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Modern Telescopes and Ancient
SkiesNew Views of the Universe
An IU Lifelong Learning ClassTuesdays, May 10, 17, 24
Size and Scale Surveying
the Universefrom the Earth to the farthest reaches of the visible Universe
Galileo Galilei's "The Phases of the Moon"Image courtesy of Biblioteca Nazionale Florence, Italy
Our closest neighbor
Visualizing the Earth from Space
• What do you see?– Earth
– Moon
– Sun
– Stars
Copyright 1980 by DC Comics Inc.
EarthRadius: 6400 kmDistance from Sun: 150,000,000 km
1 AU, 8 light minutes
Moon
Radius: ¼ Earth’s radiusDistance from Earth:
384,000 km
Solar System
Sizes of planets NOT to scale
Distance to Pluto: about 40 AU(about 320 light minutes)
The Nearest
Stars
The closest star to our Sun is Proxima Centauri, about 4 light years distant.
Most of the stars we see in the sky are within
250 light years
Our Sector of the Galaxy
The Sun lies along one of our Galaxy’s spiral arms, known as the Orion Arm
View of theMilky Way Galaxy
Our Milky Way galaxy contains two hundred billion stars.
The Sun is about 26,000
light years from the center.
Our Milky Way Galaxy is part of a small cluster of galaxies.
Virgo Supercluster
Our Local Group of galaxies is part of a larger supercluster of galaxy groups.
Galaxies and clusters of galaxies collect into vast streams, sheets and walls of galaxies.
The Visible Universe
On the largest scales, the universe seems to be more or less uniform
With thanks to Bill Watterson, 1990
What will we cover?????
How telescopes work
Modern telescopes
Sky viewing
Space telescopesSpace telescopes
Kirkwood Obs
Visiting the Gemini Observatory
Future telescopes
Beginnings…
This sketch of a telescope was included in a letter
written by Giovanpattista della Porta in August 1609
Thomas Harriet’s Drawings of the
Moon and Sun
Telescopes and
how they work
from lenses…
to mirrors
Technology moves forward…
The 3.5-meter WIYN telescope Kitt Peak, Arizona
New Telescope Technology
“Fast” mirror Lightweight mirror
Mirror shape controlled Mechanically simpler
mount Temperature control
Casting the WIYN Mirror
Polishing the WIYN Mirror
The WIYN New Technology “Dome”
Compact telescope chamber Open for ventilation Insulated to keep cool Heated spaces kept separate
Breaking the “cost curve”
New technology provides better performance at lower cost
WIYN
in 6-8 meter telescopes
WIYN TECHNOLOGY
text
The importance of image quality
typical ground-based image
Hubble image
WIYN image
The Ring Nebula
Connecting the First Nanoseconds to the Origin of Life
How is the Universe put together? The Wilkinson Microwave Anisotropy
Probe tells us about the state of the Universe 400,000 years after the Big Bang.
How did the UniverseHow did the Universeevolve from this…evolve from this…
…to this?
The cosmic web of intergalactic gas and galaxies in a young universe
Intergalacticgas
Clumpsconcentratedby darkmatter lead to galaxies
Observing the assembly of galaxies
Galaxy building blocks
observed withHubble
Simulation
WMAP also providesevidence of the first stars
Tiny fluctuations in polarization
About 200 million years after the Big Bang
We can almost see the first stars
Simulation
What we might see with a 30-meter telescope(Barton et al., 2004)
4 million LY
hydrogen emission from hot stars
Green=hot gas yellow=stars
The composition of stars and gas:
everythingelse
90% hydrogen atoms
10% helium atoms
Less than 1% everything else
What is the Universe made of?
But ordinary matter is only part of the story…
96% of the Universe is something else
Galaxy interactions require more mass than we can see
Antennae Galaxy (HST)
Computersimulation
The real thing
Dark Matter The universe contains additional matter
we cannot see Dark matter interacts with normal
matter through gravity Dark matter does NOT interact with light
the way the normal matter does The Universe contains 5 or 6 times
MORE dark matter than normal matterAll galaxies are embedded in clouds of
dark matter We do not know what it is!
“Redshift” of Galaxies
The spectra of galaxies are shifted to the red: galaxies are moving away from us.
The farther away a galaxy is, the faster it recedes from us!
Hubble’s Law
Distance - Velocity Relation
0
1000
2000
3000
0 20000 40000
Velocity (km/sec)
Dis
tan
ce (
LY
)
The speeds of very distant galaxies tell us the Universe
is expanding faster today than in the past
The brightness of stellar explosions tells
us how far away galaxies are
The universe is expanding faster today than it did in early times
This expansion cannot be caused by ordinary or dark matter, which slows expansion.
The acceleration suggests a new repulsive force (anti-gravity) acting on very large scales
The Universe is speeding up!
Dark energy accounts for 73% of the content of the universe
Dark matter accounts for 23%The content we’re familiar with is only 4%
The New Force Is Called “Dark Energy”
We don’t know
What is Dark Energy?
Identifying what dark energy is requires bigger
telescopes and new techniques
Connecting the First Nanoseconds to the Origin of Life
Kirkwood Observatory ViewingTuesday evenings, weather permitting
Night Sky Viewing
• Scheduled nights–Tuesday, May 17
–Tuesday, May 24
• Roof of Swain West
Next Week• Telescopes in Space,
including the Hubble Space Telescope
• New Views of the Universe – Planets around other Suns
• Kirkwood Obs and Rooftop, weather permitting
Is there life elsewhere?
Artist’s conception of 55 Cancri’s planetary system
More than 150 planets found around other stars
Most are vastly different fromour Solar System
detecting planets directly is hardplanets are small and dimplanets are near much brighter stars
detecting planets directly requires large telescopes (30-meters) and/or special instruments
Detecting Planets
Imaging planets around other stars
“Brown Dwarf” orbiting a star
at the same distance as
Saturn from our Sun
Gemini/Keck AO detectionby Michael Liu (IfA), 2002
With a 30-metertelescope we canobtain the spectraof planets aroundother stars to searchfor the signatures of life
Simulation by Sudarskyet al. 2003
Simulation of the spectra of 55 Cancri’s planets
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