x1
y2
x4
✃ 3 ✁ 3
✃
3
✃3
Wh
en
th
e U
niv
ers
ew
as
ve
ryd
en
se
a
nd
ho
t (T
= 1
01
2 K
), sh
ort
lya
fte
rt
he
Big
Ba
ng
*, itc
on
ta
ine
do
nly
ele
me
nt
ary
pa
rtic
les
of m
at
te
r(q
ua
rks
, ele
ct
ron
s, n
eu
trin
os
) an
d
‘gra
ins
’ of lig
ht
ca
lled
ph
ot
on
s.
As
th
ey
co
ole
d, t
he
qu
ark
s c
om
bin
ed
int
op
rot
on
sa
nd
ne
ut
ron
sin
eq
ua
la
mo
un
ts
. Bu
t a
s t
he
te
mp
era
tu
red
rop
pe
d, m
os
tn
eu
tro
ns
tu
rne
din
to
pro
to
ns
wh
ich
are
les
sm
as
siv
e. W
he
nt
he
te
mp
era
tu
refe
llbe
low
10
9 K
, t
he
rew
ere
7p
rot
on
sfo
r eve
ryn
eu
tro
n.
Ne
ut
ron
s a
nd
pro
to
ns
th
en
co
mb
ine
dt
o fo
rmn
uc
lei. T
he
mo
st
st
ab
len
uc
leu
st
ha
tc
ou
ldb
efo
rme
da
t t
ha
tt
ime
wa
sh
eliu
m. A
ll th
e a
va
ilab
len
eu
tro
ns
we
reu
se
dt
o fo
rmh
eliu
m,
giv
ing
on
e h
eliu
mn
uc
leu
sfo
r ev
ery
12
h
yd
rog
en
nu
cle
iat
th
e e
nd
of t
he
p
rimo
rdia
l ep
oc
h.
* se
e t
uim
p 1
2
Hy
dro
ge
n a
nd
he
lium
51
2
Nu
m. o
f
pro
ton
s
So
lar
syste
m
Ea
rth’s
crust
Hu
ma
n
bo
dy
H1
70
.50
.14
9.5
He
22
7.5
--
C6
0.3
00
.03
01
8.5
N7
0.1
10
.00
53
.2
O8
0. 9
64
6.6
65
Si
14
0.0
65
27
.70
.00
00
2
S1
60
.04
00
.05
00
.3
Ca
20
0.0
06
3.6
1.5
Fe
26
0.1
17
5.0
0.0
06
Ma
ss
pe
rce
nt
ag
e o
f th
e c
he
mic
al e
lem
en
ts
in
diffe
ren
t lo
ca
tio
ns
Fro
m th
e B
ig B
an
g to
us
BANG !
Win
ds
, co
llisio
ns
, ex
plo
sio
ns
So
me
of t
he
ele
me
nt
sfo
rme
din
st
ars
a
re e
jec
te
din
to
th
e in
te
rst
ella
rm
ed
ium
w
hile
th
e re
st
are
loc
ke
du
p fo
rev
er
in
th
e ‘s
te
llar
co
rps
es
’ th
at
are
wh
ite
d
wa
rfs, n
eu
tro
ns
ta
rs a
nd
bla
ck
ho
les
.
St
ars
wit
ha
ma
ss
of le
ss
th
an
8
tim
es
th
at
of t
he
Su
n d
isp
ers
e t
he
iro
ut
er
lay
ers
in a
pe
ac
efu
lma
nn
er,
eje
ct
ing
nit
rog
en
, ca
rbo
na
nd
so
me
ele
me
nt
sh
ea
vie
rt
ha
niro
n.
Th
e m
ore
ma
ss
ive
st
ars
en
d t
he
irlife
in
a s
pe
ct
ac
ula
re
xp
los
ion
, a s
up
ern
ova
, a
nd
ex
pe
lca
rbo
n, o
xy
ge
n, n
eo
n,
ma
gn
es
ium
an
d s
ilico
n, a
mo
ng
ot
he
rs.
Ot
he
rh
ea
vy
ele
me
nt
s, s
uc
ha
s g
old
a
nd
ura
niu
m re
qu
irea
ve
ryh
igh
de
ns
ity
of n
eu
tro
ns
to
form
, an
d t
his
is m
ore
lik
ely
to
ha
pp
en
in n
eu
tro
n s
ta
r c
ollis
ion
s.
