see our way out of the woods. Olber s Paradox. This is called Olber s Paradox

If there is an edge to the universe, we should be able to see our way out of the woods. Olber s Paradox. This is called Olber s Paradox Suppose the Universe were not expanding, but was in some kind of steady state. How should galaxy recession velocities correlate with distance? They should a) be directly proportional to distance. b) reverse

More information

Energy Source for Active Galactic Nuclei

Energy Source for Active Galactic Nuclei Quasars Quasars are small, extremely luminous, extremely distant galactic nuclei Bright radio sources Name comes from Quasi-Stellar Radio Source, as they appeared to be stars! Can have clouds of gas near

More information

The Expanding Universe

The Expanding Universe Cosmology Expanding Universe History of the Universe Cosmic Background Radiation The Cosmological Principle Cosmology and General Relativity Dark Matter and Dark Energy Primitive Cosmology If the universe

More information

Chapter 23: Dark Matter, Dark Energy & Future of the Universe. Galactic rotation curves

Chapter 23: Dark Matter, Dark Energy & Future of the Universe. Galactic rotation curves Chapter 23: Dark Matter, Dark Energy & Future of the Universe Galactic rotation curves Orbital speed as a function of distance from the center: rotation_of_spiral_galaxy.htm Use Kepler s Third Law to get

More information

The Contents of the Universe (or/ what do we mean by dark matter and dark energy?)

The Contents of the Universe (or/ what do we mean by dark matter and dark energy?) The Contents of the Universe (or/ what do we mean by dark matter and dark energy?) Unseen Influences Dark Matter: An undetected form of mass that emits little or no light but whose existence we infer from

More information

It is possible for a couple of elliptical galaxies to collide and become a spiral and for two spiral galaxies to collide and form an elliptical.

It is possible for a couple of elliptical galaxies to collide and become a spiral and for two spiral galaxies to collide and form an elliptical. 7/16 Ellipticals: 1. Very little gas and dust an no star formation. 2. Composed of old stars. 3. Masses range from hundreds of thousands to 10's of trillions of solar masses. 4. Sizes range from 3000 ly

More information

Chapter 23 Lecture. The Cosmic Perspective Seventh Edition. Dark Matter, Dark Energy, and the Fate of the Universe Pearson Education, Inc.

Chapter 23 Lecture. The Cosmic Perspective Seventh Edition. Dark Matter, Dark Energy, and the Fate of the Universe Pearson Education, Inc. Chapter 23 Lecture The Cosmic Perspective Seventh Edition Dark Matter, Dark Energy, and the Fate of the Universe Curvature of the Universe The Density Parameter of the Universe Ω 0 is defined as the ratio

More information

Chapter 23 Lecture. The Cosmic Perspective Seventh Edition. Dark Matter, Dark Energy, and the Fate of the Universe Pearson Education, Inc.

Chapter 23 Lecture. The Cosmic Perspective Seventh Edition. Dark Matter, Dark Energy, and the Fate of the Universe Pearson Education, Inc. Chapter 23 Lecture The Cosmic Perspective Seventh Edition Dark Matter, Dark Energy, and the Fate of the Universe Curvature of the Universe The Density Parameter of the Universe Ω 0 is defined as the ratio

More information

Homework 6 Name: Due Date: June 9, 2008

Homework 6 Name: Due Date: June 9, 2008 Homework 6 Name: Due Date: June 9, 2008 1. Where in the universe does the general expansion occur? A) everywhere in the universe, including our local space upon Earth, the solar system, our galaxy and

More information

Lecture 37 Cosmology [not on exam] January 16b, 2014

Lecture 37 Cosmology [not on exam] January 16b, 2014 1 Lecture 37 Cosmology [not on exam] January 16b, 2014 2 Structure of the Universe Does clustering of galaxies go on forever? Looked at very narrow regions of space to far distances. On large scales the

More information

Today. life the university & everything. Reminders: Review Wed & Fri Eyes to the web Final Exam Tues May 3 Check in on accomodations

Today. life the university & everything. Reminders: Review Wed & Fri Eyes to the web Final Exam Tues May 3 Check in on accomodations life the university & everything Phys 2130 Day 41: Questions? The Universe Reminders: Review Wed & Fri Eyes to the web Final Exam Tues May 3 Check in on accomodations Today Today: - how big is the universe?

More information

2. The evolution and structure of the universe is governed by General Relativity (GR).

2. The evolution and structure of the universe is governed by General Relativity (GR). 7/11 Chapter 12 Cosmology Cosmology is the study of the origin, evolution, and structure of the universe. We start with two assumptions: 1. Cosmological Principle: On a large enough scale (large compared

More information

Chapter 19 Galaxies. Hubble Ultra Deep Field: Each dot is a galaxy of stars. More distant, further into the past. halo

Chapter 19 Galaxies. Hubble Ultra Deep Field: Each dot is a galaxy of stars. More distant, further into the past. halo Chapter 19 Galaxies Hubble Ultra Deep Field: Each dot is a galaxy of stars. More distant, further into the past halo disk bulge Barred Spiral Galaxy: Has a bar of stars across the bulge Spiral Galaxy 1

More information

Planetarium/Observing: the clock is ticking! Don t forget to fill out your Planetarium/ Observing impression online.

