WHAT KIND OF UNIVERSE DO YOU LIVE IN?

Slides:



Advertisements
Similar presentations
Chapter 18: Cosmology For a humorous approach to quarks, check out the Jefferson Lab’s game.  In Looking for the Top Quark, each player receives six quarks.
Advertisements

If you look up at the sky at night, the heavens appear to be unchanging. In 1917 Einstein wrote down the theory of General Relativity. His equations indicated.
Chapter 26: Cosmology Why is the sky dark? The expanding universe Beginning of the universe: The Big Bang Cosmic microwave background The early universe.
The Fate of the Universe. The cosmological principle The simplest universes is: Homogenous – the same everywhere you go Isotropic – the same in all directions.
Dark Energy. Conclusions from Hubble’s Law The universe is expanding Space itself is expanding Galaxies are held together by gravity on “small” distance.
1 Announcements Cosmos Assignment 5, due Monday 4/26, Angel Quiz Monday, April 26 Quiz 3 & Review, chapters Wednesday, April 28, Midterm 3: chapters.
Universe: Space-time, Matter, Energy Very little matter-energy is observable Critical matter-energy density balances expansion and gravitational collapse.
In Search of the Big Bang
Chapter 26: Cosmology How big is the universe? How long has it been around and how long will it last?
Chapter 26.
Please press “1” to test your transmitter.
Expanding Universe 1)Hubble’s Law 2)Expanding Universe 3)Fate of the Universe November 20, 2002 Final Exam will be held in Ruby Diamond Auditorium NOTE.
© 2007 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their.
Cosmology: The Study of the Universe as a Whole Physics 360 Geol 360 Astronomy John Swez.
Announcements The final exam will be at Noon on Monday, December 13 in Van Allen Hall LR1. The final exam will be cumulative. The final will be 40 questions,
COSMOLOGY SL - summary. STRUCTURES Structure  Solar system  Galaxy  Local group  Cluster  Super-cluster Cosmological principle  Homogeneity – no.
Our Evolving Universe1 Vital Statistics of the Universe Today… l l Observational evidence for the Big Bang l l Vital statistics of the Universe   Hubble’s.
The Fate of the Universe
So, how’s it gonna end? The Big Bang started the universe expanding fast, but gravity should have put on the brakes. Expansion should slow down after.
Hubble’s Observations - Edwin Hubble, in the late 1920's, discovered that all galaxies are moving away from each other as he observed the red shift in.
Universe Scale We can’t measure size of universe (especially if infinite), so compare distances at different times in history: Distances between non-moving.
10B The Big Bang Where do we come from, where are we going?
THEORIES OF UNIVERSE FORMATION. Studying Space Cosmology – the study of the origin, structure, and future of the universe Astronomers study planets, stars,
Copyright © 2010 Pearson Education, Inc. Chapter 17 Cosmology Lecture Outline.
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.
To do: Run through the ppt on Big Bang and Cosmology (resources.faulkes-telescope.com > GCSE Astronomy > Class Exercises > Cosmology Complete the following.
Cosmology- the study of the origin, evolution and composition of the universe.
Cosmology (Chapter 14) NASA. Student Learning Objectives Describe the Big Bang theory Analyze possible fates of our universe.
Announcements Final exam is Monday, May 9, at 7:30 am. –Students with last names A-K go to 225 CB. –Students with last names L-Z go to 300 CB. –All students.
Homework for today was WORKBOOK EXERCISE: “Expansion of the Universe” (pg in workbook)
The Beginning of Time Review: evidence for dark matter evidence for dark matter comes from  motions of stars and gas in galaxies  motions of galaxies.
The Fate of the Universe. The fate depends on the rate of expansion and the density Density greater than critical value – gravity will halt expansion.
Milky Way Galaxy. Galaxy A group of stars, dust and gases held together by gravity. 170 billion galaxies in the universe 200 billion stars in a galaxy.
Option D. 3. Universe was born around 13.8 billion years ago in process called Big Bang In the beginning, all matter & energy in the entire universe was.
Cosmology. Olbers’s Paradox The Universe may be infinite – if it is, why is the night sky dark?
WHAT KIND OF UNIVERSE DO YOU LIVE IN? What is the fate of the Universe?
Cosmology in the 21 st Century. Olbers’s Paradox Why is the sky dark at night? If the universe is infinite, then every line of sight should end on the.
© 2017 Pearson Education, Inc.
Astrophysics and Cosmology
© 2017 Pearson Education, Inc.
Universe.
Chapter 30 Section 4 Big Bang Theory.
The Universe
Doesn’t that mean we are in the centre of the universe?
The Big Bang The Big Bang
Matter Unit BIG BANG NOTES.
Where do we come from, where are we going?
dark matter and the Fate of the Universe
FORMATION OF THE UNIVERSE
Olber’s Paradox The universe is expanding! Hubbles Law.
Galaxies and the Universe
From small to big scales
Chapter 17 Cosmology.
Warm-up Listen to the theme song of Big Bang Theory.
The Big Bang Theory.
Warm-up Listen to the theme song of Big Bang Theory.
Cosmology The study of the structure and evolution of the Universe as a whole. Seeks to answer questions such as: How big is the Universe? What shape is.
Key Areas covered Evidence for the expanding Universe
Matter Unit BIG BANG NOTES.
Cosmology.
Georges LeMaitre theorized The Big Bang in 1927 two years before
Cosmology: The Origin and Evolution of the Universe
The Big Bang The Big Bang
Cosmology What is Cosmology? Study of the universe as a whole
Theories of Universe Formation
Absorption lines of a galaxy shift toward the blue end of the spectrum when it moves toward Earth. The lines shift to the red end of the spectrum when.
Origin of Universe - Big Bang
Chapter 15 – Stars, Galaxies and the Universe
How was it formed? How old is it? What does the future hold?
Galaxies and the Universe
Presentation transcript:

