The Universe has been around for thirteen billion years, though we don’t know the exact age. We are still just scratching the surface of how the universe works and what is in it. The universe is big and will only continue to grow. Though what is causing the universe to grow, scientists believe there is a strange force that we can not see responsible for this. They call this strange thing dark energy.

Now let’s answer the big question what is dark energy? Dark energy is a theoretical repulsive force that acts in opposition to gravity causing the universe to expand at an accelerating rate. It is said that dark energy makes up most of the universe and accounts for most of the energy. Dark energy was discovered in 1998 by two international teams which included the American astronomers Adam Riess, Saul Perlmutter, and Australian astronomer Brian Schmidt. They used telescopes from the Keck Observatory and the MMT Observatory. Though the idea of dark energy was hypothesized in 1917 by the famous physicist Albert Einstein.

Einstein introduced the idea in his theory of general relativity and called it “c0smological constant.” He introduced it to counteract the attractive force of gravity. It was later discovered in 1920 that the universe was not static (not expanding nor contracting) by Edwin Hubble. People before this believed the universe was static. You may be wondering how we detect dark energy? We detect it by looking at the effect it has on the rate the universe expands. It is also detected by looking at the effect on galaxies and clusters of galaxies through gravitational instabilities.

We can not confuse dark energy with dark matter. According to CERN dark matter is what is possibly giving galaxies extra mass which gives the galaxies the extra gravity they need to stay together. Dark matter is said to not interact with the electromagnetic force. It also does not absorb, reflect or emit light making it hard to spot. Researchers can infer its existence based on the gravitational effect it appears to have on visible matter. The Large Hadron Collider (LHC) is the world’s largest particle accelerator in the world located in Switzerland. They have been running experiments there looking for any clues that could help inform us about dark matter.

We will continue to study these strange events to hopefully confirm the existence of dark energy and dark matter. The universe is still not fully explored. We are still trying to learn everything we can about the universe. Dark energy is just one of the many things that we are still trying to prove. We may never fully get to discover the mysteries of the universe due to its sheer size. Its human nature to want to learn everything we can. Space is the final frontier and we won’t stop investigating it until we know all we can.