Planetarium/Observing: the clock is ticking! Don t forget to fill out your Planetarium/ Observing impression online. Announcements HW #5 Due Wed, Dec. 10th. Planetarium/Observing: the clock is ticking! Don t forget to fill out your Planetarium/ Observing impression online. NOTE: Planetarium: Large dome you sit inside.

More information

COSMOLOGY The Universe what is its age and origin?

COSMOLOGY The Universe what is its age and origin? COSMOLOGY The Universe what is its age and origin? REVIEW (SUMMARY) Oppenheimer Volkhoff limit: upper limit to mass of neutron star remnant more than 1.4 M à neutron degeneracy Supernova à extremely dense

More information

IB Physics - Astronomy

IB Physics - Astronomy Solar System Our Solar System has eight planets. The picture below shows their relative sizes, but NOT their relative distances. A planet orbits the sun, and has gravitationally cleared its orbital area

More information

Olbers Paradox. Lecture 14: Cosmology. Resolutions of Olbers paradox. Cosmic redshift

Olbers Paradox. Lecture 14: Cosmology. Resolutions of Olbers paradox. Cosmic redshift Lecture 14: Cosmology Olbers paradox Redshift and the expansion of the Universe The Cosmological Principle Ω and the curvature of space The Big Bang model Primordial nucleosynthesis The Cosmic Microwave

More information

Lecture Outlines. Chapter 26. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc.

Lecture Outlines. Chapter 26. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc. Lecture Outlines Chapter 26 Astronomy Today 8th Edition Chaisson/McMillan Chapter 26 Cosmology Units of Chapter 26 26.1 The Universe on the Largest Scales 26.2 The Expanding Universe 26.3 The Fate of the

More information

Cosmologists dedicate a great deal of effort to determine the density of matter in the universe. Type Ia supernovae observations are consistent with

Cosmologists dedicate a great deal of effort to determine the density of matter in the universe. Type Ia supernovae observations are consistent with Notes for Cosmology course, fall 2005 Dark Matter Prelude Cosmologists dedicate a great deal of effort to determine the density of matter in the universe Type Ia supernovae observations are consistent

More information

BROCK UNIVERSITY. Test 2, March 2018 Number of pages: 9 Course: ASTR 1P02, Section 1 Number of Students: 465 Date of Examination: March 12, 2018

BROCK UNIVERSITY. Test 2, March 2018 Number of pages: 9 Course: ASTR 1P02, Section 1 Number of Students: 465 Date of Examination: March 12, 2018 BROCK UNIVERSITY Page 1 of 9 Test 2, March 2018 Number of pages: 9 Course: ASTR 1P02, Section 1 Number of Students: 465 Date of Examination: March 12, 2018 Number of hours: 50 min Time of Examination:

More information

Today: Start Ch. 18: Cosmology. Homework # 5 due next Wed. (HW #6 is online)

Today: Start Ch. 18: Cosmology. Homework # 5 due next Wed. (HW #6 is online) Today: Start Ch. 18: Cosmology Homework # 5 due next Wed. (HW #6 is online) Dark Matter! A rotation curve is a graph of how fast a something is rotating, as a function of distance from the center.! We

More information

Cosmology. Assumptions in cosmology Olber s paradox Cosmology à la Newton Cosmology à la Einstein Cosmological constant Evolution of the Universe

Cosmology. Assumptions in cosmology Olber s paradox Cosmology à la Newton Cosmology à la Einstein Cosmological constant Evolution of the Universe Cosmology Assumptions in cosmology Olber s paradox Cosmology à la Newton Cosmology à la Einstein Cosmological constant Evolution of the Universe Assumptions in Cosmology Copernican principle: We do not

More information

3 The lives of galaxies

3 The lives of galaxies Discovering Astronomy : Galaxies and Cosmology 24 3 The lives of galaxies In this section, we look at how galaxies formed and evolved, and likewise how the large scale pattern of galaxies formed. But before

More information

Cosmology II: The thermal history of the Universe

Cosmology II: The thermal history of the Universe .. Cosmology II: The thermal history of the Universe Ruth Durrer Département de Physique Théorique et CAP Université de Genève Suisse August 6, 2014 Ruth Durrer (Université de Genève) Cosmology II August

More information

A100H Exploring the Universe: Quasars, Dark Matter, Dark Energy. Martin D. Weinberg UMass Astronomy

A100H Exploring the Universe: Quasars, Dark Matter, Dark Energy. Martin D. Weinberg UMass Astronomy A100H Exploring the :, Dark Matter, Dark Energy Martin D. Weinberg UMass Astronomy astron100h-mdw@courses.umass.edu April 19, 2016 Read: Chaps 20, 21 04/19/16 slide 1 BH in Final Exam: Friday 29 Apr at

More information

Today. Last homework Due next time FINAL EXAM: 8:00 AM TUE Dec. 14 Course Evaluations Open. Modern Cosmology. Big Bang Nucleosynthesis.

