Scientists Conclude: Aliens Exist or Existed

Astronomers calculate that the chance of us being the only civilization in the history of the Universe is just 1 in 10 billion trillion.

 
 

“Yes, aliens existed”, with this definitive title, astrophysicist Adam Frank, from the University of Rochester, begins the article he published in the New York Times.

Not that Adam Frank found aliens or flying saucers. What he did, along with his colleague Frank Sullivan of the University of Washington, was a little less exciting than that: calculations.

But, after finishing the calculations, the two no longer have any doubts: “it is very unlikely that at least one other technological civilization, in addition to ours, did not appear in the history of the Universe.”

 

The starting point of Frank and Sullivan’s calculations is the famous Drake Equation, devised in 1961 by astronomer Frank Drake to try to determine the probability of there being advanced extraterrestrial civilizations that could be detected elsewhere in the Universe.

The equation says the following:

It means:

The number of alien civilizations in the Universe (N) is equal to the multiplication of 7 other factors. The first (R*) is the rate of new star formation. The second is the percentage of these stars that contain planets. The third is the number of planets capable of supporting life on each of these stars. The fourth is the fraction of these planets that actually contain life. The fifth is the percentage of that life that has developed intelligence. The sixth number is the percentage of this intelligent life that has developed communication technologies that can be detected. And the seventh is how long this civilization has been emitting signals that we can detect.

The equation is thought-provoking, but when Drake formulated it, it didn’t have much use. After all, of those seven numbers, six were absolutely unknown: only the rate of new star formation was known.

As we know, it is impossible to solve an equation if you know almost none of the variables involved. That’s why Drake’s equation was always being cited, but it never solved anything. Optimists imagined that the variables had high values, while pessimists thought they were low.

But since 1961 a lot has changed. At that time, no planet was known outside the Solar System and today more than 5,000 are known and many more are discovered every day.

Astronomers now believe that there are planets revolving around virtually every star system: that is, ‘fp’ appears to be close to 100 (100% of stars have planets). Another number that seems to be quite high is ‘ne’: there is no way of knowing for sure how many planets orbit each star, but everything indicates that there are several. And, judging by the planets found to date, somewhere between 20% and 25% are in an area where life is possible.

Starting from these known numbers, Frank and Sullivan decided to reverse the meaning of the old equation. Instead of using it to calculate how many extraterrestrial civilizations there are, they calculated the probability that our civilization was the only one to emerge in the Universe.

The result is that this probability is incredibly low.

“Unless the probability of a civilization evolving on a planet located in the habitable zone is 1 in 10 billion trillion, then we are not alone”, Frank wrote.

In other words: it’s extremely unlikely. Almost impossible.

So we must keep looking. The truth is out there.