Kind: captions
Language: en
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they're the most mysterious particles
ever
discovered tiny ghosts hidden in our
world now scientists are on a mission to
unlock their
secrets they're called
neutrinos the story of their Discovery
is almost impossible to believe if they
had bolted the detector in place the
nuclear bomb would have just smashed to
smithin with links to a dramatic Cold
War defection he disappeared through the
Iron Curtain and for 5 years disappeared
off the face of the planet and
astonishing experiments that keep
defying the laws of physics even as
someone who builds these experiments for
a living it just seems mind-blowing that
they ever work today scientists are
using neutrinos to probe the edges of
our Detective Universe they're on a
mission to reveal a hidden world of
particles
unknown right now on
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Nova as an american-based supplier to
the construction industry carile is
committed to developing a diverse
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.c we live in a world of
matter a realm of tiny particles far
smaller than atoms that build the
universe that we
know but there is a
mystery scientists theorize there exists
a hidden parallel world of
particles So-Cal called Dark
Matter so far no one has managed to
detect a single
one but now there might be a
way of all the particles scientists have
discovered the most elusive on the very
edge of
detectability are
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neutrinos neutrinos are really
remarkable particles there are trillions
and trillions of them streaming through
our bodies and we don't even notice they
are kind of ghostlike and yet they're
everywhere everywhere and
nowhere neutrinos are so ghostly they
can pass through solid matter as if it
didn't
exist and yet they hold the secrets to
why the stars shine and what our
universe is made of the reason we care
about these elusive particles is because
they do play a fundamentally important
role in the universe in the nature of
matter in some of the most violent
Cosmic
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phenomena first theorized in the
1930s they would soon become linked to
nuclear secrets and a dramatic Cold War
defection behind the Iron
Curtain he goes off to Europe and never
returns now the quest to detect
neutrinos has triggered vast experiments
all over the globe even as someone who
builds these experiments for a living it
just seems mindblowing that they ever
work today scientists are on the cusp of
an astonishing Discovery tantalizing
evidence suggests neutrinos could be a
doorway between our world of matter and
the Hidden World of Dark Matter waiting
to be discovered it would be a game Cher
what exactly are these particles what is
its role in the evolution of our
universe The Quest For answers has
driven scientists to the edge of what is
experimentally
possible to reveal a universe we've
never seen
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before first fmy lab in bavia
Illinois world-renowned Physics
laboratory thousands of scientists build
enormous experiments to probe the very
smallest particles that make up our
universe leading one of the teams is Sam
Zeller hey
team my interest in physics started when
I signed up for a field trip to come to
fmy lab in high school it just blew my
mind from from that point on I was a
particle
physicist turns out that the Universe
can be described by a small number of
subatomic
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particles today scientists have
discovered 17 basic particles that make
up our
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universe some are the building blocks of
atoms others are the things that hold
matter together
it's an understanding of our world that
physicists call the standard
model the standard model of particle
physics describes the most fundamental
constituents of matter and how they
interact with each
other it is in fact the most
mathematically well-defined physical
Theory we as humans have ever written
down for 50 years the standard model has
withstood test after test confirming the
hierarchy of all the fundamental
particles but one type remains far more
mysterious than
others they're called
neutrinos a nutrino is a type of
elementary particle a basic fundamental
building block of the universe and they
come in three different
flavors neutrinos are everywhere they
are produced in the Sun there are
neutrinos that were left over after the
big bang humans emit
neutrinos neutrinos have got no electric
charge they've almost got no mass at all
there as near to nothing as you can
imagine they're so reluctant to interact
with stuff they pass through the Earth
as if it wasn't
there and yet at fery lab scientists are
constructing a complex two-stage
experiment with the means to create them
and study
them in its first stage a powerful ring
of magnets accelerates positively
charged particles called protons to
colossal speeds sending them smashing
into a
Target the Collision creates a shower of
new particles including a powerful beam
