by Ryan Ripsman
Sometimes it seems like scientists have it all figured out. We have planes that can circle the globe, instant communication across the planet, and cures to diseases that were once deadly. But once you leave the warm comfort of Earth and enter the cold void of space, you begin to realize how little we truly understand. How little we can understand.
While humans have marveled at the vast reaches of the heavens since the earliest times of man and studied space rigorously since the days of Copernicus, there is still so much that we don’t understand. In part, this is due to the vast distances in space. Even traveling to the closest solar system at the speed of light would take 4 years. As of now, the fastest human-made spacecraft, the unmanned Parker solar probe, only reaches 0.02% of the speed of light; at that rate, it would take the spacecraft over 100 years to reach the closest solar system. Because of these vast distances, mysteries that could be easily solved on earth through simple exploration can’t be solved when they are located in space. For instance, in 1977, a signal was detected by the Big Ear, a radio telescope at Ohio State University. The signal was 72 seconds long, and incredibly strong. Other than its strength, the signal was notable because its wavelength was almost the same as the wavelength of the light given off by a high-energy hydrogen atom. Since hydrogen is the most common element, it was postulated that any non-terrestrial life would use that recognizable signal to contact other life. The signal has only been observed once ever. If a signal like that were discovered on earth, it could be traced to its origin and explored. However, because the signal originated from a far-off star system, it’s impossible for us to try this approach.
There are many possible explanations for the source of the WOW! signal. Many of the obvious solutions, however, have been ruled out. The signal could not be a reflected signal from a source on Earth, like a military or commercial aircraft, due to its strength, and because the frequency of the signal is protected, meaning sources on earth are not supposed to use it. It has also been proposed that the signal came from a hydrogen cloud surrounding a comet; however, such a strong signal coming from a comet was deemed unlikely. It could have come from another large celestial body, but none have been discovered near the source of the signal that could satisfactorily explain its origin. There have been plenty of more non-traditional suggestions for the signal’s origin, like an extraterrestrial civilization. However, it is difficult to understand why the signal would only have occurred once. If there is a civilization of aliens out there trying to send a message, why did they stop? And, if it isn’t alien life, what could have possibly sent that signal? We may never know.
The WOW! signal isn’t the only unexplained mystery in space. In theory, the universe should have, with minor exceptions, a constant heat density. This means that no matter what direction you look at, you should measure roughly the same temperature. However, it was discovered that this is not the case. An area of space dubbed “the Axis of Evil” has been shown to have a much lower heat density than expected. Different scientists disagree on how , and different suggestions have been made for how we can adjust our theories to compensate for this apparent lack of uniformity. But at the end of the day, it can be chilling to speculate on what may lurk in the coldest part of our universe.
Space mysteries even exist closer to Earth. One such mystery is the heat of the outer layer of the sun. For some reason the outer layer of the sun is its hottest layer, even though energy is produced almost exclusively in its core. Explanations have been proposed for this problem, but it is almost impossible to determine which if any are correct. This difficulty is because of a fundamental problem with astronomy: astronomy is not an experimental science. Most phenomena on Earth can be replicated in a lab in some form or another. Most phenomena in space, on the other hand, cannot be replicated due to the size and energy levels of most cosmic objects. Simulating something as huge and energy dense as the sun is impossible with our current technology and may never be possible. But if we can’t even understand our own star, how can we possibly begin to understand all of the dark mysteries of our universe?
With all these space mysteries, the obvious question is, will we ever be able to solve them? While more scientists than ever are working on these problems, there are limitations we may never overcome. Without being able to exceed the speed of light, it will be difficult to explore even the closest star systems in a reasonable time. With our current energy constraints, experimentally simulating cosmic objects like stars or pulsars or gamma rays remains in the realm of science fiction. Maybe one day we will be able to accomplish these herculean tasks, or, maybe, the mysteries of space will be forever outside our grasp – remaining a source of inspiration, confusion, and wonder for us earth-bound humans.
