Life may evolve in trillions of planets in the habitable zones, yet sentient, bipedal, balanced, walking, talking, thinking life, one that is able to decipher the missing links to trace our origins - like the gravitation waves, Higgs boson and search for GUT - is as big an obstacle as 'The Big Bang' itself. Self-aware, productive, creative thinking life is an extreme rarity in the universe.
Volcanoes can trigger cellular life but will those microbes take the same trajectory over 3.5 billion years to produce a bipedal being who could produce LIGO Hubble LHC within 10,000 years of the inception of civilisation in Jericho emerging from the 300-500,000 years of modest hunting and gathering stage?
Self-aware life needs not only a habitable zone but a million of chances where things have to fall into place. What a sad prospect that all this universe has such few sentient admirers. I am perplexed with these searches - our biggest enigma lies around 7.3 billion of us who are very unique. Let's search them and remove inequity.
Self-aware life is not easy to evolve. I am humbled and floored with cosmic humility watching the miraculous journey of our status to self awareness. It is a huge credit to the universe that it conspired to help stardust become sentient. The universe wants us to decipher the mysteries therefore we are on our way to find GUT.
No alien will make rockets without their Industrial Age and they all will go through a hunter-gatherer stage, and civilisational era like Jericho leading to quantum age. The whole idea to make an alien like ET sucks; we have unique imagination; we have visualised future uniquely, "Beam me up, Scotty" symbolises 4 billion years of future advancement post GUT, but we imagined it a few decades ago.
We visualise and think of aliens with reptilian soft skins, drooling tongues, huge soft heads totally disproportionate bodies, naked like faqirs, long index fingers, bulging eyes -- the laws of physics rule the entire universe, we cannot have sentient time travellers with such biological formations and round machines 'huge flying saucers' with little regard to escape velocities and aerodynamic shapes.
The whole idea of a 'habitable zone' is based on carbon water life (The definition of all habitable zones is temperate zones where water and carbon is sustainable). To think of our self-created ET like a creature able to construct warp machines and flying saucers is dopey. Forget any flying saucers or machinery, such an alien will not be able to work on any kind of anvil, their eyes and index finger will be busted first. No alien will be born in the space age. Everyone in the universe will go through the evolutionary process governed by the universal laws of physics.
We are hopefully not looking at a silicon planet, rather life like us - our shorter index fingers, our eyes within the sockets, the unique thumb and index finger relationship, bipedalism, our slight dropping of larynx due to which we are able to articulate vowels and not grunt like chimps are all very unique milestones of a very special chancy journey of evolution notwithstanding the sweeper of solar system, Jupiter, that helped earth prosper by taking all the hits of stray asteroids.
We have evolved more by chance than any fixed trajectory that any unicellular life will follow in any other habitable zone to become sentient in 4.6 billion years. There are lots and lots of dead real estate around in the universe. Maybe we are very alone and unique!
This is my line of thinking and I am a proponent of this theory that 'we are a product of an evolutionary jackpot and carbon-based sentient beings are an extreme rarity and our life is very unique.'