New Map of Universe may open a window to Dark Energy

What’s in today’s article?

• Why in News?
• What are Ordinary matter and Dark Matter?
• What is Dark Energy?
• New map of universe
• What is Dark Energy Spectroscopic Instrument (DESI)?
• Key highlights of the study using DESI

Why in news?

An international team of researchers has released the most comprehensive “three-dimensional” map of the universe. Scientists hope that this development could reveal some clues about dark energy.

What’s in today’s article?

• Dark Energy
• New map of universe

Ordinary matter and Dark Matter

• Normal Matter
  • Normal matter makes up everything we can directly observe. We can view it in visible light with our own eyes or through a telescope that can detect light we can’t see, like ultraviolet or infrared.
  • Most normal matter is made up of atomic particles: protons, neutrons, and electrons. It can exist as a gas, solid, liquid, or plasma of charged particles.
  • While normal matter is everywhere in our daily lives, it composes less than 5% of the total universe.
• Dark Matter
  • Like ordinary matter, dark matter takes up space and holds mass. But it doesn’t reflect, absorb, or radiate light – at least not enough for us to detect yet.
  • While scientists have measured that dark matter makes up about 27% of the cosmos, they’re not sure what it is.
    • Scientists believe that it forms a huge, web-like structure throughout the universe. This structure acts like a gravitational framework, pulling most of the regular matter in the cosmos towards it.
    • They’ve determined that dark matter isn’t composed of known particles of matter. The search for what makes up dark matter continues.

Dark Energy

• About
  • Dark energy is a mysterious form of energy that astronomers believe is causing the universe to expand at an accelerated rate.
  • Some describe dark energy as a negative pressure that pushes space outward. However, it's not known if dark energy has the effect of any type of force.
  • Dark energy may compose roughly 68% of the universe, but scientists know even less about it than they do about dark matter.
• Nature of Dark energy
  • Dark energy, in contrast to both forms of matter (ordinary matter & Dark matter), is relatively uniform in time and space.
  • It is gravitationally repulsive, not attractive, within the volume it occupies. The nature of dark energy is still not well understood.
  • Dark energy is detected by its effect on the rate at which the universe expands and its effect on the rate at which large-scale structures such as galaxies and clusters of galaxies form through gravitational instabilities.
• Need to study the nature of dark energy
  • 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.

New map of universe

Recently, a group of researchers published the most comprehensive “three-dimensional” map of the universe from the first year of observations by the Dark Energy Spectroscopic Instrument, or DESI.

About Dark Energy Spectroscopic Instrument (DESI)

• DESI is a unique piece of equipment that, once fitted over a telescope, can capture light from 5,000 galaxies at the same time.
  • DESI is a collaboration of more than 900 researchers in institutions across the world. From India, TIFR (Tata Institute of Fundamental Research) is the only participating institution.
• 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.
• This was used to prepare the most detailed map of the universe as yet.

Key highlights of the study using DESI

• 3-D Map of Universe
  • Using the data obtained from the study by DESI, scientists were able to measure the distances between these galaxies with a very high degree of accuracy.
  • As result, they have been able to create 3D map of the universe.
• Measurement of the expansion rate of universe
  • The DESI collaboration has measured that the expansion rate of the universe was increasing by 68.5 km per second after every 3.26 million light years of distance, a unit astronomers define as megaparsec.

Q.1. What is Tata Institute of Fundamental Research (TIFR)?

TIFR stands for Tata Institute of Fundamental Research, and it's a research institution in India that focuses on basic research in mathematics and the sciences. It was established in 1945 by scientist Homi Bhabha with support from the Sir Dorabji Tata Trust, and it's a National Centre of the Government of India under the Department of Atomic Energy.

Q.2. What is Mayall 4-Meter Telescope?

The Nicholas U. Mayall 4-meter Telescope, also known as the Mayall Telescope, is a 158-inch (4-meter) reflector telescope at the Kitt Peak National Observatory in Arizona. It's the largest telescope at the observatory and is visible from more than 50 miles away.