Latest / Boring Science / 100 Sleepy Facts About Dark Matter _ The Invisible Universe Explained for Sleep

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100 Sleepy Facts About Dark Matter _ The Invisible Universe Explained for Sleep · Boring Science

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  Speaker 1: Good evening, and welcome back to Boring Science for Sleep. Tonight,
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  here on this quiet little corner of the internet, we
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  are going to drift gently into one of the deepest
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  mysteries of the cosmos. So before we begin, take a
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  slow breath, settle into your pillow, and allow the night
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  to grow a little quieter around you. If you're comfortable,
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  feel free to leave a comment below and share something
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  simple with us. Where in the world are you listening
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  from tonight? And what time is it where you are?
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  It's always wonderful to see how many different corners of
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  the planet gather under the same sky. Now, let's begin
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  our slow journey. Imagine for a moment that you are
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  floating far above the Earth. The blue glow of our
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  planet fades behind you as you drift deeper into space.
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  Stars stretch endlessly in every direction. Galaxies spiral quietly in
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  the distance. Nebula clouds glow softly like cosmic fog At
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  first glance, the universe seems full of light stars, galaxies,
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  brilliant explosions of energy scattered across the darkness. But something
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  remarkable hides behind that beauty. Something enormous. Something invisible. Because
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  the truth is, most of the universe cannot be seen
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  at all. Not with telescopes. Not with cameras. Not even
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  with the most powerful instruments humanity has ever built. In fact,
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  everything we can see, every star, every planet, every galaxy,
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  is only a tiny fraction of what actually exists. The
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  rest is something scientists call dark matter. Dark matter does
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  not shine. It does not reflect light. It does not
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  glow or sparkle or flicker across the night sky. It
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  is completely invisible. And yet, it seems to be everywhere.
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  Galaxies spin as if enormous unseen masses are holding them together.
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  Light bends around invisible structures drifting through space. Clusters of
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  galaxies move as though they are surrounded by giant halos
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  of hidden gravity. Again and again, astronomers look into the
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  universe and see the same strange clue. Something is there.
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  Something massive. But we cannot see it. It is almost
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  like a shadow Not a shadow cast by light, but
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  a shadow woven into the very structure of the cosmos.
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  A silent partner to the universe we know. Some scientists
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  like to imagine dark matter as the hidden skeleton of
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  the universe. If ordinary matter stars, gas and galaxies is
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  the glowing skin of the cosmos, then dark matter may
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  be the invisible framework beneath it. Holding everything in place,
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  shaping the largest structures in existence, guiding the slow dance
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  of galaxies across billions of years. And yet, we still
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  do not know exactly what it is. Tonight, we are
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  not going to rush through complicated equations or dense physics. Instead,
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  we will take a gentle journey. 100 quiet facts about
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  dark matter. 100 small glimpses into one of the universe's
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  greatest mysteries. Along the way, we'll explore how astronomers first
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  discovered hints of this invisible substance, how galaxies revealed its
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  presence through their motion, how enormous cosmic webs stretch across
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  the universe, and how scientists are still searching for the
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  particles that might finally explain what dark matter truly is.
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  Each idea will arrive slowly, softly, like distant stars appearing
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  one by one in the night sky. Because dark matter
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  reminds us of something profound. The universe is not only
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  what we can see, most of it remains hidden. And
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  perhaps that is part of what makes the cosmos so beautiful.
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  Even after centuries of astronomy, even with telescopes that can
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  see billions of light years into space, the universe still
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  holds secrets. Quiet ones, waiting patiently for us to discover them.
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  So tonight, As your mind begins to relax and your
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  thoughts grow lighter, imagine yourself drifting through the invisible architecture
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  of the cosmos. Galaxies floating like islands in a dark ocean.
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  And around them, vast halos of unseen matter guiding their motion.
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  A universe where the greatest structures are shaped by something
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  we cannot even see. Let the mystery settle gently into
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  your thoughts. And as we begin our journey through these
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  sleepy facts about dark matter, allow the quiet rhythm of
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  the cosmos to guide you slowly toward rest. When we
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  look up at the night sky, the universe appears full
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  of light. Stars shimmer across the darkness. Galaxies glow faintly
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  in the distance. Nebulae spread like delicate clouds between the stars.
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  For centuries, Astronomers believed that these glowing objects made up
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  the universe itself. Everything that existed could be seen, or
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  so it seemed. But as telescopes grew more powerful and
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  measurements became more precise, scientists began to notice something strange.
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  The universe was behaving as though much more matter existed
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  than we could actually see. Something unseen seemed to be
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  shaping the motion of galaxies. Something invisible was pulling on
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  the cosmos. And slowly, almost quietly, astronomers began to realise
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  that the visible universe might only be a small part
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  of the whole story. In fact, modern science suggests something
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  rather astonishing. All the stars, planets, dust, gas and galaxies
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  we can observe make up only about 5% of the universe.
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  Speaker 2: 5%.
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  Speaker 1: Everything we have ever seen through telescopes. Every galaxy photographed
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  by space observatories, every glowing nebula drifting across the cosmic ocean,
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  together they form only a tiny fraction of what exists.
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  The remaining 95% appears to be made of something else entirely.
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  Some of it is called dark energy, which influences the
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  expansion of the universe, and a large portion of it
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  is something more mysterious. Something that does not shine, does
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  not glow, and cannot be seen directly. This mysterious substance
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  is what scientists call dark matter. The name might sound dramatic,
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  but it simply reflects the fact that this matter is invisible.
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  It does not emit light. It does not absorb light.
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  It does not reflect light. In fact, Dark matter interacts
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  with light so weakly that even our most sensitive instruments
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  cannot detect it directly. And yet, its presence can be
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  felt through gravity. Gravity is the key that revealed the
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  hidden universe. Because while dark matter may be invisible, its
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  mass still pulls on other objects. Just like the gravity
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  of a star can guide the orbit of a planet,
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  dark matter influences the motion of galaxies and clusters of galaxies.
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  In this way, astronomers began to see its fingerprints scattered
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  throughout the cosmos. The first clues appeared nearly a century ago.
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  In the 1930s, a Swiss astronomer named Fritz Zwicky studied
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  clusters of galaxies, vast collections of hundreds or even thousands
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  of galaxies bound together by gravity. Zwicky carefully measured how
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  fast these galaxies were moving inside their clusters. What he
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  found puzzled him. the galaxies were moving far too quickly.
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  According to the visible mass in the cluster, the stars
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  and gas we could see, the cluster should not have
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  had enough gravity to hold itself together. If only visible
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  matter were present, the galaxies should have drifted apart long ago.
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  But they had not. Something unseen was holding the cluster together.
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  Something heavy. Something invisible. Zwicky suggested that the cluster must
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  contain large amounts of missing mass, mass that could not
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  be seen with telescopes. At the time, many astronomers considered
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  the idea unusual, even speculative. But over the decades that followed,
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  more evidence began to appear. In the 1970s, astronomer Vera
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  Rubin made one of the most important discoveries in modern astronomy.
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  Rubin studied how stars move inside galaxies. In a galaxy
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  like the Milky Way, stars orbit the galactic center, much
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  like planets orbit the Sunday. If most of the mass
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  in a galaxy were concentrated near its center, we would
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  expect stars farther away to move more slowly. This is
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  how planetary systems behave. Planets close to the Sun move quickly,
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  while distant planets move more slowly. But when Rubin measured
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  the motion of stars in galaxies, she found something surprising.
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  Stars at the edges of galaxies were moving just as
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  fast as stars much closer to the centre. According to
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  visible matter alone, those outer stars should not have been
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  moving that quickly. If they were, they should have flown
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  off into intergalactic space. Yet they remained in stable orbits.
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  The only explanation that made sense was that galaxies were
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  surrounded by enormous halos of unseen matter. These halos contained
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  far more mass than the visible stars and gas combined.
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  Once again, gravity was revealing something hidden. Imagine a galaxy
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  floating in the darkness of space. Its spiral arms glow
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  with billions of stars. Clouds of gas drift between them,
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  From a distance, the galaxy appears like a luminous island
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  in a cosmic ocean. But according to modern astronomy, the
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  glowing stars we see may only be the bright center
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  of something much larger. Surrounding the galaxy is an enormous
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  sphere of dark matter, a halo extending far beyond the
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  visible edges of the galaxy. Invisible, silent, yet incredibly massive,
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  This halo's gravity helps hold the galaxy together, guiding the
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  motion of its stars across billions of years. Without it,
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  many galaxies might not exist in the stable forms we
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  observe today. Dark matter also shapes the universe on the
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  largest scales imaginable. If we could somehow map the distribution
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  of matter across billions of light years, we would see
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  something remarkable. Galaxies are not scattered randomly through space. Instead,
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  They form enormous patterns, long filaments stretching across the cosmos,
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  vast clusters connected by invisible structures. Between them lie enormous
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  empty regions called cosmic voids. Astronomers call this arrangement the
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  cosmic web, and according to computer simulations, dark matter may
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  form the underlying framework of this web. Ordinary matter, The
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  gas that forms stars and galaxies collects along the gravitational
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  scaffolding created by dark matter. In this sense, dark matter
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  may have shaped the entire architecture of the universe. Yet
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  despite all this evidence, dark matter itself remains unseen. No
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  telescope has ever photographed it. No laboratory has definitively detected
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  its particles. Scientists know it exists primarily through its gravitational influence,
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  It is like watching leaves move across a still pond
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  and realizing that something unseen must be stirring the water
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  beneath the surface. The effects are visible, but the cause
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  remains hidden. And that is part of what makes dark
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  matter so fascinating. It reminds us that the universe still
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  contains deep mysteries. Even now, after centuries of scientific discovery,
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  we are only beginning to understand the true nature of
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  the cosmos. Most of the universe is invisible, and yet
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  it quietly shapes everything we see. Galaxies spin within halos
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  of unseen mass. Clusters of galaxies drift through oceans of
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  hidden gravity, and the largest structures in existence may be
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  built upon a foundation we cannot yet fully understand. As
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  we continue our gentle journey tonight, we will explore how
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  astronomers uncovered more clues about this invisible substance. Because galaxies
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  themselves hold some of the most intriguing hints. When scientists
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  carefully studied how galaxies rotate, they discovered patterns that could
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  not be explained by ordinary matter alone. Something unseen was
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  guiding the motion of the stars. And that puzzle led
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  to one of the most important discoveries in modern astronomy.
