# PHYSICS 107. Lecture 27 What s Next?

Size: px
Start display at page:

Transcription

1 PHYSICS 107 Lecture 27 What s Next? The origin of the elements Apart from the expansion of the universe and the cosmic microwave background radiation, the Big Bang theory makes another important set of predictions: the abundance of the elements. There has been a long program of research in astronomy to figure out what atoms are actually out there, and how many of each kind of atom there is. In the early universe the speeds of the particles are so fast and the densities are so high that nuclear reactions are happening very often. This enables nuclei to be built up from protons and neutrons. This happens at a temperature of about K. This is when the universe is about 1 second old! Here is a sample of the most important reactions that lead to the production of H (which of course is just a proton), 2 H, which is a bound state of a proton and neutron), 3 H (a proton and 2 neutrons this doesn t make it to the present days because it has a half-life of only yrs), 3 He ( 2 protons and a neutron, but rare) and finally 4 He (2 protons and 2 neutrons). p + n d + γ d + d 3 He + n 3 H + p 3 H + d 4 He + n p + d 3 He + γ

2 n + d 3 H + γ p + 3 H 4 He + γ n + 3 He + γ d + d 4 He + γ 3 He + 4 He 7 Li So there is also a tiny amount of 7 Li produced in the first few seconds. Heavier elements are not produced in the Big Bang because at mass numbers A = 5 and A = 8 there are no stable nuclei, so when those nuclei are produced they break apart immediately and this prevents heavier elements from forming. We are able to calculate the abundances of all these light elements very accurately. The computer calculations are very similar to the very well-developed science of chemical reactions. There is one very important prediction that comes out: the universe should be about 92% regular hydrogen ( 1 H) atoms and 8% 4 He atoms (by number), which is about 74% and 25% (by mass). This turns out to be a very accurate prediction. In addition, deuterium is present at the level of about 27 parts per million, again in excellent agreement with the Big Bang theory. Everything else should be much more rare than hydrogen and helium, and they are. These three predictions: the expansion of the universe, the cosmic background radiation, and the abundance of the light elements, are the 3 main predictions of the Big Bang theory, and all have been verified in detail. The other heavier elements have been made in stars and supernova explosions much later in the age of the universe. The heavier elements tend to clump together to make planets, so they are much more prevalent on earth than they are in the

3 universe as a whole. Predicting all the elemental abundances is a very complicated and ongoing field of research, but there are no really big mysteries remaining in it. The Future Now run to the final question. What's going to happen? Does the universe expand forever? Does it come to a steady state? Does it fall back on itself? We can formulate this question a little more precisely by making a plot of the radius of the universe a(t), again using the word radius in quotation marks. If a(t) just goes on increasing forever then indeed the universe will continue to expand, and we will get further and further away from all the other galaxies forever. But there is also the possibility that a(t) will peak and then start to decrease, perhaps even going back to zero at some stage, a big crunch instead of a big bang. It's just exactly these two possibilities that are present in the solutions of Einstein's gravitational equations for the evolution of the universe. The solutions are named after their discoverer Alexandre Friedman. (Einstein wrote down the equations, but he did not find all the solutions.) What Friedman showed was that the scenario that ultimately plays out depends on the density of the universe, that is, the energy per cubic centimeter. If this energy density is high enough then the galaxies and other matter are attracting each other sufficiently to stop the expansion, and turn it back around. But if there is not enough energy density in the universe then the expansion will indeed go on forever. It's much like the problem of the escape velocity for a rocket. If we shoot it up fast enough then it will escape the Earth's pull and fly off into space and never come back. But if we don't give enough of a push it will fall back to earth. It depends on the speed it is going. These two possibilities are connected with the curvature of the space in which we find ourselves. The general theory of relativity predicts that space can actually be curved, in the same sense that the surface of the earth is. If you think of drawing a triangle on the surface of the earth with two vertices at the equator and one at the North Pole, you'll see that the sum of the three angles is greater than 180. This is called positive curvature. It can also happen that the sum of the three angles is less than 180. This is called negative curvature. Flat space is a third alternative in

