Question corner

November 22, 2015 07:25 pm | Updated 07:26 pm IST

Dark Energy

What is dark energy?

RAKESH PANDEY

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).

S P S JAIN

Former Member, Engineering, Indian Railways

Greater Noida

THIS WEEK’S QUESTIONS

Is there any effect of neutrinos when they pass through our body?Bhanu Jamwal, Jandial, Jammu & Kashmir

Why is it very difficult to burn a heap of fresh green leaves but once the leaves dry up they burn easily?

SHARATH CHANDRA

What are gravitational waves?

Chaitanya Vuddanti, Hyderabad

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in

Comments

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.