of
neutrinos 150 trillion per second pass
through the Earth at nearly the speed of
light racing towards the second stage
three giant neutrino
detectors the largest is called
Icarus once complete this immense tank
filled with a web of electronics and
cryogenic liquid will be bombarded by
hundreds of trillions of
neutrinos all in the hope of catching
just one each minute
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that alone will be a remarkable
achievement but the scientists have even
bigger
Ambitions one of the big goals here at
firm lab is to try to search for
possibly a new type of nutrino that no
one has yet
observed experiments have hinted there
could be an even more elusive neutrino
beyond the three types already known to
exist some have suggested that it could
be a link to a hidden realm of particles
that could finally lead to new
discoveries beyond the standard model
have we found evidence of a new type of
nutrio that would be really astounding
that's what gets me excited in the
morning that's what gets me coming into
work it would be a major and massive
Discovery making that Discovery would be
groundbreaking because while ordinary
neutrinos are extremely hard to
detect this fourth type of of nutrino
could break the standard
model what brought them to this moment
and possibly to the brink of upending
one of the bedrocks of modern
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physics that Story begins almost 100
years ago half a world
away in
Rome physicist and historian professor
David Kaiser has traveled here to the
place where in the
1930s scientists were investigating the
inner workings of the
atom for Millennia for thousands of
years people had come to believe that
the world is made of atoms and those
atoms were the smallest thing there was
in fact the word Adam even means
unbreakable or indivisible the smallest
piece but by the early 1900s scientists
had revealed a deeper hidden
structure if you think about an atom
it's about a nanometer about a billion
times smaller than a meter roughly the
inside the Deep core of an atom the
nucleus is about 100,000 times smaller
than that so we're really zooming in
powers of 10 powers of 10 getting to
unimaginably Tiny
scales during the early 20th century
scientists discovered the atom's tiny
nucleus contain protons particles with a
positive electric
charge these protons held in place a
cloud of negatively charged electrons
that form the atom's outer
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limit it seemed that protons and
electrons were the only two components
of all atoms permanent and
fixed but scientists had also found
something shocking
some types of atoms seem to break
apart that was just jaw-dropping
literally it contradicts the name of the
thing itself atoms are supposed to not
break
down it was as though certain atoms had
too much
energy the nucleus would spontaneously
transform and spit out an
electron this phenomenon was a type of
radioactivity known as beta
Decay it appeared to be this sort of
mysterious energy leaking from or
emanating from certain
atoms this process was remarkable in
itself but when scientists measured the
energy of the electrons from beta Decay
something was
wrong one of the basic principles and
all Sciences is that energy can change
from one form to the other but the the
total sum must be
conserved this is the principle of
conservation of
energy from collisions in the macro
world to the behavior of tiny particles
the principle states that energy should
never
disappear but when scientists measured
the energy of the electrons from beta
Decay that's exactly what seemed to
happen so every time rather than having
energy conserved what they were seeing
is that some amount of energy would be
missing where was the energy
going it seemed that the particles
themselves were breaking the fundamental
rules of
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physics in
1926 a young Italian physicist called
enrio fmy was working at the University
of Rome's physics Institute
it was here that FY probed into the
developing field of nuclear
physics enrio fmy was really a towering
figure of 20th century physics by any
measure one of the greatest physicists
of the 20th century this is the site
where fairy built what became an
absolutely worldclass group of
researchers they were known as the Via
panisperna
boys this is really an iconic photograph
it captures them in the middle of what
would become world changing research
fairy himself was remarkably young he
was just 26 years old and already had
been made the big senior Professor
around which this young group would come
together they referred to fairy as the
pope he was the great leader retti was
next in line he was a
cardinal the person taking the
photograph the very young Bruno Ponto
corvo the youngest member of the group
they called him the
puppy the group's ideas would have a
profound impact on the
world in October
1931 they invited a group of the world's
leading physicists to a Conference held
at the physics
institute High on the agenda was the
problem of the missing radioactive