4 which the sum of the angles is always 180. There is a nice picture of these triangles on two-dimensional surfaces in the book. Of course the real universe is three-dimensional, which unfortunately makes the geometry very hard to draw or to visualize. Fascinatingly, the shape of the universe is also connected to the expansion. If the curvature is flat or negative the universe must expand forever, according to the gravity equations. It's only possible for the expansion of the universe to stop and then start shrinking if the curvature is positive. These alternatives are shown in the accompanying figure. Actually, the figure is plotted in terms of the relative size of the universe, with units. You can think of the vertical axis as the distance to the nearest galaxy. Furthermore, these alternatives have a precise connection with the density of the universe. There is a critical value of the density, given by the equation role critical equals ρ crit = 3 H 2 / 8 π G. This is only about g/ cm 3, which is only about 6 H atoms per cubic meter. (But remember there is a lot of space between stars and galaxies.) If the density is greater than this value, then the universe should be closed and the expansion will eventually stop. If it's less than the critical value than the curvature is negative and the universe expands forever. If

5 the density is exactly equal to the critical density, then the universe is flat and again it will expand forever. Longer Distances The way to investigate the curvature is to look for changes in Hubble's constant H as a function of time. If H is getting bigger, then the expansion is accelerating, while if it is getting smaller, then the expansion is decelerating. We can check this by looking out at more and more distant objects, since that is like looking backward in time. For increasingly distant objects, the red shift z gets bigger and bigger. They also get fainter and fainter, but plotting the redshift versus the brightness for very distant objects is the key to understanding if the expansion is speeding up or slowing down. Starting in the 1990s, this became possible. The idea was to look at the red shift of supernovas which are very bright explosions of stars. It turned out that the intrinsic brightness of so-called type Ia supernovas is very predictable, which means we have a good way of telling how far away they are. This means we can plot the redshift as a function of how far away an object is. I won't go into the details but suffice it to say that the apparent brightness of a supernova does not go down as fast as one would expect as a function of the distance as measured by the red shift z. The curve of brightness versus red shift can be used to settle the question of the shape of the universe, and it appears, to a very good approximation, to be flat. This means both that ρ = ρ crit and that the universe will expand forever; not only that but it appears from these observations that the expansion is actually accelerating! The figure plots the brightness (which astronomers refer to as the magnitude, or mag for short) versus the redshift parameter z. Each point represents a single supernova. As z gets bigger, the supernovas are further and further away, but they do not get fainter as fast as one would expect. This is the evidence for the acceleration of the expansion of the universe.

6 The discovery of the acceleration came as a huge surprise, though the possibility was always there in the equation for the expansion of the universe. It requires a form of matter or energy that exerts a kind of negative pressure, pushing the galaxies apart much faster than one would get from an expansion that is counteracted only by ordinary matter, which always exerts a positive pressure. No one expected that such a form of matter should exist, since there is no evidence for

7 it in other observations. For the same reason it s not even clear that we should call it matter all we can say is that it is some kind of energy and we can t see it anywhere else but in the expansion. So it goes under the name of dark energy. The shape of the brightness versus redshift curve has now been investigated in such detail that we can use it to determine the density of ordinary matter that exerts a positive pressure, and also to determine the density of this other kind of matter that exerts a negative pressure the dark energy. Because the universe is flat the actual total density of matter must be equal to the critical density ρ crit, as we mentioned above. Breaking this down into ordinary (positive pressure) matter and dark energy, it turns out that the amount of ordinary matter is about 32% of the total density and the dark energy is 68% of the total density. This is not good because the actual matter that we see in the universe is only about 4.6% of the total density ρ crit. Dark Matter This gave rise to the hypothesis that there must be other matter, so-called dark matter that we just can't see, but it's somewhere out there in the sky. This must be stuff in addition to the particles in the standard model (unless they are combined in some way that we don t understand at all) because it certainly cannot have electric charge. Electric charge necessarily leads to electromagnetic radiation, and it's exactly that that we don't see from this dark matter. It certainly feels the gravitational interaction because that's what is contributing to the red shift curve. There is now a lot of independent evidence for the existence of dark matter, all of which comes from its gravitational effects. The first evidence is in the speeds of rotations of galaxies. The outer reaches of galaxies tend to rotate much faster than we would expect based on the visible matter, and the additional mass provided by the dark matter explains this commonly observed phenomenon in observations of galaxies. Another effect that is now ascribed to dark matter is the prevalence and strength of gravitational lensing. All matter bends the paths of light in its vicinity which causes a kind of focusing effect when light from a distant galaxy passes through a region of high mass on its way towards us. The strength of this lensing effect is much greater than one would get if only the visible matter was causing. The pattern of anisotropy in the cosmic background radiation also supports the