98
Co
mp
os
ite
ima
ge
of t
he
C
at
’sE
ye
pla
ne
ta
ryn
eb
ula
. Th
is o
bje
ct
res
ult
sfro
ms
ev
era
lep
iso
de
so
f s
te
llar
win
ds
em
an
at
ing
from
th
e c
en
tra
l st
ar
wh
ich
isn
ow
in t
he
p
roc
es
so
f be
co
min
ga
w
hit
e d
wa
rf.
Th
e C
at’s
Eye
pla
ne
tary
ne
bu
la. (C
red
it: R. C
orra
di
with
the
NO
T te
lesco
pe
).
G2
92
.0 + 1
.8: A
s
up
ern
ova
re
mn
an
tc
om
ing
from
a s
ta
r of
gre
at
ma
ss
wh
ich
eje
ct
ed
a lo
t o
f o
xy
ge
n, m
ag
ne
siu
ma
nd
ne
on
int
ot
he
in
te
rst
ella
rm
ed
ium
.
G2
92
.0+
1.8
in
X-ra
ys. Cre
dit
: N
AS
A/C
XC
/SA
O.
Re
pre
se
nt
at
ion
of t
he
c
ollis
ion
of t
wo
ne
ut
ron
s
ta
rs. G
old
, ura
niu
m a
nd
o
th
er h
ea
vy
ele
me
nt
s in
t
he
Un
ive
rse
are
be
liev
ed
to
ha
ve
form
ed
du
ring
su
ch
an
ev
en
t.
Artist v
iew
(Da
na
Be
rry, S
kyW
orks D
igita
l).
Pro
to
n :
form
ed
of
th
ree
ele
me
nt
ary
pa
rtic
les
, t
he
qu
ark
s. I
t h
as
a p
os
itiv
e e
lec
tri
cc
ha
rge
an
d
its
ma
ss
is1
.67
2 6
49
×1
0−24
g.
Ne
ut
ron
: als
ofo
rme
do
f t
hre
eq
ua
rks
bu
t d
oe
sn
ot
ha
ve a
n e
lec
tri
cc
ha
rge
. It
sm
as
s is
1.6
74
9
3 ×
10
−24
g.
Ele
ct
ron
: pa
rtic
leo
f n
eg
at
ive
ele
ct
ric
ch
arg
e,
wh
os
em
as
s i
sa
bo
ut
1/2
00
0o
f t
ha
to
f t
he
p
rot
on
. H
yd
rog
en
: th
e li
gh
te
st
of
th
e e
lem
en
ts
.It
c
on
sis
ts
of
a p
rot
on
an
d a
n e
lec
tro
n.
He
lium
: th
e li
gh
te
st
st
ab
le e
lem
en
ta
fte
rh
yd
ro-
ge
n. I
t c
on
sis
t o
f a
n𝛼
pa
rtic
le a
nd
2 e
lec
tro
ns
.
4
It w
as
Ge
org
e G
am
ow
, in
an
art
icle
wit
hA
lph
er
an
d B
et
he
in 1
94
8, w
ho
pro
po
se
dt
he
th
eo
ryo
f t
he
fo
rma
tio
n o
f p
rim
ord
ial h
yd
rog
en
an
d
he
lium
.In
th
isa
rtic
le, t
he
au
th
ors
furt
he
r a
rgu
ed
th
at
all
th
e o
th
er
ele
me
nt
sw
ere
als
ofo
rme
din
th
e B
igB
an
g b
ys
uc
ce
ss
ive
ly a
dd
ing
ne
ut
ron
s. B
ut
on
th
isp
oin
t t
he
yw
ere
wro
ng
.
pp
p
pp
n
n
n
n
n
np
n
pro
ton
ne
utr
on
de
ute
riu
m
trit
ium
a p
art
icle
On
e p
roc
es
s o
f h
eliu
m f
orm
at
ion
Fro
m s
ta
rs t
o li
vin
g b
ein
gs
Be
fore
be
co
min
g p
art
of
a li
vin
g b
ein
g,
ele
me
nt
sm
us
t p
as
st
hro
ug
hm
an
ys
ta
ge
s t
ha
ta
re s
till
po
orl
yu
nd
ers
to
od
.