Today. Last homework Due next time FINAL EXAM: 8:00 AM TUE Dec. 14 Course Evaluations Open. Modern Cosmology. Big Bang Nucleosynthesis. Today Modern Cosmology Big Bang Nucleosynthesis Dark Matter Dark Energy Last homework Due next time FINAL EXAM: 8:00 AM TUE Dec. 14 Course Evaluations Open Elements of Modern Cosmology 1.Expanding Universe

More information

A. Thermal radiation from a massive star cluster. B. Emission lines from hot gas C. 21 cm from hydrogen D. Synchrotron radiation from a black hole

A. Thermal radiation from a massive star cluster. B. Emission lines from hot gas C. 21 cm from hydrogen D. Synchrotron radiation from a black hole ASTR 1040 Accel Astro: Stars & Galaxies Prof. Juri Toomre TA: Nicholas Nelson Lecture 26 Thur 14 Apr 2011 zeus.colorado.edu/astr1040-toomre toomre HST Abell 2218 Reading clicker what makes the light? What

More information

BROCK UNIVERSITY. Test 2, March 2015 Number of pages: 9 Course: ASTR 1P02 Number of Students: 420 Date of Examination: March 5, 2015

BROCK UNIVERSITY. Test 2, March 2015 Number of pages: 9 Course: ASTR 1P02 Number of Students: 420 Date of Examination: March 5, 2015 BROCK UNIVERSITY Page 1 of 9 Test 2, March 2015 Number of pages: 9 Course: ASTR 1P02 Number of Students: 420 Date of Examination: March 5, 2015 Number of hours: 50 min Time of Examination: 18:00 18:50

More information

Cosmology. Clusters of galaxies. Redshift. Late 1920 s: Hubble plots distances versus velocities of galaxies. λ λ. redshift =

Cosmology. Clusters of galaxies. Redshift. Late 1920 s: Hubble plots distances versus velocities of galaxies. λ λ. redshift = Cosmology Study of the structure and origin of the universe Observational science The large-scale distribution of galaxies Looking out to extremely large distances The motions of galaxies Clusters of galaxies

More information

Chapter 17 Cosmology

Chapter 17 Cosmology Chapter 17 Cosmology Over one thousand galaxies visible The Universe on the Largest Scales No evidence of structure on a scale larger than 200 Mpc On very large scales, the universe appears to be: Homogenous

More information

i>clicker Quiz #14 Which of the following statements is TRUE?

i>clicker Quiz #14 Which of the following statements is TRUE? 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 at the center of the Universe B. The Universe started

More information

3/6/12! Astro 358/Spring 2012! Galaxies and the Universe! Dark Matter in Spiral Galaxies. Dark Matter in Galaxies!

3/6/12! Astro 358/Spring 2012! Galaxies and the Universe! Dark Matter in Spiral Galaxies. Dark Matter in Galaxies! 3/6/12 Astro 358/Spring 2012 Galaxies and the Universe Dark Matter in Galaxies Figures + Tables for Lectures (Feb 16-Mar 6) Dark Matter in Spiral Galaxies Flat rotation curve of Milky Way at large radii

More information

Chapter 22 What do we mean by dark matter and dark energy?

Chapter 22 What do we mean by dark matter and dark energy? Chapter 22 What do we mean by dark matter and dark energy? Unseen Influences Dark Matter: An undetected form of mass that emits little or no light, but whose existence we infer from its gravitational influence

More information

Dark Energy and Dark Matter

Dark Energy and Dark Matter Dark Energy and Dark Matter Attendance Quiz Are you here today? (a) yes (b) no Here! (c) The Dark Lord wants his ring back! Final Exam The final exam is Thursday, 6/8, from 11:30am to 1:30pm (2 hours),

More information

Lecture 10: Cosmology and the Future of Astronomical Research

Lecture 10: Cosmology and the Future of Astronomical Research Lecture 10: Cosmology and the Future of Astronomical Research 1 ! The study of the Universe " Origin " Evolution " Eventual Fate! Physical Cosmology " Includes studies of large-scale structure and dynamics

More information

Cosmology, Galaxies, and Stars OUR VISIBLE UNIVERSE

Cosmology, Galaxies, and Stars OUR VISIBLE UNIVERSE Cosmology, Galaxies, and Stars OUR VISIBLE UNIVERSE Cosmology Cosmology is the study of the universe; its nature, origin and evolution. General Relativity is the mathematical basis of cosmology from which

