Dark Energy

• Dark energy is some kind of energy which is said to exist but scientists know very little details of it. About 14 to 15 billion years ago, when the Big Bang happened, the universe came into existence. The matter formed from huge energy started expanding due to outward force of the Big bang. From the theory of gravity postulated by Einstein, the particles having mass should attract each other and the expansion of the Universe should stop at one point of time.
  
• However from the observations made by the astronomers, it appeared that the rate of expansion has increased after about 7 billion years. This shows that some other force is acting against the gravity which is forcing the expansion of universe instead of contraction. Scientists gave name to this unknown force as the ‘dark energy’.
• It is interesting to know that what we see as the matter in the universe in the form of stars, planets, clouds of dust, only forms about 5 per cent of the universe’ mass, rest being dark energy (about 68 per cent) and dark matter (about. 27 per cent).