New map of universe may open a window to dark energy (GS Paper 3, Science & Tech)
Why in news?
- An international team of researchers has just released the most comprehensive “three-dimensional” map of the universe, which, scientists hope, could reveal some clues about dark energy, the mysterious force that is believed to be causing the universe to expand uncontrollably.
Conducted Research
- The researchers, including an Indian team led by Shadab Alam at the Tata Institute of Fundamental Research in Mumbai, has published its findings from the first year of observations by the Dark Energy Spectroscopic Instrument, or DESI, a unique piece of equipment that, once fitted over a telescope, can capture light from 5,000 galaxies at the same time.
Outcome of Research
- Using DESI, which is mounted over the Mayall 4-Meter Telescope in Arizona, United States, researchers have been able to measure light from six million galaxies — some of which existed as far back as 11 billion years ago — to prepare the most detailed map of the universe as yet with very precise information about the distances between these galaxies.
- The key thing is that it has been possible to measure the distances between these galaxies with a very high degree of accuracy. That's why it is called a three-dimensional map. Otherwise, there is a catalogue of tens of billions of objects in the universe. Objects have been identified, but distance for most of them from us is not known. Knowing the precise distances of the galaxies is crucial because that allows to calculate the expansion rate of the universe.
- And that, scientists hope, could offer them their first clues into the mystery of dark energy that is supposed to make up almost 70 per cent of the universe but about which nothing is known.
Hypothesis of Dark Energy
- The hypothesis of dark energy comes mainly from the observed phenomenon of the universe expanding at a rapid rate.
- The vast empty spaces between stars and galaxies have been measured to be expanding at an accelerating pace, despite the countervailing force of gravitation that has the effect of pulling things together.
- Scientists have been unable to find any explanation for this rapid expansion, and have been forced to hypothesise that there must be some “dark” energy causing this expansion.
Conclusion
- Understanding the nature of dark energy is one of the fundamental problems in science right now, because it can offer key insights into the origin and evolution of the universe, as well as its eventual fate.
- It can reveal new fundamental forces at work, and could unravel our entire knowledge of the physical world.
- The problem is that, so far, scientists have not been able to figure out even the first piece of the puzzle. But the data from DESI is causing some excitement.