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  When astronomers first began studying galaxies in detail, they expected
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  them to behave much like smaller systems we already understood.
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  For example, consider our own solar system. The Sun sits
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  at the center, holding the planets in orbit through gravity.
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  The closer a planet is to the Sun, the faster
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  it moves. Mercury completes its orbit quickly, racing around the
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  Sun in just 88 days. Farther away, Neptune moves much
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  more slowly, taking more than a century to circle the
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  Sun once. This pattern makes sense. The Sun contains almost
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  all the mass in the solar system, so its gravity
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  dominates everything else. Astronomers once assumed that galaxies would behave
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  in a similar way. At the center of a galaxy
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  lies a dense region filled with stars, gas, and often
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  a supermassive black hole. Farther out, the spiral arms stretch
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  into the darkness. If most of the mass were concentrated
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  near the center, then stars near the edges should move
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  more slowly than those closer in just as distant planets
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  move more slowly around the Sunday. But when astronomers actually
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  measured how stars move within galaxies, they discovered something unexpected.
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  Something puzzling. Something that did not match their predictions at all.
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  In the mid-20th century, astronomers began mapping the rotation curves
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  of galaxies. A rotation curve is simply a graph showing
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  how fast stars move at different distances from the galactic center.
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  To measure this, scientists observe the light coming from stars
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  and gas clouds. Because these objects are moving, their light
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  shifts slightly in frequency, a phenomenon known as the Doppler effect.
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  By measuring these shifts, astronomers can determine how fast the
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  stars are orbiting. And when they plotted those speeds against
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  distance from the galactic center, They expected to see a
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  curve that gradually dropped. Stars near the centre would move quickly.
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  Stars farther away would slow down. But the results told
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  a different story. Instead of slowing down, the stars at
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  the edges of galaxies were moving almost just as fast
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  as those much closer to the centre. The rotation curves flattened.
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  Imagine watching a spinning carousel. You might expect the outer
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  horses to move more slowly, gently circling the centre. But instead,
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  they race around at nearly the same speed as those
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  near the middle. This is essentially what astronomers observed in galaxies.
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  The outer stars were moving far too quickly to be
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  held by the gravity of visible matter alone. According to
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  the amount of mass we could see the stars, gas
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  and dust The outer regions of galaxies should not have
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  enough gravitational pull to keep those stars in orbit. If
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  the visible matter were all that existed, many of those
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  stars should simply escape. They would drift away into the
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  vast emptiness between galaxies. But they do not. Galaxies remain stable.
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  Their stars continue orbiting calmly for billions of years. Something
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  unseen must be holding them together. This realisation slowly led
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  scientists to a remarkable conclusion. Galaxies must be embedded in
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  enormous halos of invisible matter. These halos extend far beyond
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  the visible edges of the galaxy itself. While the stars
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  and gas form the bright spiral arms we see in photographs,
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  the majority of the galaxy's mass lies in this invisible
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  halo surrounding it. The halo acts like a gravitational cocoon,
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  It provides the additional pull needed to keep the outer
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  stars moving at their observed speeds. Without it, galaxies might unravel.
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  Their stars would slowly drift away into intergalactic space. But
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  with dark matter present, the galaxies remain intact, spinning slowly
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  through the cosmic darkness. Imagine standing far above a spiral galaxy.
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  From that vantage point, you would see a beautiful disk
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  of glowing stars arranged in delicate spiral arms. At the
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  center lies a bright core where billions of stars cluster
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  tightly together. But beyond the visible light lies something far larger,
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  an enormous sphere of dark matter, invisible, silent, extending many
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  times farther than the galaxy's luminous disk. Inside this vast halo,
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  the galaxy's stars move like tiny sparks embedded in a
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  much larger gravitational structure. It is almost as if the
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  galaxy is floating inside an invisible bubble of mass. This
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  invisible halo also helps explain why galaxies formed in the
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  first place. In the early universe, matter was not evenly distributed.
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  Small clumps of dark matter began pulling material together through gravity.
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  Over time, ordinary matter gas and dust fell into these
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  dark matter structures. Inside these gravitational wells, stars eventually formed.
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  Galaxies were born. In this way, dark matter may have
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  played a crucial role in shaping the structure of the
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  cosmos from the very beginning. Without it, galaxies might not
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  have formed as easily. The universe might look very different
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  from the one we see today. Astronomers have now measured
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  rotation curves for hundreds of galaxies, from small dwarf galaxies
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  to enormous spirals like the Milky Way. And again and again,
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  they find the same pattern. The stars move too quickly.
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  The visible matter is not enough to explain the gravitational
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  pull required to hold galaxies together. Once more, the hidden
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  mass of dark matter appears to be guiding the motion
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  of the cosmos. Even our own galaxy, the Milky Way,
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  seems to be surrounded by such a halo. The visible
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  disk of the Milky Way stretches about 100,000 light-years across,
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  but the dark matter halo surrounding it may extend several
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  times farther. Some estimates suggest it could reach hundreds of
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  thousands of light-years into space. Within that enormous sphere lies
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  most of the galaxy's mass. Yet it remains invisible. We
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  detect it only through the motions of stars and satellite
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  galaxies orbiting the Milky Way. They move as though they
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  are responding to a gravitational presence we cannot see. And
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  so the galaxy puzzle became one of the most important
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  clues in modern cosmology. The strange motion of stars revealed
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  that the universe contains far more matter than our eyes
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  can detect. Something hidden surrounds galaxies. Something massive and silent.
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  Something that shapes the structure of the universe itself. We
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  call it dark matter, but its true nature remains one
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  of the greatest mysteries in science. As our journey continues,
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  astronomers will discover even more ways to observe the influence
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  of this invisible substance. Because sometimes, dark matter reveals itself
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  not through the motion of stars, but through the bending
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  of light itself. And that strange phenomenon will lead us
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  to another powerful clue about the hidden universe. By now,
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  we have seen how the motion of stars inside galaxies
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  revealed something mysterious. Stars at the outer edges of galaxies
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  move far too quickly. Galaxies themselves behave as if they
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  contain far more mass than we can see. But astronomers
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  did not stop there. If dark matter truly exists, if
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  enormous halos of invisible mass surround galaxies, then its gravitational
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  influence should appear in other ways as well. And one
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  of the most beautiful clues appears not in the motion
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  of stars, but in the way light itself travels through space.
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  According to Einstein's theory of general relativity, gravity does not
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  simply pull objects together. Instead, Massive objects bend the fabric
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  of space and time. You can imagine space like a
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  stretched sheet. If a heavy ball is placed on the sheet,
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  it creates a dip in the surface. Smaller objects rolling
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  nearby will curve toward that dip. In the universe, massive objects, stars, galaxies,
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  and clusters of galaxies create similar distortions in the structure
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  of space itself. And when light passes through those distortions,
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  its path bends. This phenomenon is known as gravitational lensing. Normally,
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  light travels in straight lines. But when it passes near
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  a massive object, the curvature of space causes it to
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  follow a curved path instead. In some cases, this bending
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  can act like a cosmic lens. Light from distant galaxies
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  can be magnified, stretched, or even duplicated as it passes
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  through the gravitational field of another massive object. To observers
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  on Earth, the distant galaxy may appear distorted into arcs
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  or rings. Sometimes multiple images of the same galaxy appear
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  in slightly different positions, all because gravity has bent the
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  path of the light along its journey. It is as
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  if the universe itself contains giant natural telescopes. Gravitational lensing
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  provides astronomers with a powerful tool, because the amount of
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  bending depends on the mass of the object causing the distortion.
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  By carefully measuring how light is bent, scientists can estimate
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  how much mass is present even if that mass is invisible.
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  And when astronomers began applying this technique to galaxy clusters,
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  they discovered something remarkable. The visible galaxies and gas inside
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  the cluster did not contain nearly enough mass to produce
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  the observed lensing effects. The distortions were far too strong.
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  Something else had to be contributing to the gravitational pull.
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  Once again, the conclusion pointed toward dark matter. Galaxy clusters
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  are some of the largest gravitationally bound structures in the universe.
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  Each cluster can contain hundreds or even thousands of galaxies.
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  Between those galaxies lies vast amounts of hot gas glowing
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  in X-ray light. This gas alone contains more mass than
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  all the stars combined. But even when astronomers include the
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  mass of this hot gas, the numbers still do not
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  add up. The gravitational lensing, observed around many clusters, suggests
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  that most of their mass is still hidden, invisible, yet
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  undeniably present through its gravitational influence. One of the most
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  famous examples of this phenomenon is known as the Bullet Cluster.
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  This system consists of two galaxy clusters that have collided
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  with one another. During the collision, the galaxies themselves mostly
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  pass through each other because the distances between stars are enormous.
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  But the clouds of hot gas inside the clusters slowed
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  down and piled up in the center of the collision.
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  This created a remarkable situation. The visible gas, which contains
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  much of the ordinary matter, became separated from the regions
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  where the strongest gravitational lensing was observed. In other words,
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  the gravitational mass did not line up with the visible matter. Instead,
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  it appeared concentrated in regions where there was little visible
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  material at all. The simplest explanation was that a large
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  amount of invisible mass had passed straight through the collision.