8 presence of dark matter. Finally it appears that dark matter plays a very important role in the formation of galaxies. Current models of galaxy formation are in pretty good agreement with what we see looking out into the sky, but only if dark matter is there to help things out. If there were no dark matter it would take much longer for galaxies to form, and the history of stars and galaxies would have been quite different. So we are pretty confident these days of the existence of dark matter and of the amount of it. It's about 27% of the total energy density in the universe. However we still have almost no idea what it is. Dark Energy That leaves us with 68% of the universe coming from the amazing and strange dark energy. It's dark because we do not see it anywhere in the universe. It seems to have no function other than to accelerate the expansion of the universe. It doesn't seem to clump together with other matter like dark matter does. So far, there are not even really any serious proposals for trying to determine the nature of dark energy. Is it some kind of other particle? Does it have something to do with quantum tunneling? Could it be particles going in and out of existence, providing a kind of background energy that so far we just don't know how to detect? Science is a continual process of expanding the known into the unknown, always trying to enlarge the area so we understand, and spread the boundaries of knowledge outwards. But that means that there's always a boundary between the known and the unknown. So that's where we are now at the end of our course: standing at that boundary looking out at a mystery.

9

### 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

### 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?

### 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

### Modern Physics notes Spring 2005 Paul Fendley Lecture 38

Modern Physics notes Spring 2005 Paul Fendley fendley@virginia.edu Lecture 38 Dark matter and energy Cosmic Microwave Background Weinberg, chapters II and III cosmological parameters: Tegmark et al, http://arxiv.org/abs/astro-ph/0310723

### 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

### 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

### ASTRO 114 Lecture Okay. We re now gonna continue discussing and conclude discussing the entire

ASTRO 114 Lecture 55 1 Okay. We re now gonna continue discussing and conclude discussing the entire universe. So today we re gonna learn about everything, everything that we know of. There s still a lot

### Chapter 18. Cosmology. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 18 Cosmology Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cosmology Cosmology is the study of the structure and evolution of the Universe as a whole

### The Universe. Unit 3 covers the following framework standards: ES 8 and 12. Content was adapted the following:

Unit 3 The Universe Chapter 4 ~ The Formation of the Universe o Section 1 ~ The Scale of the Universe o Section 2 ~ The Formation of the Universe o Section 3 ~ The Future of the Universe Chapter 5 ~ Galaxies

### 4.3 The accelerating universe and the distant future

Discovering Astronomy : Galaxies and Cosmology 46 Figure 55: Alternate histories of the universe, depending on the mean density compared to the critical value. The left hand panel shows the idea graphically.

### 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

### 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

### The best evidence so far in support of the Big Bang theory is:

Notes about the final exam: Saturday May 17th, 7:45 AM-9:45 AM Chamberlain 2103 If you have a CONFLICT email me or Ella before the end of this week. No excuses accepted after exam. Comprehensive, covering

### TA Final Review. Class Announcements. Objectives Today. Compare True and Apparent brightness. Finding Distances with Cepheids

Class Announcements Vocab Quiz 4 deadline is Saturday Midterm 4 has started, ends Monday Lab was in the Planetarium. You still need to do the 2 questions Check PS100 webpage, make sure your clicker is