Fir
st
th
ere
ist
he
fo
rma
tio
n o
f c
lou
ds
of
mo
lec
ule
sa
nd
du
st
, in
wh
ich
st
ars
are
b
orn
. W
hile
st
illve
ryy
ou
ng
, th
es
es
ta
rs
are
su
rro
un
de
db
y a
pro
to
pla
ne
ta
ryd
isk,
m
ad
e u
p o
f c
lum
ps
of
du
st
an
d ic
e.
It is
fro
mt
his
dis
km
at
eri
alt
ha
tp
lan
et
sa
re f
orm
ed
. Th
eir
ch
em
ica
lco
mp
os
itio
nd
iffe
rsa
cc
ord
ing
to
th
e d
ist
an
ce
fro
mt
he
st
ar:
Th
e s
ma
ller
th
e d
ist
an
ce
, th
e
ea
sie
rit
isfo
r t
he
vo
lat
ile e
lem
en
ts
to
d
iss
ipa
te
. It
als
od
ep
en
ds
on
th
e p
lan
et
s'
ma
ss
: T
he
sm
alle
rt
he
ma
ss
, th
e e
as
ier
itis
for
th
e li
gh
te
rp
art
icle
st
o e
sc
ap
e.
As
th
e p
lan
et
form
s, a
se
gre
ga
tio
no
f e
lem
en
ts
oc
cu
rss
ot
ha
tt
he
co
reh
as
a
dif
fere
nt
co
mp
os
itio
n f
rom
th
e c
rus
t.
Fin
ally
, it
is f
rom
th
e m
at
eri
als
in t
he
c
rus
t t
ha
t li
vin
g b
ein
gs
are
fo
rme
d.
13
Qu
iz
An
sw
er
on
ov
erl
ea
f
Wh
at
ist
he
o
rig
ino
f g
old
?
Gra
ży
na
St
as
ińs
ka
Pa
ris
Ob
se
rva
to
ry
Th
e U
niv
ers
e in
my
po
ck
et
ES-001
No
. 1
4
Le
s é
to
ile
s e
t m
oi
We
co
me
fro
m t
he
st
ars
+
Ou
r bo
die
s a
re m
ad
e u
p o
f wa
te
r (6
3%
), pro
te
ins
(20
%), fa
t (1
0%
), s
ug
ars
(2%
) an
d v
ario
us
min
era
ls(5
%).
Sin
ce
ch
em
ist
ryw
as
de
ve
lop
ed
, at
th
e
en
d o
f th
e 1
8t
h c
en
tu
ry, w
ekn
ow
th
at
all t
he
se
ma
te
rials
are
co
mp
os
ed
of
co
mp
lex
mo
lec
ule
sw
hic
hc
on
ta
ina
to
ms
of h
yd
rog
en
, ca
rbo
n, o
xy
ge
na
nd
o
th
er
ele
me
nt
sin
sm
alle
rq
ua
nt
itie
s.
Th
es
ee
lem
en
ts
are
ex
ac
tly
th
e s
am
ea
s t
ho
se
fou
nd
in p
lan
ts
, in t
he
Ea
rth
'sc
rus
ta
nd
in t
he
at
mo
sp
he
re.
Us
ing
sp
ec
tro
sc
op
y, a
st
ron
om
ers
ha
ve
sh
ow
nt
ha
tt
he
se
sa
me
ele
me
nt
sa
re a
lso
fou
nd
in s
ta
rs. B
ut
itw
as
no
t
un
tilt
he
mid
dle
of t
he
20
th
ce
nt
ury
th
at
as
tro
no
me
rss
uc
ce
ed
ed
in
un
de
rst
an
din
gt
he
orig
ino
f th
es
ee
lem
en
ts
an
d in
dis
co
ve
ring
th
e v
ery
clo
se
link
wh
ich
co
nn
ec
ts
us
to
th
e
st
ars
.