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  Mass that interacts very weakly with normal matter. mass that
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  behaves exactly as dark matter is expected to behave. Gravitational
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  lensing also reveals the presence of dark matter halos around
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  individual galaxies. When astronomers observe distant galaxies through powerful telescopes,
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  they sometimes detect subtle distortions in the shapes of background galaxies.
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  These distortions occur because the foreground galaxy bends the light
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  travelling behind it. By analysing these tiny changes in shape,
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  scientists can map the distribution of mass surrounding the galaxy.
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  The results consistently show that galaxies are surrounded by enormous
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  halos of unseen matter. These halos extend far beyond the
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  visible stars and gas. In fact, the dark matter halo
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  may contain five to ten times more mass than the
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  visible galaxy itself. Imagine once again looking at a galaxy
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  from afar, Its spiral arms glow softly with billions of stars.
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  But beyond those luminous arms stretches a vast invisible structure.
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  A halo of dark matter surrounding the galaxy like a
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  faint gravitational cocoon. This halo does not emit light. It
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  cannot be photographed directly. Yet its presence can be mapped
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  through the bending of light and the motion of stars.
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  It shapes the galaxy's structure. guides its rotation, and influences
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  how it interacts with neighboring galaxies. Gravitational lensing has now
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  become one of the most powerful tools in modern astronomy.
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  Space telescopes such as Hubble and James Webb routinely observe
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  lensing effects across the universe. Some distant galaxies appear stretched
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  into long arcs. Others form nearly perfect rings known as
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  Einstein rings. where light from a background galaxy is bent
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  symmetrically around a massive foreground object. Each of these distortions
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  tells a story about the distribution of mass in the universe.
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  And time after time, that story reveals the same surprising conclusion.
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  Most of the mass is invisible. Most of the universe
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  is hidden. Through these delicate distortions of light, astronomers have
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  begun mapping the invisible structure of the cosmos, like tracing
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  the outline of something hidden beneath a sheet. The galaxies
• 28:07
  we see may simply be the glowing markers of a
• 28:09
  much larger gravitational framework, dark matter forming the scaffolding upon
• 28:15
  which the universe is built. And yet, despite all these clues,
• 28:19
  the rotation of galaxies, the motion of clusters, the bending
• 28:24
  of light, we still do not know exactly what dark
• 28:26
  matter is made of. It remains one of the deepest
• 28:30
  mysteries in modern science. As our quiet journey continues, we
• 28:35
  will begin to explore the possibilities. Because scientists have proposed
• 28:40
  many ideas about what dark matter might be. Some believe
• 28:44
  it may consist of entirely new particles. Others imagine hidden
• 28:48
  sectors of physics waiting to be discovered. And somewhere in
• 28:52
  those possibilities may lie the answer to one of the
• 28:54
  universe's most enduring questions. So far, we have followed the
• 28:59
  quiet clues scattered across the universe. Stars moving too quickly
• 29:05
  inside galaxies. Clusters held together by unseen mass. Light bending
• 29:11
  around invisible structures drifting through space. All of these observations
• 29:16
  point toward the same mysterious conclusion. Something massive exists throughout
• 29:22
  the cosmos, yet it cannot be seen. But what exactly
• 29:26
  is dark matter? What substance could fill the universe, shaping
• 29:30
  galaxies and clusters, while remaining completely invisible to our telescopes?
• 29:36
  To answer that question, scientists have turned to the strange
• 29:40
  world of particle physics, because dark matter might not be
• 29:44
  made of ordinary atoms like the matter we know. Instead,
• 29:48
  it may consist of entirely new kinds of particles, particles
• 29:52
  that rarely interact with the familiar matter around us. Particles
• 29:57
  that pass silently through the universe and through us, almost
• 30:01
  without leaving a trace. One of the earliest and most
• 30:05
  widely studied ideas involves particles known as WIMPs. The name
• 30:09
  stands for Weakly Interacting Massive Particles. It may sound technical,
• 30:15
  but the idea is actually quite simple. WIMPs would be
• 30:19
  particles with mass, meaning they contribute to gravity. but they
• 30:23
  interact only through extremely weak forces. Unlike ordinary matter, which
• 30:29
  interacts strongly with light and electromagnetic forces, WIMPs would mostly
• 30:34
  ignore these interactions. Light would pass right through them. They
• 30:39
  would not glow or absorb radiation. And because they interact
• 30:43
  so rarely with ordinary matter, detecting them would be incredibly difficult. Yet,
• 30:49
  if large numbers of these particles filled the universe, Their
• 30:53
  combined mass could easily explain the gravitational effects we observe
• 30:57
  in galaxies and clusters. Imagine drifting through the galaxy, surrounded
• 31:02
  by countless invisible particles. Trillions of them passing quietly through space.
• 31:09
  Even passing through your own body without you ever noticing.
• 31:12
  If WIMPs exist, this may be happening right now. Because
• 31:17
  dark matter halos surrounding galaxies would contain enormous numbers of
• 31:21
  these particles. they would move silently through stars, planets, and
• 31:26
  interstellar gas.
• 31:28
  Speaker 3: Invisible.
• 31:30
  Speaker 1: Undetectable to our senses. Yet quietly shaping the universe through
• 31:34
  their gravity. For decades, scientists have designed experiments to try
• 31:39
  to detect WIMPs directly. Some of these experiments are located
• 31:44
  deep underground, shielded by thick layers of rock. The reason
• 31:49
  for this unusual location is simple. Deep beneath the surface,
• 31:53
  detectors are protected from cosmic rays and other particles that
• 31:57
  might interfere with the measurements. In these quiet underground laboratories,
• 32:02
  sensitive instruments wait patiently. If a WIMP particle were to
• 32:06
  collide with an atom inside the detector, even very gently,
• 32:11
  it might produce a tiny signal, a faint flash of light,
• 32:15
  a small vibration in the detector material. Scientists watch carefully
• 32:20
  for these signals hoping to catch the rare moment when
• 32:24
  a dark matter particle reveals its presence. So far, no
• 32:28
  confirmed detection has been made. But the search continues. Another
• 32:34
  fascinating possibility involves particles called axions. Axions are hypothetical particles
• 32:41
  that were originally proposed to solve a completely different problem
• 32:44
  in physics. But over time, scientists realized that axions might
• 32:49
  also make excellent candidates for dark matter, Unlike WIMPs, axions
• 32:54
  would be extremely light. In fact, they might be billions
• 32:59
  of times lighter than an electron, yet they could still
• 33:03
  exist in enormous numbers throughout the universe. And if enough
• 33:07
  of them were present, their combined mass could account for
• 33:10
  the gravitational effects attributed to dark matter. One of the
• 33:14
  intriguing properties of axions is that they may interact with
• 33:18
  magnetic fields in unusual ways, Under certain conditions, an axion
• 33:24
  particle might convert into a photon, a particle of light.
• 33:29
  And that possibility has inspired a new kind of dark
• 33:32
  matter detector. Some experiments place powerful magnets around extremely sensitive
• 33:38
  instruments designed to detect faint photons. If axions are passing
• 33:43
  through these magnetic fields, they might occasionally transform into detectable signals.
• 33:49
  These experiments are incredibly delicate. Scientists must eliminate almost all
• 33:55
  background noise. The faintest whisper of light could hold the
• 33:59
  key to discovering a new particle. A third possibility involves
• 34:03
  particles we already know exist. These particles are called neutrinos.
• 34:10
  Neutrinos are tiny, nearly massless particles produced in enormous numbers
• 34:15
  inside stars, supernova explosions and nuclear reactions. Every second, trillions
• 34:22
  of neutrinos pass through your body, yet you never notice them.
• 34:27
  They interact so weakly with matter that they almost always
• 34:30
  pass straight through. For this reason, some scientists once wondered
• 34:35
  whether neutrinos might account for dark matter. After all, they
• 34:40
  are invisible and extremely abundant. But over time, researchers discovered
• 34:46
  that neutrinos are probably too light and move too quickly
• 34:49
  to explain the structures we see in the universe. Dark
• 34:53
  matter appears to form stable halos around galaxies and clusters. Neutrinos,
• 34:59
  moving at nearly the speed of light, would tend to
• 35:02
  spread out too evenly across space. So while neutrinos contribute
• 35:06
  a small amount of mass to the universe, they are
• 35:09
  unlikely to account for the majority of dark matter. Even so,
• 35:14
  Studying neutrinos has helped scientists understand the strange world of
• 35:18
  particles that interact only weakly with matter. And this understanding
• 35:23
  continues to guide the search for dark matter. Today, researchers
• 35:28
  explore many possible candidates. Some theories suggest entirely new families
• 35:34
  of particles. Others propose hidden sectors of physics that interact
• 35:39
  only through gravity. There may even be particles we have
• 35:42
  not yet imagined. The possibilities stretch as wide as the
• 35:46
  universe itself. What makes the mystery of dark matter so
• 35:50
  fascinating is that it sits at the crossroads of two
• 35:54
  great scientific fields. Astronomy reveals its gravitational influence across galaxies
• 36:00
  and clusters. Particle physics attempts to identify the particles that
• 36:05
  might produce that influence. Together, these disciplines are working toward
• 36:10
  the same goal. to uncover the nature of the invisible
• 36:14
  matter shaping the cosmos. And yet, for now, dark matter
• 36:19
  remains just beyond our reach. We see its effects everywhere,
• 36:24
  in the motion of galaxies, in the bending of light,
• 36:29
  in the structure of the cosmic web stretching across the universe.
• 36:33
  But the particles themselves remain hidden, like faint shadows behind
• 36:38
  the glowing stars. As our journey continues, we will begin
• 36:43
  to explore how this mysterious substance may surround every galaxy.
• 36:48
  Invisible halos stretching far beyond the luminous disks of stars.
• 36:54
  Massive structures that help hold galaxies together as they spin
• 36:57
  slowly through the cosmic night. And within those halos lies
• 37:02
  one of the most important pieces of the dark matter puzzle.
