Largest-ever 3D map of the universe lets us travel back in time

Source: https://www.earth.com/news/largest-ever-3d-map-of-the-universe-lets-us-travel-back-11-billion-years/

Summary

Scientists have created the largest 3D map of the universe using the Dark Energy Spectroscopic Instrument (DESI), charting 18.7 million celestial objects. This groundbreaking map acts as a "time machine," allowing scientists to observe the universe's evolution and probe the mysteries of dark energy. DESI uses redshift measurements to determine the distance of galaxies and quasars, offering unprecedented precision in mapping cosmic structure. Researchers aim to understand dark energy's influence on the universe's expansion, galaxy formation, and dark matter distribution. This monumental achievement marks a significant leap in cosmology, promising revolutionary insights into the cosmos's fundamental forces and ultimate fate.

Full News Report

Here's the article: **Largest-Ever 3D Map of the Universe Lets Us Travel Back in Time: DESI Unveils Cosmic Tapestry** Berkeley, CA – Scientists have unveiled the **largest-ever** 3D **map** of the **universe**, a monumental achievement that **lets** us peer into the distant past and unlock secrets about the cosmos's evolution. The Dark Energy Spectroscopic Instrument (DESI) has meticulously charted the positions of an astounding 18.7 million celestial objects, providing an unprecedented dataset for researchers studying dark energy, the formation of galaxies, and the very expansion of the **universe** itself. The groundbreaking map, the result of years of meticulous observation, promises to revolutionize our understanding of the fundamental forces shaping the cosmos. This landmark accomplishment, detailed in a series of scientific papers published today, marks a significant leap forward in cosmology. It gives scientists a powerful new tool to investigate the mysteries of dark energy, a mysterious force believed to be driving the accelerated expansion of the universe. **What is DESI and Why is This Map So Important?** DESI, installed on the Mayall Telescope at Kitt Peak National Observatory in Arizona, is a state-of-the-art spectrograph designed to measure the redshifts of millions of galaxies and quasars. Redshift is the phenomenon where light from distant objects is stretched, shifting towards the red end of the spectrum. The amount of redshift indicates how much the universe has expanded since the light was emitted, effectively telling scientists how far back in time they are looking. The significance of this **largest-ever** 3D **map** of the **universe** cannot be overstated. Unlike previous surveys, DESI’s data provides a far more comprehensive and precise view of the cosmic structure. This precision allows scientists to test theoretical models of dark energy and the universe's evolution with unprecedented accuracy. “This is more than just a pretty picture,” explained Dr. Ashley Villar, a lead researcher on the DESI project. “This **map** is a time machine. By studying the distribution of galaxies at different distances, we’re essentially looking at the **universe** at different points in its history. This **lets** us trace how the **universe** has changed over billions of years and gain insight into the forces driving its expansion.” **How Does DESI Create This Incredible Map?** DESI’s strength lies in its ability to rapidly and accurately measure the spectra of millions of galaxies. The instrument boasts 5,000 robotic positioners, each holding a fiber optic cable. These cables are precisely positioned to capture light from individual galaxies and quasars. The light is then fed into spectrographs, which split it into its constituent colors. By analyzing the spectrum, scientists can determine the redshift of the object and, therefore, its distance. The process is painstakingly slow, requiring years of dedicated observation. However, the resulting dataset is a treasure trove of information, allowing researchers to: * **Precisely measure the expansion rate of the universe at different times.** This provides critical constraints on models of dark energy. * **Study the distribution of matter in the universe on large scales.** This helps scientists understand how gravity and dark energy have shaped the cosmic web. * **Investigate the formation and evolution of galaxies.** By studying the properties of galaxies at different redshifts, scientists can learn how they formed and evolved over cosmic time. **Unlocking the Secrets of Dark Energy** One of the primary goals of the DESI project is to unravel the mystery of dark energy. Dark energy is thought to make up about 68% of the total energy density of the **universe**, yet its nature remains largely unknown. It is believed to be responsible for the accelerated expansion of the universe, counteracting the attractive force of gravity. The **largest-ever** 3D **map** provides a unique opportunity to probe the effects of dark energy on the large-scale structure of the universe. By precisely measuring the distribution of galaxies, scientists can look for subtle patterns that are influenced by dark energy. This allows them to test different theoretical models of dark energy and potentially identify the correct one. "By comparing our observations with theoretical predictions, we can begin to understand the properties of dark energy," said Dr. Michael Levi, Director of DESI. "Is it a constant force, or does it change over time? Does it behave as Einstein predicted, or does it require new physics to explain? DESI's data will help us answer these fundamental questions." **Impact on Galaxy Formation and Universe Expansion Studies** Beyond dark energy, the DESI data will also have a profound impact on our understanding of galaxy formation and the overall expansion of the universe. The 3D **map** will allow scientists to study the evolution of galaxies in unprecedented detail. They can trace how galaxies cluster together, how they merge and interact, and how their properties change over time. Furthermore, the **map lets** us understand the role of dark matter in shaping the **universe**. Dark matter, which accounts for about 27% of the universe's composition, is invisible to telescopes but exerts a gravitational pull on visible matter. The distribution of galaxies in the **map** is influenced by the underlying distribution of dark matter, allowing scientists to infer its properties and distribution. The sheer scale and precision of this dataset will enable researchers to test fundamental cosmological models with unparalleled accuracy. This will lead to a deeper understanding of the universe's origins, its evolution, and its ultimate fate. **Related Trends and Future Directions** The DESI project is part of a broader trend in cosmology towards large-scale surveys that map the universe in ever greater detail. Other notable projects include the Sloan Digital Sky Survey (SDSS) and the Euclid mission, which are also contributing to our understanding of the cosmos. Looking ahead, scientists plan to continue collecting data with DESI, extending the **map** to even greater distances and probing even earlier epochs in the universe's history. Future surveys, such as the planned next-generation Dark Energy Spectroscopic Instrument, will build upon DESI's success and provide even more detailed insights into the mysteries of the cosmos. **Conclusion: A Window to the Past** The unveiling of the **largest-ever** 3D **map** of the **universe** by the DESI collaboration represents a monumental achievement in cosmology. This intricate cosmic tapestry, meticulously crafted from the light of 18.7 million celestial objects, **lets** us travel back in time, witnessing the **universe** at different stages of its evolution. The data from this groundbreaking survey promises to revolutionize our understanding of dark energy, galaxy formation, and the expansion of the universe, ushering in a new era of discovery in our quest to unravel the mysteries of the cosmos. The knowledge gained from this endeavor will undoubtedly shape our understanding of the **universe** for generations to come.