DARK ENERGY

1.Dark Energy :

• Our universe is expanding at an accelerating rate & the reason is unknown. This seemingly contradicts current scientific knowledge of how gravity works & affects the world we live in.
• The cause of this acceleration is called “Dark Energy” and is a mystery.
• NASA scientists are helping probe this enigma by testing gravity.
• According to the space agency, this phenomenon where the universe is expanding at an accelerating rate is almost as if an apple is thrown in the air and it continued to move upwards faster and faster.
• The latest effort to understand whether this is all a misunderstanding from a new study by Dark Energy Survey(DES).
• DES is an international collaborative effort that maps hundreds of millions of galaxies, detects thousands of supernovae & finds patterns of cosmic structure.
• The new study uses the 4-meter Victo M Blanco Telescope in Chile to conduct the most precise tests by space agency yet of Albert Einstein’s theory of gravity at the cosmic scale.
• The results were presented at the International Conference on Particle Physics & Cosmology in Rio de Janeiro.
• Einstein’s theory of General Relativity was developed more than a century ago & describes gravity in a way that has accurately predicted various phenomena, including the existence of black holes.
• According to some scientists, there may be a need to modify some of its equations or add new components if it can’t explain dark energy.
• DES members looked for evidence that gravity’s strength has varied throughout the universe’s history or over distances.
• If that were the case, it would indicate that Einstein’s theory is incomplete, which would bring us closer to explaining the universe’s accelerating expansion.
• In addition to the Blanco telescope, the members also examined data from ESA’s Planck satellite.
• But the study found that Einstein’s theory still holds, meaning that there is still no explanation for dark energy.
• To arrive at this conclusion, scientists needed to look deep into the universe’s past, which was done by looking at objects that are far away.
• A light year is about 9.5 trillion kilometres or the distance that light can travel in a year, which means that billions of light-years away galaxies appear as if billions of years ago.
• The observations made by the scientist matched the predictions of Einstein’s theory, leaving dark energy with no explanation.
• This research will be furthered by two upcoming NASA missions.
• Euclid, slated for a 2023 launch & Nancy Grace Roman Space Telescope, scheduled for a 2027 launch.
• Both telescopes will help scientists look further back in time to further probe the presence of dark energy.