“once you can accept the universe as being something ...raghavan/astr1010/class_01.pdf · things...
TRANSCRIPT
“Onc
e yo
u ca
n ac
cept
the
univ
erse
as
bein
g so
met
hing
exp
andi
ng in
to a
n in
finite
not
hing
whi
ch is
som
ethi
ng,
wea
ring
strip
es w
ith p
laid
is e
asy.
”A
lber
t Ein
stei
n
AS
TR
101
0: A
stro
nom
y of
the
Sol
ar S
yste
m
Fal
l 200
7M
on/W
ed/F
ri 11
:00
a.m
. –11
:50
a.m
.A
derh
old
Lear
ning
Cen
ter
5
Dee
pak
Rag
hava
n
“The
div
ersi
ty o
f the
phe
nom
ena
of n
atur
e is
so
grea
t, an
d th
e tr
easu
res
hidd
en in
the
heav
ens
so r
ich,
pre
cise
ly in
ord
er th
at th
e hu
man
min
d sh
all n
ever
be
lack
ing
in fr
esh
nour
ishm
ent.”
Joha
nnes
Kep
ler
1597
-16
30
Why
Ast
rono
my?
Cha
pter
1 o
peni
ng fi
gure
Top
ics
Cov
ered
in th
is C
ours
e
•T
he b
ig p
ictu
re u
nder
stan
ding
of t
he c
osm
os•
Com
mon
obs
erva
tions
–U
nive
rse
as v
iew
ed f
rom
the
Ear
th
–S
easo
ns, L
unar
Pha
ses,
Ecl
ipse
s
•D
evel
opm
ent o
f ast
rono
my
thro
ugh
the
ages
•P
hysi
cal l
aws
of th
e un
iver
se•
Ligh
t and
its
inte
ract
ion
with
mat
ter
•T
eles
cope
s &
Tec
hniq
ues
•S
olar
Sys
tem
For
mat
ion
•T
he S
un, P
lane
ts, M
oons
, and
oth
er S
S b
odie
s•
Ext
raso
lar
plan
ets
•Li
fe o
n E
arth
and
in th
e U
nive
rse
Ass
essi
ng Y
our
Per
form
ance
•4
Hom
ewor
k A
ssig
nmen
ts
15%
•In
-cla
ss A
ctiv
ities
/Qui
zzes
10
%•
Labo
rato
ry w
ork
25%
•In
-cla
ss E
xam
s (B
est 2
of 3
) 30
%•
Fin
al E
xam
on
Dec
embe
r 12
th20
%
•G
radi
ng S
cale
�A
9
4 –
100%
A-
90 –
93%
�B
+ 8
7 –
89%
B
84
–86
%B
-80
–83
%�
C+
77
–79
%C
74
–76
%C
-70
–73
%�
D
60
–69
%F
0
–59
%
Key
s to
You
r S
ucce
ss
•“E
ight
y pe
rcen
t of s
ucce
ss is
sho
win
g up
” -
Woo
dy A
llen
•P
artic
ipat
e ac
tivel
y in
the
clas
sroo
m•
Sto
p m
e fo
r qu
estio
ns, c
larif
icat
ions
, com
men
ts•
Don
’t fo
rget
the
labs
!•
Off
ice
Hou
rs–
I wan
t all
of y
ou to
suc
ceed
–If
you
need
ext
ra h
elp,
ple
ase
com
e se
e m
e!•
Wor
k H
ard
–I’l
l try
to c
halle
nge
you,
but
als
o su
ppor
t you
and
m
ake
it fu
n•
Util
ize
the
clas
s w
ebsi
te:
http
://w
ww
.cha
ra.g
su.e
du/~
ragh
avan
/teac
hing
.htm
l
Thi
ngs
to P
urch
ase
•N
ew te
xtbo
ok$1
13–
"The
Cos
mic
Per
spec
tive
4th
editi
on“
•B
enne
tt, D
onah
ue, S
chne
ider
, Voi
t
–C
omes
with
•
Ast
rono
my
Med
ia W
orkb
ook
•M
aste
ring
Ast
rono
my
web
site
acc
ess
–U
sed
book
$85
, doe
s no
t inc
lude
web
acc
ess
($22
)
•La
b w
orkb
ook
$ 41
.95
–A
ctiv
ities
in A
stro
nom
y, 2
007-
2008
edi
tion
•Jo
hn W
ilson
–U
sed
copy
will
not
wor
k!
