Shedding light on DARK MATTER .

On the clear starry night how many stars are you able to see at sky, hundred ,thousand may be lakh ,let me tell you if you take a needle and hold it against the sky from the tip of the needle you can see at least 1000 to 2000 galaxies . That much amount of matter is there in the universe.

well you,me,your family,earth,planets,stars, galaxies and all the matter which is visible to your eyes comprises of only 5% of the universe. Yes! you read it right only 5%

credits : North Western university 

so, what is there,hiding behind the darkness of the space. In early 1990's scientists studying the expansion of the universe generated a theory , the universe is full of matter and the attractive force of gravity pulls all the matter together hence instead of  expanding universe had to slow down. Then came 1998 and the observation from hubble space telescope of distant supernovae proved that universe is not slowing down instead the expansion of the universe is accelerating . That observations shocked the whole scientific community .Eventually there is something  which is causing this cosmic acceleration ,theorists still does not know what the correct explanation is ,but they have given  solution a name .It is called Dark Energy .

image shows Dragonfly telephoto array which discovered Dragonfly 44,
a galaxy which is made up of 99.9% dark matter.

Galaxies in our universe is also doing some magic. Scientists studying the galaxies noted that they are rotating with such a speed that the gravity generated by the observable matter is not enough to hold it together, with such a rotating speed they should have torn themselves apart long time ago.which leads scientists to conclude that there is something we cannot directly detect is giving these galaxies extra mass- providing extra gravity which galaxies needed to stay intact. These strange and unknown  matter was called Dark Matter.

So,what is dark matter?

Well,most simple and accurate answer to that question is "we don't know". Unlike normal matter, dark matter does not interact with electromagnetic force .That means it  neither absorbs nor reflect nor emit  any form of light , makes extremely difficult to spot this matter. Detection of dark matter  can only be possible because of its gravitational effect it seems to have on visible matter.

  blue streaks near the center of the image shows bending of the light
due to gravitational effect of dark matter.
Source: NASA ,Hubble Space Telescope

Dark matter makes up 27% and Dark energy makes approximately 68% of the universe . Dark matter candidates had tried to explain it with various theories,such as SUSY ( no it's not the name of my hypothetical girlfriend ,it stands for 'Supersymmetry' theory).Our friends at CERN are trying to create dark matter , until that happens Dark matter is still a mystery . Dark Matter and Dark energy together makes 95% of the universe.So,when you think about how much matter is out there which we cannot see , we are drawn to the question ...

                                   " is the universe made of Dark Matter and

                                                                               rest of us Doesn't  matter  ?"

                                                                                               

      

                                                                                                              - Michelle Thaller

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