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energy one scientist at the conference
the famous Wulf gang poy proposed a
radical idea
wol gang poy had written a letter to
colleagues and he put forward what he
called A desperate remedy of F's five
Felton asck it was just ridiculous and
he says so in his letter it's a really
quite strange sounding
idea what if there was a new type of
particle in the world that no one had
ever seen or detected
before POI suggested that instead of
just an
electron perhaps there was an unknown
particle that was carrying away the
missing
energy very few people seem to have been
convinced that this is the right way to
go at that time physicists were quite
confident there existed Two basic kinds
of particles electrons and protons but
poy was suggesting let's make this
enormous
leap a new particle of matter seemed to
step too
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far but for enrio fmy the pope of via
panisperna
he took the wacky idea and ran with
it fairy dedicated the next two years of
his life to describe the Obscure ghost
particle it would be neutral and carry
no electric
charge it would be tiny far smaller than
an electron and it would pass through
atoms as if they weren't there at
all he named the particle the neutrino
Italian for little neutral one
this was a really quite remarkable step
but many physicists fairy included
thought it should be nearly impossible
perhaps impossible forever to detect
such a particle even if it really
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exists outside the intellectual fervor
of the lab fascism was about to cast a
shadow over the nutrino
mystery in 1939 fairy immigrated to the
USA and was quickly put to
work he helped to develop the first
operational nuclear
reactor that led
eventually to the atomic
bomb but not everybody had forgotten
about the elusive
neutrino Bruno ponticorvo the puppy of
the Via panisperna
boys upon moving to England after the
second world war he continued to think
about
neutrinos until his life took a shocking
turn Ponte corvo was a man who created
Big Ideas the work that he did on
neutrinos alone could have won him
certainly one Nobel Prize and been a
candidate maybe for
two but it wasn't to
be in 1950 in the midst of the Cold War
Pont corvo and his family mysteriously
went
missing Bruno
ponticorvo disappeared through the Iron
Curtain in
1950 and for 5 years disappeared off the
face of the
planet only after 5 years of Silence did
he reappear in the Soviet
Union so what happened was he
kidnapped was he a
spy Professor Frank close has spent
years researching ponticorvo and his
mysterious
disappearance he has come to the British
national archives in
London earlier in his life ponac corvo
had been a member of a Communist
party and there are now British
intelligence files under his
name looking at these old folders
they're worn down the sides they have
red stamps top
secret the case of Ponte corvo it is
dripping with
Intrigue after the war while working for
the UK's atomic energy program
ponticorvo devised a method to try and
detect
neutrinos he reasoned that nuclear
reactors which derive energy from
splitting atoms should produce neutrinos
in vast quantities
ities but the government classified his
paper now I conjecture that this paper
was classified secret
because if you could indeed detect
neutrinos coming from a nuclear reactor
you would be able to work out how
powerful the nuclear reactor was so they
classified
it as the Cold War escalated the USA
became paranoid of of atomic
Espionage in 1950 the Rosenberg spy ring
was
uncovered and it triggered a communist
Witch
Hunt a secret letter reveals the FBI
wrote to a British intelligence service
about Pont
corvo the FBI now ask if we can send
them any information which would
indicate that Ponte corvo may be engaged
in communist activities
the letter was received in London on the
19th of
July 5 days later ponti corvo goes off
to Europe and never
returns flight manifests reveal Pon
corvo and his family flew from Rome
across Europe to Helsinki alongside two
suspected KGB
agents Pont corvo's son just 12 years
old at the time revealed they were then
driven across the border to Moscow with
Bruno in the trunk he said to me I knew
something was
up Frank believes a Soviet mole passed
the FBI letter to Moscow who then
pressured ponticorvo to
defect there's no clear evidence that he
had been a spy but whatever his reason
for leaving Bruno's Time in the West was
over was he a spy or not we don't yet
know in any event it was clear that
Ponte corvo was a top quality scientist
who had taken his brain to the Soviet
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Union by 1950 the USA and the Soviet
Union were engaged in a nuclear arms
race with it came a new opportunity to
hunt for
neutrinos when a nuclear bomb go goes
off there is this huge Cascade of
particles that spew out protons
electrons a lot of light particles
carrying off
energy and along with these particles
spewing out lots and lots of neutrinos
come out for
free if neutrinos were real could a
nuclear weapon finally be the key to
detect them
in
