‘Dark Energy’: Insights from the Universe’s Largest New Map

A highly powerful instrument equipped with 5,000 fiber-optic sensors has produced an immense map of the universe. This unprecedentedly large map challenges current understandings of our cosmos. Located at the Kitt Peak National Observatory in Arizona, USA, the device called the Dark Energy Spectroscopic Instrument (DESI) has captured images of over 47 million galaxies and quasars, as well as more than 20 million stars. This number is six times greater than the total number of galaxies and other cosmic objects counted previously. These images depict objects approximately 11 billion light-years away, meaning DESI has photographed galaxies from the early stages of the universe’s formation. According to astronomer Luz Angela Garcia from ECCI University in Colombia, this era dates back roughly 13.7 billion years.

This map enhances our understanding of galaxy structures and their formation processes while providing new clues about “dark energy,” a major scientific mystery until now. Over five years, DESI has mapped one-third of the sky. Remarkably, the instrument measured more than 100,000 galaxies in a single night. The light emitted by these galaxies enters the device through fiber-optic detectors, allowing measurement of their spectra, which helps calculate the extent of the universe’s expansion. Another significant achievement of DESI is offering a new perspective on dark energy. It is believed that dark energy constitutes 70 percent of the universe and acts as a force driving its expansion.

Until now, dark energy has been regarded as the “cosmological constant,” a concept Albert Einstein incorporated into his general relativity equations. Clare Cameron, in an article published in Scientific American, explains that this concept assumes the universe is expanding steadily. This new discovery reinforces the idea that dark energy is not constant but evolves over time, strengthening the theory of a dynamic, developing dark energy.