Bizarre ‘Dark Forest’ Theory Explains Absence of Aliens

For a long time, humanity has been looking up at the stars wondering if we truly are alone in the universe.

Given the vastness of the universe, it seems strange that intelligence only exists on one very ordinary planet that revolves around a very ordinary star in a very ordinary galaxy while trillions of such galaxies exist with no apparent signs of life.

This contradiction has always baffled scientists.

Fermi Paradox

The famous Fermi paradox is about this contradiction between the high likelihood of alien existence and our lack of evidence about it.

Enrico Fermi was a famous Italian physicist who contributed a lot to his field of study but he became famous for one of the casual sentences he uttered during lunch with his friends in New York in 1950.

While discussing UFOs and alien life, he said “But where are they?” pointing at the lack of any conclusive evidence of alien life in the universe.

Aliens should exist (in abundance)

There are billions of stars in the Milky Way galaxy that are similar to our own sun. Most stars similar to our own sun have Earth-like planets in their orbits. Some of these planets will exist in Goldilock zones where temperatures are moderate and liquid water can exist.

From Kepler mission findings so far, it seems like earth-like planets are not very rare in our galaxy and some exist in Goldilock zones as well. If we extrapolate these to our galaxy and beyond, there should be trillions of Earth-like planets around their host stars.

Our sun is much younger compared to other stars in the universe so these other Earth-like planets might have received sufficient time to groom intelligent life.

Some of these intelligent life should build interstellar communication and travel and we should have received either communication, a visit or at least a probe from them.

But despite the high probability of the existence of life everywhere else in the universe, we have no evidence so far of alien existence.

So, Where are they?

The Dark Forest Hypothesis

Many theories have been put forward to solve the Fermi paradox but nothing conclusive has been established so far.

But now, there is a new hypothesis that might finally put this mystery to rest. It’s called the Dark Forest hypothesis.

According to the Dark Forest hypothesis, the universe is teeming with life but all these alien civilizations remain hidden out of fear that other more advanced and hostile civilizations will detect and destroy them.

The ‘dark forest’ hypothesis assumes that any advanced civilization would view other intelligent civilizations as a threat to their survivability and hence will try to destroy any life that will make itself known in the dark forest of the universe.

This hypothesis is a special case of game theory called “sequential and incomplete information game”. In this game theory, all players act in sequence and none have complete information about the other player.

In the context of the dark forest universe, all the civilizations are located far enough to make instant communication and information sharing impossible. Therefore, when a civilization announces itself on a cosmic scale, there are three options the other cosmic civilizations have:

  1. Stay silent, don’t respond, and do nothing.
  2. Immediately attack and destroy it to guarantee your own continued existence.
  3. Respond and try to find out if the other civilization is friendly or hostile.

However, the only winning situation in this cosmic game is one own’s survival.

If the listening civilization stays silent, there is a chance that the new civilization turns out to be evil, discover its location, and destroy it.

If the listening civilization responds to find out the nature of the other civilization, it again exposes itself and can’t be sure the other civilization is friendly.

The only way to win this game is to immediately attack the other civilization and destroy it. It’s like shooting first and asking questions later.

So when a civilization makes its location known to others in the grand universe, at least one civilization among billions would pull the trigger without asking questions or ignoring the call and hence destroy it.

“is a dark forest, and every civilisation is an armed hunter stalking through the forest. If the hunter finds another living being, no matter its identity, it must open fire and destroy them first.”

Due to this, intelligent civilization would prefer to keep quiet and maintain radio silence in its neighborhood.

Where did the name “Dark Forest” come from?

Although the concept behind the dark forest is old and rooted in game theory, the name originates from the 2008 Sci-Fi novel of the same name ‘Dark Forest’ by Chinese writer Liu Cixin.

In the novel, the main protagonist Lou Ji proposes the concept of “cosmic sociology” which explains that the goal of every civilization is to survive for as long as possible and the resources of the universe are limited but civilizations keep growing.

Therefore, when some civilization makes itself known to the universe (either accidentally or not knowing the rules of the dark forest), it becomes a target and at least one of the more advanced civilizations will preemptively strike and eliminate the threat.

Have we exposed ourselves to cosmic hunters?

If the dark forest theory is true and we indeed have been living in a hostile ‘shoot first, ask questions never’ kind of universe, the question is, have we exposed our locations to cosmic hunters already?

The first ever radio signal was generated in the late 19th Century when radio was first invented by Marconi around 1895 but power radio stations were set up in the early 20th century.

Considering this, the first powerful enough signal to be detected by any alien civilization has only traveled from Earth a mere 100 light-years or so.

On the cosmic scale or even on the scale of our Milky Way galaxy, this distance is minuscule. The signal bubble of 100 light years only reaches a few star systems in our close neighborhood.

Considering the fact that signal strength degrades over long distances, the chances of us being heard are practically nonexistent.

Therefore, even if the dark forest proposition is true, we haven’t shouted loud enough or long enough to be heard by the cosmic hunters.