• 37:05
  When we look at photographs of galaxies, what we see
• 37:09
  is beautiful but incomplete. A spiral galaxy appears like a
• 37:13
  glowing pinwheel in the darkness of space. Billions of stars
• 37:17
  stretch outward in elegant arms, circling a bright central core.
• 37:22
  Clouds of gas and dust weave delicate patterns between the stars,
• 37:26
  sometimes forming luminous nebulae where new stars are born. But
• 37:31
  this shining disk of stars is only the visible portion
• 37:34
  of something much larger. Astronomers now believe that every galaxy
• 37:39
  is surrounded by an enormous halo of dark matter, a vast,
• 37:43
  invisible sphere that extends far beyond the galaxy's glowing edges.
• 37:48
  These halos cannot be seen directly. They emit no light
• 37:52
  and reflect none, yet their presence is revealed through the
• 37:56
  quiet pull of gravity. And in many cases, the halo
• 38:00
  contains far more mass than the stars themselves. Imagine drifting
• 38:05
  far above a galaxy and watching it from a distance.
• 38:10
  The spiral arms glow softly, slowly turning like a cosmic carousel.
• 38:16
  At first, it appears that the stars themselves form the
• 38:19
  entire structure. But if we could somehow see the dark
• 38:23
  matter halo surrounding the galaxy, the picture would change dramatically.
• 38:28
  Instead of a flat disk floating in empty space, the
• 38:33
  galaxy would appear embedded within a huge spherical cloud of
• 38:37
  invisible mass. This halo might extend several times farther than
• 38:42
  the visible galaxy. While the bright disk of stars may
• 38:45
  stretch 100,000 light years across, the dark matter halo could
• 38:50
  reach three or four times that distance. The galaxy we
• 38:53
  see is simply the luminous center of a much larger
• 38:57
  gravitational structure. These halos help explain many of the puzzles
• 39:02
  astronomers have encountered. Earlier, we spoke about how stars near
• 39:06
  the edges of galaxies move too quickly to be held
• 39:09
  by visible matter alone. The dark matter halo provides the
• 39:13
  extra gravity needed to keep those stars in orbit. Without it,
• 39:18
  the outer regions of galaxies might slowly unravel. Stars would
• 39:22
  drift away into intergalactic space. But with the halo present,
• 39:27
  the galaxy remains stable. the invisible. mass surrounding it gently
• 39:31
  guides the motion of billions of stars. Dark matter halos
• 39:36
  may also influence the shape of galaxies. Galaxies are not
• 39:40
  all the same. Some form elegant spirals like the Milky Way.
• 39:45
  Others appear as smooth ellipses, Some are small dwarf galaxies
• 39:50
  containing only a few billion stars, while others are enormous
• 39:53
  systems with hundreds of billions. The structure of each galaxy
• 39:58
  is shaped by the distribution of matter within it, and
• 40:01
  dark matter halos play a major role in that distribution.
• 40:06
  As ordinary gas falls into the gravitational well created by
• 40:09
  dark matter, it begins to cool and condense. Over time,
• 40:14
  that gas forms stars, Those stars gather into rotating disks, clusters,
• 40:21
  and bulges. In this way, the invisible halo acts like
• 40:25
  a kind of cosmic framework. Ordinary matter settles into this framework,
• 40:31
  creating the galaxies we observe. In the early universe, this
• 40:36
  process was especially important. Shortly after the Big Bang, matter
• 40:41
  was spread almost evenly across space. Tiny fluctuations in density
• 40:46
  gradually grew as gravity pulled matter together. Dark matter may
• 40:51
  have been the first substance to form these gravitational clumps.
• 40:55
  Because it interacts very weakly with radiation, it could begin
• 40:59
  gathering long before ordinary matter cooled enough to form stars.
• 41:04
  Over time, these clumps grew into larger and larger halos.
• 41:09
  Gas fell into them, stars formed, galaxies emerged. In this way,
• 41:16
  dark matter may have acted as the scaffolding of the universe,
• 41:19
  guiding the formation of the first cosmic structures. Astronomers have
• 41:24
  developed sophisticated computer simulations to study how dark matter halos evolve.
• 41:30
  In these simulations, billions of particles representing dark matter interact
• 41:35
  through gravity. Over time, they form complex structures that resemble
• 41:40
  the cosmic web observed across the universe. Within that web,
• 41:45
  Halos grow and merge. Small halos combine to form larger ones.
• 41:51
  Galaxies form within them. Clusters of galaxies gather at the
• 41:55
  intersections of massive filaments of dark matter. When scientists compare
• 42:00
  these simulations with observations of real galaxies, the results are
• 42:05
  strikingly similar. The patterns match. The structures align. It is
• 42:11
  as though the invisible matter predicted by the models truly
• 42:14
  exists shaping the architecture of the cosmos. Dark matter halos
• 42:20
  are not smooth, uniform spheres. They are thought to contain
• 42:24
  smaller clumps known as subhalos. These substructures may host smaller
• 42:29
  galaxies often called dwarf galaxies that orbit larger systems like satellites.
• 42:35
  The Milky Way itself is surrounded by many such companions.
• 42:39
  Tiny galaxies drifting quietly through the halo Some contain only
• 42:44
  a few million stars. Others are even fainter. Yet their
• 42:49
  motions reveal that they are embedded within the same invisible
• 42:53
  gravitational environment. Each satellite galaxy traces the contours of the
• 42:58
  Milky Way's dark matter halo. Even galaxy clusters, the largest
• 43:03
  gravitationally bound systems in the universe, possess enormous dark matter halos.
• 43:10
  In these clusters, the halos become immense. They extend millions
• 43:14
  of light years across space. Galaxies orbit within them like
• 43:19
  small islands floating in a vast ocean of invisible mass.
• 43:23
  Hot gas fills the space between galaxies, glowing faintly in
• 43:27
  X-ray light. But most of the cluster's mass remains unseen.
• 43:32
  Dark matter dominates the gravitational landscape. Sometimes astronomers can even
• 43:38
  map these halos indirectly. Using gravitational lensing, They measure how
• 43:43
  the halo bends the light of more distant galaxies. By
• 43:48
  studying these distortions carefully, scientists can reconstruct the distribution of
• 43:53
  mass surrounding the cluster. The result often reveals intricate patterns
• 43:57
  of dark matter stretching across the cluster like an invisible map.
• 44:02
  A map drawn not in light, but in gravity. All
• 44:06
  of this evidence points toward a remarkable idea. The universe
• 44:10
  may be filled with structures we cannot see, Galaxies are
• 44:14
  not isolated islands of stars. They are luminous markers embedded
• 44:19
  within vast halos of dark matter. Clusters of galaxies float
• 44:23
  inside even larger structures. And all of these systems connect
• 44:28
  through the immense cosmic web that stretches across billions of
• 44:32
  light years. The visible universe, the stars and galaxies we photograph,
• 44:37
  is only the glowing surface of something much deeper. Beneath
• 44:41
  that surface lies an invisible architecture shaping the cosmos. And yet,
• 44:47
  despite the growing evidence, one profound mystery remains. We still
• 44:53
  do not know what dark matter is made of. We
• 44:56
  see its influence everywhere. But the particles themselves remain hidden.
• 45:01
  Somewhere in the depths of space, or perhaps even passing
• 45:05
  quietly through the Earth right now, those particles may be
• 45:09
  waiting to be discovered. As our journey continues, we will
• 45:13
  explore how scientists are searching for them. Because around the world,
• 45:18
  researchers have built experiments designed to detect the faintest whisper
• 45:22
  of dark matter itself. And those experiments are listening carefully
• 45:27
  in the deepest, quietest places on Earth. If we could
• 45:31
  travel far enough away from the Milky Way, far beyond
• 45:35
  the stars of our galaxy, and look back at the
• 45:37
  universe from an unimaginable distance, the cosmos would reveal a
• 45:42
  structure that is both beautiful and surprising. At first, we
• 45:47
  might imagine galaxies scattered randomly through space, tiny islands of
• 45:52
  stars drifting in every direction. But that is not what
• 45:55
  astronomers observe. When scientists map the positions of millions of
• 46:00
  galaxies across the universe, a pattern begins to emerge. A
• 46:05
  vast network. A delicate structure stretching across billions of light-years.
• 46:11
  This immense arrangement is known as the cosmic web. In
• 46:15
  this web-like structure, galaxies gather along enormous strands called filaments.
• 46:21
  These filaments stretch across space like threads of glowing silk.
• 46:25
  Where several filaments intersect, massive clusters of galaxies form. And
• 46:31
  between these filaments lie enormous empty regions known as cosmic voids.
• 46:36
  Vast spaces where very few galaxies exist at all. If
• 46:40
  we could see the universe from far away, the pattern
• 46:43
  might resemble a sponge, or perhaps a network of rivers
• 46:47
  and tributaries spreading across the darkness. The luminous galaxies we
• 46:52
  see are simply the bright nodes along these filaments. But
• 46:56
  the true structure of the web extends far beyond what
• 46:59
  our eyes can detect. Dark matter is believed to form
• 47:02
  the invisible framework of this cosmic web. In the earliest
• 47:06
  moments of the universe, tiny fluctuations in density began to grow.
• 47:11
  Gravity slowly pulled matter toward the slightly denser regions. Over
• 47:16
  millions of years, those small irregularities became larger structures. Dark matter,
• 47:23
  interacting mainly through gravity, began gathering into vast filaments and halos.
• 47:29
  Ordinary matter, gas, and dust followed this gravitational blueprint. As
• 47:34
  gas flowed into the densest regions of the web, It
• 47:37
  cooled and condensed. Stars formed. Galaxies appeared. In this way,
• 47:44
  dark matter may have acted as the architect of the
• 47:46
  large-scale universe. The galaxies we see today formed along the
• 47:51
  invisible scaffolding created by dark matter. Computer simulations of the
• 47:56
  universe offer remarkable glimpses into how this process might have unfolded.