More information

The Big Bang Theory PRESS Chung Wai Man Camus, Wong Lai Yin Rita, Kum Kit Ying Cathy, Yeung Shuet Wah Sarah, Yu Wai Sze Alice

The Big Bang Theory PRESS Chung Wai Man Camus, Wong Lai Yin Rita, Kum Kit Ying Cathy, Yeung Shuet Wah Sarah, Yu Wai Sze Alice The Big Bang Theory PRESS-2002 Chung Wai Man Camus, Wong Lai Yin Rita, Kum Kit Ying Cathy, Yeung Shuet Wah Sarah, Yu Wai Sze Alice Supervised by: Dr KY Szeto, HKUST Abstract: We did a survey at our current

More information

Chapter 18. Cosmology in the 21 st Century

Chapter 18. Cosmology in the 21 st Century Chapter 18 Cosmology in the 21 st Century Guidepost This chapter marks a watershed in our study of astronomy. Since Chapter 1, our discussion has focused on learning to understand the universe. Our outward

More information

Island Universes. Up to 1920 s, many thought that Milky Way encompassed entire universe.

Island Universes. Up to 1920 s, many thought that Milky Way encompassed entire universe. Island Universes Up to 1920 s, many thought that Milky Way encompassed entire universe. Observed three types of nebulas (clouds): - diffuse, spiral, elliptical - many were faint, indistinct - originally

More information

Large Scale Structure

Large Scale Structure Large Scale Structure Measuring Distance in Universe-- a ladder of steps, building from nearby Redshift distance Redshift = z = (λ observed - λ rest )/ λ rest Every part of a distant spectrum has same

More information

Name Date Period. 10. convection zone 11. radiation zone 12. core

Name Date Period. 10. convection zone 11. radiation zone 12. core 240 points CHAPTER 29 STARS SECTION 29.1 The Sun (40 points this page) In your textbook, read about the properties of the Sun and the Sun s atmosphere. Use each of the terms below just once to complete

More information

Galaxies 626. Lecture 3: From the CMBR to the first star

Galaxies 626. Lecture 3: From the CMBR to the first star Galaxies 626 Lecture 3: From the CMBR to the first star Galaxies 626 Firstly, some very brief cosmology for background and notation: Summary: Foundations of Cosmology 1. Universe is homogenous and isotropic

More information

Chapter 26: Cosmology

Chapter 26: Cosmology Chapter 26: Cosmology Cosmology means the study of the structure and evolution of the entire universe as a whole. First of all, we need to know whether the universe has changed with time, or if it has

More information

2) On a Hertzsprung-Russell diagram, where would you find red giant stars? A) upper right B) lower right C) upper left D) lower left

2) On a Hertzsprung-Russell diagram, where would you find red giant stars? A) upper right B) lower right C) upper left D) lower left Multiple choice test questions 2, Winter Semester 2015. Based on parts covered after mid term. Essentially on Ch. 12-2.3,13.1-3,14,16.1-2,17,18.1-2,4,19.5. You may use a calculator and the useful formulae

More information

Review of Lecture 15 3/17/10. Lecture 15: Dark Matter and the Cosmic Web (plus Gamma Ray Bursts) Prof. Tom Megeath

Review of Lecture 15 3/17/10. Lecture 15: Dark Matter and the Cosmic Web (plus Gamma Ray Bursts) Prof. Tom Megeath Lecture 15: Dark Matter and the Cosmic Web (plus Gamma Ray Bursts) Prof. Tom Megeath A2020 Disk Component: stars of all ages, many gas clouds Review of Lecture 15 Spheroidal Component: bulge & halo, old

More information

Today. Course Evaluations Open. Modern Cosmology. The Hot Big Bang. Age & Fate. Density and Geometry. Microwave Background

Today. Course Evaluations Open. Modern Cosmology. The Hot Big Bang. Age & Fate. Density and Geometry. Microwave Background Today Modern Cosmology The Hot Big Bang Age & Fate Density and Geometry Microwave Background Course Evaluations Open Cosmology The study of the universe as a physical system Historically, people have always

More information

Galaxy A has a redshift of 0.3. Galaxy B has a redshift of 0.6. From this information and the existence of the Hubble Law you can conclude that

Galaxy A has a redshift of 0.3. Galaxy B has a redshift of 0.6. From this information and the existence of the Hubble Law you can conclude that Galaxy A has a redshift of 0.3. Galaxy B has a redshift of 0.6. From this information and the existence of the Hubble Law you can conclude that A) Galaxy B is two times further away than Galaxy A. B) Galaxy