3T
ran
sla
tio
n: S
ta
n K
urt
zT
UIM
P C
rea
tive
Co
mm
on
s
To
lea
rnm
ore
ab
ou
t t
his
se
ries
an
d a
bo
ut
th
e t
op
ics
p
res
en
te
din
th
isb
oo
klet
, p
lea
se
visit
ht
tp
://ww
w.t
uim
p.o
rg
Th
e U
niv
ers
e in
my
po
ck
et
No
. 14
Nr
1
Co
ve
r ima
ge
: ex
tra
ct
of a
pa
int
ing
by
ja
pa
ne
se
art
ist
KA
GA
YA
Th
is b
oo
kle
tw
as
writ
te
nin
20
20
by
G
raż
yn
aS
ta
siń
sk
ao
f th
e P
aris
Ob
se
rva
to
ry(F
ran
ce
)a
nd
rev
ise
d b
y N
iko
s P
ran
tz
os
from
th
e P
aris
Ins
tit
ut
e o
f As
tro
ph
ys
ics
.
Answer
A c
res
ide
: a g
old
c
oin
, st
ruc
k b
y K
ing
C
roe
su
s in
th
e 6
th
c
en
tu
ry B
C. in
Ly
dia
.
Go
ldis
th
ou
gh
tt
o
form
du
ring
th
e
co
llisio
n o
f ne
ut
ron
s
ta
rs lik
et
he
on
e
sh
ow
nin
th
isp
ict
ure
Th
e C
rab
su
pe
rno
va
re
mn
an
t
Pla
ne
ta
ry n
eb
ula
IC 4
18
Th
e s
ta
r B
et
elg
eu
se
Pla
ne
tJ
up
ite
r
At
om
sa
re t
he
ele
me
nt
ary
co
ns
tit
ue
nt
so
f m
at
te
r. Th
ey
co
ns
ist
of a
nu
cle
us
(wh
ich
co
nt
ain
sp
rot
on
sa
nd
ne
ut
ron
s) a
nd
of
ele
ct
ron
s. A
to
ms
co
mb
ine
int
om
ole
cu
les
by
s
ha
ring
th
eir
ele
ct
ron
s. T
he
ce
llso
f th
e
hu
ma
nb
od
y a
re m
ad
e u
p o
f billio
ns
of
mo
lec
ule
s.
2
Th
e h
ist
ory
of s
te
llar
nu
cle
os
yn
th
es
is:
Ro
be
rt d
'Es
co
urt
At
kin
so
n A
pu
blis
he
dh
isa
rtic
le "A
to
mic
sy
nt
he
sis
an
d s
te
llar
en
erg
y" in
19
31
. Ha
ns
Be
th
e B
ide
nt
ified
in
19
38
an
d 1
93
9 t
he
tw
om
ec
ha
nis
ms
th
at
tra
ns
form
hy
dro
ge
nin
to
he
lium
in s
ta
rs.
Fre
d H
oy
le s
ho
we
din
19
46
ho
w t
he
e
lem
en
ts
are
sy
nt
he
siz
ed
from
hy
dro
ge
n.
Ma
rga
ret
an
d G
eo
ffrey
Bu
rbid
ge
, Willia
m
Fo
wle
r an
d F
red
Ho
yle
B2
FH
pu
blis
he
din
1
95
7 t
he
irv
ery
de
ta
iled
art
icle
"Sy
nt
he
sis
of t
he
ele
me
nt
sin
st
ars
" an
d, t
he
sa
me
ye
ar, A
las
ta
ir Ca
me
ron
Cp
ub
lish
ed
"Nu
cle
ar
rea
ct
ion
sin
st
ars
an
d n
uc
leo
ge
ne
sis
".
AB
C
B2F
H6
p
p
p
p
pp
ppp
n
n
n
nnn
nn
nn
nn
np p
n
p
nn
pp
pp
Be
ryll
ium
-8
Ca
rbo
n-1
2
α p
art
icle
α p
art
icle
α p
art
icle
hy
dro
ge
n
he
liu
m
carb
on
ox
yg
en
sili
con
iro
n
Ca
rbo
n
form
at
ion
fro
m
th
ree
he
liu
mn
uc
lei
Dia
gra
mo
f t
he
on
ion
st
ruc
tu
re o
f a
ma
ss
ive
s
ta
r a
t t
he
en
d o
f it
se
vo
lut
ion
.Ea
ch
lay
er
ha
s a
dif
fere
nt
co
mp
os
itio
n. E
lem
en
ts
he
av
ier
th
an
iro
na
re p
rod
uc
ed
by
ne
ut
ron
ca
pt
ure
.