### 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

### The LARGE POP TREMENDOUS EXPLOSION GIANT POW ENORMOUS WALLOP. BIG BANG(theory)!

The LARGE POP TREMENDOUS EXPLOSION GIANT POW ENORMOUS WALLOP BIG BANG(theory)! What IS the Big Bang? One of many plausible theories that tries to answer the question: How did the universe get to be the

### The expansion of the Universe, and the big bang

The expansion of the Universe, and the big bang Q: What is Hubble s law? A. The larger the galaxy, the faster it is moving way from us. B. The farther away the galaxy, the faster it is moving away from

### The Big Bang Theory was first proposed in the late 1920 s. This singularity was incredibly dense and hot.

The Big Bang Theory was first proposed in the late 1920 s. It states that there was an infinitely small, infinitely dense point that contained everything that is the universe. This singularity was incredibly

### 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

### 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

### 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

### 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

### Astronomy 162, Week 10 Cosmology Patrick S. Osmer Spring, 2006

Astronomy 162, Week 10 Cosmology Patrick S. Osmer Spring, 2006 Information Makeup quiz Wednesday, May 31, 5-6PM, Planetarium Review Session, Monday, June 5 6PM, Planetarium Cosmology Study of the universe

### 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

### 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

### Pic of the day: From April 15, Messier 101, 170,000 light years across, twice the size of the Milky Way.

April 18, 2011 Exam back Wednesday Reading: Chapter 12 Astronomy in the news: new experiment in the Gran Sasso tunnel under the Alps may have a slight suggestion of the direct detection of particles of

### Agenda. Chapter 17. Cosmology. Cosmology. Observations of the Universe. Observations of the Universe

Agenda Chapter 17 3/17/09 Measure Solar Altitude is it really 2pm? Announce: Observation: Tue March 24 Test 2: Tue March 24 Online stuff due by Test 2 Ch. 17 Cosmology Labwork: Hubble s Law & Large Scale

### 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

### Observing the Night Sky. Observing the Night Sky. Observing the Night Sky. Observing the Night Sky. Observing the Night Sky. Chapter 29 THE UNIVERSE

Hewitt/Lyons/Suchocki/Yeh Conceptual Integrated Science Constellations are groups of stars named over antiquity. A familiar constellation is Ursa Major, the Great Bear. Chapter 29 THE UNIVERSE The monthly

### The State of the Universe [2010] There is only data and the interpretation of data (green text = assumptions)

The State of the Universe [2010] There is only data and the interpretation of data (green text = assumptions) Current thinking in cosmology says that the universe is filled with dark matter and dark energy.

### The Formation of the Solar System

Earth and the Solar System The Formation of the Solar System Write a number beside each picture to rank each from the oldest (1) to the youngest (4). The universe includes everything that exists: all matter,

### 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

### 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

### Dark Energy and the Accelerating Universe

Dark Energy and the Accelerating Universe Dragan Huterer Department of Physics University of Michigan The universe today presents us with a grand puzzle: What is 95% of it made of? Shockingly, we still

### 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

### Lecture 25: Cosmology: The end of the Universe, Dark Matter, and Dark Energy. Astronomy 111 Wednesday November 29, 2017

Lecture 25: Cosmology: The end of the Universe, Dark Matter, and Dark Energy Astronomy 111 Wednesday November 29, 2017 Reminders Online homework #11 due Monday at 3pm One more lecture after today Monday

### Big Bang Theory PowerPoint

Big Bang Theory PowerPoint Name: # Period: 1 2 3 4 5 6 Recombination Photon Epoch Big Bang Nucleosynthesis Hadron Epoch Hadron Epoch Quark Epoch The Primordial Era Electroweak Epoch Inflationary Epoch

### How Did the Universe Begin?

How Did the Universe Begin? As we will discuss in this lecture, it looks like the Universe started about 14 billion years ago and has been expanding (space stretching) ever since. The model of what happened