• 48:01
  In these simulations, scientists model billions of particles representing dark matter.
• 48:07
  As the simulation evolves, gravity pulls the particles together. Over time,
• 48:13
  the particles arrange themselves into complex structures that strongly resemble
• 48:18
  the cosmic web observed by astronomers. Filaments stretch across vast distances,
• 48:25
  clusters form where filaments intersect, and enormous voids open between them.
• 48:30
  When researchers compare these simulated maps with real observations of
• 48:34
  galaxy distributions, the similarities are striking. It is as though
• 48:39
  the dark matter blueprint, predicted by theory, matches the structure
• 48:44
  of the real universe. These filaments are truly immense. Some
• 48:50
  stretch across hundreds of millions of light years. Galaxies drift
• 48:54
  slowly along them, pulled by the gravitational currents of dark matter.
• 48:59
  Clusters grow larger as matter flows inward along the filaments.
• 49:04
  like water moving through channels toward a lake. Even our
• 49:07
  own Milky Way galaxy is part of this cosmic web.
• 49:11
  We reside in a region of the universe known as
• 49:13
  the Laniakea Supercluster, a vast structure containing tens of thousands
• 49:19
  of galaxies connected by these invisible gravitational threads. Our galaxy
• 49:24
  drifts quietly within this enormous network, one small node in
• 49:28
  a structure that spans the observable universe. Although dark matter
• 49:33
  itself cannot be seen, astronomers have found indirect ways to
• 49:37
  trace the cosmic web. One method involves studying faint clouds
• 49:42
  of hydrogen gas that lie between galaxies. When light from
• 49:45
  distant quasars passes through this gas, it leaves subtle fingerprints
• 49:50
  in the spectrum of the light. By analysing these patterns,
• 49:54
  scientists can map the distribution of matter across large regions
• 49:57
  of space. These maps reveal the same filamentary structures predicted
• 50:02
  by simulations. The glowing galaxies appear to trace the outlines
• 50:07
  of a much larger invisible network. like dew droplets clinging
• 50:11
  to the threads of a spider's web. Another technique involves
• 50:16
  gravitational lensing. Just as dark matter halos around galaxies bend light,
• 50:22
  the massive filaments of the cosmic web can also distort
• 50:25
  the light of distant galaxies. By carefully measuring these distortions,
• 50:30
  astronomers can infer where large concentrations of dark matter must exist.
• 50:35
  The results again point toward an enormous interconnected network. An
• 50:40
  invisible structure binding the universe together. What makes the cosmic
• 50:45
  web especially fascinating is its scale. Individual galaxies may span
• 50:50
  tens or hundreds of thousands of light years, but the
• 50:54
  cosmic web extends across billions of light years. It is
• 50:58
  the largest structure known in the universe. Yet even this
• 51:02
  vast network continues evolving. Galaxies slowly drift along the filaments.
• 51:08
  Clusters grow larger as they gather surrounding matter, and the
• 51:12
  cosmic voids between filaments gradually expand. Over billions of years,
• 51:18
  the web slowly changes shape, a slow cosmic dance unfolding
• 51:23
  across unimaginable distances. Dark matter plays a crucial role in
• 51:29
  maintaining this structure. Because dark matter interacts primarily through gravity,
• 51:34
  it remains stable over immense periods of time, It forms
• 51:38
  the gravitational backbone that keeps the cosmic web intact. Ordinary matter,
• 51:43
  the stars and galaxies we observe, simply traces the outlines
• 51:48
  of this hidden framework. In this sense, dark matter may
• 51:52
  be the true skeleton of the universe, invisible yet essential.
• 51:58
  Without it, the large-scale structure of the cosmos might look
• 52:01
  entirely different. Galaxies might never have gathered into the patterns
• 52:06
  we see today. And so, once again, we encounter the
• 52:10
  same remarkable idea. The universe we can see is only
• 52:14
  part of the story. The glowing galaxies and stars are
• 52:18
  merely the visible threads in a much larger tapestry. Beneath
• 52:22
  them lies an invisible structure woven from dark matter. A
• 52:26
  cosmic web stretching across the universe, guiding the formation of galaxies,
• 52:33
  shaping the architecture of the cosmos. and reminding us that
• 52:37
  even the largest structures in existence may be built upon
• 52:40
  something we cannot yet fully understand. As our quiet journey continues,
• 52:45
  we will turn our attention to the scientists searching for
• 52:48
  the particles that might make up dark matter. Because while
• 52:52
  astronomers map the cosmic web across the universe, physicists here
• 52:56
  on Earth are building experiments designed to detect the invisible
• 52:59
  particles themselves. Deep underground, In the quietest laboratories imaginable, instruments
• 53:07
  are listening for the faintest whispers of the dark universe.
• 53:11
  By now, the clues pointing toward dark matter are scattered
• 53:15
  everywhere across the cosmos. Galaxies spin as though invisible halos
• 53:20
  surround them. Clusters of galaxies bend light more strongly than
• 53:25
  visible matter can explain. The vast cosmic web stretches across
• 53:29
  the universe, guided by hidden gravitational structures, And yet, despite
• 53:35
  all of this evidence, one important piece of the puzzle
• 53:38
  remains missing. No one has ever directly detected a particle
• 53:43
  of dark matter. Astronomers can see its influence through gravity,
• 53:48
  but the particles themselves remain hidden. So scientists have begun
• 53:52
  searching for them in a different way. Instead of looking
• 53:55
  only into the sky, they have built experiments here on
• 53:58
  Earth quiet laboratories designed to detect the faintest whisper of
• 54:03
  invisible particles passing through our planet. If dark matter exists
• 54:08
  as particles drifting through space, then our galaxy should be
• 54:11
  filled with them. The Milky Way's dark matter halo surrounds
• 54:15
  our galaxy like a vast invisible ocean. And because the
• 54:19
  Earth orbits within that halo, we are constantly moving through it.
• 54:24
  This means that dark matter particles may be passing through
• 54:27
  the Earth right now, passing through the atmosphere, through the
• 54:31
  ground beneath our feet, even through our bodies. But because
• 54:36
  dark matter interacts so weakly with ordinary matter, these particles
• 54:40
  rarely leave any trace of their passage. Detecting them requires
• 54:45
  instruments of extraordinary sensitivity. To build such detectors, scientists must
• 54:51
  first eliminate as much background noise as possible. Cosmic rays
• 54:55
  constantly bombard the Earth's surface. Particles from space collide with
• 55:00
  the atmosphere and produce showers of energetic radiation. These signals
• 55:05
  could easily overwhelm the delicate measurements needed to detect dark matter.
• 55:11
  So many dark matter experiments are built deep underground, hundreds
• 55:15
  or even thousands of meters beneath the surface. The thick
• 55:19
  layers of rock above act as a natural shield, blocking
• 55:23
  most cosmic radiations. In these quiet underground environments, detectors can
• 55:28
  listen more carefully for rare interactions. One such experiment might
• 55:32
  be located inside an abandoned mine or deep within a mountain.
• 55:37
  In these silent chambers, enormous tanks filled with ultra-pure materials
• 55:42
  wait patiently. Some detectors use liquid xenon, a dense noble
• 55:47
  gas cooled into liquid form. Others use crystals of germanium
• 55:51
  or silicon. The idea is simple. If a dark matter
• 55:55
  particle passes through the detector and collides with an atom,
• 55:59
  it might transfer a tiny amount of energy. That energy
• 56:03
  could produce a faint flash of light or a small
• 56:06
  electrical signal. Sensitive instruments monitor the detector continuously, searching for
• 56:12
  these rare events. Even a single confirmed signal could be
• 56:16
  a historic discovery. These experiments must operate with extraordinary precision.
• 56:23
  The materials used in the detectors must be extremely pure,
• 56:27
  free from natural radioactive contaminants. Even a tiny amount of
• 56:32
  radiation from the surrounding environment could produce signals that mimic
• 56:36
  the effect of dark matter. Scientists carefully select materials, filter
• 56:42
  the air, and design elaborate shielding systems. In some laboratories,
• 56:47
  the detectors sit inside water tanks or layers of lead
• 56:50
  designed to block stray radiation. The goal is to create
• 56:54
  one of the quietest environments on Earth, a place where
• 56:58
  even the smallest signal might be noticed. So far, these
• 57:02
  experiments have not produced a definitive detection, but they have
• 57:07
  dramatically improved our understanding of what dark matter cannot be.
• 57:11
  Each new generation of detectors becomes more sensitive than the last.
• 57:16
  They rule out certain possibilities while narrowing the range of
• 57:19
  particle masses and interaction strengths that dark matter might have.
• 57:24
  In science, sometimes discovering what something is not is just
• 57:28
  as important as discovering what it is. While underground experiments
• 57:32
  listen quietly for dark matter particles drifting through Earth, another
• 57:37
  search is taking place in powerful particle accelerators. One of
• 57:41
  the most famous of these machines is the Large Hadron Collider,
• 57:45
  or LHC, Located beneath the border between France and Switzerland,
• 57:50
  the LHC is the largest and most powerful particle accelerator
• 57:55
  ever built. Inside a circular tunnel nearly 27 kilometers in circumference,
• 58:01
  protons are accelerated to extraordinary speeds, approaching the speed of light.
• 58:07
  These protons are then collided head-on inside massive detectors. The
• 58:13
  energy released in these collisions briefly recreates conditions similar to
• 58:17
  those that existed just after the Big Bang. Physicists hope
• 58:21
  that these high-energy collisions might produce new particles. Particles that
• 58:26
  have never been observed before. If dark matter consists of
• 58:30
  previously unknown particles, the LHC might be capable of creating them.