More information

Chapter 16 Dark Matter, Dark Energy, & The Fate of the Universe

Chapter 16 Dark Matter, Dark Energy, & The Fate of the Universe 16.1 Unseen Influences Chapter 16 Dark Matter, Dark Energy, & The Fate of the Universe Dark Matter: An undetected form of mass that emits little or no light but whose existence we infer from its gravitational

More information

The Cosmic Microwave Background

The Cosmic Microwave Background The Cosmic Microwave Background Class 22 Prof J. Kenney June 26, 2018 The Cosmic Microwave Background Class 22 Prof J. Kenney November 28, 2016 Cosmic star formation history inf 10 4 3 2 1 0 z Peak of

More information

Implications of the Hubble Law: - it is not static, unchanging - Universe had a beginning!! - could not have been expanding forever HUBBLE LAW:

Implications of the Hubble Law: - it is not static, unchanging - Universe had a beginning!! - could not have been expanding forever HUBBLE LAW: Cosmology and the Evolution of the Universe Edwin Hubble, 1929: -almost all galaxies have a redshift -moving away from us -greater distance greater redshift Implications of the Hubble Law: - Universe is

More information

Cosmology and the Evolution of the Universe. Implications of the Hubble Law: - Universe is changing (getting bigger!) - it is not static, unchanging

Cosmology and the Evolution of the Universe. Implications of the Hubble Law: - Universe is changing (getting bigger!) - it is not static, unchanging Cosmology and the Evolution of the Edwin Hubble, 1929: -almost all galaxies have a redshift -moving away from us -exceptions in Local Group -with distance measurements - found a relationship greater distance

More information

IoP. An Introduction to the Science of Cosmology. Derek Raine. Ted Thomas. Series in Astronomy and Astrophysics

IoP. An Introduction to the Science of Cosmology. Derek Raine. Ted Thomas. Series in Astronomy and Astrophysics Series in Astronomy and Astrophysics An Introduction to the Science of Cosmology Derek Raine Department of Physics and Astronomy University of Leicester, UK Ted Thomas Department of Physics and Astronomy

More information

Newtonian Gravity and Cosmology

Newtonian Gravity and Cosmology Chapter 30 Newtonian Gravity and Cosmology The Universe is mostly empty space, which might suggest that a Newtonian description of gravity (which is valid in the weak gravity limit) is adequate for describing

More information

Dark Matter: What is it?

Dark Matter: What is it? Dark Matter: What is it? Dark Matter: What is it? Key Concepts 1) Some dark matter consists of MACHOs (MAssive Compact Halo Objects). 2) Some dark matter may consist of WIMPs (Weakly Interacting Massive

More information

The Cosmic Microwave Background

The Cosmic Microwave Background The Cosmic Microwave Background The Cosmic Microwave Background Key Concepts 1) The universe is filled with a Cosmic Microwave Background (CMB). 2) The microwave radiation that fills the universe is nearly

More information

26. Cosmology. Significance of a dark night sky. The Universe Is Expanding

26. Cosmology. Significance of a dark night sky. The Universe Is Expanding 26. Cosmology Significance of a dark night sky The Universe is expanding The Big Bang initiated the expanding Universe Microwave radiation evidence of the Big Bang The Universe was initially hot & opaque

More information

Energy and Matter in the Universe

Energy and Matter in the Universe Chapter 17 Energy and Matter in the Universe The history and fate of the Universe ultimately turn on how much matter, energy, and pressure it contains: 1. These components of the stress energy tensor all

More information

Astronomy 113. Dr. Joseph E. Pesce, Ph.D. The Big Bang & Matter. Olber s Paradox. Cosmology. Olber s Paradox. Assumptions 4/20/18

Astronomy 113. Dr. Joseph E. Pesce, Ph.D. The Big Bang & Matter. Olber s Paradox. Cosmology. Olber s Paradox. Assumptions 4/20/18 Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Big Bang & Matter Cosmology ³The study of the origins, structure, and evolution of the universe ³Key moments: ²Einstein General Theory of Relativity ²Hubble

More information

Astronomy 113. Dr. Joseph E. Pesce, Ph.D Joseph E. Pesce, Ph.D.

Astronomy 113. Dr. Joseph E. Pesce, Ph.D Joseph E. Pesce, Ph.D. Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Big Bang & Matter 17-2 Cosmology ³ The study of the origins, structure, and evolution of the universe ³ Key moments: ² Einstein General Theory of Relativity

More information

The Early Universe: A Journey into the Past

The Early Universe: A Journey into the Past Gravity: Einstein s General Theory of Relativity The Early Universe A Journey into the Past Texas A&M University March 16, 2006 Outline Gravity: Einstein s General Theory of Relativity Galileo and falling

More information

Modeling the Universe A Summary

Modeling the Universe A Summary Modeling the Universe A Summary Questions to Consider 1. What does the darkness of the night sky tell us about the nature of the universe? 2. As the universe expands, what, if anything, is it expanding