1951 a young American called Fred Ry was
working on the US nuclear program at Los
Alamos National
Laboratory it was here that ryes along
with his colleague Clyde Cowen decided
to take advantage of destructive bomb
tests to investigate the mystery of the
missing
nutrino Ry went back to a question that
had been kind of abandoned in the
decades before the second world war the
question of could physicists ever Act
actually detect these very strange
elusive ghostlike
particles they called their mission
project
Poltergeist for detecting the neutrino
the good news was you could calculate
the chance of doing it and the bad news
was it was almost
zero ryes and Cowan needed to tip the
odds in their favor and knew and nuclear
bomb test could be the
key an atom bomb should produ prod
thousands of times more neutrinos than
even the biggest nuclear
reactor but it also created a
problem if they had bolted the detector
in place the nuclear bomb would just
smash to
Smithers so instead The Proposal was to
dig a shaft about 150 ft deep right near
where the bomb would eventually be
detonated above
ground the team planed to drop a
detector down the shaft to avoid the
shock wave of the bomb
inside that shaft they would pad the
bottom with foam and feathers and kind
of like mattress
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cushions it was I mean a a a creative
ambitious and maybe slightly crazy kind
of idea to try to catch these neutrinos
in the midst of this very dramatic very
worldly set of events in the early years
of the Cold
War work digging the shaft had begun but
the head of physics at losal was
concerned that the experiment couldn't
be
repeated he urged the team to find
another way couldn't they use a nuclear
reactor
instead late one evening Ry and Cowen
had a
realization in the same way that the
nucleus of an atom could Decay and
release a
neutrino they knew in theory the process
should be reversible
on the rare occasion a neutrino could
interact with a nucleus it should
produce two new particles called a
neutron and a
positron and if they traveled through
the right medium those two Telltale
particles should produce two distinctive
flashes of
light so R and Cowen built a detector
essentially a big tank filled with a
solvent
that could pick up this two coincident
signal flip deep under a nuclear
reactor after 5 years of experiments in
1956 finally they got their
answer they recorded the two t Telltale
flashes of
light for the first time they saw
evidence of The elusive
nutrino what they had done was a
remarkable achievement one that um
seemed
impossible neutrinos exist they're real
they part of the world and not only a
clever
idea knowing nutrino exist put a whole
extra set of of Investigations on a kind
of firmer
path if neutrinos were pouring from
nuclear reactors on
Earth then surely they would be
generated in abundance in the largest
nuclear furnaces of
All
Stars for a long long time scientists
had been wondering what makes the stars
shine what drives that enormous output
of energy
people theorize that our sun is like a
giant nuclear reactor except rather than
heavier elements breaking down into
smaller ones and releasing energy you
have lighter elements that fuse together
through nuclear
fusion in the heart of the sun
tremendous heat and pressure Force
hydrogen nuclei to fuse together to make
helium and in
theory vast quantities of
neutrinos that pass freely through the
Sun and out into
space so if we could detect neutrinos
from the sun we could learn about the
processes that fuel it we could Peak
inside the core of our sun
in the historic gold mining town of
lead people descend into the depths of
the
Earth but no longer to mine precious
metal they're hunting for
neutrinos it was here in
1965 that an experimentalist called Ray
Davis came to try and prove what makes
the sun shine
Davis got very excited that there is
this new thing in the world called a
nutrino he began realizing that other
kinds of nuclear reactors that occur
throughout the Universe like stars they
should be spewing out these neutrinos
all the
time but catching them wouldn't be
easy calculations showed that neutrinos
from the Sun would be so faint a
detector near the Earth's surface would
be overwhelmed by background radiation
his only option was to go to the bottom
of a
mine beneath almost a mile of solid rock
Davis's team built a steel tank the size
of a house and filled it with 100,000
Gall of dry cleaning
fluid in theory if a neutrino from the
Sun collided with a chlorine atom inside
the tank it would cause a reaction that
Ray Davis could detect
here was something that was completely
fresh nobody knew anything about it but
the key thing was that if neutrinos hit
chlorine which you could get in cleaning
fluid it would turn the atoms of
chlorine into a radioactive form of
argon and that's when Davis got excited
because he was a radiochemist and for
him detecting radioactive forms of argon
Was Easy
Street scientists had calcul ated that
around a million trillion neutrinos from
the sun should pass through Davis's tank
each
minute but the probability of them
hitting the fluid and making an argon