### Modern Physics notes Spring 2005 Paul Fendley Lecture 37

Modern Physics notes Spring 2005 Paul Fendley fendley@virginia.edu Lecture 37 The red shift The Hubble constant Critical density Weinberg, chapters I and II cosmological parameters: Tegmark et al, http://arxiv.org/abs/astro-ph/0310723

### 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

### The Early Universe and the Big Bang

The Early Universe and the Big Bang Class 24 Prof J. Kenney June 28, 2018 Final Exam: Friday June 29 at 2-5pm in Watson A48 What the Final Exam will emphasize: Classroom lectures 10-24 (starting FRI June

### 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

### Cosmology and particle physics

Cosmology and particle physics Lecture notes Timm Wrase Lecture 3 Our universe (and its fate) In this lecture we discuss the observed values for the different forms of energy and matter in our universe.

### What is the 'cosmological principle'?

What is the 'cosmological principle'? Modern cosmology always starts from this basic assumption the Universe is homogeneous and isotropic. This idea seems strange there's empty space between me and the

### Friday, April 28, 2017

Friday, April 28, 2017 Fifth exam and sky watch, FRIDAY, May 5. Lectures end of 30 to 38. Review Sheet posted today Reading for Exam 5: Chapter 9 Sections 9.6.1, 9.6.2, 9.7; Chapter 10 - Sections 10.1-10.4,

### Cosmology. What is Cosmology?

Cosmology What is Cosmology? The study of the structure and evolution of the entire universe The idea is to form picture of the entire Universe: origin, size, and future We will make assumptions that what

### According to the currents models of stellar life cycle, our sun will eventually become a. Chapter 34: Cosmology. Cosmology: How the Universe Works

Chapter 34: Cosmology According to the currents models of stellar life cycle, our sun will eventually become a a) Cloud of hydrogen gas b) Protostar c) Neutron star d) Black hole e) White dwarf id you

### 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

### Today. Announcements. Big Bang theory cont d Introduction to black holes

Today Announcements HW #8 due Friday (tomorrow) 8am Test #2 average was 31/40 not as bad as it first appeared (several answer sheets were put in the wrong pile) Big Bang theory cont d Introduction to black

### Lecture 05. Cosmology. Part I

Cosmology Part I What is Cosmology Cosmology is the study of the universe as a whole It asks the biggest questions in nature What is the content of the universe: Today? Long ago? In the far future? How

### Astronomy 100 Exploring the Universe Tuesday, Wednesday, Thursday. Tom Burbine

Astronomy 100 Exploring the Universe Tuesday, Wednesday, Thursday Tom Burbine tomburbine@astro.umass.edu Mass-to-Light Ratio You can compare the measured mass to the luminosity of a galaxy Milky Way Milky

### 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

### The Universe: What We Know and What we Don t. Fundamental Physics Cosmology Elementary Particle Physics

The Universe: What We Know and What we Don t Fundamental Physics Cosmology Elementary Particle Physics 1 Cosmology Study of the universe at the largest scale How big is the universe? Where What Are did

### mass times that of the Sun - it once the white dwarf reaches a critical material from its binary companion, and

Learning about the composition of our universe has involved multiple astronomical surveys. Below are a collection of the types of observations that have led to astronomers' current understanding of the

### Chapter 21 Evidence of the Big Bang. Expansion of the Universe. Big Bang Theory. Age of the Universe. Hubble s Law. Hubble s Law

Chapter 21 Evidence of the Big Bang Hubble s Law Universal recession: Slipher (1912) and Hubble found that all galaxies seem to be moving away from us: the greater the distance, the higher the redshift

### Particles in the Early Universe

Particles in the Early Universe David Morrissey Saturday Morning Physics, October 16, 2010 Using Little Stuff to Explain Big Stuff David Morrissey Saturday Morning Physics, October 16, 2010 Can we explain

### SOLAR SYSTEM, STABILITY OF ORBITAL MOTIONS, SATELLITES

SOLAR SYSTEM, STABILITY OF ORBITAL MOTIONS, SATELLITES Q1. The figure below shows what scientists over 1000 years ago thought the solar system was like. Give one way that the historical model of the solar

