Transcript So What All Is Out There, Anyway?

So What All Is
Out There,
Anyway?
The untold story of
Alice’s Adventure in
Wonderverse
She went on
growing, and
growing, and
very soon had
to kneel down
on the floor: in
another minute
there was not
even room for
this . . .
She looks down and sees
Earth
The Moon comes into view
Soon she can see the Sun . . .
. . . and the other inner
planets
There’s the
asteroid belt!
The outer planets . . .
. . . the Kuiper Belt . . .
. . .and the Oort
Cloud
comprise our
solar system
The closest star, Proxima
Centauri, is a red dwarf 4
light years (LY) away
Other stars with planetary
systems
Our galaxy, the Milky Way, is
~100,000 LY across
Clusters of galaxies: Our
Local Group
Clusters of galaxies: The
Virgo Cluster
Superclusters of galaxies
Filaments of
Superclusters
Distance = Time
Proxima Centauri is ~ 4 LY away.
Light leaving star takes 4 years to
arrive at Earth.
Result: We see Proxima Centauri as
it looked 4 years ago!
The Sun 8 Minutes Ago
The Andromeda Galaxy
2.2 million years ago
NGC 1399, 65 Million Years
Ago
• Just Suppose:
– There is a
planet in NGC
1399
– That planet is
exactly like
Earth
– We could see
that planet from
Earth
• What might
we see?
Abell 1825
13.2 billion years ago