These are the most frequently used words in this book.
background
bang
baryons
between
big
billion
black
cent
clouds
cluster
constant
core
cosmic
cosmological
cosmology
dark
density
disc
distance
earth
effect
electrons
elements
energy
even
experiments
far
few
first
fluctuations
force
form
formation
formed
found
future
galaxies
gas
gravitational
gravity
high
hole
however
hundred
hydrogen
indeed
infinite
inflation
interstellar
large
life
light
long
mass
massive
matter
may
mergers
microwave
milky
million
must
neutron
new
now
number
once
particles
past
per
physics
point
present
pressure
principle
protons
provide
quantum
radiation
rays
redshift
result
scales
second
see
since
small
solar
space
stars
structure
sun
temperature
theory
thousand
time
two
universe
waves
years