• 58:35
  But detecting such particles is not straightforward. Dark matter particles
• 58:40
  would likely interact very weakly with the detectors. In many cases,
• 58:44
  they might escape the detector entirely without leaving a direct trace. Instead,
• 58:50
  scientists look for missing energy. If a collision produces particles
• 58:54
  that carry away energy without interacting with the detector, that
• 58:59
  missing energy might suggest the presence of dark matter. Another
• 59:03
  approach involves looking for indirect signals of dark matter. If
• 59:07
  dark matter particles occasionally collide with one another in space,
• 59:11
  they might produce other particles that telescopes can detect. For example,
• 59:16
  collisions between dark matter particles might generate gamma rays or
• 59:20
  other high-energy radiation. Astronomers search for these signals in regions
• 59:25
  where dark matter is expected to be abundant, such as
• 59:28
  the centers of galaxies. These observations are incredibly challenging, because
• 59:33
  many other processes can also produce similar radiation. But by
• 59:38
  studying the patterns carefully, scientists hope to find subtle clues
• 59:42
  pointing toward the nature of dark matter. All of these
• 59:46
  efforts underground detectors, particle accelerators, and astronomical observations are part
• 59:52
  of a global search. Thousands of scientists across the world
• 59:56
  are working together to solve one of the greatest mysteries
• 59:59
  in modern physics. What is the invisible matter that shapes
• 1:00:03
  the universe? What particles fill the vast halos surrounding galaxies?
• 1:00:09
  And why do these particles interact so weakly with everything
• 1:00:12
  we know? For now, the answer remains just out of reach.
• 1:00:17
  The detectors continue listening quietly beneath mountains and mines. The
• 1:00:22
  particle accelerators continue smashing protons together at incredible energies, and
• 1:00:28
  telescopes continue scanning the heavens for subtle hints of the
• 1:00:32
  dark universe. Each experiment brings us a little closer to
• 1:00:36
  understanding the invisible side of the cosmos. As our journey continues,
• 1:00:41
  we will explore how scientists use powerful computer simulations to
• 1:00:45
  understand how dark matter shapes the formation of galaxies and
• 1:00:48
  the cosmic web. Because even when we cannot see dark
• 1:00:52
  matter directly, its influence can still be modeled. And through
• 1:00:56
  those simulations, we may glimpse the hidden architecture of the
• 1:01:00
  universe itself. Even though dark matter cannot be seen directly,
• 1:01:05
  scientists have found a remarkable way to study it. They
• 1:01:08
  build entire universes inside computers. These digital universes begin with
• 1:01:14
  simple ingredients. Particles representing dark matter, laws of gravity based
• 1:01:20
  on Einstein's equations, and the conditions believed to exist shortly
• 1:01:24
  after the Big Bang. From there, the simulation begins. Tiny
• 1:01:30
  fluctuations in density appear across a virtual cosmos. Gravity slowly
• 1:01:35
  pulls particles together. And over time, millions, then billions of
• 1:01:40
  simulated years, the universe begins to take shape. Clusters form.
• 1:01:46
  Filaments stretch across vast distances. Galaxies gather at the intersections
• 1:01:51
  of the cosmic web, all guided by the invisible pull
• 1:01:55
  of dark matter. These simulations are not simple animations. They
• 1:02:00
  are complex scientific experiments performed inside powerful supercomputers. Each particle
• 1:02:07
  in the simulation represents a large amount of dark matter,
• 1:02:11
  sometimes millions. Sometimes billions of particles attract at once. At
• 1:02:17
  every moment, the computer calculates how gravity pulls each particle
• 1:02:21
  toward all the others. These calculations must be repeated again
• 1:02:26
  and again as the simulated universe evolves. The result is
• 1:02:31
  an incredibly detailed model of cosmic structure, one that allows
• 1:02:35
  scientists to explore how the universe might have grown over
• 1:02:39
  billions of years. One of the most famous simulations is
• 1:02:42
  known as the Millennium Simulation. In this project, researchers used
• 1:02:47
  a massive supercomputer to simulate the evolution of the universe
• 1:02:51
  across more than 13 billion years. The simulation tracked billions
• 1:02:57
  of dark matter particles as they formed halos, clusters, and filaments.
• 1:03:02
  When scientists visualized the results, something extraordinary appeared. The simulated
• 1:03:08
  universe looked strikingly similar to the real one. The same
• 1:03:12
  web-like structures emerged. The same clusters formed at the intersections
• 1:03:17
  of filaments. Even the distribution of galaxies resembled the patterns
• 1:03:22
  astronomers observe in the night sky. It was as though
• 1:03:26
  the invisible architecture of the cosmos had been revealed through mathematics.
• 1:03:31
  But simulations can do more than simply reproduce what we see.
• 1:03:35
  They allow scientists to explore how galaxies might form within
• 1:03:39
  dark matter halos. In the early universe, clouds of gas
• 1:03:44
  were drawn into these halos by gravity. As the gas cooled,
• 1:03:48
  it began to collapse into rotating disks. Inside those disks,
• 1:03:53
  stars ignited. Over millions of years, those stars gathered into
• 1:03:59
  the galaxies we observe today. By adjusting the physical conditions
• 1:04:03
  in simulations such as the strength of gravity or the
• 1:04:06
  properties of dark matter particles, scientists can study how these
• 1:04:10
  changes affect galaxy formation. If the results no longer match
• 1:04:15
  the real universe, the model must be adjusted. In this way,
• 1:04:19
  simulations become powerful tools for testing cosmological theories. Many modern
• 1:04:25
  simulations also include the effects of ordinary matter. Gas flows
• 1:04:30
  through the cosmic web Supernova explosions release energy into surrounding regions.
• 1:04:37
  Black holes at the centers of galaxies generate powerful jets
• 1:04:40
  that influence star formation. These processes interact with the dark
• 1:04:45
  matter framework, shaping the final appearance of galaxies. The simulations
• 1:04:50
  must carefully balance all of these effects. Too much energy
• 1:04:54
  from supernovae and galaxies may fail to form properly. Too
• 1:04:59
  little and galaxies become unrealistically massive. By comparing simulated galaxies
• 1:05:06
  with real observations, scientists refine their understanding of how the
• 1:05:10
  universe evolves. One of the most fascinating insights from these
• 1:05:15
  simulations is the idea that galaxies grow through a process
• 1:05:18
  of cosmic merging. Small dark matter halos form first. Over time,
• 1:05:24
  gravity pulls them together. They merge into larger halos. The
• 1:05:29
  galaxies inside them collide and combine as well. This process
• 1:05:33
  continues across billions of years, gradually building larger and more
• 1:05:38
  complex structures. Our own Milky Way galaxy likely grew this way.
• 1:05:44
  Over its long history, it may have absorbed many smaller
• 1:05:47
  galaxies drifting through the cosmic web. The faint stellar streams
• 1:05:52
  observed around the Milky Way today may be the remnants
• 1:05:55
  of those ancient mergers. Simulations also reveal how dark matter
• 1:06:00
  halos surround galaxies in complex shapes. Rather than perfect spheres,
• 1:06:06
  many halos appear slightly stretched or irregular. They contain smaller subhalos,
• 1:06:12
  tiny clumps of dark matter orbiting within the larger halo.
• 1:06:16
  Some of these subhalos host dwarf galaxies. Others remain dark,
• 1:06:21
  containing very few stars at all. These invisible structures may
• 1:06:25
  still influence the motion of stars and gas within larger galaxies.
• 1:06:30
  Astronomers continue searching for evidence of these hidden substructures through
• 1:06:34
  careful observations. Another important role of simulations is predicting how
• 1:06:40
  the universe should appear when observed through telescopes. By generating
• 1:06:44
  virtual galaxies and clusters, scientists can compare them directly with
• 1:06:49
  real astronomical surveys. Large sky surveys such as those conducted
• 1:06:54
  by modern observatories map millions of galaxies across enormous regions
• 1:06:59
  of space. When these maps are compared with simulated universes
• 1:07:04
  researchers can test whether the models accurately describe reality. So
• 1:07:09
  far the presence of dark matter provides one of the
• 1:07:13
  best explanations for the patterns observed in these surveys. Without
• 1:07:17
  dark matter the simulated universe fails to produce the structures
• 1:07:22
  we see. Galaxies do not cluster correctly, the cosmic web
• 1:07:27
  becomes far less pronounced, and the distribution of matter no
• 1:07:31
  longer matches observations. In this way, computer simulations act like
• 1:07:36
  a bridge between theory and observation. They allow scientists to
• 1:07:41
  explore the hidden forces shaping the universe. They provide a
• 1:07:45
  way to test ideas that cannot yet be examined directly.
• 1:07:49
  And they reveal how invisible matter might sculpt the grand
• 1:07:53
  structure of the cosmos. The universe inside the computer becomes
• 1:07:58
  a laboratory where astronomers can experiment with cosmic history. Despite
• 1:08:03
  their sophistication, these simulations still rely on assumptions about the
• 1:08:07
  nature of dark matter. Scientists must choose how dark matter behaves.
• 1:08:13
  Does it interact only through gravity? Does it have additional forces?
• 1:08:18
  Does it consist of heavy particles or extremely light ones?
• 1:08:23
  Each possibility produces slightly different cosmic structures. By comparing these
• 1:08:28
  models with observations, researchers slowly narrow the range of possibilities.