More information

Other Galaxy Types. Active Galaxies. A diagram of an active galaxy, showing the primary components. Active Galaxies

Other Galaxy Types. Active Galaxies. A diagram of an active galaxy, showing the primary components. Active Galaxies Other Galaxy Types Active Galaxies Active Galaxies Seyfert galaxies Radio galaxies Quasars Origin??? Different in appearance Produce huge amount of energy Similar mechanism a Galactic mass black hole at

More information

The Early Universe: A Journey into the Past

The Early Universe: A Journey into the Past The Early Universe A Journey into the Past Texas A&M University March 16, 2006 Outline Galileo and falling bodies Galileo Galilei: all bodies fall at the same speed force needed to accelerate a body is

More information

Dark Matter & Dark Energy. Astronomy 1101

Dark Matter & Dark Energy. Astronomy 1101 Dark Matter & Dark Energy Astronomy 1101 Key Ideas: Dark Matter Matter we cannot see directly with light Detected only by its gravity (possible future direct detection in the lab) Most of the matter in

More information

Module 3: Astronomy The Universe Topic 1 Content: Cosmology Presentation Notes

Module 3: Astronomy The Universe Topic 1 Content: Cosmology Presentation Notes Pretend that you have been given the opportunity to travel through time to explore cosmology. Cosmology is the study of how the universe formed and what will happen to it. Watch through your viewport as

More information

Introduction and Fundamental Observations

Introduction and Fundamental Observations Notes for Cosmology course, fall 2005 Introduction and Fundamental Observations Prelude Cosmology is the study of the universe taken as a whole ruthless simplification necessary (e.g. homogeneity)! Cosmology

More information

Cosmology. An Analogy 11/28/2010. Cosmology Study of the origin, evolution and future of the Universe

Cosmology. An Analogy 11/28/2010. Cosmology Study of the origin, evolution and future of the Universe Cosmology Cosmology Study of the origin, evolution and future of the Universe Obler s Paradox If the Universe is infinite why is the sky dark at night? Newtonian Universe The Universe is infinite and unchanging

More information

Cosmology: Building the Universe.

Cosmology: Building the Universe. Cosmology: Building the Universe. The term has several different meanings. We are interested in physical cosmology - the study of the origin and development of the physical universe, and all the structure

More information

Astr 102: Introduction to Astronomy. Lecture 16: Cosmic Microwave Background and other evidence for the Big Bang

Astr 102: Introduction to Astronomy. Lecture 16: Cosmic Microwave Background and other evidence for the Big Bang Astr 102: Introduction to Astronomy Fall Quarter 2009, University of Washington, Željko Ivezić Lecture 16: Cosmic Microwave Background and other evidence for the Big Bang 1 Outline Observational Cosmology:

More information

Announcements. Homework. Set 8now open. due late at night Friday, Dec 10 (3AM Saturday Nov. 11) Set 7 answers on course web site.

Announcements. Homework. Set 8now open. due late at night Friday, Dec 10 (3AM Saturday Nov. 11) Set 7 answers on course web site. Homework. Set 8now. due late at night Friday, Dec 10 (3AM Saturday Nov. 11) Set 7 answers on course web site. Review for Final. In class on Thursday. Course Evaluation. https://rateyourclass.msu.edu /

More information

Introduction to Cosmology Big Bang-Big Crunch-Dark Matter-Dark Energy The Story of Our Universe. Dr. Ugur GUVEN Aerospace Engineer / Space Scientist

Introduction to Cosmology Big Bang-Big Crunch-Dark Matter-Dark Energy The Story of Our Universe. Dr. Ugur GUVEN Aerospace Engineer / Space Scientist Introduction to Cosmology Big Bang-Big Crunch-Dark Matter-Dark Energy The Story of Our Universe Dr. Ugur GUVEN Aerospace Engineer / Space Scientist The Age of the Universe Through various measurements

More information

FXA ρ 0 = 3(H 0 ) 2. UNIT G485 Module Universe Evolution. Candidates should be able to : age of the universe 1/H 0

FXA ρ 0 = 3(H 0 ) 2. UNIT G485 Module Universe Evolution. Candidates should be able to : age of the universe 1/H 0 1 Candidates should be able to : Explain that the standard (hot big bang) model of the universe implies a finite age for the universe. Select and use the expression : age of the universe 1/H 0 Describe

More information

Dark Matter, Dark Energy, and all that stuff

Dark Matter, Dark Energy, and all that stuff Dark Matter, Dark Energy, and all that stuff From cosmology to particle physics K. Ragan/McGill 1 Let s start close to home: The Milky Way A faintly brighter band of light is visible across the sky on