### Cosmology. Big Bang and Inflation

Cosmology Big Bang and Inflation What is the Universe? Everything we can know about is part of the universe. Everything we do know about is part of the universe. Everything! The Universe is expanding If

### 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

### Big Bang, Black Holes, No Math

ASTR/PHYS 109 Dr. David Toback Lecture 19 1 Was due Today L19 Reading: (Unit 4) Unit 5: Assigned today Pre-Lecture Reading Questions (PLRQ) Unit 3 (Original or Revision) and Unit 4 Let us know if you think

### What is the evidence that Big Bang really occurred

What is the evidence that Big Bang really occurred Hubble expansion of galaxies Microwave Background Abundance of light elements but perhaps most fundamentally... Darkness of the night sky!! The very darkness

### 5% of reality is all we have ever seen

Sean Carroll University of Chicago http://pancake.uchicago.edu/ 5% of reality is all we have ever seen What does the universe look like? stars and galaxies; uniform, expanding What is the universe made

### Astronomy 150: Killer Skies. Lecture 35, April 23

Assignments: ICES available online Astronomy 150: Killer Skies HW11 due next Friday: last homework! Lecture 35, April 23 note: lowest HW score dropped but: HW11 material will be on Exam 3, so be sure to

### PHY326/426:Lecture 19

PHY326/426:Lecture 19 Dark Energy Finish WIMP signals Evidence for Dark Energy Type Ia Supernovae What is Dark Energy The fate of the Universe The Distance-Redshift relation Recall from lecture 2: The

### 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.

### Astronomy 122 Final Exam

Astronomy 122 Final Exam This Class (Lecture 28): The Beginning is the End. HW11 due Wednesday In this classroom, May 6 th from 1:30-4:30pm Multiple choice 70 questions. Can bring one sheet of notes Can

### 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

### Lec 9: Stellar Evolution and DeathBirth and. Why do stars leave main sequence? What conditions are required for elements. Text

1 Astr 102 Lec 9: Stellar Evolution and DeathBirth and Evolution Why do stars leave main sequence? What conditions are required for elements Text besides Hydrogen to fuse, and why? How do stars die: white

### The Cosmological Principle

Cosmological Models John O Byrne School of Physics University of Sydney Using diagrams and pp slides from Seeds Foundations of Astronomy and the Supernova Cosmology Project http://www-supernova.lbl.gov

### Chapter 33 The History of a Star. Introduction. Radio telescopes allow us to look into the center of the galaxy. The milky way

Chapter 33 The History of a Star Introduction Did you read chapter 33 before coming to class? A. Yes B. No You can see about 10,000 stars with the naked eye. The milky way Radio telescopes allow us to

### Relative Sizes of Stars. Today Exam#3 Review. Hertzsprung-Russell Diagram. Blackbody Radiation

Today Exam#3 Review Exam #3 is Thursday April 4th in this room, BPS 40; Extra credit is due 8:00 am Tuesday April 9 Final Exam is 3:00pm Monday April 8 in BPS 40 The exam is 40 multiple choice questions.

### Killer Skies. HW 10/Moon Report due today Exam 3, Dec 11 Last time: Galaxies Collide Today: Hubble s Law

Killer Skies HW 10/Moon Report due today Exam 3, Dec 11 Last time: Galaxies Collide Today: Hubble s Law Music: The Universe is You Sophie Ellis-Bextor 1 Hour Exam 3 Hour Exam 3 Wed, Dec 11th, in class

### What is the difference between a galaxy and a solar system?

What is the difference between a galaxy and a solar system? By NASA, adapted by Newsela staff on 09.19.17 Word Count 819 Level 970L An image of the Milky Way galaxy taken In celebration of the International

### Origin, early history, and fate of the Universe Does the Universe have a beginning? An end? What physics processes caused the Universe to be what it

Cosmology Origin, early history, and fate of the Universe Does the Universe have a beginning? An end? What physics processes caused the Universe to be what it is? Are other universes possible? Would they

### 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)

### 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

### Expanding Universe. 1) Hubble s Law 2) Expanding Universe 3) Fate of the Universe. Final Exam will be held in Ruby Diamond Auditorium

Expanding Universe November 20, 2002 1) Hubble s Law 2) Expanding Universe 3) Fate of the Universe Final Exam will be held in Ruby Diamond Auditorium NOTE THIS!!! not UPL Dec. 11, 2002 10am-noon Review

### 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

### 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

### Chapter 22 Reading Quiz Clickers. The Cosmic Perspective Seventh Edition. The Birth of the Universe Pearson Education, Inc.