atom was so
small Ray Davis could only expect to
find 10 individual atoms of argon from
10 neutrino collisions per
week his task was almost impossible many
of his own physicist colleagues doubted
this experiment would ever
work and he was having to convince
people that out of these millions and
millions and millions and millions of
atoms inside this tank he could identify
the collisions of one or two and
convince you that these were neutrinos
coming from the
Sun around each month Davis flushed out
the giant tank to extract the Argon
atoms to everybody's
amazement he found them
but there was a
problem instead of detecting the number
of atoms that theory predicted his
measurements fell
short they knew the target number based
on the Nuclear Physics theoretical
explanation of how stars shine and that
led to a very particular Target number
and Davis's remarkable experiment kept
coming in not close to it not 80% but
only at onethird of that Target
number what happened had the experiment
gone wrong another scientist carried out
a blind trial to test the accuracy of
Ray's atom
detection a colleague put in 500 kind of
Rogue atoms uh without telling Davis the
number and Davis was able to go through
the whole process sift it through and he
count it exactly the number that had
been put in if the experimental results
were accurate then perhaps scientists
had gotten their theory about neutrinos
from the Sun
wrong everybody was blaming everybody
else there were even suggestions has the
sun already burnt out in the core it was
just an enormous puzzle all these
advances in understanding how stars
shine and then hitting this kind of
brick wall where Theory and experiment
just would not agree with each
other the puzzle became known as the
solar neutrino problem
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1970 20 years since Bruno ponticorvo
defected to the Soviet
Union even after all that time his life
behind the Iron Curtain remained
shrouded in
secrecy but in a government lab outside
Moscow pontac corvo worked tirelessly to
explain the puzzling behavior of
neutrinos
he suggested that instead of just one
there may be two or even three different
kinds of
nutrino known as different
flavors if this wasn't strange enough he
calculated that something peculiar might
happen as they traveled through
space a neutrino would always be born as
one definite flavor but over time it
would change its
identity it would transform mixing back
and forth between the three different
types this was called neutrino
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oscillation Ponto coro's idea really is
it's it's sort of delicious these
neutrinos could be not taking one
identity dropping that adopting another
one dropping that but going into this
even stranger mixture where in neither
and both States at once it was a bold
idea no other fundamental particle
seemed to spontaneously change its
identity but if neutrinos were
transforming into flavors that Ray
Davis's detector couldn't see it might
explain why 2/3 of the neutrinos from
the Sun appeared to be
missing but there was a catch the
standard model the most precise
scientific theory in human history made
one important prediction that stood in
the
way the standard model of anticipated
neutrinos would be completely
massless they would have no mass at all
much like the photon of light and if
they had no mass that meant that they
could not
oscillate if neutrinos had no Mass one
of Albert Einstein's most important
theories predicted that neutrinos could
not possibly
oscillate there's this mindboggling
phenomenon from Einstein's relativity
that says that a clock that is moving
closer and closer to the speed of light
will tick at a slower and slower
rate if that clock were moving literally
at the speed of light it would never
tick at all no time would pass for that
object that moves at a exactly the speed
of
light according to Einstein's theories
the faster a particle travels the more
its internal clock slows
down a particle with no Mass can only
travel at the speed of light which is
where time
stops so if a neutrino had zero Mass it
would not experience the passage of
time and would never be able to change
if a particle has zero Mass what that
means is that its internal clock is not
ticking there's no way for that particle
to experience time if there's no passage
of time then how could they change over
time from one identity to
another if neutrino oscillation was real
neutrinos must have some
Mass but could the standard model really
be wrong
throughout the 1950s and 60s Clues from
experiments performed at CERN alongside
fermilab helped to lay the foundation of
the standard model what they found
revolutionized our understanding of the
particles that make up our
universe by means of this machine it is
possible to see the tracks of subnuclear
particles the smaller particles known to
man the electron the positron the photon
and the
neutrino over the years work at CERN led
to groundbreaking new technologies
medical advances like pet scans even the
birth of the worldwide
web perhaps cern's biggest success came
in
2012 nearly 50 years after the standard
