Out of millions of star systems across billions of galaxies, the only intelligent life form that we as the human race know of is ourselves. It makes us wonder why we haven’t made contact with any sort of extraterrestrial life form if so many planets exist.
Astrobiologists, people who study the potential for life on other planets, have been wondering about this same question for generations. Numerous theories, such as how most alien races might have wiped themselves out, known as the Great Filter Theory, or how humans simply aren’t worth the time of any advanced extraterrestrial civilization, have popped up over the years.
The point is, it is completely possible that not only do aliens exist, but they have become advanced enough to at least get messages relayed through the vast distances in spacetime. In fact, according to the Drake Equation, an equation proposed by famous astrophysicist Frank Drake, there should be at least 36 advanced civilizations in our galaxy alone.
So why haven’t we heard from any of them? If we truly are just one of many civilizations, why haven’t we been able to establish contact with any of them?
The answer lies in the speed of light. Light, as you might know, is the fastest thing in the universe; nothing with mass can accelerate fast enough to even reach the speed of light, let alone surpass it. Along with that, although the light is incredibly fast, it’s not infinitely fast; it takes time for the light photons to reach us, and with the massive distances stretching across space-time, this usually takes years for signals to pass. For reference, the closest star system to us, Alpha Centauri, is about four light-years away. This means that if we send a signal to Alpha Centauri in April 2021, the signal would not reach the Centauri System -- the closest star system to humanity -- until late 2025. Now, the Milky Way Galaxy is 100,000 light-years across.
Just sending signals would take ages, and by the time those signals reached an alien world, the human race could already be dead. It’s because of this factor that communications have been shady between extraterrestrial civilizations.
However, what if, somehow, a civilization was able to invent a mode of transportation faster than light speed travel? Humans haven’t found a way yet, but it is possible that an ancient advanced civilization was able to crack that code and find a method that was able to get them places faster than the speed of light. This would classify them as an early Type III civilization on the Kardashev scale because they would be able to travel between numerous star systems.
If such a civilization ever came to Earth, their hyper-advanced technology would make them appear to be like Gods, which makes you wonder where we get the inspirations for our deities in ancient mythologies. If such a civilization did exist, would they really care about some weird-looking apes radioing from a dying world? Likely not. They would be looking around for any civilizations that posed a threat to them in any way.
Right now, humanity hasn’t even been able to use the total amount of energy of its home planet; this would classify us as a type 0.87 -- almost a Type I but not quite there. Instead of presenting themselves at a point of development where we would be able to comprehend the existence of extraterrestrials, it is much more efficient to wait until we became a threat of any kind. Therefore, although there could be many civilizations out there, many other factors prevent us from coming into contact with any of them, so don’t get your hopes up too much.
Sources
“Imagine the Universe!” NASA, NASA, imagine.gsfc.nasa.gov/features/cosmic/milkyway_info.html#:~:text=The%20Milky%20Way%20is%20about,Arm%20of%20the%20Milky%20Way.
Carter, Jamie. “There Are At Least 36 Intelligent Alien Civilizations In Our Galaxy, Say Scientists.” Forbes, Forbes Magazine, 20 June 2020, www.forbes.com/sites/jamiecartereurope/2020/06/15/there-are-36-intelligent-alien-civilizations-in-our-galaxy-say-scientists/?sh=2172fa5f694f.
Mahoney, Trevor. “Why Humanity May Simply Be Alone in the Universe.” Medium, Predict, 24 June 2020, medium.com/predict/why-humanity-may-simply-be-alone-in-the-universe-fb216b26947d.