The Missing Piece in the Puzzle of Space
The universe is expanding at an exponential rate as time goes on. Why could this be happening?
Our universe is a magnificent yet intricate system of stars, planets, galaxies, and so much more that we have yet to discover. It all started with one simple discovery that fortified our understanding of the universe: the universe is expanding. Soon, this understanding became confusing when we realized the universe’s rate of expansion increased over time.
As of now, we know that the universe is expanding and we can justify this expansion. Thus, the puzzle pieces start to fit together. Soon, however, we come to an impasse: the universe is not only expanding, but it is expanding faster and faster as time goes on. The cause for this exponential growth is hypothesized, but as of now, there is no clear cut answer. Let us explore why this might occur as well as how and when we will get a more clear answer.
What We Know
One important discovery occurred in 1925 when Dr. Edwin P. Hubble made a breakthrough that forever changed our understanding of the universe. His first crucial discovery was when he found previous gas clusters classified at the time as “nebulae” to actually be distant galaxies beyond ours (the Milky Way). As he wrote in his famous 1929 seminal PNAS (Proceedings of the National Academy of Sciences) paper, the universe was constantly expanding.
At the time, this concept was unheard of, yet, it was also quite plausible. The Big Bang Theory, the theory that explains the origins of our universe, was supported by Dr. Hubble’s discovery. If you think about it, the initial explosion that caused the creation of the universe sent matter flying from the starting point. As such, these pieces of matter, which are all of the celestial bodies in our universe, have been traveling away from each other as time passes.
This discovery was a “we should have known this” type of observation. To categorize the exponential velocity for expansion, the Hubble constant was created. Simply put, this was the roughly constant ratio between speed and distance. This stated that as the distance between galaxies increases, so does the rate at which they continue to travel.
Recently, however, we observed that the universe was expanding much faster than we calculated. The Hubble constant was becoming less and less accurate as time passed. Many suspect a third party mass to be the cause of this expansion, but the identity of this mass is currently unknown.
Hypotheses on the Increased Rate of Expansion
One highly common misconception on the expansion of the universe is that it is caused by dark matter or dark energy. As fancy as these names sound, their meanings are much more important. A key understanding to have is that dark matter is a type of mysterious matter thought to keep the universe together. It causes a gravitational force (attracted to each other) to keep the universe together. This was theorized from the understanding that the current matter in our universe from celestial bodies is not large enough to construct a gravitational force of such magnitude.
Dark energy, on the other hand, is the cause of the universe’s increasing rate of expansion over time. Without dark energy, the universe would actually expand at a slower rate as time passes. Dark energy is kind of like the opposite of dark matter. It is an anti-gravitational force pushing the galaxies away from each other. What is truly fascinating is that dark matter and dark energy make up around 96% of our universe, yet we cannot see it and we do not know much about these two forces.
Even with these two forces, the expansion of our universe is much faster than it should be. Some common hypotheses are that there is a factor of dark energy that we have not yet discovered, which could be turbo-charging the expansion. The same concept applies to dark matter, as it might be more complex than we have discovered so far. The last possibility is that there is a completely new, undiscovered force with complex properties that are currently unheard of.
We know so little about space, and even the very little that we do know is constantly changing. Take the Hubble constant for example. We thought the value was set in stone and it would provide a permanent expectation for the expansion of the universe, yet we keep getting reminded about how very little we know. With this exciting mystery, we must be detectives and solve this puzzle.
With the possibilities so vast, the chances so endless, our perception of the universe we live in must adapt to our new found discoveries. Scientists all around the world are working to find a solution to this strange puzzle. Even aspiring scientists or students interested in such fields could help. As a famous person once said, “Where there’s a will, there’s a way,” and if you want to make a discovery, your will is all you need.
Want to learn more about the missing piece in this astronomical ‘puzzle’? Check out these informative websites:
