Dark Energy

Dark Energy

News: The Dark Energy Spectroscopic Instrument (DESI) is designed to explore the nature of dark energy by creating a detailed three-dimensional map of the universe.

About:
• Unseen Majority: Over 95% of the universe consists of entities and phenomena that are not directly observable, including dark energy.
• Nature of Dark Energy: Dark energy is an invisible force that behaves repulsively, countering the gravitational pull between matter and causing the universe to expand at an accelerating rate.
• Discovery: The existence of dark energy was inferred from observations of distant supernovae in the late 1990s. These observations revealed unexpected cosmic acceleration contrary to prior expectations.
• Cosmic Influence: Dark energy dominates the universes energy content, accounting for approximately 68% of its total energy density and driving the observed accelerated expansion.
• Baryon Acoustic Oscillations (BAO): Scientists use baryon acoustic oscillations (BAO) as a cosmic ruler to study dark energy. These oscillations are imprints left in the distribution of galaxies due to sound waves in the early universe.
• Mystery of Dark Energy: Despite its crucial role in the universes dynamics, dark energy remains one of the most profound mysteries in astrophysics. Its origin, nature, and behavior continue to elude complete understanding.

Highlights of the 3D map by DESI: 
• Unprecedented Data: DESI has gathered light from 6 million galaxies, including some dating back 11 billion years, to create the most detailed map of the universe to date.
• Studying Dark Energy: DESI examines how dark energy influences cosmic expansion by using baryon acoustic oscillations (BAO) as a precise cosmological standard ruler.
• Precision in Expansion Measurement: The experiment has achieved exceptional precision, exceeding 1%, in measuring the rate of the universes expansion, enhancing our understanding of cosmic evolution.
• Measured Expansion Rate: The DESI team has determined the universes expansion rate to be 68.5 kilometers per second per megaparsec, providing valuable insights into the nature of dark energy.
• Mystery of Dark Energy: The detailed map suggests that dark energy may not remain constant over time, challenging the conventional model of cosmology.
• Scientific Surprise: Despite the gravitational pull that typically holds matter together, DESIs observations reveal that vast empty spaces between stars and galaxies are expanding at an accelerating pace.
• Hypothesis on Dark Energy: Scientists are puzzled by this rapid expansion and propose the existence of dark energy as the driving force behind it.
• Future Insights: With four more years of data collection planned, DESI aims to uncover potential changes in dark energy over time, refining our cosmological understanding and models.