Reading Quiz Clickers The Cosmic Perspective Seventh Edition The Birth of the Universe 22.1 The Big Bang Theory What were conditions like in the early universe? How did the early universe change with time?

Wallace Hall Academy CfE Higher Physics Unit 1 - Universe Notes Name 1 Newton and Gravity Newton s Thought Experiment Satellite s orbit as an Application of Projectiles Isaac Newton, as well as giving

### 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

### The first 400,000 years

The first 400,000 years All about the Big Bang Temperature Chronology of the Big Bang The Cosmic Microwave Background (CMB) The VERY early universe Our Evolving Universe 1 Temperature and the Big Bang

### NSCI 314 LIFE IN THE COSMOS

NSCI 314 LIFE IN THE COSMOS 2 BASIC ASTRONOMY, AND STARS AND THEIR EVOLUTION Dr. Karen Kolehmainen Department of Physics CSUSB COURSE WEBPAGE: http://physics.csusb.edu/~karen MOTIONS IN THE SOLAR SYSTEM

### What does Dark Matter have to do with the Big Bang Theory?

Lunar Society What does Dark Matter have to do with the Big Bang Theory? Prof. David Toback Texas A&M University Mitchell Institute for Fundamental Physics and Astronomy Prologue We live in a time of remarkable

### o Terms to know o Big Bang Theory o Doppler Effect o Redshift o Universe

Standard 1: Students will understand the scientific evidence that supports theories that explain how the universe and the solar system developed. They will compare Earth to other objects in the solar system.

### 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

### 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

### Inflationary Universe and. Quick survey about iclickers Review of Big Bang model of universe Review of Evidence for Big Bang Examining Inflation

Inflationary Universe and Quick survey about iclickers Review of Big Bang model of universe Review of Evidence for Big Bang Examining Inflation Survey questions 1. The iclickers used in class encouraged

### Survey questions. Inflationary Universe and. Survey Questions. Survey questions. Survey questions

Inflationary Universe and Quick survey about iclickers Review of Big Bang model of universe Review of Evidence for Big Bang Examining Inflation Survey questions 1. The iclickers used in class encouraged

### Figure 19.19: HST photo called Hubble Deep Field.

19.3 Galaxies and the Universe Early civilizations thought that Earth was the center of the universe. In the sixteenth century, we became aware that Earth is a small planet orbiting a medium-sized star.

### Ta-Pei Cheng PCNY 9/16/2011

PCNY 9/16/2011 Ta-Pei Cheng For a more quantitative discussion, see Relativity, Gravitation & Cosmology: A Basic Introduction (Oxford Univ Press) 2 nd ed. (2010) dark matter & dark energy Astronomical

### How do we measure properties of a star? Today. Some Clicker Questions - #1. Some Clicker Questions - #1

Today Announcements: HW#8 due Friday 4/9 at 8:00 am. The size of the Universe (It s expanding!) The Big Bang Video on the Big Bang NOTE: I will take several questions on exam 3 and the final from the videos

### 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

### The Earth in the Universe

The Earth in the Universe (OCR) Evidence for the age of the Earth Scientists once thought that the Earth was only 6000 years old. Rocks have provided lots of evidence for the world being older. 1) Erosion

### What does Dark Matter have to do with the Big Bang Theory?

MSC Bethancourt Lecture What does Dark Matter have to do with the Big Bang Theory? Prof. David Toback Texas A&M University Mitchell Institute for Fundamental Physics and Astronomy Prologue We live in a