as we look out into the night sky
we are both dazzled and comforted by the
patches of light we find there
stars planets galaxies and a moon
but as instruments became more advanced
astronomers began to suspect there was
something more out there something
hiding in the dark spaces we can't see
it feel it or touch it
but it's there it doesn't emit light or
reflect it it's a substance so
mysterious there's only one way to
describe it dark matter
it's so massive its gravitational pull
influences the brightest and most
colossal objects in space
it's so powerful it can change the
course of light itself
it's a humbling reminder that there's
more to this universe than meets the eye
in order to understand this mysterious
substance physicists on earth are
hunting down a very elusive particle
they believe exists in the subatomic
world
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this is CERN the European Center for the
study of particle physics it's the home
of the world's largest particle
accelerator the Large Hadron Collider
hidden deep underground the Large Hadron
Collider is the only place on earth
powerful enough to bring this mystery
particle into existence at 27 kilometers
in circumference
that's 17 miles it straddles the border
between France and Switzerland as we
enter the accelerator tunnel will
experience firsthand the fastest chase
seen on earth here inside the beam pipe
particles called protons are pushed to
velocities approaching the speed of
light
some of them will smash into other
protons racing straight toward them it's
all part of the hunt for a new kind of
fundamental particle that forms Dark
Matter
already the Large Hadron Collider has
made an incredible discovery that lends
weight to our story not that long ago
there were fireworks at CERN on a recent
4th of July as scientists announced the
discovery of a particle called the Higgs
boson physicists had searched for this
particle for 50 years ever since
theorists showed that the source of the
mass of all fundamental particles
requires its presence particles like
electrons and quarks get their mass when
they pass through the Higgs field and so
might the particle that makes up dark
matter now the search of the Large
Hadron Collider turns to finding the
Dark Matter particle itself
astrophysicists
have demonstrated that over 80% of the
mass in the cosmos consists of dark
matter this is the amazing story of how
we discovered that most of the matter in
the universe is of an extraordinary
invisible type
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Dark Matter has been around since the
beginning of time the very beginning our
universe was born in the form of a hot
dense frenzy of energy expanding at an
incredible rate
a tiny fraction of a second later energy
transformed into a first particles of
our universe tiny particles called
quarks formed protons and neutrons these
combined with electrons to create the
first atoms atoms in turn make up
regular matter the substance of which
physical objects are made as conditions
cooled and space expanded Dark Matters
mass coalesced into strands these
strands formed an invisible skeleton in
space
over hundreds of millions of years the
gravity from Dark Matters maths was so
powerful it pulled regular mass to it
like meat to its ribs and formed the
sinuous structure of the universe
the first galaxies grew at the
intersections of these filaments
galaxies collided with other galaxies
and merged again to form super clusters
of galaxies countless galaxies were
drawn together by Dark Matters pull and
from there they grew into the structure
of the universe we see today without
dark matter there would be no stars no
galaxies no planets no life without dark
matter we ourselves would not exist
Dark Matter lay hidden from human view
for millennia until finally traces of
its influence became apparent to
astronomers the first was Fritz Zwicky a
Swiss astronomer who worked at Caltech
in the 1930s tricky turned his telescope
towards a group of galaxies not too far
from our own Milky Way
this swarming network of over a thousand
galaxies is known as the Coma Cluster
and Swick his mission was to determine
its mass he could do this by measuring
its brightness
and by measuring the speed of galaxies
orbiting inside the cluster ricky
discovered that the galaxies were moving
much faster than he expected especially
considering the amount of mass in the
cluster as indicated by brightness at
these speeds the visible mass wasn't
great enough to hold the cluster
together
Wiki theorized there must be some
invisible substance lying and hiding
holding the speeding galaxies into the
cluster he called the substance dark
matter but some ideas are ahead of their
time
switches revolutionary findings went
largely unnoticed until forty years
later when astronomer Vera Rubin studied
the orbital speeds of stars in galaxies
what she observed surprised and
confounded her according to Newton's law
of gravitation the sun's powerful mass
creates a gravitational pull that causes
the inner planets to travel at faster
speeds than planets that are further out
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since stars orbit around a galaxy's
center much the way planets orbit the
Sun Ruben thought she'd see similar
speed patterns when she observed the
nearby Andromeda galaxy but what she saw
was radically different stars that were
in orbit far from the galaxy's center
were whizzing along at high speeds
identical to the Stars much closer in
this was not at all like the speeds of
planets in our solar system where the
inner planets go much faster than the
outer planets
at these incredible speeds without
adequate gravitational pull from
something massive the stars should fly
out of control and jettison out into
space something was keeping the
Andromeda galaxy together what could it
be Rubin and her team concluded that
there must be some strange invisible
mass that extended to the outer edges of
the galaxy and beyond it was as if an
invisible cloud held the Stars together
like a kind of glue we can see visual
evidence of these Dark Matter halos in
other parts of the universe as well we
see the most dramatic evidence for dark
matter in a celestial structure
astronomers refer to as the bullet
cluster when astronomers looked closely
at galaxies in the cluster they saw
subtle distortions caused by something
invisible the suspect dark matter
astronomers used an x-ray telescope in
space to detect massive concentrations
of hot interstellar gas whose bullet
like shapes give the cluster its name
the bullet cluster was formed when two
