math says theres life everywhere in the universe. but time and space are abysmally huge so well probably never know about it (/ω＼)
i remember a physics teacher played this video in class...
scientists cant count planet by planet, but they make estimates based on telescope data like Kepler and the numbers are bizarrely huge.
almost every star has at least one planet orbiting it. in the observable universe there are more stars than grains of sand on all earth beaches. if we count all types of planets, the total estimate revolves around 100 sextillion, that is, 10^23 planets. its planets nonstop (o.o)
worlds like our earth are rarer, but still absurdly common. about 10% to 20% of sun-like stars may have a rocky planet in the habitable zone. that gives something around 100 quintillion earth-like planets in the universe, or 10^20 worlds with potential for liquid water. just in the Milky Way there must be about 40 billion of them (⊙_⊙)
with so many worlds out there its hard to imagine were alone. but then comes the problem. its not lack of planets, its lack of time.
the abyss of time and fermis paradox
the idea of time is one of the biggest arguments of a thing called contemporaneity hypothesis, which tries to solve the famous Fermi paradox, that mystery of "if there are so many planets out there, where is everyone?"
we almost never stop to think how our existence is just a blink in the universe.
the universe is about 13.8 billion years old. earth is 4.5 billion. modern humans have existed for only 300 thousand years. and technology to send signals to space, we only managed that about 100 years ago.
so our technological civilization has existed for a microfraction of a second in the history of the cosmos. for two species to talk they dont just need to exist in the same universe, they need to reach the top of technology at exactly the same era. and thats bizarrely hard to coincide.
the great filter and distance
imagine a super intelligent species lived on a planet 5000 light-years from here. they thrived, built megastructures, sent radio signals to space for 100 thousand whole years and then disappeared for some reason, meteor, war, their sun died, etc.
if their civilization ended 1 million years ago, their signals already passed straight by earth long before the first human even dreamed of inventing a radio. we simply missed the transmission because of time (╥_╥)
and space is too big too. a radio signal travels at light speed, so if someone sends a "hi" from a neighboring galaxy now, the signal may take millions of years to arrive. when it gets here, maybe our own species is already gone.
even if the universe is full of life, civilizations may be born, shining and dying isolated in time and space, never managing to synchronize their clock with anyone else.