How Much of the Universe is Made of Dark Energy?

Dark energy accounts for around 69 percent of the total energy in the universe, according to a recent study. The other 31 percent is made up of matter, both regular matter that is the particles and forces that constitute up everything we can see and dark matter, the mysterious electromagnetic force that causes effects and movements that are currently unable to be described by other means.

According to astronomer Mohamed Abdullah of the National Research Institute of Astronomy and Geophysics in Egypt and Chiba University in Japan, just around 20 percent of the universe's total mass is believed to be made up of regular or "baryonic" matter, which includes stars, galaxies, atoms, and life. Dark matter, which makes up about 80 percent of the universe but whose intriguing composition is still unknown, may be made up of some subatomic particles that have not yet been identified.

Meanwhile, dark energy is more of a force. We have no idea what it is either. It is the term we use to describe whatever it is that is causing the Universe to expand at an increasingly rapid rate. According to numerous measurements, it accounts for the majority of the universe's matter-energy density, with a percentage that typically hovers around 70 percent.

There are many compelling reasons why scientists want to determine the Universe's expansion rate, yet doing so has so far proven to be incredibly difficult. Researchers may be able to better understand dark energy by reducing the Universe's matter-energy density. They may also be able to predict what might happen in the future, including whether the Universe will continue to expand indefinitely or reverse course and contract to a Big Crunch.

Clusters of galaxies are one reliable method for calculating the amount of dark energy. This is due to the fact that they are made up of matter that has combined through gravity over the course of the universe's estimated 13.8 billion-year history. Scientists can determine the ratios of matter and energy by contrasting the number of galaxies in a cluster and their mass to computer simulations.

However, it is challenging to directly estimate the mass of a galaxy cluster since the majority of the mass is provided by dark matter. Instead, by calculating the number of galaxies in each galaxy cluster in their database, the researchers were able to calculate the mass of the clusters. Each galaxy cluster was thoroughly examined using the team's GalWeight technique to ensure that it only contained cluster galaxies. The mass-richness relation (MMR), which states that more massive clusters have more galaxies, allowed the researchers to calculate the total mass of each of their sample clusters.