model was proposed physicists detected
the final particle it
predicted the higs
bozan I think we have
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it finally all the pieces needed to
describe the detectable physical
universe seem to be in
place along with the higs Bon there are
Force carriers like the photon of
light quarks which form the nuclei of
atoms leptons including the electron
muon and
toao and three corresponding flavors of
neutrinos it is a map of what's out
there what we're made of and how we fit
all of us we are made of these
things and that is a kind of basic
understanding of nature of of our own
world that I I I think is is just a
remarkable human
achievement and yet for all its success
the standard model had no equations to
explain how or why the neutrinos would
have
mass for Ray Davis and his missing solar
neutrino
it seemed an unsolvable
Paradox for decades Davis
persists but he still only finds
onethird of the neutrinos that were
supposed to be coming from the
Sun well we've been carrying on this
experiment for about 20 years right here
but we're still observing a low Flux Of
neutrinos
eventually the problem is too big to
ignore in the 1990s scientists in Canada
and Japan construct a new generation of
supersized neutrino detectors to finally
settle the
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mystery one of them lies deep beneath
Japan's iino Mountain scientists fit
11,000 light detectors to the inside of
a gigantic container and fill it with
50,000 tons of Ultra Pure
Water this $100 million detector is
named Super
K the Super K experiment ended up being
a game
changer in the rare event that a
neutrino collides with the liquid in
Super K the reaction produces a Trail of
Light which the sensors can pick up
unlike Davis's detector this signal
allows scientists to calculate which
type of nutrino has hit and the
direction it came from Super K allows
scientists to test the theory of
neutrino oscillation by catching them
from a new source the Earth's
atmosphere Theory suggests that when
radiation from space hits the atmosphere
it creates neutrinos that travel
directly through the Earth
some travel a short
distance but others will come from the
other side of the planet to reach the
detector if the neutrinos are not
changing the combination of flavors they
record coming from a short distance will
be the same as those coming from
afar if they are changing over a long
distance the combination of flavors will
be different
after 2 years of recording data the team
finally has an
answer what they were saying was that
one type of neutrinos was depleting when
traveling through the Earth the Super K
results combined with results from
another experiment were able to
definitively show that neutrinos can
change from one type to the other for
that to
happen you must have nonzero nutrino
Mass the results are
groundbreaking neutrinos change their
identity neutrinos have mass after all
and the standard model's prediction of
the nature of neutrinos must be
wrong with the new input the evidence
that neutrinos really o at they really
change their identities therefore they
really really have a mass this
longstanding decades long challenge to
understand the solar nutrino problem
finally fell into
place nuclear fusion in the sun produces
one type of
nutrino but on the long journey through
space the neutrinos oscillate and turn
into a mixture of all
three on Earth
Ray Davis's detector only picked out one
flavor his results had been accurate all
along 37 years after the experiment
began Ray Davis was awarded the Nobel
[Applause]
Prize for Bruno pontac corvo and his
theory of
oscillations sadly the discovery came
too
late Nobel prizes aren't everything but
by the time the oscillations had been
sorted out and the whole thing finally
understood ponovo was dead so that's the
final tragedy of his
life after almost 100 Years of research
and Discovery today neutrino physicists
face perhaps their biggest puzzle
yet the standard models equations which
are so precise for other particles
cannot explain why neutrinos have mass
or why they
oscillate it's a sign that our
understanding of matter is still
incomplete today neutrino experiments
are in overdrive hunting for
Clues we're in the midst of really a
nutrino Bonanza I mean they are just
they're popping up all over the field of
physics at the South Pole scientists
have built the largest neutrino detector
on the
planet it's made of more than 5,000
sensors drilled into a cubic kilometer
of Antarctic
Ice it's known as Ice
Cube Ice Cube is in this this huge field
around me I'm sitting kind of standing
in the middle uh of Ice Cube
it's kind of amazing to think that uh we
were able to haul something like 5
million pounds of cargo down to the
South Pole this is instrumentation
cables drill equipment
fuel as well as probing nutrino
oscillations Ice Cube acts like a
nutrino telescope catching Cosmic
neutrinos from billions of light years
away this is the universe that has
really only been open to our eyes for
the last 50 years
there's all kinds of discoveries that
are waiting out
