ALIENS - Are they real? If so, can we meet them?

 

Are they real?

The Universe came into being in the Big Bang 13.7 billion years ago and is expanding relentlessly ever since.  Therefore, the Universe is vast, containing at least a hundred billion galaxies.  If each galaxy has a few million to many trillion stars, each with several planets; we can safely say that there are many trillions of planets in the Universe. 

We definitely exist. Earth definitely exists, so does the sun, the other planets in our Solar system and the Milky Way galaxy.  If one planet called Earth contains intelligent life, it stands to reason that life as we know it should also exist elsewhere throughout the Universe because of the sheer vast numbers of possible similar planets of the same age.

So, aliens should quite probably exist.

In 1961, the astrophysicist Frank Drake formulated the Drake Equation to estimate the possible number of aliens technologically advanced enough to cross the vast void of space that may exist in our galaxy. 

The Drake equation states that:

       N = R*. fp . ne . fe . fi . fc . L

where:

N = the number of civilizations in our galaxy with which communication might be possible;

R^* = the average rate of star formation per year in our galaxy

f_p = the fraction of those stars that have planets

n_e = the average number of planets that can potentially support life per star that has planets

f_ℓ = the fraction of the above that actually go on to develop life at some point

f_i = the fraction of the above that actually go on to develop intelligent life

f_c = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L = the length of time for which such civilizations release detectable signals into space

He estimated that there should be 10,000 alien civilizations in our Milky Way alone!

Can we meet them?

 

But, since the Universe is so vast, there is very little chance of meeting them. Carl Sagan calculated that if you were to just spontaneously appear in the Universe, the odds of you being anywhere near another planet, let alone one with life on, would be less than one in a billion trillion trillion or 10 to the power of 33!