Concluding Comments For the Course

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Concluding Comments For the Course

• Cosmology
• Fascinating Past
• Highly accomplished present (for example, the
  material covered in this course).
• Really exciting future

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Time
The History of the Universe
Today
Anti-Gravity?!
Galaxy Formation
Last Scattering
Nuclear High Energy Physics
Inflation?
Extra Dimensions?
High Energy Temp
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Concluding Comments For the Course

• Cosmology
• Fascinating Past
• Highly accomplished present (for example, the
  material covered in this course).
• Really exciting future

4
Past Cosmology provided a great source of
inspiration and new ideas
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Concluding Comments For the Course

• Cosmology
• Fascinating Past
• Highly accomplished present (for example, the
  material covered in this course).
• Really exciting future

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Present Deep understanding of our universe
comes from 1) Application of known laws of
physics
Atomic energy levels
Emission
Absorption
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Present Deep understanding of our universe
comes from 1) Application of known laws of
physics
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Present Deep understanding of our universe
comes from 2) Collecting amazing data sets
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The Keck 10m Telescopes on Mauna Kea, Hawaii
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Segments of the Keck 10m Telescope Mirror
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1996
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Mass inferred from lensing Must have dark matter
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Present Deep understanding of our universe
comes from 3) Putting Data and physics together
to get the big picture ? Big Bang Theory
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What we know about the big picture
1) On large scales the matter in the Universe is
spread out very smoothly (Homogeneous)
Mean density
2) The Universe is expanding
Hubble law
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The homogeneity of the Universe
Galaxy
Isotropy of the microwave background (from the
edge of the observable universe) to one part in
100,000
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The homogeneity of the universe
We are here
Radial Direction
Galaxy surveys
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The homogeneity of the universe
We are here
Radial Direction
From 1986
Galaxy surveys
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The Hubble law
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Time
The History of the Universe
Today
Anti-Gravity?!
Galaxy Formation
Last Scattering
Nuclear HEP
Inflation?
Extra Dimensions?
High Energy Temp
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Present Deep understanding of our universe
comes from 4) Exploring and observing
consequences of the Big Bang such as CMB The
edge of the observable universe
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The Edge of the Observable Universe As we look
back in space we look back in time. We see
Light traveling from far away from distant past
Here Now
Long ago (about 14 Billion years) the Universe
was so hot and dense it was opaque The edge of
the observable universe
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Properties of the Edge of the Observable Universe
Similar to surface of Sun at time of emission

• Today
• Only 2.726K above absolute Zero
• Microwave Radiation (The Cosmic Microwave
  Background CMB)
• 1,000,000 times weaker than ambient radiation in
  a pitch dark room.

Here Now
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Properties of the Edge of the Observable Universe
Similar to surface of Sun at time of emission
Cools off due to cosmic expansion Same thing
happens with stars Oblers paradox (see section
23.4)

• Today
• Only 2.726K above absolute Zero
• Microwave Radiation (The Cosmic Microwave
  Background CMB)
• 1,000,000 times weaker than ambient radiation in
  a pitch dark room.

Here Now
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Observing the Microwave Background, Past, present
and future
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Time
The History of the Universe
New Image of the Last Scattering Surface from
NASAs WMAP satellite released Feb 11 2003
High Energy Temp
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Maps of the microwave sky (the edge of the
observable universe
1993
Real data
Updated after WMAP announcement, Feb 2003
Real data !
2009
Simulated data
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WMAP map of the edge of the observable universe
plotted as a sphere
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WMAP map of the edge of the observable universe
plotted as a sphere
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Present Deep understanding of our universe
comes from 4) Exploring and observing
consequences of the Big Bang such as Formation of
Nuclei
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Time
The History of the Universe
Today
Anti-Gravity?!
Galaxy Formation
Last Scattering
Nuclear High Energy Physics
Inflation?
Extra Dimensions?
High Energy Temp
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Present Deep understanding of our universe
comes from 5) New ideas such as cosmic
inflation that seem to explain the start of the
Big Bang and fit the data nicely
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WMAP

• Characteristic oscillations in the CMB power

Inflation
Temperature Power ?
Active models
Adapted from Bennett et al Feb 11 03
? Angular scale
I.1 Successes
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• The future is exciting because of
• Deep Mysteries
• Dark Matter
• Dark Energy

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Cosmic acceleration (newest data) Using
supernovae (exploding stars) as cosmic
mileposts, acceleration of the Universe has
been detected.
Here for inflation
Preferred by modern data
? Amount of antigravity matter?
Gravitating non accelerating matter
Supernova
? Amount of gravitating matter?
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Here for inflation
Preferred by modern data
? Amount of antigravity matter?
Gravitating non accelerating matter
Supernova
? Amount of gravitating matter?

• Accelerating Dark Energy is what makes ?U1
  (required to give consistency with inflation)
• Acceleration or (required for inflation) is
  possible ()
• Dark Energy very poorly understood (-/)

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95 of the cosmic matter/energy is a mystery. It
has never been observed even in our best
laboratories
Ordinary Matter (observed in labs) 5
Dark Matter 25
Dark Energy (accelerating) 70
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The future is exciting because 2) Fantastic new
data sets will enable us to explore these
mysteries (and hopefully resolve some of them)
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The future of cosmological data

• The James Webb (Next Generation) Space Telescope

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The SNAP Satellite
Here for inflation
Preferred by modern data
? Amount of antigravity matter?
Proposed new experiment
Ordinary non accelerating matter
Supernova
? Amount of ordinary matter?
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The future of cosmological data

• The LSST (Large-aperture Synoptic Survey
  Telescope) NB the director of LSST is Prof Tony
  Tyson of UCD

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The future of cosmological theory

• The new data will allow us to resolve hotly
  contested issues
• Expect progress on
• Can we explain/understand the beginning of the
  universe?
• What is accelerating the universe?
• What caused the galaxies to form?
• What is the fundamental nature of matter and
  gravity?

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• For the future
• -I hope this course has made you better able to
  understand new results as they are reported in
  the press.
• Feel free to come around to my office hours at
  any time in the future with questions.
• Perhaps some of you would like to make a career
  in cosmology research (feel free to see me
  discuss that)