•La
b m
ater
ials
car
d$
20–
At t
he G
SU
boo
ksto
re
–S
ubm
it to
lab
inst
ruct
or
•A
ll th
is w
ill w
ork
for
AS
TR
102
0 as
wel
l
A F
ew T
hing
s T
hat I
Ask
of Y
ou
•T
urn
off c
ell p
hone
s, p
ager
s et
c.•
Don
’t w
ork
on o
ther
stu
ff w
hile
in c
lass
•D
on’t
dist
urb
clas
s w
ith s
ide
disc
ussi
ons
•If
you
mus
t lea
ve d
urin
g cl
ass,
ple
ase
do
so q
uiet
ly•
Par
ticip
ate,
Inte
ract
, Enj
oy…
So,
let t
he jo
urne
y be
gin!
Wha
t We
Will
Lea
rn T
oday
•W
here
did
we
com
e fr
om?
–Y
our
pers
onal
con
nect
ion
to a
stro
nom
y
•W
hat i
s a
“sci
ence
”?•
Wha
t is
our
plac
e in
the
univ
erse
?•
How
can
we
lear
n ab
out h
ow th
e un
iver
se
was
in th
e pa
st?
Whe
re D
id Y
ou C
ome
Fro
m?
“We’
re a
ll st
ar-s
tuff”
Car
l Sag
an
Fig
1.2
A Q
uick
Rec
ap o
f Uni
vers
al H
isto
ry•
Sta
rts
with
a “
Big
Ban
g” a
bout
14
billi
on y
ears
ago
–S
eede
d th
e un
iver
se w
ith H
ydro
gen
& H
eliu
m
•S
ets
into
a p
erpe
tual
exp
ansi
on•
Loca
l poc
kets
of m
atte
r co
nden
se to
form
gal
axie
s, a
nd
with
in th
em, s
tars
•S
tars
bur
n hy
drog
en to
hel
ium
, and
suc
cess
ivel
y, to
hi
gher
ele
men
ts in
thei
r co
re•
The
mor
e m
assi
ve s
tars
die
in a
spe
ctac
ular
exp
losi
on
(sup
erno
va)
blas
ting
the
elem
ents
into
spa
ce•
Nex
t gen
erat
ion
star
s &
pla
nets
(in
clud
ing
terr
estr
ial)
form
with
the
help
of t
hese
hig
her
elem
ents
•A
t lea
st o
ne p
lane
t fos
ters
life
!•
A fe
w o
f the
se li
ving
bei
ngs
regi
ster
for
this
ast
rono
my
cour
se!
Ast
rono
my
is a
Sci
ence
•S
cien
ceis
the
pro
cess
of a
cqui
ring
know
ledg
e ga
ined
via
a r
igor
ous
tech
niqu
e ca
lled
the
scie
nti
fic
met
ho
d
•S
cien
ce is
no
ta
body
of
fact
sF
ig 3
.25
The
Hal
lmar
ks o
f Sci
ence
•T
he s
impl
est
expl
anat
ion
win
s!–
Occ
am’s
Raz
or
•V
erifi
able
Obs
erva
tions
Fig
3.2
6
Sci
entif
ic T
heor
y
•T
he m
eani
ng o
f the
ory
is d
iffer
ent i
n sc
ienc
e th
an in
eve
ryda
y lif
e•
In s
cien
ce, a
theo
ry is
not
the
sam
e as
a
hypo
thes
is, r
athe
r:•
A s
cien
tific
theo
ry m
ust:
–E
xpla
in a
wid
e va
riety
of o
bser
vatio
ns w
ith a
fe
w s
impl
e pr
inci
ples
–M
ust b
e su
ppor
ted
by a
larg
e, c
ompe
lling
bo
dy o
f evi
denc
e–
Mus
t NO
T h
ave
faile
d an
y cr
ucia
l tes
t of i
ts
valid
ity
Mat
hem
atic
s in
Ast
rono
my
•R
emem
ber
it is
a to
ol to
hel
p yo
u•
We
will
onl
y ne
ed c
alcu
latio
ns a
nd s
impl
e al
gebr
a–
You
will
be
usin
g a
scie
ntifi
c ca
lcul
ator
•C
ome
see
me
if yo
u ne
ed h
elp
Anc
ient
Pon
derin
gs
•H
ow d
o w
e kn
ow w
hat w
e kn
ow?