More information

3. It is expanding: the galaxies are moving apart, accelerating slightly The mystery of Dark Energy

3. It is expanding: the galaxies are moving apart, accelerating slightly The mystery of Dark Energy II. Cosmology: How the universe developed Outstanding features of the universe today: 1. It is big, and full of galaxies. 2. It has structure: the galaxies are clumped in filaments and sheets The structure

More information

Fire and Ice. The Fate of the Universe. Jon Thaler

Fire and Ice. The Fate of the Universe. Jon Thaler Fire and Ice The Fate of the Universe Jon Thaler Saturday Physics Honors Program Oct. 13, 2007 Some say the world will end in fire, Some say in ice. From what I've tasted of desire I hold with those who

More information

The Big Bang Theory. Rachel Fludd and Matthijs Hoekstra

The Big Bang Theory. Rachel Fludd and Matthijs Hoekstra The Big Bang Theory Rachel Fludd and Matthijs Hoekstra Theories from Before the Big Bang came from a black hole from another universe? our universe is part of a multiverse? just random particles? The Big

More information

Astronomy 102: Stars and Galaxies Review Exam 3

Astronomy 102: Stars and Galaxies Review Exam 3 October 31, 2004 Name: Astronomy 102: Stars and Galaxies Review Exam 3 Instructions: Write your answers in the space provided; indicate clearly if you continue on the back of a page. No books, notes, or

More information

Cosmology: The History of the Universe

Cosmology: The History of the Universe Cosmology: The History of the Universe The Universe originated in an explosion called the Big Bang. Everything started out 13.7 billion years ago with zero size and infinite temperature. Since then, it

More information

8/30/2010. Classifying Stars. Classifying Stars. Classifying Stars

8/30/2010. Classifying Stars. Classifying Stars. Classifying Stars Classifying Stars In the early 1900s, Ejnar Hertzsprung and Henry Russell made some important observations. They noticed that, in general, stars with higher temperatures also have brighter absolute magnitudes.

More information

AST1100 Lecture Notes

AST1100 Lecture Notes AST1100 Lecture Notes 4 Stellar orbits and dark matter 1 Using Kepler s laws for stars orbiting the center of a galaxy We will now use Kepler s laws of gravitation on much larger scales. We will study

More information

BASICS OF COSMOLOGY Astro 2299

BASICS OF COSMOLOGY Astro 2299 BASICS OF COSMOLOGY Astro 2299 We live in a ΛCDM universe that began as a hot big bang (BB) and has flat geometry. It will expand forever. Its properties (laws of physics, fundamental constants) allow

More information

Cosmology: The Origin and Evolution of the Universe Chapter Twenty-Eight. Guiding Questions

Cosmology: The Origin and Evolution of the Universe Chapter Twenty-Eight. Guiding Questions Cosmology: The Origin and Evolution of the Universe Chapter Twenty-Eight Guiding Questions 1. What does the darkness of the night sky tell us about the nature of the universe? 2. As the universe expands,

More information

CH 14 MODERN COSMOLOGY The Study of Nature, origin and evolution of the universe Does the Universe have a center and an edge? What is the evidence

CH 14 MODERN COSMOLOGY The Study of Nature, origin and evolution of the universe Does the Universe have a center and an edge? What is the evidence CH 14 MODERN COSMOLOGY The Study of Nature, origin and evolution of the universe Does the Universe have a center and an edge? What is the evidence that the Universe began with a Big Bang? How has the Universe

More information

Isotropy and Homogeneity

Isotropy and Homogeneity Cosmic inventory Isotropy and Homogeneity On large scales the Universe is isotropic (looks the same in all directions) and homogeneity (the same average density at all locations. This is determined from

More information

Learning Objectives: Chapter 13, Part 1: Lower Main Sequence Stars. AST 2010: Chapter 13. AST 2010 Descriptive Astronomy

Learning Objectives: Chapter 13, Part 1: Lower Main Sequence Stars. AST 2010: Chapter 13. AST 2010 Descriptive Astronomy Chapter 13, Part 1: Lower Main Sequence Stars Define red dwarf, and describe the internal dynamics and later evolution of these low-mass stars. Appreciate the time scale of late-stage stellar evolution

More information

Lecture PowerPoints. Chapter 33 Physics: Principles with Applications, 7 th edition Giancoli

Lecture PowerPoints. Chapter 33 Physics: Principles with Applications, 7 th edition Giancoli Lecture PowerPoints Chapter 33 Physics: Principles with Applications, 7 th edition Giancoli This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching

More information

Beyond Our Solar System Chapter 24

Beyond Our Solar System Chapter 24 Beyond Our Solar System Chapter 24 PROPERTIES OF STARS Distance Measuring a star's distance can be very difficult Stellar parallax Used for measuring distance to a star Apparent shift in a star's position

More information

Type Ia Supernova Observations. Supernova Results:The Context. Supernova Results. Physics 121 December 4, fainter. brighter