there with new experiments like Ice Cube
scientists believe that neutrinos May
reveal discoveries beyond the standard
model neutrinos could even help unlock
one of the biggest mysteries in physics
today it seems that most of what our
universe is made
of is missing
the whole quest of particle physics is
to explain the matter contents of the
universe and we seem to be doing this
phenomenally good job you crank through
the math of the standard model and
everything makes
sense and yet it only describes some
very small fraction of what the universe
is made out
of looking into space cosmologists can
see the gravitational influence of a
material that binds entire galaxies
together but that is completely
invisible to their
detectors scientists call this material
dark matter because nothing in the
standard model can describe what it
is and yet it seems to be what most of
the matter in the universe is made
of the standard model is very good at
describing about 5% of the
universe 95% of the stuff is an utter
complete mystery made of dark stuff
whether it's dark matter or dark energy
and what either of those are we don't
know all we really know about dark
matter is that it creates gravity but
it's not interacting with the
instruments that we have used to observe
the
universe whatever is filling space much
more of it than the ordinary matter that
makes up us and our planet and Our Stars
it's some other other kind of
particle whatever Dark Matter particles
are scientists must look beyond the
standard model to find
them neutrinos might be the
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key at fery lab for over 20 years
scientists have been investigating trino
oscillations what they've found doesn't
add
up the first observation that something
was a Miss was in the late
1990s something that we don't quite
understand is going
on at fery lab scientists fired a beam
of neutrinos just 500 yards to their
detector neutrinos oscillate too slowly
for the detector to see them change over
such a short distance at least according
to
Theory but the detectors saw an increase
in one type of
neutrinos neutrinos seem to oscillate
faster than is theoretically
possible the strange thing that we're
seeing is that neutrinos seem to be
changing from one type to the other
much faster than
expected in order for that to happen we
think it's possible that there are extra
neutrinos out
there in addition to the three flavors
of nutrino that the standard model
describes there could be a fourth
nutrino that affects them making them
oscillate
faster scientists call it a sterile
nutrino
and it's never been directly
detected so we call it a sterile nutrino
in essence just because it interacts
even less with other particles than the
regular neutrinos
do a sterile neutrino would be the
ultimate ghost particle it would never
collide with atoms in our world no
detector could ever see
it but it may reveal itself through its
effects on the neutrinos we can
see the only way that we can tell they
exist is through their effects on
nutrino
oscillation if sterile neutrinos exist
it would break the neat symmetry of the
standard model that organizes particles
in groups of
three what if there is a Fourth Kind of
nutrino a so-called sterile nutrino well
where would you put that on our map
there's no room to kind of shoehorn in
to squeeze in a fourth nutrino so I
think there really is a lot riding on
this if they're real sterile neutrinos
would have mass but not interact with
our
detectors just like dark
matter they could be the first particle
of Dark Matter ever discovered and
through their effects on the neutrinos
we can see
they could give scientists a window into
another
world nutrino might be a kind of Link
almost a kind of messenger or portal to
this whole other possible kind of stuff
out
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there at fery lab scientists are edging
towards the
truth I think we're getting a lot closer
neutrino physicists are incredibly
patient it takes a long time for us to
to collect our data and we really want
to be sure in what we're seeing before
we potentially make a very important
Discovery we're trying to answer some of
the biggest questions in physics I think
it's really unique that neutrinos May
hold all the
answers what began as a hypothetical
particle that no one thought possible to
detect could now be a key that unlocks
what most of our universe is made of and
how it works
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every time we look up there seem to be
these very curious nutr they are
constantly bedeviling our mental maps of
how we carve up nature and try to dig in
and study it and that's just amazingly
exciting so they've gone from maybe they
exist maybe they don't we might never
know to being our shest ticket to the
next
step history has shown that with every
little bit of progress we've learned
huge surprising things about our Cosmos
to me that's really exciting and I'm
curious to know where else could we go
wherever we go
neutrinos could be our guide
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to
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