• 1:08:34
  The hope is that one day, the simulations will match
• 1:08:38
  reality so closely that the true nature of dark matter
• 1:08:42
  becomes clear. For now, these digital universes offer a fascinating
• 1:08:47
  glimpse into the invisible side of the cosmos. They show
• 1:08:50
  us how dark matter may weave the cosmic web, how
• 1:08:54
  galaxies might grow within hidden halos, and how the universe
• 1:08:58
  itself evolves around it. across billions of years. Even when
• 1:09:02
  we cannot see dark matter directly, we can still explore
• 1:09:06
  its influence through the language of mathematics and computation. As
• 1:09:10
  our quiet journey continues, we will turn our attention to
• 1:09:13
  some of the more unusual ideas scientists have proposed about
• 1:09:17
  dark matter. Because while many theories focus on new particles
• 1:09:22
  like WIMPs or axions, others suggest that our understanding of
• 1:09:26
  gravity itself might need to change. And those possibilities open
• 1:09:30
  the door to some of the most intriguing questions in
• 1:09:33
  modern physics. So far in our journey, dark matter has
• 1:09:37
  appeared as a quiet but powerful presence in the universe.
• 1:09:41
  It shapes galaxies. It bends light. It forms the invisible
• 1:09:47
  scaffolding of the cosmic web. But despite decades of research,
• 1:09:51
  scientists still do not know exactly what dark matter is
• 1:09:55
  made of. And whenever a mystery remains unsolved for this long,
• 1:09:59
  scientists begin exploring many different possibilities. Some ideas follow the
• 1:10:04
  path of particle physics, searching for entirely new particles. But
• 1:10:09
  others ask a deeper question. What if the mystery is
• 1:10:12
  not hidden matter at all? What if the laws of
• 1:10:15
  gravity themselves behave differently on cosmic scales? This idea leads
• 1:10:20
  to one of the most intriguing alternatives to dark matter,
• 1:10:24
  a concept known as modified gravity. According to our current understanding,
• 1:10:30
  gravity follows the rules described by Newton and later refined
• 1:10:34
  by Einstein. These theories have been incredibly successful. They explain
• 1:10:39
  the motion of planets, the bending of light around stars,
• 1:10:43
  and the expansion of the universe. But some scientists wonder
• 1:10:47
  whether these laws might change slightly under certain conditions, especially
• 1:10:52
  when dealing with extremely large distances or extremely weak gravitational fields.
• 1:10:59
  One proposed theory is called MOND, which stands for Modified
• 1:11:03
  Newtonian Dynamics. MOND suggests that gravity may become stronger than
• 1:11:08
  expected when the gravitational pull becomes very weak, such as
• 1:11:12
  in the outer regions of galaxies. If this is true,
• 1:11:16
  then the stars moving quickly at the edges of galaxies
• 1:11:19
  might not require invisible matter after all. Instead, gravity itself
• 1:11:25
  might behave differently than we once thought. Mond has had
• 1:11:28
  some success in explaining the rotation of galaxies. In some cases,
• 1:11:33
  the theory predicts star motions quite accurately without requiring dark
• 1:11:38
  matter halos. But Mond also faces challenges. When astronomers study
• 1:11:43
  galaxy clusters and gravitational lensing, the modified gravity models often
• 1:11:48
  struggle to explain all the observations. This has led many
• 1:11:52
  scientists to believe that dark matter still provides a more
• 1:11:55
  complete explanation. Yet the idea remains fascinating. It reminds us
• 1:12:01
  that even the fundamental laws of physics may still hold surprises.
• 1:12:05
  Another intriguing possibility is the existence of something known as
• 1:12:09
  the dark sector. If dark matter consists of new particles,
• 1:12:14
  those particles might not exist alone. Just as ordinary matter
• 1:12:19
  includes many different particles, electrons, protons, neutrons and more, the
• 1:12:24
  dark universe might contain an entire hidden family of particles
• 1:12:29
  interacting with one another. Some scientists imagine that dark matter
• 1:12:33
  particles could interact through forces that are invisible to us.
• 1:12:38
  Perhaps there are dark equivalents of photons, mediating interactions between
• 1:12:43
  dark particles. Perhaps dark atoms and dark radiation exist in
• 1:12:47
  parallel with the ordinary matter we know. This hypothetical realm
• 1:12:52
  is sometimes called the dark sector. It would be a
• 1:12:55
  shadow universe overlapping our own, interacting only weakly with ordinary matter.
• 1:13:01
  Most of its activity would remain invisible to our instruments,
• 1:13:06
  but its gravitational influence would still shape the cosmos. If
• 1:13:10
  such a dark sector exists, the universe might be far
• 1:13:14
  more complex than we currently imagine. Entire processes could unfold
• 1:13:19
  within the dark sector structures forming, particles interacting without producing
• 1:13:23
  light or radiation that we can detect. From our perspective,
• 1:13:28
  these events would remain hidden, yet their combined mass would
• 1:13:32
  still influence the motion of galaxies and the growth of
• 1:13:35
  cosmic structures. In a way, the universe might contain layers
• 1:13:40
  of reality. the visible universe we observe with telescopes, and
• 1:13:45
  a hidden universe made of particles we have yet to discover.
• 1:13:49
  Some theories even propose the existence of exotic particles beyond
• 1:13:53
  the familiar categories studied in particle physics. These particles could
• 1:13:57
  have unusual properties. Some might be extremely heavy, interacting only
• 1:14:03
  through gravity. Others might be incredibly light, forming wave-like structures
• 1:14:08
  across galaxies. In certain models dark matter could behave almost
• 1:14:13
  like a cosmic fluid. In others it might form clumps
• 1:14:18
  or vortices on enormous scales. Each possibility leads to slightly
• 1:14:23
  different predictions about how galaxies form and evolve. By comparing
• 1:14:27
  these predictions with astronomical observations scientists attempt to narrow the
• 1:14:32
  field of possibilities. One particularly unusual idea involves something called
• 1:14:37
  ultralight dark matter. In this model Dark matter particles are
• 1:14:42
  so incredibly light that their quantum properties become important on
• 1:14:47
  galactic scales. Instead of behaving like individual particles, they may
• 1:14:52
  act more like waves spread across vast distances. These waves
• 1:14:56
  could form gentle interference patterns, influencing how stars move within galaxies.
• 1:15:03
  Such models might explain certain features observed in the distribution
• 1:15:07
  of stars in dwarf galaxies. Though still speculative, they offer
• 1:15:12
  a reminder that the universe may operate in ways far
• 1:15:15
  stranger than our everyday experience suggests. Another possibility involves particles
• 1:15:20
  that interact through entirely new forces. Just as the electromagnetic
• 1:15:25
  force governs interactions between charged particles, dark matter might experience
• 1:15:30
  its own unique force. This force would not affect ordinary matter.
• 1:15:35
  It would operate only within the dark sector. If such
• 1:15:39
  forces exist, they might influence how dark matter clumps together
• 1:15:43
  or spreads across the universe. Detecting these effects would be
• 1:15:48
  extremely challenging, but subtle patterns in galaxy formation might provide clues.
• 1:15:54
  Despite the many theories, scientists remain cautious. The mystery of
• 1:15:59
  dark matter sits at the frontier of modern physics. Each
• 1:16:03
  idea must be carefully tested against observations. Some models will
• 1:16:08
  eventually be ruled out, others may gain stronger support, and
• 1:16:12
  perhaps somewhere among these possibilities lies the true explanation. The
• 1:16:18
  invisible substance shaping galaxies might turn out to be a
• 1:16:22
  new particle, or a hidden sector of physics, or even
• 1:16:26
  a subtle modification of gravity itself. For now, the dark
• 1:16:31
  universe remains largely unexplored, But that uncertainty is part of
• 1:16:36
  what makes the search so exciting. Science moves forward not
• 1:16:41
  only through answers, but through questions. Each observation opens the
• 1:16:46
  door to new possibilities. Each theory invites deeper investigation. And
• 1:16:52
  with every experiment and telescope observation, we move a little
• 1:16:57
  closer to understanding the hidden side of the cosmos. As
• 1:17:00
  we approach the final part of our journey tonight, we
• 1:17:04
  will turn our thoughts toward the future. Because new telescopes,
• 1:17:08
  new detectors, and new experiments are already being built. These
• 1:17:13
  instruments may soon reveal clues that have remained hidden until now.
• 1:17:18
  And somewhere in the quiet darkness between the stars, the
• 1:17:22
  true nature of dark matter may finally begin to emerge.
• 1:17:26
  Even after decades of research, dark matter remains one of
• 1:17:29
  the greatest mysteries in modern science. we have seen its
• 1:17:33
  influence across the universe, in the spinning motion of galaxies,
• 1:17:39
  in the bending of light through gravitational lensing, in the
• 1:17:43
  delicate threads of the cosmic web stretching across billions of
• 1:17:46
  light years. And yet, the particles responsible for all of
• 1:17:51
  this remain unseen. But the search is far from over.
• 1:17:56
  In fact, The coming decades may be the most exciting
• 1:18:00
  period yet in humanity's effort to understand the invisible universe.
• 1:18:04
  Because new telescopes, new detectors and new experiments are being built,
• 1:18:10
  each designed to reveal more about the hidden structure of
• 1:18:13
  the cosmos. One of the most powerful tools in this
• 1:18:16
  search will be the next generation of space telescopes. Observatories
• 1:18:21
  such as the Nancy Grace Roman Space Telescope are being
• 1:18:24
  designed to map the universe with extraordinary precision. By observing
• 1:18:29
  millions of galaxies across vast regions of space, these telescopes
• 1:18:34
  will measure subtle distortions caused by gravitational lensing. Through these measurements,
• 1:18:40
  scientists can create detailed maps of dark matter across enormous
• 1:18:44
  areas of the sky. These maps may reveal how dark
• 1:18:48
  matter clusters around galaxies, how it flows through the cosmic web,
• 1:18:52
  and how it influences the growth of cosmic structures over
• 1:18:56
  billions of years. In essence, astronomers will be able to
• 1:19:00
  trace the invisible architecture of the universe with unprecedented clarity.
• 1:19:06
  At the same time, New ground-based observatories are also preparing
• 1:19:10
  to survey the sky in remarkable detail. The Vera C.
