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Hey Vsauce
Michael here. This symbol commonly called a Yen Yang
symbol is a taijitu meaning diagram
of the supreme ultimate the principal
of Yen and Yang opposites existing in harmony
is associated with ancient Chinese philosophy
but the very first use of the iconography the classic symbol
actually comes from a shield pattern used by the ancient
Romans seven hundred years before its first
known use in China. A connection between the two
has yet to be found regardless of who came up with it first
the symbol was a bright idea but what's the brightest object in the entire universe?
well apparent magnitude
commonly used when stargazing refers to how bright an object
appears to us say when looking up from Earth
it depends on Earth's intrict factors like how close the object is
to our planet. Magnitudes are logarithmic
and arranged like golf where a smaller number
means a greater brightness but today
i'm looking for absolute magnitude
a measure of how bright things all over the universe near
and far would be if we looked at them from the same distance
absolute magnitude will guide us to the most blinding
light in the universe irrespective of it looking faint
to us here on earth just because it's far away
the difference is significant a 100-watt light bulb
placed closer than 8 centimeters about three inches from your eye
will appear brighter than the Sun in the sky
but that's not fair if you could see the Sun and the bulb
from the same distance the Sun would be a septillion times brighter
that's bright, but the Sun
shines punily compared to the rest of the cosmos
if you could line the Sun up with everything else out there
giving every star and cosmological phenomenon
a fair chance the Suns absolute magnitude
would be 4.8, not bad but check out
R136a1 this nuclear fueled beast isn't
the biggest star in terms of volume but its 256
times more massive than our Sun it's the most massive star
ever found and it's also the brightest
remember that lower absolute magnitudes are brighter
R136a1 isn't 4.8
like our Sun it is -12.6
which means it is 8.7 million times brighter
than our own Sun, but R136a1
isn't the brightest thing out there. When a giant star dies it explodes violently
in what is known as a supernova
or hypernova. As I mentioned in my video
how hot can it get supernovas can eject terrifying flashes of
radiation known as gamma ray bursts arguably
the brightest electromagnetic events in the universe
a typical gamma-ray burst releases as much
energy in a few seconds as our Sun
will release altogether in its entire
10 billion year lifetime. If WR104
a gamma-ray burst future candidate directly struck
Earth with such a beam for only 10 seconds
astronomers predict it could deplete 25 percent of our
ozone layer and lead to mass extinction and starvation
the largest thermonuclear bomb ever detonated
didn't do anything close to that and it was exploded right
here in our atmosphere whereas WR104
is eight thousand light years away you can't even see it with your naked eye
or a pair of binoculars. But gamma ray bursts are merely brief
events lasting only a few minutes at most sometimes
just a matter of milliseconds if you want the brightest
sustained thing you'll paradoxically have to look
at the darkest thing. Black holes
to be fair dark matter is ostensibly
darker but because dark matter has been hypothesized
to not even interact with light with electromagnetism
at all calling dark matter not bright
is kind of like calling your peanut butter sandwich
a not fast airplane it's not really even in the same category
black holes however do interact with light
reflecting so little, well they don't let any
escape at least not in a form resembling the way
it came in. That's dark
but the intense energies created by black holes in the process of eating
things like stars
is anything but dark. Gas and debris from the stars they eat swirl into
arcipluvian cosmic gallows known as accretion discs
before making their final death plunge into the black hole
in the disc debris spins at unfathomable speeds pulled around by a black hole
billions of times more massive
than our Sun friction in the accretion disk generates heat
on a level difficult to fully appreciate
just as hot things glow the disk does to
so brightly it has its own name a
a quasar. Quasars shine thousands of times more brightly
then even the brightest stars
I'm kidding it's scarier
than that. Quasars shine thousands of times more brightly
than galaxies containing billions of stars
the first identified quasar 3C 273 has an absolute magnitude
of -26.7 making it
four trillion times brighter than our Sun
about 100 times more luminous than the total amount of light produced by the
entire Milky Way. If you put 3C 273
33 light years away from us it would shine as brightly as our Sun
A mere 8 light minutes away, blocking the brightness of a quasar with the corona
graph reveals that quasars exist in the centers of galaxies
that are larger than them in area but are nonetheless
drowned out by their light
such galactic centers are called active galactic nuclei
the bulk of their energy spewing forth in the form of a powerful radiation jet
the length of which puts even
our solar system to shame. The visible part of the jet
in this photograph for instance is so long it could stretch from the Sun
to Pluto and back one-and-a-half million times
now specifically if a large portion of this ajected energy heads toward Earth
it's responsible for what we call a quasar
but if Earth is right in the active galactic nucleus' sights
it's got a scarier name, a blazar
and its blazar 3C 454.3 that clocked in the greatest brightness
ever observed at historically high levels of activity is registered in
absolute magnitude of -31.4
to put the brightness of quasars
in yet another perspective take a look at the one hundred thousandth
picture snapped by the Hubble telescope
this is a star a few 100 light years away
and this thing looks just about as bright
but it is a quasar
9 billion light years away
why are quasars so far away?
well a quasar is not forever
they are billions of light-years away
which means the light we receive from them the pictures we take of them
are pictures of things happening billions of years ago
they represent a phenomenon more common
early in the universe's history when monster black holes hadn't eaten
all the stars around them to fuel their accretion discs and
before those holes became too fat to be active
Neil DeGrasse Tyson points out that in order to remain
a quasar producer a black hole must consume
about 10 stars a year. Many
consume more than a thousand stars a year, 600
Earths worth of matter every single minute the more
stars a black hole consumes the larger it's event horizon becomes
until eventually it no longer shreds stars apart
to fuel an accretion disc instead it just swallows them whole
in one demmer but still terrifying gulp
quasars are some of the most ancient things in our universe
if you could teleport instantaneously to one right now
faster than light it would most likely no longer be burning what we see
are just there ghosts light that left when they were
active that traveled longer than they could live
but quasars can still be born they can even be born
right here in fact in my video
what will we miss I pointed out that the Andromeda Galaxy
is headed our way
in three to five billion years it will collide
with our own galaxy the Milky Way and the collision
could be arranged stars near the galaxy's central black holes to be consumed
reigniting a quasar right here in our galactic backyard
funny enough right now very few of us even see
Andromeda even though all you need is your unaided eye
light from our cities drowns out the night sky like a
quasar drowns out its host galaxy. Artist Thierry Cohen mocked up what big cities
would look like if all their lights were
off and the sky above them could be seen
fully. New York, Hong Kong, Shanghai
Tokyo, Los Angeles, it's beautiful
and rare. In the 1990s
during a blackout in the city of Los Angeles a number of residence
actually called the police they were afraid of mysterious glowing clouds
hovering above the city they were seeing
our galaxy for the first time in their lives
at night artificial lights allow us to see
what's around us but be lose
what's above us the brightest places
have the darkest emptiest skies
there's Yin and Yang again. A taijitu has actually been lurking in this video
the entire time
the brightest things in the universe quasars
are caused by the darkest things in the universe
black holes the process that unshackles the most light
is caused by the thing that best imprisons it
and as always
thanks for watching