Th
e c
os
mic
od
ys
se
y o
f t
he
ele
me
nt
s
On
ce
re
lea
se
din
to
th
e in
te
rst
ell
ar
me
diu
m, t
he
ele
me
nt
sb
eg
ina
lon
g
jou
rne
ya
cro
ss
th
e g
ala
xie
s, b
efo
reb
ein
gt
rap
pe
dd
uri
ng
th
e f
orm
at
ion
o
f n
ew
st
ars
. Th
us
, su
cc
es
siv
e
ge
ne
rat
ion
so
f s
ta
rs b
ec
om
ein
cre
as
ing
lyri
ch
in c
arb
on
, nit
rog
en
, o
xy
ge
na
nd
ot
he
re
lem
en
ts
.
Th
e jo
urn
ey
of
th
ee
lem
en
ts
th
rou
gh
th
e in
te
rst
ell
ar
me
diu
m c
an
be
ve
ryt
ort
uo
us
, wit
hp
ert
urb
at
ion
s li
nk
ed
to
co
llis
ion
s b
et
we
en
ga
lax
ies
. E
lem
en
ts
rele
as
ed
du
rin
gs
up
ern
ov
a
ex
plo
sio
ns
ca
ne
ve
nm
ak
ein
cu
rsio
ns
in
to
th
e in
te
rga
lac
tic
me
diu
m, a
nd
fi
na
lly
en
d u
p in
ot
he
rg
ala
xie
s.
In f
ac
t, r
ec
en
tn
um
eri
ca
ls
imu
lat
ion
s s
ug
ge
st
th
at
ma
ny
of
th
e e
lem
en
ts
pre
se
nt
in t
he
Mil
ky
Wa
yc
am
e f
rom
ot
he
rg
ala
xie
s.
11
10
Th
e s
ym
bo
lsin
dic
at
et
he
ab
un
da
nc
eo
f o
xy
ge
n(r
ed
wh
ere
ab
un
da
nt
, blu
ew
he
res
ca
rce
).
Cre
dit
: Ló
pe
z-S
án
ch
ez
(AA
O/M
QU
) & K
ori
ba
lski
(CS
IRO
).
Th
e g
ala
xie
s N
GC
15
12
a
nd
NG
C 1
51
0 s
ee
nin
u
ltra
vio
let
lig
ht
. B
rig
ht
a
rea
s a
re r
eg
ion
sw
he
res
ta
rs h
av
e r
ec
en
tly
form
ed
.C
red
it: G
AL
EX
(N
AS
A)
NG
C 1
51
2
NG
C 1
51
0
Th
e v
ery
ho
t a
nd
de
ns
e c
ore
of
a s
ta
r p
rovi
de
sid
ea
lco
nd
itio
ns
fo
r p
rod
uc
ing
larg
er
an
d la
rge
rn
uc
lei.
Fir
st
, hy
dro
ge
na
to
ms
co
mb
ine
to
fo
rmh
eliu
m. T
his
co
rre
sp
on
ds
to
th
e lo
ng
es
tp
ha
se
in t
he
life
of
a s
ta
r. A
lmo
st
all
of
th
e s
ta
rs w
es
ee
sh
inin
gg
et
th
eir
en
erg
yfr
om
th
isp
roc
es
s.
On
ce
th
e h
yd
rog
en
isu
se
du
p, t
he
he
lium
co
rec
on
de
ns
es
an
d it
st
em
pe
rat
ure
ris
es
.Th
en
th
e h
eliu
mn
uc
leif
us
e in
g
rou
ps
of
th
ree
to
fo
rmc
arb
on
, wh
ileh
yd
rog
en
co
nt
inu
es
to
pro
du
ce
he
lium
in
th
e o
ut
er
lay
ers
of
th
e s
ta
r.
He
avi
er
nu
cle
iare
th
en
fo
rme
d, b
y f
urt
he
ra
dd
itio
ns
of 𝛼
pa
rtic
les
in d
iffe
ren
tla
ye
rs. I
f t
he
st
ar
ism
as
siv
e e
no
ug
h, t
his
pro
ce
ss
co
nt
inu
es
un
til
th
e c
ore
ism
ad
e
of
iro
n, t
he
mo
st
st
ab
le e
lem
en
t.
Nu
cle
ihe
avi
er
th
an
iro
na
re c
rea
te
du
nd
er
dif
fere
nt
co
nd
itio
ns
by
th
e a
dd
itio
n o
f n
eu
tro
ns
.
Fu
sio
n in
st
ars
7
+