• 1:19:14
  Rubin Observatory, for example, will conduct one of the most
• 1:19:18
  ambitious sky surveys ever attempted. Over the course of 10 years,
• 1:19:23
  this telescope will repeatedly scan the entire southern sky. It
• 1:19:28
  will capture billions of galaxies and track how they move
• 1:19:32
  and change over time. Among the many discoveries expected from
• 1:19:36
  this project are improved measurements of dark matter's distribution throughout
• 1:19:40
  the universe. By studying the shapes of galaxies and the
• 1:19:44
  subtle bending of their light, scientists can infer where dark
• 1:19:47
  matter must be concentrated. Slowly, piece by piece, the invisible
• 1:19:53
  map of the cosmos will become clearer. While telescopes look
• 1:19:57
  outward into the depth of space, Experiments on Earth continue
• 1:20:01
  their quiet search for dark matter particles. Underground detectors are
• 1:20:06
  growing larger and more sensitive with each new generation. Some
• 1:20:10
  experiments now contain several tons of liquid xenon, carefully shielded
• 1:20:15
  deep beneath mountains or mines. These detectors wait patiently for
• 1:20:19
  the faint signal of a dark matter particle colliding with
• 1:20:23
  an atom. Even a single confirmed interaction could change our
• 1:20:27
  understanding of the universe. The moment when such a signal
• 1:20:31
  is finally observed would mark one of the most important
• 1:20:34
  discoveries in the history of physics. Particle accelerators may also
• 1:20:38
  play a role in revealing the nature of dark matter.
• 1:20:42
  Future upgrades to the Large Hadron Collider and proposed new
• 1:20:45
  accelerators may reach even higher energies. By recreating conditions similar
• 1:20:50
  to those just after the Big Bang, these machines may
• 1:20:53
  produce entirely new particles. If dark matter consists of such particles,
• 1:20:59
  their signatures might appear in the debris of high energy collisions.
• 1:21:03
  Physicists would detect them indirectly through missing energy or unusual
• 1:21:08
  particle interactions. These experiments require enormous precision and patience, but
• 1:21:14
  the potential reward is extraordinary. They could reveal entirely new
• 1:21:19
  forms of matter. Astronomers are also exploring new techniques for
• 1:21:23
  studying the dark universe. Some projects focus on observing faint
• 1:21:28
  hydrogen clouds between galaxies. Others measure the cosmic microwave background,
• 1:21:34
  the ancient light left over from the birth of the universe.
• 1:21:38
  Tiny variations in this background radiation can reveal how dark
• 1:21:42
  matter influenced the early cosmos. By combining these observations with
• 1:21:47
  simulations and theoretical models, scientists hope to narrow the possibilities.
• 1:21:53
  Each experiment adds another piece to the puzzle. Yet despite
• 1:21:57
  all these efforts, the mystery of dark matter remains open.
• 1:22:01
  And in some ways, that mystery is what makes it
• 1:22:04
  so fascinating. Science does not always move in straight lines.
• 1:22:09
  Sometimes it advances through decades of quiet searching, through experiments
• 1:22:14
  that rule out possibilities, through observations that raise new questions.
• 1:22:19
  Dark matter sits at the frontier of this process. It
• 1:22:23
  challenges our understanding of both particle physics and cosmology. And
• 1:22:28
  somewhere within that challenge lies the opportunity for discovery. Perhaps
• 1:22:33
  dark matter will turn out to be a new particle
• 1:22:36
  waiting to be detected. Perhaps it belongs to a hidden
• 1:22:39
  dark sector of physics. Or perhaps the answer will require
• 1:22:44
  an entirely new way of thinking about gravity and the
• 1:22:47
  structure of the universe. For now, the dark universe continues
• 1:22:52
  to surround us, invisible, silent, yet profoundly influential. It shapes galaxies,
• 1:23:01
  it guides the formation of cosmic structures, and it reminds
• 1:23:06
  us that the universe still holds many secrets. As we
• 1:23:10
  reach the end of our journey tonight, we are left
• 1:23:12
  with a quiet sense of wonder. Most of the universe
• 1:23:16
  remains unseen, yet through careful observation, patient experimentation, and the
• 1:23:22
  curiosity of countless scientists, we continue to explore its hidden depths.
• 1:23:29
  The story of dark matter is still unfolding, and somewhere
• 1:23:33
  in the vast darkness between the stars, the answer may
• 1:23:36
  already be waiting. As our quiet journey through the hidden
• 1:23:40
  universe comes to an end, we return once more to
• 1:23:44
  the night sky. When we look upward, it feels as
• 1:23:47
  though we are seeing everything the cosmos has to offer.
• 1:23:51
  Stars shimmer softly across the darkness. Galaxies glow faintly in
• 1:23:56
  distant clusters. Nebulae drift like gentle clouds of light between
• 1:24:01
  the stars. But tonight we have discovered something remarkable. Most
• 1:24:07
  of the universe cannot be seen at all. The stars,
• 1:24:10
  planets and galaxies that fill our telescopes make up only
• 1:24:14
  a small fraction of what truly exists. The rest, the
• 1:24:18
  vast majority of the cosmos, remains invisible. Dark matter forms
• 1:24:23
  enormous halos around galaxies. It stretches through the cosmic web.
• 1:24:29
  It quietly shapes the motion of galaxies across billions of years.
• 1:24:33
  Yet even now, we still do not know exactly what
• 1:24:37
  it is. And perhaps that is part of the beauty
• 1:24:40
  of science. Human beings are still learning. Still exploring. Still
• 1:24:46
  asking questions about the universe that surrounds us. Each generation
• 1:24:51
  builds new telescopes, designs new experiments, develops new ideas that
• 1:24:57
  bring us closer to understanding the cosmos. But even with
• 1:25:00
  all that knowledge, the universe continues to hold mysteries. Quiet ones,
• 1:25:07
  patient ones, waiting for curious minds to discover them. Tonight,
• 1:25:12
  as you rest, it can be comforting to remember that
• 1:25:15
  we are part of that story. Tiny observers on a
• 1:25:19
  small planet, drifting through a galaxy that floats inside an
• 1:25:23
  invisible ocean of dark matter, a universe far larger and
• 1:25:27
  stranger than we once imagined, yet also peaceful in its
• 1:25:32
  quiet rhythms, galaxies turning slowly through the darkness, stars burning
• 1:25:39
  gently across the cosmic night, and somewhere beyond the reach
• 1:25:43
  of our telescopes, the hidden structure of the universe continuing
• 1:25:47
  its silent dance. Now, It is time to let your
• 1:25:51
  thoughts slow down. Allow the vastness of the universe to
• 1:25:55
  settle softly in your mind. There is no need to
• 1:25:58
  solve every mystery tonight. The cosmos will still be there tomorrow.
• 1:26:04
  And the next night, and the night after that, endless
• 1:26:08
  questions waiting patiently beneath the stars. So close your eyes.
• 1:26:13
  Relax your breathing. and let your mind drift gently through
• 1:26:17
  the quiet universe we have explored together. In a moment,
• 1:26:22
  soft ambient music will begin to play. Let the calm
• 1:26:26
  rhythm of that music guide you into rest. Thank you
• 1:26:30
  for spending this peaceful journey beneath the stars. Good night,
• 1:26:35
  and sleep well.
• 1:26:43
  Speaker 3: Thank you for watching.
• 1:27:14
  Speaker 2: Thank you for watching.
• 1:28:47
  Speaker 3: Thank you. Thanks for watching! Thank you for watching.
• 1:30:06
  Speaker 2: This is the first time that I have seen this
• 1:30:11
  type of object. you you you.
• 1:32:02
  Speaker 3: Thank you.
• 1:32:59
  Speaker 2: Thank you for watching. you you you you you.
• 1:35:12
  Speaker 3: Thank you. Thank you for watching. Thank you. you Thank you.
• 1:38:13
  Speaker 4: You Thank you for watching. Thank you.
• 1:40:18
  Speaker 2: Thank you.
• 1:40:40
  Speaker 1: Thank you.
• 1:41:05
  Speaker 3: Thank you.
• 1:41:36
  Speaker 5: Thank you for watching. This is the first time I've
• 1:42:53
  ever seen this. I've never seen anything like this. I've
• 1:43:02
  never seen anything like this.
• 1:43:18
  Speaker 3: Thank you. Thank you. Thank you for watching.
• 1:44:29
  Speaker 2: Thank you for watching. Thanks for watching! This is the
• 1:46:51
  first time I've seen this in real life.
• 1:46:52
  Speaker 3: This is the first time I've seen this in real life.
• 1:47:22
  Speaker 2: Thank you for watching.
• 1:48:10
  Speaker 3: You you you.
• 1:48:55
  Speaker 2: Thank you.
• 1:49:18
  Speaker 3: Thank you. Thank you for watching.
• 1:50:14
  Speaker 2: Thank you for watching. Thank you.
• 1:52:36
  Speaker 3: This is the first time I've seen this in real life.
• 1:52:37
  This is the first time I've seen this in real life.
• 1:53:07
  Speaker 2: Thank you for watching.
• 1:53:36
  Speaker 3: You you you.
• 1:55:03
  Speaker 2: Thank you.
• 1:55:28
  Speaker 3: This is the first time I've seen this in real life.
• 1:55:29
  This is the first time I've seen this.
• 1:55:30
  Speaker 2: In real life. Thank you for watching. This is the
• 1:56:29
  first time that I have seen this kind of thing.
• 1:56:34
  This is the first time I have seen this kind
• 1:56:37
  of thing. Thank you.
• 1:58:00
  Speaker 3: Thank you for watching. Thank you. Thank you.
• 2:00:25
  Speaker 2: Thank you. Thank you.
• 2:01:13
  Speaker 3: Thank you for watching.
• 2:01:44
  Speaker 2: Thank you for watching. you you you
• 2:03:26
  Speaker 3: Thank you.