Ever Since the Big Bang, our Universe is expanding and reaching new feat. If gravity was playing its role, the universe would have collapsed. Also, gravity cannot explain the high rotation speed of the galaxies. Either the gravity behaves in an odd fashion or there might be some matter in the Universe that holds everything together while the Universe is expanding. Indeed there exists a substance termed as Dark Matter. Dark matter is the most mysterious yet ubiquitous substance in the Universe. Our Universe has around 68% dark energy, 37% Dark Matter. The rest 5% is everything on Earth, everything ever observed by instruments and all normal material.
I feel so tiny.
Unlike the 5 basic elements — Space, Air, Fire, Water, and Earth — of the material world, Dark Matter could not be seen, felt, smelt or tasted. In fact, It does not even interact with electromagnetic waves. This means it does not absorb, reflect or emit light, making it more difficult to spot. Researchers have seen some potential interaction with gravitational forces. What is it? As of now, we know more about what it isn’t than what it is. Dark Matter isn’t anti matter, otherwise it would have produced gamma rays when annihilated with normal matter. Neither is it a black hole, or failed stars or clouds of gas or anything else that can be made from normal matter.
Organizations are trying to figure out its presence to understand more about the Universe. Scientists have installed sensitive sensors under the Earth to see if Dark Matter interacts with classical elements. Similarly, Satellites, through a special Gamma Ray Telescope, traces the energy imprints of dark matter collision. Moreover, at CERN, researches are smashing normal particles together inside the Large Hadron Collider just to check if there is subsequent change in the property of the material inside. Although the results aren’t successful, we understand more about it.
There are several theories explaining dark matter. Albert Einstein first explained it as the property of the space, suggesting empty space is not nothing. Later, in one version of Einstein’s gravity theory, he proposed a cosmological constant. Through cosmological constant, he predicted that “empty space” can possess its own energy and would not be diluted. As more space comes, more energy will be generated. This defines the ever expanding nature of the Universe. No one actually understood why cosmological constant is even there. Another theory, derived from Quantum theory of matter, proposed that empty space is made of virtual particles that continually form and disappear. But using this theory, when the energy of dark matter was calculated, it was wrong by an order of 10120. There are other incomplete theories which, at the end, lead to nothing. So, the mystery remains unrevealed.
Dark Matter is a mystery that we want to understand. Demystifying it would be a key to a whole new understanding of physics.
Dark Matter matters!