WHAT KIND OF UNIVERSE DO YOU LIVE IN? What is the fate of the Universe?

History of the Universe in a Nutshell time History of the Universe in a Nutshell 14 billion yrs galaxies form 1 billion yrs atoms form 380,000 yrs 3 min nuclei form time

As the universe expanded it cooled and its density decreased This is what drove all the physics: temperature and density Today the universe is 2.73 degrees Kelvin (absolute)

Structure Formation (Galaxies) Driven by gravity… Dark matter is immune to temperature of normal matter (doesn’t interact with light). Dark matter has always been “cold” and so contracted under gravity and thus provided gravity seeds for overall structure growth. Compare real (above) to model (left)

We used to teach 3 possible fates: OPEN------ density < “critical”; forever expanding FLAT------- density = “critical”; expanding, but forever slowing CLOSED - density > “critical”; expanding, then contracting and collapse All we had to do was determine what the density of the universe is compared to the critical density! Closed Flat Open

Angular variations in the temperature of the cosmic microwave background provide clues to geometry of the universe. Most angular variations are about 1 degree apart. They indicate that the universe has a flat geometry…

The Universe is Flat! If the universe is flat, then it has 100% of the critical density! We would expect that normal matter comprises all the density, right?

Measurements of the abundance of deuterium and lithium (relative to hydrogen) indicate that normal matter comprises only 4% of the critical density! How can this be? The universe has critical density, but matter is only 4% What is the remaining 96% of the density of the universe?

But, 90% of matter is actually dark matter! In galaxies, the rotation speeds indicate that 90% of the matter is invisible, i.e. dark matter. In galaxy clusters, the confined hot X-ray gas also indicates that 90% of the matter is invisible, i.e. dark. Hmmm, that still accounts for only about 30% of the critical density!!! Where is the additional 70% that is required for a flat “critical” universe?

And then… all hell broke loose with the supernovae distances... Standard Candles: Supernovae Surveys of SNe yielded a surprising result: the peak brightness of the SNe is lower than predicted by Hubble’s law! This means that the SNe are farther away than if the expansion rate of the universe were just coasting and slowing down under gravity… Something is forcing space to expand faster and faster with time! The expansion is not slowing down with time… it is accelerating!!!

Precision Cosmology? MATTER + DARK MATTER + DARK ENERGY = TOTAL In Einstein’s equations, there is an anti-gravity term called the cosmological constant; at first Einstein thought it was a mistake… we now know it is a mysterious form of energy density, we call it dark energy. MATTER + DARK MATTER + DARK ENERGY = TOTAL 4% + 33% + 67% = 100% We know that the total matter/energy density is 100% of the critical value (the universe is flat)… But, we know only what 4% of the total matter/energy density is!!!!!

So, after the Big Bang, the universe decelerated as it expanded, and about 6 billion years ago it started accelerating as dark energy began to dominate gravity This may sound crazy! But, X-ray observations of galaxy clusters help determine the distances to the clusters. The results indicate that the universal expansion was slowing down at times further back than 6 billion years ago. So, yes Deceleration… Then… Acceleration.

We now speculate that the universe will continue accelerating and, if dark energy continues to grow in strength will end in what is called the Big Rip! Big Rip? Right? And what will we be saying in 10 years from now?

Whatever you do in this life…. Stay tuned to ASTRONOMY! Good luck and best wishes for you endeavors!