New Delhi, February 24 (IANS). Space is full of many mysteries. Scientists from all over the world are engaged in solving this mystery, many mysteries have been solved and many remain unsolved till date. ‘Dark Energy’ is also the name of one such mystery, which scientists say is the mysterious energy that expands the universe rapidly.
According to the American space agency NASA, dark energy is the biggest mystery of the universe. It is an invisible force that is rapidly expanding the entire universe. About 68 to 70 percent of the universe is made up of this dark energy. This tells us that the universe is not only expanding, but its speed is increasing day by day.
According to NASA, the Big Bang occurred about 13.8 billion years ago. The universe began from a small, extremely hot and dense point and began expanding rapidly. Just as a balloon expands, the universe continued to expand. On cooling, atoms and molecules were formed, then stars, galaxies and planets were formed. Even today the universe is expanding. For a long time, scientists thought that this expansion would be slowed down by the gravitational force of the matter present in the universe. Gravity pulls everything toward each other, so the expansion could have stopped or the universe could even have contracted.
However, in the late 1990s two separate teams studied the type supernova. These supernovae always emit the same brightness, so they are considered the “standard candle” for measuring the distance to distant galaxies. Only the Hubble telescope had the ability to detect these supernovae in distant galaxies. It found that the supernovae appeared fainter than they should have been, which meant that their host galaxies were further away than expected and this only makes sense if the universe is expanding rapidly and the reason behind it is not yet known. The unknown force responsible for this rapid expansion was named dark energy.
How does dark energy work? Dark energy works exactly opposite to gravity. It behaves like a repulsive force in the universe. In the early stages of the Big Bang, gravity dominated and expansion slowed. But as the universe grew, galaxies moved away from each other and gravity weakened. Then the influence of dark energy increased and the expansion intensified.
What dark energy is in the universe – a field, a constant or something else is still unknown. Hubble and the James Webb Space Telescope are trying to solve this mystery.
–IANS
MT/AS