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WEEKLY SCIENCE

Season • 01 [ Episode • 003 ]

The Dark Matter [ Part • 1 ]

What if I told you that Your entire life and everything you have ever seen everyone or you have ever met every cluster of galaxies, Every Stars and our Planet Everything, Only makes up for less than 5% of the entire Universe. The other 95% is made of stuff that we physically cannot Observe. Matter and Energy which we do not comprehend. And This has led Scientist onto one profound quest of trying to Improve our understanding of what all these Mystical Universal Ingredients might be. According to Sir Issac Newton, “Bodies have mutal Force on each other that is determined by their Masses, The greater the mass the greater the Force.” In addition a Large bodies Force on smaller orbiting bodies greatly Decreases Over Distance. During The 1930s, The Swiss American-

Astrophysicist Fritz Zwicky investigated the movements of galaxies within a Huge Galaxy Cluster named COMA. About 300 million Light Years away From Our Earth. Coma consists of thousands of Galaxies orbiting around the center of the cluster in all Possible Directions. Much like bees swarming around a Beehive. By studying the movements of a few dozen galaxies to study The Gravitational Field that holds the cluster together. Zwicky was able to conclude something that did not make much sense. The galaxy cluster rotated so rapidly that the Gravity from the Stars and Gases and Every thing in the cluster Could Not Possibly Hold Itself Together. It wasn't Close At All.

Hehe It Is The Real Picture Of Coma Cluster. Well The value he obtained said there needed to be at least 400 Times the ammount of Matter in the Cluster just in order to keep things Held together. The galaxies rotated faster than their Escape velocity. The speed that causes a celestial body to leave its Orbit called their Escape Velocity. For example if we could increase Earth's Orbital speed by just 1.5 times his current speed. Our planet would be thrown out of our warping around the Sun and leave the Solar System For Good . Based On The Insanely Fast Speeds Zwicky observed, The cluster should desolve quickly and leave only traces of its former existance. But today the cluster is more than 10 Billion years old. The Universe itself is only 13.8 Billion years old. Therefore Fritz Zwicky concluded that there must be much more Gravity in the Coma Cluster than what one could see. Some sort of Matter that we could not see. He went on and gave this missing matter a name, For the first time the term ' DARK MATTER ' was used and thus the most prolonged unresolved mystery in Modern Astrophysics was born. However Fritz's work was unpolished Becuase The term Dark Metters Zwicky was using didn't talk about the same type of Dark Matter that we know today . He Knew There Was Something There , What is it ? He Just Did Not Know.

In the 1970s, American Astronomer Vera Rubin began studying individual Stars in individual Galaxies. Think of our Solar System, Because they are closer to the Sun which by the way accounts for ever 99% of the Mass in our Solar System, Planets like Mercury have a much shorter orbital Period than planets like Saturn and Jupiter. Now slice this up to a Galactic Scale, You should imagine that as you go further twoards the Edge of the Galaxy the Stars at the edge would be moving Slower than the ones near the Center. Vera Rubin was studing this exact thing except She Discovered The Exact Opposite. Within each galaxies normal matter like Stars and Planets that are further away from the center of the Galaxy move at speeds greater than the ones near the center, This doesn't make much sense. As you got further and further from The Galactic Center the speeds at which, Stars move flattened out When in fact they should have decreased, If they moved too fast they'd be flung out of the Galaxy and lost forever, Too Slow and they'd literally fall out of their orbits. But instead the speed stayed Relatively The Same, But this should not happen . And From This Discovery The Dark Matter Gained More And More Popularity Across The World .

That Photo Was From NASA. Ahm, However Dark Matter is the supposed kind of material that doesn't emit reflect or interact any kind of Electromagnetic Radiation, Things such as Light or X-Rays or Gamma-Rays or Radio-waves and so on. The only way we've been able to figure out that Dark Matter might Exists is through Gravity. Gravity is the Bandwidth, It's the link between normal metter and dark metter. This sort of introverted metter is the reason why it's nearly impossible to detect. More direct evidence of the strange nature of Dark Matter lies in the ammounts of Hydrogen and Helium there is in the Universe. The nuclear fusion in the first few minutes after The Big Bang left around Numbers like 10 Hydrogen Nuclei for each one Helium nucleus. Calculations showed that if most of the dark metter had perticipated in nuclear fusion, There would be much much more Helium in relation to Hydrogen in the universe. From this we can conclude that most of the Dark Matter that is most of the mass in the universe does not perticipate in any fusion processes. This disqualifies it as ordinary metter which very meaning lies in the willingness to interact with the atomic and nuclear power that builds up You and I. You might be able to say that dark metter in fusion processes just don't go together. According To–

Einstein, Heavy objects can alter the Geometry of Space-Time. Instead of seeing gravity as a result of mass attracting mass as Newton did. Einstein suggested that, Space and time bend around objects with mass. Imagine the universe as a Flat Grid and and objects with mass create a well of sorts in this grid, Objects with more mass like Stars and Black Hooles creates a larger Curve That has a larger effect on matter around it. Everything follows the curvature of Space-Time, Light included. Well it's something elso that also bends light are lenses. If we were to imagine a cluster of galaxies, Its gravitational pull literally would bend light around itself, Due to the sheer mass of the galaxy cluster, It creates a huge Gravitational Well ( Curvature ), We can figure out the mass of the Galaxy Cluster based on how much light from the galaxy is being bent this is called Gravitational Lensing. Hehe This Is Todays Science. 😎

Scientists use this trick to determine the mass of two colliding galaxy clusters, And this is called the Bullet Cluster. So Thats It For Today But Hey Wait This Episode Have Not Ended Yet. The Next Part Of This Episode Will Come Soon. So Friends Stay Tuned. And –
Until The Next Part Comes What About Answering A Short Question ? Answer This Q. In Comment Section :

About 3.5 billion light years away. What will happen If The Cluster Of Galaxies Collide Into Each Other ? BYE.

Article By MD. Siam Bhuiyan

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