smaller clusters of galaxies collided if
we could travel back in time to before
the collision we'd see two distinct
clusters each enclosed in its own cloud
of dark matter when the two galaxy
clusters collided the dark matter clouds
passed right through each other
the dense clouds of gas and dust shown
in pink however crashed into one another
toward the center
what is this dark matter that can pass
right through a galactic collision
without interacting with anything a Dark
Matter particle like this one traveling
through space won't let anything stand
in its way
Dark Matter doesn't exist only out in
space it's everywhere
Dark Matter is all around us right now
if you hold up your hand
millions of dark matter particles will
pass through it within the next minute
particles you can't see or feel as a
matter of fact there are billions of
different subatomic particles flying
through this room as we speak this is
the entrance to the Homestake mine
in South Dakota it's the ultimate place
to filter the dark matter particles out
from the rest in order to isolate the
dark matter particles physicists conduct
experiments deep underground where most
ordinary particles can't travel but dark
matter particles easily can every
morning dozens of scientists travel down
a giant elevator shaft 1500 meters
underground that's almost a mile to work
with the most sensitive Dark Matter
detector in the world what they find in
this sub terrestrial labyrinth of
abandoned mining tunnels could change
the way we view the entire universe
this was once a thriving gold mine but
now instead of miners mining for gold
the physicists who work here are mining
for an even more elusive substance dark
matter this is the Sandford underground
research facility it's here that we'll
find the large underground xenon dark
matter experiment or Lux for short this
tank filled with liquid xenon will be
the perfect theater for witnessing the
first appearance of a Dark Matter
particle
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the bait for detecting the Dark Matter
particle will be the nucleus of a xenon
atom when a Dark Matter particle hits
the nucleus will give off a flash of
light or release electrons these
interactions will then be recorded by
sensors on the bottom and top of the
detector dark matter interactions of any
kind are rare but physicists hope
they'll see one very soon
on the other side of the world another
group of physicists is working on
creating their own Dark Matter particle
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they're doing it here at CERN the
world's largest Research Centre for the
study of particle physics located
outside Geneva Switzerland
here thousands of scientists from many
nations have joined together to track
down answers to humankind's most complex
and age-old questions concerning the
nature of matter
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hidden beneath CERN's sprawling 450 acre
2 square kilometre campus and the
surrounding forests and farms of the
European countryside lies the biggest
and most complex machine in the world
the Large Hadron Collider otherwise
known as the LHC inside it two beams of
protons travel in opposite directions
around the ring at incredible speeds the
protons then collide inside four
gigantic detectors
the LHC is a giant particle racetrack
instead of fuel these subatomic races
are accelerated around the track by
electric fields and steered by
high-powered magnets the particles are
then guided towards collision in the
core of each detector the largest
detector is appropriately called Atlas
it weighs 7,000 tonnes and took 15 long
years to build
at almost eight stories tall Atlas is
the size of a cathedral more than 3,000
scientists from a hundred and
seventy-five institutions in 38
countries work in collaboration on its
experiments in essence Atlas is an
enormous microscope aimed down into the
sub atomic realm with billions of
protons traveling around the track in
opposite directions the scene can seem
more like a demolition derby than a
racetrack when two protons collide
hundreds of new particles are formed
the incredible energy of the collision
can produce particles with far greater
mass than that of the two protons that
created them this is exactly what
physicists predict will happen if they
create a Dark Matter particle with great
mass every line in this collision
display reflects the presence of a newly
created particle the curvature of the
line tells us the particles momentum
Atlas records the collisions with
several devices that are arranged in
concentric layers each device is like an
extraordinary camera specially designed
to detect and record different kinds of
particles according to Sir Isaac Newton
momentum traveling in opposite
directions must balance out as it does
in this display the yellow squares show
an even distribution of particles and
momentum in the case of a Dark Matter
particle however there will be a gap
where the particle flew through Atlas
without interacting with any of its sub
detectors how can a Dark Matter particle
fly through the world's most sensitive
particle detector without leaving a
trace a theory called supersymmetry
predicts the existence of a particle
that would act in exactly this manner
according to this theory for every known
particle like an electron or quark
there's a corresponding super particle
with a much greater mass as you can see
the correspondence creates a nice
symmetry physicists believe that one of
these predicted super particles may be
the Dark Matter particle now to find it
Atlas takes pictures of the most
important collision events 40 million
times per second
collision data is stored in a massive
network of computers at CERN and around
the world called the grid computer
programs scan data in the grid looking
for patterns that might fit the profile
of a Dark Matter particle very few
collisions are expected to create dark
matter particles but if one did looking
through all the collision data would be
a daunting task
fortunately modern science is a
collaborative endeavor physicists all
over the planet are working around the
clock to analyze the data a CERN
engineer invented a thing called the
world wide web in order to share this
kind of information with all this
brainpower looking for dark matter and
exploring the fundamental nature of our
universe who knows what they may find
ultimately it's the big questions that
bring humankind closer together as we
strive to understand the workings of
this vast universe and our place in it
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