Transcript Power Point Link

The Cosmic Calendar
• If the entire age of the universe (12.5 billion years) was
compressed into one year, humans appeared about six
minutes before midnight on the last day of the year!
How is this calculated?
Assumptions:
humans “appeared”
150,000 years ago.
One year = 525600 minutes.
Use a proportion:
150,000 years
x minutes

12,500,000,000 years 525600 minutes
Solve for x = 6 minutes
Are we the new kids on the block?
• The period of massive
bombardment (the accretion
era) ended 3.8 billion years
ago
• Within a few million years
single-celled life was
reproducing like rabbits in
springtime
• Multicellular organisms didn’t
show up till about 800 million
years ago
From Humboldt State University
Museum of Natural History
Deep in Time
Read bottom left then
bottom right
Why did it take so long?
• Life might have arisen here several times before the
sterilization from bombardment ended—MORE
LATER!
• Multi-cellular life on Earth uses Oxidation for energy,
this requires oxygen in the air and water, and there
wasn’t any until…
• Cyanobateria created oxygen as a waste gas.
• Apparently it took nearly three billion years to build
up this level of oxygen…then BANG!--The Cambrian
Explosion
For more information on the
development of life on Earth:
• Check out this
website:
• http://www.geocities.c
om/capecanaveral/lab/
2948/onceupon.html
• Some 3rd generation Sun-like
Stars (with enough heavy
elements) are up to two billion
years older than the Sun
• Imagine the same
timeline…intelligent animals
could have been around for a
billion years rather than
150,000.
• They might be more interested
in Earth now if their aging star
is loosing its stability.
• Can then just fly on over?
Have they?
What about Other Solar systems?
Image from: http://users.erols.com/feanor17/UFO.JPG
Looking back in time
• Light, although fast, travels at
a finite speed.
• It takes:
– 8 minutes to reach us from the
Sun
– 8 years to reach us from Sirius
(8 light-years away)
– 1,500 years to reach us from the
Orion Nebula
– 12 billion years from the edge
of the observable universe
The Solar System is part of the
Milky Way Galaxy
• We can’t see our
galaxy from the
outside, but we can see
the Neighbors.
• Here is M31-the
Andromeda Galaxy—
over one hundred
billions stars!
Look out from within the Milky Way
Galaxy
This animated gif shows the streaks of meteors against the
backdrop of the Milky Way--particles of space dust burning up
in the air—be patient!
How large is the Solar System?
• Let’s view it
to scale
– say the Sun
is the size of
a large
grapefruit
(14 cm in
diamter) in
Washing DC
how far
away would
the next star
(grapefruit_
be?
There is plenty of space between the
stars!
The next closet star (Alpha
Centauri) would be 5000
Km away—San Fransisco
is the right distance!
A galaxy of stars!
Sun
Alpha Centairi
On a scale
showing the
entire Milky
Way Galaxy,
the sun and
nearest star are
nearly
touching!
The
distance
from the
sun to the
center of
the
gabblaxy
is about
30,000
light years
How far away is the nearest galaxy?
The Milky Way
and M31 (the
andromeda Galaxy
are shown here
side by side
If each were the
size of a Compact
Disk, how far
apart would the
two disks be?
The answer is
about 2.2 meters
apart (about 12
feet)
In other words, you could put about
twenty galaxies between the two.
The actual sepeartion is about two
million light years.
What is your universal address?
• Correct
address:
Your street, city,
state, country,
then …
The Earth
This swirling storm is Hurricane Katrina
bearing down on New Orleans.
Next line
: Solar System
From APOD—copyright Jimmy Westlake
Milky Way Galaxy
Image reconstruction from Spitzer Space Telescope Data.
Local Group
We are part of approximately 30 galaxies. Most are much
smaller than the Milky way and M31. b
Local Supercluster
The Virgo cluster is
at the heart of the
Virgo
supercluster….our
“local supercluster”
Universe
• Superclusters and
Voids are the largest
structures.
• Check out
http://micro.magnet.f
su.edu/primer/java/s
cienceopticsu/powers
of10/index.html
Distance Quiz
• How many Kilometers in a Mile?
Answer:
• 1.6
• You can also remember that 10 kilometers is
6 miles
• Or one kilometer is 6/10 of a mile.
• How many Kilometers in diameter is the
Earth?
Answer:
• 12700 km (about 13,000)
• You can also convert this to miles:
• 12700 km x 6 miles/10 km = 7900 miles
• How Far away is the moon?
Answer:
• 384,000 km
• In scientific notion this is:
• 3.84 x 105 km
• In terms of the Earth’s diameter, how far
away is the moon (in other words, how
many earths can fit between the Earth and
moon)?
Answer:
• 30 Earth diameters
• So if the Earth was one foot in diamter (a
classroom globe) the moon would be thirty
feet away!
• Pretty close, huh!
Distance Quiz continued
Compared with the distance to the moon, the
sun is how much farther away?
400 times (150,000,000 km or one AU)
How long does it take light to get from the
Sun to the Earth?
8 minutes
Distance quiz p3
•
•
•
•
•
•
•
•
How many Light minutes to Jupiter?
5 AU x 8 minutes/AU = 40 minutes
How many AU to Neptune?
30
How many AU in one light year?
65000
How many light years to the NEAREST star?
4
Distance quiz –celestrial section
• How many light years away is the farthest
star we can see with our naked eyes?
Answer
• About 3000 light years (Deneb is 2200)
• How far to the Center of Galaxy
Answer:
• 30,000 light years (10,000 pc)
• How far to the Andromeda Galaxy?
Answer:
• Two million light years
• Remember—about twenty times the
diameter of the Milky Way
Last question!
• How far to the edge of the observable
Universe?
• 12 billion light years!
• But what is the observable universe?
• It’s a sphere with a radius equal to the age
of the universe in light years.
• If something is farther away than this, then
light hasn’t reached yet, so we cant see it!
Time to get Moving—a universe in
motion
• Contrary to our perception, we are not “sitting still.”
• We are moving with the Earth.
– and not just in one direction
– Note that 1500 km/hr = 2200 ft/sec
•Jump up so that you are
in the air for half a
second…where should
you land?
•Without gravity and
inertia, you would land
1100 feet west of where
you started.
We’re moving pretty fast
around the sun…
distance
1 billion km

time
30 million sec
km
speed  30
sec
speed 
Our Sun moves relative to the other
stars in the local Solar neighborhood!
The sun is about 22 Galactic years
old!
Our Sun and the stars of the local
Solar neighborhood orbit around
the center of the Milky Way
Galaxy every 230 million years!
The Milky Way moves with the expansion of
the Universe!
• Mostly all galaxies
appear to be moving
away from us.
• The farther away they
are, the faster they are
moving.
– Just like raisins in a raisin
cake; they all move apart
from each other as the
dough (space itself)
expands.
Time waits for no one
We live in a changing
universe, with a past
and future.
As we speed around
our star, it is also
changing and evolving
towards a violent end
Will we be around to
watch?
Will humans still be
around billions of
years from now?
Will any life on earth have the technology to reverse the sun’s
evolution, or move on to another star system?
Additional Resources:
• http://www.geocities.com/capecanaveral/lab
/2948/onceupon.html
• http://micro.magnet.fsu.edu/primer/java/scie
nceopticsu/powersof10/index.html