–F
lat E
arth
or
Rou
nd E
arth
?–
Sun
aro
und
Ear
th o
r E
arth
aro
und
Sun
?
You
r C
osm
ic A
ddre
ss
Let’s
wat
ch th
e P
ower
s of
Ten
Mov
ie…
Fig
1.1
Mai
n P
oint
s S
een
in th
e M
ovie
•T
he U
nive
rse
is e
xtre
mel
y la
rge
(102
6m
)•
The
re is
a lo
t goi
ng o
n ev
en in
the
mic
rosc
opic
rea
lm–
We’
ve s
een
stru
ctur
e do
wn
to 1
0-18
m
•T
he U
nive
rse
is m
ostly
em
pty
–O
n la
rge
scal
es (
sola
r sy
stem
, gal
axy
etc.
)–
On
smal
l sca
les
(ato
ms,
mol
ecul
es e
tc.)
•Lo
cal p
ocke
ts o
f den
sity
mak
e th
e U
nive
rse
inte
rest
ing
The
Cos
mic
Jou
rney
•In
this
cou
rse,
we’
ll di
scus
s al
l 40
orde
rs o
f mag
nitu
de
cove
red
in th
e m
ovie
!•
We
deal
with
the
extr
emel
y sm
all…
–S
ize
of a
n at
om ~
0.0
0000
0000
1 m
•T
o th
e ve
ry la
rge…
–D
ista
nce
to n
eare
stst
ar ~
40,
000,
000,
000,
000,
000
m•
We
use
two
tool
s to
hel
p us
–S
cien
tific
Not
atio
n•
103
= 1
,000
•10
-3=
0.0
01
–In
vent
new
uni
ts•
Ang
stro
m =
10-
10m
(ap
prox
. the
siz
e of
an
atom
)
•Li
ght-
Yea
r ~
101
3km
(or
der
of th
e di
stan
ce to
the
near
est s
tar)
The
Spe
ed o
f Lig
ht
•30
0,00
0 km
/s =
186
,000
mile
s/s
= 6
70 m
illio
nm
ph•
Ext
rem
ely
fast
, but
stil
l a fi
nite
spe
ed•
Aro
und
the
Ear
th ~
8 ti
mes
in o
ne s
econ
d!•
To
the
Moo
n ~
1 s
econ
d•
To
the
Sun
~ 8
min
utes
•T
o th
e ne
ares
tsta
r ~
4 y
ears
•T
o th
e ne
ares
tgal
axy
~ 2
.5 m
illio
nye
ars
1 Li
ght Y
ear
= D
ista
nce
trav
elle
d by
ligh
t in
one
year
App
roxi
mat
ely
6 tr
illio
n m
iles
Ligh
t Yea
r
•1
Ligh
t Yea
r =
Dis
tanc
etr
avel
led
by li
ght
in o
ne y
ear.
•D
ista
nce
= S
peed
x T
ime
1 ly
= s
peed
of l
ight
x 1
yea
r of
tim
e=
300
,000
km
/s x
(36
5 x
24 x
60
x 60
s)=
9,4
60,0
00,0
00,0
00 k
m1
light
yea
r is
–A
ppro
xim
atel
y 10
trill
ion
km–
6 tr
illio
n m
iles
•N
ote:
The
nea
rest
sta
r is
abo
ut 4
lyaw
ay
Look
-bac
k T
ime
•T
he fa
rthe
r w
e lo
ok o
ut, t
he fu
rthe
r in
to th
e pa
stw
e se
e!–
Dire
ct c
onse
quen
ce o
f the
fini
te s
peed
of
ligh
t
•T
he S
un w
e se
e is
as
it w
as 8
m
inut
es a
go!
•A
ndro
med
a G
alax
y is
a 2
.5 m
illio
n ye
ars
old
imag
e!
Fig
1.5