Type Ia Supernova Observations. Supernova Results:The Context. Supernova Results. Physics 121 December 4, fainter. brighter Physics 11 December 4, 009 Today Supernovae revisited Galaxy Rotation Curves Dark Matter & Dark Energy Scaling Factor a(t) Course Evaluations Type Ia Supernova Observations Distant supernovae are than

More information

Astronomy Hour Exam 2 March 10, 2011 QUESTION 1: The half-life of Ra 226 (radium) is 1600 years. If you started with a sample of 100 Ra 226

Astronomy Hour Exam 2 March 10, 2011 QUESTION 1: The half-life of Ra 226 (radium) is 1600 years. If you started with a sample of 100 Ra 226 Astronomy 101.003 Hour Exam 2 March 10, 2011 QUESTION 1: The half-life of Ra 226 (radium) is 1600 years. If you started with a sample of 100 Ra 226 atoms, approximately how many Ra 226 atoms would be left

More information

Astronomy 102: Stars and Galaxies Spring 2003 Final Exam Review Topics

Astronomy 102: Stars and Galaxies Spring 2003 Final Exam Review Topics Astronomy 102: Stars and Galaxies Spring 2003 Final Exam Review Topics The final exam will cover material from the whole course (including the galaxies and cosmology material from after Exam 3). The topics

More information

Astro Assignment 1 on course web page (due 15 Feb) Instructors: Jim Cordes & Shami Chatterjee

Astro Assignment 1 on course web page (due 15 Feb) Instructors: Jim Cordes & Shami Chatterjee Astro 2299 The Search for Life in the Universe Lecture 4 This time: Redshifts and the Hubble Law Hubble law and the expanding universe The cosmic microwave background (CMB) The elements and the periodic

More information

D.V. Fursaev JINR, Dubna. Mysteries of. the Universe. Problems of the Modern Cosmology

D.V. Fursaev JINR, Dubna. Mysteries of. the Universe. Problems of the Modern Cosmology Mysteries of D.V. Fursaev JINR, Dubna the Universe Problems of the Modern Cosmology plan of the lecture facts about our Universe mathematical model, Friedman universe consequences, the Big Bang recent

More information

Cosmology. Chapter 18. Cosmology. Observations of the Universe. Observations of the Universe. Motion of Galaxies. Cosmology

Cosmology. Chapter 18. Cosmology. Observations of the Universe. Observations of the Universe. Motion of Galaxies. Cosmology Cosmology Chapter 18 Cosmology Cosmology is the study of the structure and evolution of the Universe as a whole How big is the Universe? What shape is it? How old is it? How did it form? What will happen

More information

VU lecture Introduction to Particle Physics. Thomas Gajdosik, FI & VU. Big Bang (model)

VU lecture Introduction to Particle Physics. Thomas Gajdosik, FI & VU. Big Bang (model) Big Bang (model) What can be seen / measured? basically only light _ (and a few particles: e ±, p, p, ν x ) in different wave lengths: microwave to γ-rays in different intensities (measured in magnitudes)

More information

The Dawn of Time - II. A Cosmos is Born

The Dawn of Time - II. A Cosmos is Born The Dawn of Time - II. A Cosmos is Born Learning Objectives! Why does Olbers paradox show the Universe began?! How does Hubble s Law tell us the age of the Universe? If Hubble s Constant is large, is the

More information

What forms AGN Jets? Magnetic fields are ferociously twisted in the disk.

What forms AGN Jets? Magnetic fields are ferociously twisted in the disk. What forms AGN Jets? Magnetic fields are ferociously twisted in the disk. Charged particles are pulled out of the disk and accelerated like a sling-shot. Particles are bound to the magnetic fields, focussed

More information

Exam #3. Final Exam. Exam 3 review. How do we measure properties of a star? A detailed outline of study topics is here:

Exam #3. Final Exam. Exam 3 review. How do we measure properties of a star? A detailed outline of study topics is here: Exam #3 Exam #3 is Thursday 4/9 in this room You can bring page of notes (front and back) Bring your calculator and a # pencil Exam 3 covers material from 4/1 onward (only 8 lectures) Consequently, no

More information

Lecture #25: Plan. Cosmology. The early Universe (cont d) The fate of our Universe The Great Unanswered Questions

Lecture #25: Plan. Cosmology. The early Universe (cont d) The fate of our Universe The Great Unanswered Questions Lecture #25: Plan Cosmology The early Universe (cont d) The fate of our Universe The Great Unanswered Questions Announcements Course evaluations: CourseEvalUM.umd.edu Review sheet #3 was emailed to you

More information

Formation of the Universe. What evidence supports current scientific theory?

Formation of the Universe. What evidence supports current scientific theory? Formation of the Universe What evidence supports current scientific theory? Cosmology Cosmology is the study of the Nature, Structure, Origin, And fate of the universe. How did it all begin? Astronomers

More information