Wed. Oct 4th, 2023
    New Measurement Confirms Dark Energy Makes Up Majority of the Universe

    A recent measurement of the Universe has provided further evidence that dark energy constitutes a significant portion of the cosmos. According to the findings, dark energy accounts for approximately 69 percent of the total matter-energy density, leaving 31 percent for both normal matter and dark matter. Normal matter, also known as baryonic matter, includes stars, galaxies, atoms, and life, and is estimated to make up only 20 percent of total matter. Dark matter, which consists of yet-undiscovered subatomic particles, accounts for the remaining 80 percent.

    Dark energy, on the other hand, is a force responsible for the accelerating expansion of the Universe. Scientists have yet to determine what dark energy exactly is, but it plays a significant role in the matter-energy density. Previous measurements have consistently shown dark energy to comprise around 70 percent of the Universe.

    Understanding the expansion rate of the Universe is crucial for scientists to comprehend the nature of dark energy and its impact on cosmic expansion. Determining the matter-energy density can shed light on the future of the Universe, whether it will continue to expand indefinitely or eventually reverse and shrink in a phenomenon known as the Big Crunch.

    To measure the amount of dark energy, astronomers rely on galaxy clusters. These clusters form over billions of years under the influence of gravity. By comparing the number and mass of galaxies in a cluster and conducting numerical simulations, scientists can calculate the proportions of matter and energy. The researchers used a technique called GalWeight to estimate the mass of galaxy clusters by counting the number of galaxies in each cluster. By comparing their results with simulated clusters, they determined that the Universe consists of 31 percent matter.

    This measurement aligns closely with previous efforts and other measurements of the Universe’s matter-energy density, providing a more accurate estimation. It also emphasizes the significance of cluster abundance as a technique for understanding cosmological parameters. The findings contribute to a better understanding of dark energy and bring us closer to unraveling the mysteries of the Universe.

    – The Astrophysical Journal